Water-level fluctuation in wetlands as a function of landscape condition in the prairie pothole region

USGS Publications Warehouse

Euliss, Ned H.; Mushet, David M.

1996-01-01

We evaluated water-level fluctuation (maximum water depth - minimum water depth/catchment size) in 12 temporary, 12 seasonal, and 12 semipermanent wetlands equally distributed among landscapes dominated by tilled agricultural lands and landscapes dominated by grassland. Water levels fluctuated an average of 14.14 cm in wetlands within tilled agricultural landscapes, while water levels in wetlands within grassland landscapes fluctuated an average of only 4.27 cm. Tillage reduces the natural capacity of catch meets to mitigate surface flow into wetland basins during precipitation events, resulting in greater water-level fluctuations in wetlands with tilled catchments. In addition, water levels in temporary and seasonal wetlands fluctuated an average of 13.74 cm and 11.82 cm, respectively, while water levels in semipermanent wetlands fluctuated only 2.77 cm. Semipermanent wetlands receive a larger proportion of their water as input from ground water than do either temporary or seasonal wetlands. This input of water from the ground has a stabilizing effect on water-levels of semipermanent wetlands. Increases in water-level fluctuation due to tillage or due to alteration of ground-water hydrology may ultimately affect the composition of a wetland's flora and fauna. In this paper, we also describe an inexpensive device for determining absolute maximum and minimum water levels in wetlands.

Use of individualistic streamflow-vegetation relations along the Fremont River, Utah, USA to assess impacts of flow alteration on wetland and riparian area

USGS Publications Warehouse

Auble, G.T.; Scott, M.L.; Friedman, J.M.

2005-01-01

We analyzed the transverse pattern of vegetation along a reach of the Fremont River in Capitol Reef National Park, Utah, USA using models that support both delineation of wetland extent and projection of the changes in wetland area resulting from upstream hydrologic alteration. We linked stage-discharge relations developed by a hydraulic model to a flow-duration curve derived from the flow history in order to calculate the inundation duration of 361 plots (0.5 × 2 m). Logistic regression was used to relate plant species occurrence in plots to inundation duration. A weighted average of the wetland indicator values of species was used to characterize plots as Aquatic, Wetland, Transitional, or Upland. Finally, we assessed how alterations in the flow duration curve would change the relative widths of these four zones. The wetland indicator values of species and the wetland prevalence index scores of plots were strongly correlated with inundation duration. Our results support the concept that plants classified as wetland species typically occur on sites inundated at least two weeks every two years. The portion of the riparian zone along the high-gradient study reach of the Fremont River that satisfied the vegetation criterion for a regulatory wetland was narrow (2 m wide). Both the unvegetated Aquatic zone (7.8 m) and the Transitional zone (8 m) were substantially wider. The Transitional zone included the maxima of several species and was, therefore, not merely a combination of elements of the Wetland and Upland zones. Multiplicative increases or decreases in streamflow regime produced a wetter, or drier, bottomland vegetation, respectively. Systematic reductions in flow variability reduced the width of both the Wetland and Transitional zones and increased the width of the Upland zone. Our approach is widely applicable to inform water management decisions involving changes in flow regime.

Floodwater utilisation values of wetland services - a case study in Northeastern China

NASA Astrophysics Data System (ADS)

Lü, S. B.; Xu, S. G.; Feng, F.

2012-02-01

Water plays a significant role in wetlands. Floodwater utilisation in wetlands brings a wide range of wetland services, from goods production and water regulation to animal protection and aesthetics related to water supply in wetlands. In this study, the floodwater utilisation values of wetland services were estimated within the Momoge wetland and Xianghai wetland in western Jilin province of northeastern China. From 2003 to 2008, the floodwater diverted from the Nenjiang and Tao'er River is 381 million m3, which translates into a monetary value of approximately 1.35 billion RMB in 2008 (RMB: Chinese Currency, RMB 6.80 = US 1), and the ratio of economic value, eco-environmental value, and social value is 1:12:2. Besides the monetary value of the water itself, excessive floodwater utilisation may bring losses to wetlands; the threshold floodwater utilisation volumes in wetlands are discussed. Floodwater utilisation can alleviate water shortages in wetlands, and the evaluation of floodwater utilisation in wetland services in monetary terms is a guide for the effective use of the floodwater resources and for the conservation of wetlands.

Estimating pothole wetland connectivity to Pipestem Creek ...

EPA Pesticide Factsheets

Understanding hydrologic connectivity between wetlands and perennial streams is critical to understanding how reliant stream flow is on wetlands within their watershed. We used the isotopic evaporation signal in water to examine hydrologic connectivity within Pipestem Creek, North Dakota, with a watershed dominated by prairie potholes. During a decadal period of wet conditions, Pipestem Creek contained evaporated water that had approximately half the isotopic evaporative enrichment signal found in most evaporated permanent wetlands. If evaporation was mainly occurring within the stream, we expected the evaporation signal to increase from the headwaters with distance downstream. However, the signal either remained similar or decreased downstream over the two years of sampling. Groundwater measured at the water table adjacent to Pipestem Creek had isotopic values that indicated recharge from winter precipitation and had no significant evaporation. Using isotopic theory and discharge data, we estimated the surface area of open water necessary to generate the evaporation signal found within Pipestem Creek over time. The range of evaporating surface-area estimates was highly dynamic, spanning from 43 to 2653 ha and varying primarily with discharge. The average value (just over 600 ha) was well above the surface area of Pipestem Creek network (245 ha). This estimate of contributing area indicated that Prairie Pothole wetlands were important sources of stream fl

Effects of capillarity and microtopography on wetland specific yield

USGS Publications Warehouse

Sumner, D.M.

2007-01-01

Hydrologic models aid in describing water flows and levels in wetlands. Frequently, these models use a specific yield conceptualization to relate water flows to water level changes. Traditionally, a simple conceptualization of specific yield is used, composed of two constant values for above- and below-surface water levels and neglecting the effects of soil capillarity and land surface microtopography. The effects of capiltarity and microtopography on specific yield were evaluated at three wetland sites in the Florida Everglades. The effect of capillarity on specific yield was incorporated based on the fillable pore space within a soil moisture profile at hydrostatic equilibrium with the water table. The effect of microtopography was based on areal averaging of topographically varying values of specific yield. The results indicate that a more physically-based conceptualization of specific yield incorporating capillary and microtopographic considerations can be substantially different from the traditional two-part conceptualization, and from simpler conceptualizations incorporating only capillarity or only microtopography. For the sites considered, traditional estimates of specific yield could under- or overestimate the more physically based estimates by a factor of two or more. The results suggest that consideration of both capillarity and microtopography is important to the formulation of specific yield in physically based hydrologic models of wetlands. ?? 2007, The Society of Wetland Scientists.

Global meta-analysis of leaf area index in wetlands indicates uncertainties in understanding of their ecosystem function

NASA Astrophysics Data System (ADS)

Dronova, I.; Taddeo, S.; Foster, K.

2017-12-01

Projecting ecosystem responses to global change relies on the accurate understanding of properties governing their functions in different environments. An important variable in models of ecosystem function is canopy leaf area index (LAI; leaf area per unit ground area) declared as one of the Essential Climate Variables in the Global Climate Observing System and extensively measured in terrestrial landscapes. However, wetlands have been largely under-represented in these efforts, which globally limits understanding of their contribution to carbon sequestration, climate regulation and resilience to natural and anthropogenic disturbances. This study provides a global synthesis of >350 wetland-specific LAI observations from 182 studies and compares LAI among wetland ecosystem and vegetation types, biomes and measurement approaches. Results indicate that most wetland types and even individual locations show a substantial local dispersion of LAI values (average coefficient of variation 65%) due to heterogeneity of environmental properties and vegetation composition. Such variation indicates that mean LAI values may not sufficiently represent complex wetland environments, and the use of this index in ecosystem function models needs to incorporate within-site variation in canopy properties. Mean LAI did not significantly differ between direct and indirect measurement methods on a pooled global sample; however, within some of the specific biomes and wetland types significant contrasts between these approaches were detected. These contrasts highlight unique aspects of wetland vegetation physiology and canopy structure affecting measurement principles that need to be considered in generalizing canopy properties in ecosystem models. Finally, efforts to assess wetland LAI using remote sensing strongly indicate the promise of this technology for cost-effective regional-scale modeling of canopy properties similar to terrestrial systems. However, such efforts urgently require more rigorous corrections for three-dimensional contributions of non-canopy material and non-vegetated surfaces to wetland canopy reflectance.

Evaluation of recharge to the Skunk Creek Aquifer from a constructed wetland near Lyons, South Dakota

USGS Publications Warehouse

Thompson, Ryan F.

2002-01-01

A wetland was constructed in the Skunk Creek flood plain near Lyons in southeast South Dakota to mitigate for wetland areas that were filled during construction of a municipal golf course for the city of Sioux Falls. A water-rights permit was obtained to allow the city to pump water from Skunk Creek into the wetland during times when the wetland would be dry. The amount of water seeping through the wetland and recharging the underlying Skunk Creek aquifer was not known. The U.S. Geological Survey, in cooperation with the city of Sioux Falls, conducted a study during 1997-2000 to evaluate recharge to the Skunk Creek aquifer from the constructed wetland. Three methods were used to estimate recharge from the wetland to the aquifer: (1) analysis of the rate of water-level decline during periods of no inflow; (2) flow-net analysis; and (3) analysis of the hydrologic budget. The hydrologic budget also was used to evaluate the efficiency of recharge from the wetland to the aquifer. Recharge rates estimated by analysis of shut-off events ranged from 0.21 to 0.82 foot per day, but these estimates may be influenced by possible errors in volume calculations. Recharge rates determined by flow-net analysis were calculated using selected values of hydraulic conductivity and ranged from 566,000 gallons per day using a hydraulic conductivity of 0.5 foot per day to 1,684,000 gallons per day using a hydraulic conductivity of 1.0 foot per day. Recharge rates from the hydrologic budget varied from 0.74 to 0.85 foot per day, and averaged 0.79 foot per day. The amount of water lost to evapotranspiration at the study wetland is very small compared to the amount of water seeping from the wetland into the aquifer. Based on the hydrologic budget, the average recharge efficiency was estimated as 97.9 percent, which indicates that recharging the Skunk Creek aquifer by pumping water into the study wetland is highly efficient. Because the Skunk Creek aquifer is composed of sand and gravel, the 'recharge mound' is less distinct than might be found in an aquifer composed of finer materials. However, water levels recorded from piezometers in and around the wetland do show a higher water table than periods when the wetland was dry. The largest increases in water level occur between the wetland channel and Skunk Creek. The results of this study demonstrate that artificially recharged wetlands can be useful in recharging underlying aquifers and increasing water levels in these aquifers.

Wonderful Wetlands: An Environmental Education Curriculum Guide for Wetlands.

ERIC Educational Resources Information Center

King County Parks Div., Redmond, WA.

This curriculum guide was designed to give teachers, students, and society a better understanding of wetlands in the hope that they learn why wetlands should be valued and preserved. It explores what is meant by wetlands, functions and values of wetlands, wetland activities, and wetland offerings which benefit animal and plant life, recreation,…

Carbon stocks in mangroves, salt marshes, and salt barrens in Tampa Bay, Florida, USA: Vegetative and soil characteristics.

NASA Astrophysics Data System (ADS)

Moyer, R. P.; Radabaugh, K.; Chappel, A. R.; Powell, C.; Bociu, I.; Smoak, J. M.

2017-12-01

When compared to other terrestrial environments, coastal "blue carbon" habitats such as salt marshes and mangrove forests sequester disproportionately large amounts of carbon as standing plant biomass and sedimentary peat deposits. This study quantified total carbon stocks in vegetation and soil of 17 salt marshes, salt barrens, and mangrove forests in Tampa Bay, Florida, USA. The sites included natural, restored, and created wetlands of varying ages and degrees of anthropogenic impacts. The average vegetative carbon stock in mangrove forests was 60.1 ± 2.7 Mg ha-1. Mangrove forests frequently consisted of a few large Avicennia germinans trees with smaller, abundant Rhizophora mangle and/or Laguncularia racemosa trees. The average vegetative carbon stock was 11.8 ± 3.7 Mg ha-1 for salt marshes and 2.0 ± 1.2 Mg ha-1 for salt barrens. Vegetative carbon did not significantly differ between natural and newly created salt marsh habitats, indicating that mature restored wetlands can be included with natural wetlands for the calculation of vegetative carbon in coastal blue carbon assessments. Peat deposits were generally less than 50 cm thick and organic content rapidly decreased with depth in all habitats. Soil in this study was analyzed in 1 cm intervals; the accuracy of subsampling or binning soil into depth intervals of 2-5 cm was also assessed. In most cases, carbon stock values obtained from these larger sampling intervals were not statistically different from values obtained from sampling at 1 cm intervals. In the first 15 cm, soil in mangrove forests contained an average of 15.1% organic carbon by weight, salt marshes contained 6.5%, and salt barrens contained 0.8%. Total carbon stock in mangroves was 187.1±17.3 Mg ha-1, with 68% of that carbon stored in soil. Salt marshes contained an average of 65.2±25.3 Mg ha-1 (82% soil carbon) and salt barrens had carbon stocks of 21.4±7.4 Mg ha-1 (89% soil carbon). These values were much lower than global averages for carbon stocks in mangroves and salt marshes, likely due to Tampa Bay's location near the northern limit of mangrove habitat, recent habitat conversion from salt marshes to mangroves, young age of the restored wetlands, and proximity to intense coastal development. Vulnerability of these blue carbon habitats to climate change and sea-level rise will also be discussed.

Water Use in Wetland Kalo Cultivation in Hawai`i

USGS Publications Warehouse

Gingerich, Stephen B.; Yeung, Chiu W.; Ibarra, Tracy-Joy N.; Engott, John A.

2007-01-01

Ten cultivation areas (8 windward, 2 leeward) were selected for a kalo water-use study, primarily on the basis of the diversity of environmental and agricultural conditions under which wetland kalo is grown and landowner permission and availability. Flow and water-temperature data were collected at the lo`i complex level and at the individual lo`i level. To ensure that flow and temperature data collected at different lo`i reflect similar irrigation conditions (continuous flooding of the mature crop), only lo`i with crops near the harvesting stage were selected for water-temperature data collection. The water need for kalo cultivation varies depending on the crop stage. In this study, data were collected during the dry season (June-October), when water requirements for cooling kalo approach upper limits. Flow measurements generally were made during the warmest part of the day, and temperature measurements were made every 15 minutes at each site for about a two-month period. Flow and temperature data were collected from kalo cultivation areas on four islands - Kaua`i, O`ahu, Maui, and Hawai`i. The average inflow value for the 19 lo`i complexes measured in this study is 260,000 gallons per acre per day, and the median inflow value is 150,000 gallons per acre per day. The average inflow value for the 17 windward sites is 270,000 gallons per acre per day, and the median inflow value is 150,000 gallons per acre per day. The average inflow value for the two leeward sites is 150,000 gallons per acre per day. The average inflow value measured for six individual lo`i is 350,000 gallons per acre per day, and the median inflow value is 270,000 gallons per acre per day. The average inflow value for the five windward lo`i is 370,000 gallons per acre per day, and the median inflow value is 320,000 gallons per acre per day. The inflow value for the one leeward lo`i is 210,000 gallons per acre per day. These inflow values are consistent with previously reported values for inflow and are significantly higher than values generally estimated for water consumption during kalo cultivation. These measurements of inflow are important for future considerations of water-use requirements for successful kalo cultivation. Of the 17 lo`i complexes where water inflow temperature was measured, only 3 had inflow temperatures that rose above 27 ?C, the threshold temperature above which wetland kalo is more susceptible to fungi and associated rotting diseases. The coldest mean inflow temperature was 20.0 ?C and the warmest inflow temperature was 24.9 ?C. All 15 of the sites where outflow temperatures were measured had some temperatures greater than 27 ?C. Outflow temperatures exceeded 27 ?C between 2.5 percent and about 40 percent of the time. Mean outflow temperatures ranged from 23.0 ?C to 26.7 ?C.

Analysis of Water Vapour Flux Between Alpine Wetlands Underlying the Surface and Atmosphere in the Source Region of the Yellow River

NASA Astrophysics Data System (ADS)

Xie, Y.; Wen, J.; Liu, R.; Wang, X.; JIA, D.

2017-12-01

Wetland underlying surface is sensitive to climate change. Analysis of the degree of coupling between wetlands and the atmosphere and a quantitative assessment of how environmental factors influence latent heat flux have considerable scientific significance. Previous studies, which focused on the forest, grassland and farmland ecosystems, lack research on the alpine wetlands. In addition, research on the environmental control mechanism of latent heat flux is still qualitative and lacks quantitative evaluations and calculations. Using data from the observational tests of the Maduo Observatory of Climate and Environment of the Northwest Institute of Eco-Environment and Resource, CAS, from June 1 to August 31, 2014, this study analysed the time-varying characteristics and causes of the degree of coupling between alpine wetlands underlying surface and the atmosphere and quantitatively calculated the influences of different environmental factors (solar radiation and vapour pressure deficit) on latent heat flux. The results were as follows: Due to the diurnal variations of solar radiation and wind speed, the diurnal variations of the Ω factor present a trend in which the Ω factor are small in the morning and large in the evening. Due to the vegetation growing cycle, the seasonal variations of the Ω factor present a reverse "U" trend . These trends are similar to the diurnal and seasonal variations of the absolute control exercised by solar radiation over the latent heat flux. This conforms to omega theory. The values for average absolute atmospheric factor (surface factor or total ) control exercised by solar radiation and water vapour pressure are 0.20 (0.02 or 0.22 ) and 0.005 (-0.07 or -0.06) W·m-2·Pa-1, respectively.. Generally speaking, solar radiation and water vapour pressure deficit exert opposite forces on the latent heat flux. The average Ω factor is high during the vegetation growing season, with a value of 0.38, and the degree of coupling between the alpine wetland surface and the atmosphere system is low. The actual measurements agree with omega theory. The latent heat flux is mainly influenced by solar radiation. From the above, our study has provided reference information for exploring the influences of environmental factors on the latent heat flux over the alpine wetlands of the Yellow River source region.

Forested wetland habitat

USGS Publications Warehouse

Duberstein, Jamie A.; Krauss, Ken W.; Kennish, Michael J.

2015-01-01

A forested wetland (swamp) is a forest where soils are saturated or flooded for at least a portion of the growing season, and vegetation, dominated by trees, is adapted to tolerate flooded conditions. A tidal freshwater forested wetland is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity of soil porewater less than 0.5 g/l. It is known locally as tidal várzea in the Amazon delta, Brazil. A tidal saltwater forested wetland (mangrove forest) is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity often exceeding 3 g/l and reaching levels that can exceed seawater. Mangrove ecosystems are composed of facultative halophytes that generally experience better growth at moderate salinity concentrations.

Evaluating the potential for site-specific modification of LiDAR DEM derivatives to improve environmental planning-scale wetland identification using Random Forest classification

NASA Astrophysics Data System (ADS)

O'Neil, Gina L.; Goodall, Jonathan L.; Watson, Layne T.

2018-04-01

Wetlands are important ecosystems that provide many ecological benefits, and their quality and presence are protected by federal regulations. These regulations require wetland delineations, which can be costly and time-consuming to perform. Computer models can assist in this process, but lack the accuracy necessary for environmental planning-scale wetland identification. In this study, the potential for improvement of wetland identification models through modification of digital elevation model (DEM) derivatives, derived from high-resolution and increasingly available light detection and ranging (LiDAR) data, at a scale necessary for small-scale wetland delineations is evaluated. A novel approach of flow convergence modelling is presented where Topographic Wetness Index (TWI), curvature, and Cartographic Depth-to-Water index (DTW), are modified to better distinguish wetland from upland areas, combined with ancillary soil data, and used in a Random Forest classification. This approach is applied to four study sites in Virginia, implemented as an ArcGIS model. The model resulted in significant improvement in average wetland accuracy compared to the commonly used National Wetland Inventory (84.9% vs. 32.1%), at the expense of a moderately lower average non-wetland accuracy (85.6% vs. 98.0%) and average overall accuracy (85.6% vs. 92.0%). From this, we concluded that modifying TWI, curvature, and DTW provides more robust wetland and non-wetland signatures to the models by improving accuracy rates compared to classifications using the original indices. The resulting ArcGIS model is a general tool able to modify these local LiDAR DEM derivatives based on site characteristics to identify wetlands at a high resolution.

Index-based framework for assessing climate change impact on wetlands in Poland

NASA Astrophysics Data System (ADS)

O'Keeffe, Joanna; Marcinkowski, Paweł; Utratna, Marta; Szcześniak, Mateusz; Piniewski, Mikołaj; Okruszko, Tomasz

2017-04-01

Climate change is expected to impact the water cycle through changing the precipitation levels, river streamflows, soil moisture dynamics and therefore pose a threat to groundwater and surface-water fed wetlands and their biodiversity. We examined the past trends and future impacts of climate change on streamflow and soil water content. Simulation results from 1971 to 2000 (historical period) and from 2021 to 2100 (future period) were obtained with the use of the Soil and Water Assessment Tool (SWAT). Hydrological modelling was driven by a set of nine EUROCORDEX Regional Climate Models under two Representative Concentration Pathways (RCP's) of greenhouse gas concentration trajectories: 4.5 and 8.5. A special focus was made on water dependent habitats within the Special Areas of Conservation (SAC's) of the Natura 2000 network located within Odra and Vistula River basins in Poland. A habitat assessment was carried out to distinguish groundwater and surface water fed wetlands. By establishing threshold values of streamflow at bankfull flow we were able to identify flood events. Changes in frequency of the floods informed about the alteration to the water supply for wetlands reliant on inundation. The groundwater-fed wetlands were assessed on the basis of the soil water content. The model outputs were used to develop indices which were calculated for the climate change scenarios. Comparisons of simulated trends in soil water content and streamflow dynamics with average annual precipitation showed largely consistent patterns. The developed indicators are sensitive to projected changes in hydrologic regime in the conditions of changing climate. The results show influence of climate change on floodplain and groundwater-fed wetlands and show the number and kind of wetlands threatened in different regions of Poland. SAC's will play an important role of buffers and water regulators as soil water content in SAC's is projected to be higher than average for the future scenarios.

Enhanced methane emissions from tropical wetlands during the 2011 La Niña

PubMed Central

Pandey, Sudhanshu; Houweling, Sander; Krol, Maarten; Aben, Ilse; Monteil, Guillaume; Nechita-Banda, Narcisa; Dlugokencky, Edward J.; Detmers, Rob; Hasekamp, Otto; Xu, Xiyan; Riley, William J.; Poulter, Benjamin; Zhang, Zhen; McDonald, Kyle C.; White, James W. C.; Bousquet, Philippe; Röckmann, Thomas

2017-01-01

Year-to-year variations in the atmospheric methane (CH4) growth rate show significant correlation with climatic drivers. The second half of 2010 and the first half of 2011 experienced the strongest La Niña since the early 1980s, when global surface networks started monitoring atmospheric CH4 mole fractions. We use these surface measurements, retrievals of column-averaged CH4 mole fractions from GOSAT, new wetland inundation estimates, and atmospheric δ13C-CH4 measurements to estimate the impact of this strong La Niña on the global atmospheric CH4 budget. By performing atmospheric inversions, we find evidence of an increase in tropical CH4 emissions of ∼6–9 TgCH4 yr−1 during this event. Stable isotope data suggest that biogenic sources are the cause of this emission increase. We find a simultaneous expansion of wetland area, driven by the excess precipitation over the Tropical continents during the La Niña. Two process-based wetland models predict increases in wetland area consistent with observationally-constrained values, but substantially smaller per-area CH4 emissions, highlighting the need for improvements in such models. Overall, tropical wetland emissions during the strong La Niña were at least by 5% larger than the long-term mean. PMID:28393869

Total economic value of wetlands products and services in Uganda.

PubMed

Kakuru, Willy; Turyahabwe, Nelson; Mugisha, Johnny

2013-01-01

Wetlands provide food and non-food products that contribute to income and food security in Uganda. This study determined the economic value of wetland resources and their contribution to food security in the three agroecological zones of Uganda. The values of wetland resources were estimated using primary and secondary data. Market price, Productivity, and Contingent valuation methods were used to estimate the value of wetland resources. The per capita value of fish was approximately US$ 0.49 person⁻¹. Fish spawning was valued at approximately US$ 363,815 year⁻¹, livestock pastures at US$ 4.24 million, domestic water use at US$ 34 million year⁻¹, and the gross annual value added by wetlands to milk production at US$ 1.22 million. Flood control was valued at approximately US$ 1,702,934,880 hectare⁻¹ year⁻¹ and water regulation and recharge at US$ 7,056,360 hectare⁻¹ year⁻¹. Through provision of grass for mulching, wetlands were estimated to contribute to US$ 8.65 million annually. The annual contribution of non-use values was estimated in the range of US$ 7.1 million for water recharge and regulation and to US$ 1.7 billion for flood control. Thus, resource investment for wetlands conservation is economically justified to create incentives for continued benefits.

Total Economic Value of Wetlands Products and Services in Uganda

PubMed Central

Kakuru, Willy; Turyahabwe, Nelson; Mugisha, Johnny

2013-01-01

Wetlands provide food and non-food products that contribute to income and food security in Uganda. This study determined the economic value of wetland resources and their contribution to food security in the three agroecological zones of Uganda. The values of wetland resources were estimated using primary and secondary data. Market price, Productivity, and Contingent valuation methods were used to estimate the value of wetland resources. The per capita value of fish was approximately US$ 0.49 person−1. Fish spawning was valued at approximately US$ 363,815 year−1, livestock pastures at US$ 4.24 million, domestic water use at US$ 34 million year−1, and the gross annual value added by wetlands to milk production at US$ 1.22 million. Flood control was valued at approximately US$ 1,702,934,880 hectare−1 year−1 and water regulation and recharge at US$ 7,056,360 hectare−1 year−1. Through provision of grass for mulching, wetlands were estimated to contribute to US$ 8.65 million annually. The annual contribution of non-use values was estimated in the range of US$ 7.1 million for water recharge and regulation and to US$ 1.7 billion for flood control. Thus, resource investment for wetlands conservation is economically justified to create incentives for continued benefits. PMID:24163614

Valuing wetland attributes in the Lake Champlain Basin

Treesearch

Donald F. Dennis; Walter F. Kuentzel

1998-01-01

This research explores the use of conjoint analysis to assess and understand wetland values. A conjoint rating survey was designed and mailed to landowners in the Laplatte River Basin (Lake Champlain) in Vermont. Landowners rated options to protect wetlands that varied by the wetland's ability to decrease pollutants entering Lake Champlain, value in providing food...

Emission of greenhouse gases from geographically isolated wetlands of Western Siberia

NASA Astrophysics Data System (ADS)

Golovatskaya, E.; Dyukarev, E.; Veretennikova, E.

2014-12-01

Wetlands are integral components of landscapes with specific nutrient dynamics and carbon sequestration potentials, which frequently differ, based on hydroperiod and seasonal hydropattern, as well as the constituent concentration of inputs, site-specific storages and vegetation structures. Human modifications have the potential to significantly alter controls on carbon dynamics. This study focused on determining carbon emissions (CO2 and CH4) from geographically isolated peatlands within the Ob-Tom River Interfluve area of Western Siberia affected by water diversion for municipal use by the city of Tomsk, Russia. Two oligotrophic wetlands within the study area were selected for site-specific CO2 studies, the Timiryazevskoe (16 ha) and Kirsanovskoe wetlands (29 ha), both affected by the Tomsk water intake (177 water wells 250 000 m3 water daily). Measurements of СО2 and CH4 emissions from peat surfaces were carried out bi-monthly in growing periods from 2008-2013 in two dominate vegetation zones, pine- shrub-sphagnum phytocenosis (ryam) and sedge-sphagnum fens. СО2 emissions were measured using OPTOGAS-500.4 infrared gas analyzer and dark chamber. Methane emissions were measured using static chamber method. Air samples were collected by syringes and analyzed at gas chromatograph Shimadzu-GC14B. Observations were accompanied by measurement of air temperature and humidity, surface temperature, peat temperature at various depths and the water table level. CО2 emission over the vegetative growing period had clearly pronounced seasonal dynamics with maximum values in the middle of the growing season (mid-July) and minimum values in spring and autumn. The average total flux over the studied period is 123±55 gС/m2 at sedge-sphagnum fen of Kirsanovskoe wetland and 323±66 gС/m2 at fen of Timiryazevskoe wetland. Total СО2 flux for the snow-free period at ryam sites of Timiryazevskoe and Kirsanovskoe wetlands is 238±84 and 260±47 gС/m2 accordingly. Methane emission from the surface of isolated wetlands for the snow-free period varies from 0.3±1.1 to 2.9±2.3 gC/m2 on ryam sites of Kirsanovskoe and Timiryazevskoe wetlands respectively. The total CH4 flux on sedge-sphagnum fen varies from 2.5±3.0 at Kirsanovskoe wetlands to 31.6±26.3 gC/m2 at Timiryazevskoe wetland.

Flooded area and plant zonation in isolated wetlands in well fields in the Northern Tampa Bay Region, Florida, following reductions in groundwater-withdrawal rates

USGS Publications Warehouse

Haag, Kim H.; Pfeiffer, William R.

2012-01-01

WAP scores and weighted average scores for wetland vegetation were generally consistent with the results of the flooded area analysis. The WAP scores and weighted average scores were higher overall and did not decline with time at four wetlands in well fields (W-33, W-56, Starkey N, and Starkey 108) during the years following reductions in groundwater-withdrawal rates. These four wetlands also had increases in the extent and duration of the flooded area during the post-reduction period. Scores for trees were more consistent than scores for shrubs and groundcover. WAP scores remained relatively low or generally declined at five well-field wetlands (Q-1, W-17, W-41, Starkey D, and Starkey E) during the years following reductions in groundwater-withdrawal rates, and weighted average scores either declined over time or remained low. These five wetlands either did not have an increase in the extent and duration of the flooded area, or if there was an increase, it was small.

Using ecosystem engineers as tools in habitat restoration and rewilding: beaver and wetlands.

PubMed

Law, Alan; Gaywood, Martin J; Jones, Kevin C; Ramsay, Paul; Willby, Nigel J

2017-12-15

Potential for habitat restoration is increasingly used as an argument for reintroducing ecosystem engineers. Beaver have well known effects on hydromorphology through dam construction, but their scope to restore wetland biodiversity in areas degraded by agriculture is largely inferred. Our study presents the first formal monitoring of a planned beaver-assisted restoration, focussing on changes in vegetation over 12years within an agriculturally-degraded fen following beaver release, based on repeated sampling of fixed plots. Effects are compared to ungrazed exclosures which allowed the wider influence of waterlogging to be separated from disturbance through tree felling and herbivory. After 12years of beaver presence mean plant species richness had increased on average by 46% per plot, whilst the cumulative number of species recorded increased on average by 148%. Heterogeneity, measured by dissimilarity of plot composition, increased on average by 71%. Plants associated with high moisture and light conditions increased significantly in coverage, whereas species indicative of high nitrogen decreased. Areas exposed to both grazing and waterlogging generally showed the most pronounced change in composition, with effects of grazing seemingly additive, but secondary, to those of waterlogging. Our study illustrates that a well-known ecosystem engineer, the beaver, can with time transform agricultural land into a comparatively species-rich and heterogeneous wetland environment, thus meeting common restoration objectives. This offers a passive but innovative solution to the problems of wetland habitat loss that complements the value of beavers for water or sediment storage and flow attenuation. The role of larger herbivores has been significantly overlooked in our understanding of freshwater ecosystem function; the use of such species may yet emerge as the missing ingredient in successful restoration. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Carbon sequestration in two created riverine wetlands in the midwestern United States.

PubMed

Bernal, Blanca; Mitsch, William J

2013-07-01

Wetlands have the ability to accumulate significant amounts of carbon (C) and thus could provide an effective approach to mitigate greenhouse gas accumulation in the atmosphere. Wetland hydrology, age, and management can affect primary productivity, decomposition, and ultimately C sequestration in riverine wetlands, but these aspects of wetland biogeochemistry have not been adequately investigated, especially in created wetlands. In this study we investigate the ability of created freshwater wetlands to sequester C by determining the sediment accretion and soil C accumulation of two 15-yr-old created wetlands in central Ohio-one planted and one naturally colonized. We measured the amount of sediment and soil C accumulated over the parent material and found that these created wetlands accumulated an average of 242 g C m yr, 70% more than a similar natural wetland in the region and 26% more than the rate estimated for these same wetlands 5 yr before this study. The C sequestration of the naturally colonized wetland was 22% higher than that of the planted wetland (267 ± 17 vs. 219 ± 15 g C m yr, respectively). Soil C accrual accounted for 66% of the aboveground net primary productivity on average. Open water communities had the highest C accumulation rates in both wetlands. This study shows that created wetlands can be natural, cost-effective tools to sequester C to mitigate the effect of greenhouse gas emissions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

A Constructed Freshwater Wetland Shows Signs of Declining Net Ecosystem Exchange

NASA Astrophysics Data System (ADS)

Anderson, F. E.; Bergamaschi, B. A.; Windham-Myers, L.; Byrd, K. B.; Drexler, J. Z.; Fujii, R.

2014-12-01

The USGS constructed a freshwater-wetland complex on Twitchell Island in the Sacramento-San Joaquin Delta (Delta), California, USA, in 1997 and maintained it until 2012 to investigate strategies for biomass accretion and reduction of oxidative soil loss. We studied an area of the wetland complex covered mainly by dense patches of hardstem bulrush (Schoenoplectus acutus) and cattails (Typha spp.), with smaller areas of floating and submerged vegetation, that was maintained at an average depth of 55 cm. Using eddy covariance measurements of carbon and energy fluxes, we found that the combination of water management and the region's Mediterranean climate created conditions where peak growing season daily means of net ecosystem exchange (NEE) reached -45 gCO2 m-2 d-1 and averaged around -30 gCO2 m-2 d-1 between 2002 through 2004. However, when measurements resumed in 2010, NEE rates were a fraction of the rates previously measured, approximately -6 gCO2 m-2 d-1. Interestingly, NEE rates in 2011 doubled compared to 2010 (-13 gCO2 m-2 d-1). Methane fluxes, collected in 2010 to assess a complete atmospheric carbon budget, were positive throughout the year, with daily mean flux values ranging from 50 to 300 mg CH4 m-2 d-1. As a result, methane flux reduced NEE values by approximately one-third, and when the global warming potential was considered, the wetland became a net global warming potential source. We found that carbon cycling in a constructed wetland is complex and can change over annual and decadal timescales. We investigated possible reasons for differences between flux measurements from 2002 to 2004 and those from 2010 and 2011: (1) changes in methodology, (2) differences in weather conditions, (3) differences in gross primary productivity relative to respiration rates, and (4) the amount of living plant tissue relative to brown accumulations of senesced plant litter. We hypothesize that large mats of senesced material within the flux footprint could have contributed to the difference in flux rates by reducing the productivity of the emergent marsh species. We conclude that for restored or constructed wetlands, it is important to implement long-term monitoring strategies to assess and manage environmental processes associated with carbon storage.

Wetlands shrinkage, fragmentation and their links to agriculture in the Muleng-Xingkai Plain, China.

PubMed

Song, Kaishan; Wang, Zongming; Li, Lin; Tedesco, Lenore; Li, Fang; Jin, Cui; Du, Jia

2012-11-30

In the past five decades, the wetlands in the Muleng-Xingkai Plain, Northeast China, have experienced rapid shrinkage and fragmentation. In this study, wetlands cover change and agricultural cultivation were investigated through a time series of thematic maps from 1954, and Landsat satellite images representing the last five decades (1976, 1986, 1995, 2000, and 2005). Wetlands shrinkage and fragmentation were studied based on landscape metrics and the land use changes transition matrix. Furthermore, the driving forces were explored according to socioeconomic development and major natural environmental factors. The results indicate a significant decrease in the wetlands area in the past five decades, with an average annual decrease rate of 9004 ha/yr. Of the 625,268 ha of native wetlands in 1954, approximately 64% has been converted to other land use types by 2005, of which conversion to cropland accounts for the largest share (83%). The number of patches decreased from 1272 (1954) to 197 (1986) and subsequently increased to 326 (2005). The mean patch size changed from 480 ha (1954) to 1521 ha (1976), and then steadily decreased to 574 ha (2005). The largest patch index (total core area index) indicates wetlands shrinkage with decreased values from 31.73 (177,935 ha) to 3.45 (39,421 ha) respectively. Climatic changes occurred over the study period, providing a potentially favorable environment for agricultural development. At the same time population, groundwater harvesting, and fertilizer application increased significantly, resulting in wetlands degradation. According to the results, the shrinkage and fragmentation of wetlands could be explained by socioeconomic development and secondarily aided by changing climatic conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Using Tradtional Ecological Knowledge to Protect Wetlands: the Swinomish Tribe's Wetland Cultural Assessment Project

NASA Astrophysics Data System (ADS)

Mitchell, T.

2017-12-01

"Traditional" wetland physical assessment modules do not adequately identify Tribal cultural values of wetlands and thus wetlands may not be adequately protected for cultural uses. This Swinomish Wetlands Cultural Assessment Project has developed a cultural resource scoring module that can be incorporated into wetland assessments to better inform wetland protections. Local native knowledge was gathered about the traditional uses of 99 native wetland plant species. A cultural scoring matrix was developed based on the presence of traditionally used plants in several use categories including: construction, ceremonial, subsistence, medicinal, common use, plant rarity, and place of value for each wetland. The combined score of the cultural and physcial modules provides an overall wetland score that relates to proscribed buffer protection widths. With this local native knowledge incorporated into wetland assessments, we are protecting and preserving Swinomish Reservation wetlands for both cultural uses and ecological functionality through the Tribe's wetland protection law.

A Total Economic Valuation of Wetland Ecosystem Services: An Evidence from Jagadishpur Ramsar Site, Nepal

PubMed Central

Basnyat, Bijendra; Khanal, Rajendra; Gauli, Kalyan

2016-01-01

Wetlands are the most productive ecosystem and provide wide arrays of wetland ecosystems (goods and services) to the local communities in particular and global communities in general. However, management of the wetland often does not remain priority and recognized as the unproductive waste land mainly due to poor realization of the economic value of the wetlands. Taking this into account, the study estimated the total economic value of the Jagadishpur Reservoir taking into account direct, indirect, and nonuse value. The study prioritized six major values of the reservoir which include wetland goods consumption, tourism, irrigation, carbon sequestration, biodiversity conservation, and conservation for future use (existence and option value). The study used market and nonmarket based valuation techniques to estimate total economic value of the reservoir. Household survey, focus group discussions, and interaction with the tourism entrepreneurs and district stakeholders were carried out to collect information. The study estimated the total annual economic value of the reservoir as NRs 94.5 million, where option/existence value remains main contributor followed by direct use value such as wetland goods and tourism and indirect use value, for example, carbon sequestration, biodiversity conservation, and irrigation. The study reveals that the local communities gave high importance to the future use value and are willing to make investment for conservation and restoration of reservoir given its conservation significance. PMID:27830175

A Total Economic Valuation of Wetland Ecosystem Services: An Evidence from Jagadishpur Ramsar Site, Nepal.

PubMed

Baral, Sony; Basnyat, Bijendra; Khanal, Rajendra; Gauli, Kalyan

Wetlands are the most productive ecosystem and provide wide arrays of wetland ecosystems (goods and services) to the local communities in particular and global communities in general. However, management of the wetland often does not remain priority and recognized as the unproductive waste land mainly due to poor realization of the economic value of the wetlands. Taking this into account, the study estimated the total economic value of the Jagadishpur Reservoir taking into account direct, indirect, and nonuse value. The study prioritized six major values of the reservoir which include wetland goods consumption, tourism, irrigation, carbon sequestration, biodiversity conservation, and conservation for future use (existence and option value). The study used market and nonmarket based valuation techniques to estimate total economic value of the reservoir. Household survey, focus group discussions, and interaction with the tourism entrepreneurs and district stakeholders were carried out to collect information. The study estimated the total annual economic value of the reservoir as NRs 94.5 million, where option/existence value remains main contributor followed by direct use value such as wetland goods and tourism and indirect use value, for example, carbon sequestration, biodiversity conservation, and irrigation. The study reveals that the local communities gave high importance to the future use value and are willing to make investment for conservation and restoration of reservoir given its conservation significance.

Investigations of subsurface flow constructed wetlands and associated geomaterial resources in the Akumal and Reforma regions, Quintana Roo, Mexico

NASA Astrophysics Data System (ADS)

Krekeler, Mark P. S.; Probst, Pete; Samsonov, Misha; Tselepis, Cynthia M.; Bates, William; Kearns, Lance E.; Maynard, J. Barry

2007-12-01

Subsurface flow constructed wetlands in the village of Akumal, Quintana Roo, Mexico were surveyed to determine the general status of the wetland systems and provide baseline information for long term monitoring and further study. Twenty subsurface flow wetlands were surveyed and common problems observed in the systems were overloading, poor plant cover, odor, and no secondary containment. Bulk mineral composition of aggregate from two subsurface flow constructed wetlands was determined to consist solely of calcite using bulk powder X-ray diffraction. Some soil structure is developed in the aggregate and aggregate levels in wetlands drop at an estimated rate between 3 and 10 cm/year for overloaded wetlands owing to dissolution. Mineral composition from fresh aggregate samples commonly is a mixture of calcite and aragonite. Trace amounts of Pb, Zn, Co, and Cr were observed in fresh aggregate. Coefficients of permeability ( k) varied from 0.006 to 0.027 cm/s with an average values being 0.016 cm/s. Grain size analysis of fresh aggregate samples indicates there are unimodal and multimodal size distributions in the samples with modes in the coarse and fine sand being common. Investigations of other geologic media from the Reforma region indicate that a dolomite with minor amounts of Fe-oxide and palygorskite is abundant and may be a better aggregate source that the current materials used. A Ca-montmorillonite bed was identified in the Reforma region as well and this unit is suitable to serve as a clay liner to prevent leaks for new and existing wetland systems. These newly discovered geologic resources should aid in the improvement of subsurface flow constructed wetlands in the region. Although problems do exist in these wetlands with respect to design, these systems represent a successful implementation of constructed wetlands at a community level in developing regions.

Cumuilative Effects of Impoundments on the Hydrology of Riparian Wetlands along the Marmaton River, west-central Missouri

USGS Publications Warehouse

Heimann, David C.; Krempa, Heather M.

2011-01-01

The effects of proposed impoundments and resulting streamflow regulation on riparian wetlands in the Marmaton River Basin, Missouri, USA were determined using measurements and numerical simulations of wetland water budgets. Calibrated and validated Soil-Plant-Air-Water (SPAW) models were used to simulate daily water depths of four riparian wetlands for Current (model scenario of existing impoundments) and Proposed (model scenario of existing and proposed impoundments) impoundment conditions. The simulated frequency of flooding decreased 19–65% at the wetlands following the additions of proposed impoundments. The reduced flooding resulted in decreases in wetland water depths at all sites during the 10 simulated growing seasons under Proposed conditions with an average duration of continuous water-depth declines of 289 days at the upstream (most regulated) site. Downstream wetlands within the zone of least regulation had an average duration of water level decreases of about 20 days. Decreased water levels under Proposed conditions resulted in a range of 65–365 additional dry days at the study wetlands during the simulated 10-year period of Proposed conditions. The areas of the four wetlands meeting the hydrologic criteria of a formal jurisdictional wetland definition decreased ranging from zero to 31% under Proposed impoundment conditions.

Field-scale simulation of methane emissions from coastal wetlands in China using an improved version of CH4MODwetland.

PubMed

Li, Tingting; Xie, Baohua; Wang, Guocheng; Zhang, Wen; Zhang, Qing; Vesala, Timo; Raivonen, Maarit

2016-07-15

Coastal wetlands are important CH4 sources to the atmosphere. Coastal wetlands account for ~10% of the total area of natural wetlands in China, but the size of this potential CH4 source remains highly uncertain. We introduced the influence of salinity on CH4 production and CH4 diffusion into a biogeophysical model named CH4MODwetland so that it can be used in coastal wetlands. The improved model can generally simulate seasonal CH4 variations from tidal marshes dominated by Phragmites and Scirpus. However, the model underestimated winter CH4 fluxes from tidal marshes in the Yellow River Delta and YanCheng Estuary. It also failed to capture the accurate timing of the CH4 peaks in YanCheng Estuary and ChongMing Island in 2012. The improved model could generally simulate the difference between the annual mean CH4 fluxes from mangrove sites in GuangZhou and HaiKou city under different salinity and water table depth conditions, although fluxes were systematically underestimated in the mangrove site of HaiKou city. Using the improved model, the seasonal CH4 emissions simulated across all of the coastal wetlands ranged from 0.1 to 44.90gm(-2), with an average value of 7.89gm(-2), which is in good agreement with the observed values. The improved model significantly decreased the RMSE and RMD from 424% to 14% and 314% to -2%, respectively, and improved the EF from -18.30 to 0.99. Model sensitivity analysis showed that CH4 emissions were most sensitive to Pox in the tidal marshes and salinity in the mangroves. The results show that previous studies may have overestimated CH4 emissions on a regional or global scale by neglecting the influence of salinity. In general, the CH4MODwetland model can simulate seasonal CH4 emissions from different types of coastal wetlands under various conditions. Further improvements of CH4MODwetland should include the specific characteristics of CH4 processes in mangroves to decrease the uncertainty in estimating regional or global CH4 emissions from natural wetlands. Copyright © 2016 Elsevier B.V. All rights reserved.

Research Challenges And Opportunities To Enhance Ecological Functions In Forested Wetlands

Treesearch

John A. Stanturf; J. Steven Meadows

1994-01-01

Protecting wetland values and functions are important goals for forest managers. Value and function are easy terms to confuse, but they are not interchangeable. Societal values are directly and indirectly associated with ecological functions. For example, forested wetlands may suppress flooding downstream, which is a value. Floodplain forests store water, impede...

The topic is the Relevance of wetland economic valuation in Uganda Acase study of Kiyanja-Kaku wetland in Lwengo District-Central Uganda.

NASA Astrophysics Data System (ADS)

Namulema, Mary Jude

2016-04-01

This study examined the relevance of economic valuation of wetlands in Uganda. A case study was done on Kiyanja-Kaku wetland in Lwengo District in Central Uganda using a semi-structured survey. Three objectives were examined i.e.: (i) To identify wetland ecosystem services in Uganda (ii) To identify the economic valuation methods appropriate for wetlands in Uganda (iii) To value clean water obtained from Kiyanja-Kaku wetland. The wetland ecosystem services were identified as provisioning, regulating, habitat, cultural and amenities services. The community had knowledge about 17 out of the 22 services as given by TEEB (2010). The economic valuation methods identified were, market price, efficiency price, travel cost, contingent valuation, hedonic pricing, and production function and benefit transfer methods. These were appropriate for valuation of wetlands in Uganda but only three methods i.e. market price, contingent valuation and productivity methods have been applied by researchers in Uganda so far. The economic value of clean water from Kiyanja-Kaku wetland to the nearby community was established by using the market price of clean water the National water and Sewerage Corporation charges for the water in Uganda to obtain the low value and the market price of water from the survey was used to obtain the high value. The estimated economic value of clean water service for a household ranges from UGX. 612174 to 4054733 (US 168.0-1095.0). The estimated economic value of clean water service from Kiyanja-Kaku wetland to the entire community ranges from UGX. 2,732,133,000.0 to 18,096,274,000.0 (US 775,228.0-4,885,994.0).

Long-term Strategic Planning for a Resilient Metro Colombo: An Economic Case for Wetland Conservation and Management

NASA Astrophysics Data System (ADS)

Rozenberg, J.

2015-12-01

Colombo faces recurrent floods that threaten its long-term economic development. Its urban wetlands have been identified by local agencies as a critical component of its flood reduction system, but they have declined rapidly in recent years due to continuous infilling, unmanaged land development and dredging to create lakes. In collaboration with government agencies, NGOs and local universities, the World Bank has carried out a Robust Decision Making analysis to examine the value of Colombo urban wetlands, both in the short-term and long-term, and identify what are the most viable strategies available to increase the city's flood resilience in an unclear future (in terms of climate change and patterns of urban development). This has involved the use of numerous hydrological and socio-economic scenarios as well as the evaluation of some wetlands benefits, like ecosystem services, wastewater treatment, or recreational services. The analysis has determined that if all urban wetlands across the Colombo catchment were lost, in some scenarios the metropolitan area would have to cope with an annual average flood loss of approximately 1% of Colombo GDP in the near future. For long-term strategies, trade-offs between urban development, lake creation and wetland conservation were analyzed and it was concluded that an active management of urban wetlands was the lowest regret option. Finally, the analysis also revealed that in the future, with climate change and fast urban development, wetlands will not be sufficient to protect Colombo against severe floods. Pro-active urban planning and land-use management are therefore necessary, both to protect existing wetlands and to reduce future exposure. The use of many different scenarios, the consideration of several policy options, and the open participatory process ensured policy-makers' buy-in and lead to the decision to actively protect urban wetlands in Colombo.

Forms of organic phosphorus in wetland soils

NASA Astrophysics Data System (ADS)

Cheesman, A. W.; Turner, B. L.; Reddy, K. R.

2014-12-01

Phosphorus (P) cycling in freshwater wetlands is dominated by biological mechanisms, yet there has been no comprehensive examination of the forms of biogenic P (i.e., forms derived from biological activity) in wetland soils. We used solution 31P NMR spectroscopy to identify and quantify P forms in surface soils of 28 palustrine wetlands spanning a range of climatic, hydrogeomorphic, and vegetation types. Total P concentrations ranged between 51 and 3516 μg P g-1, of which an average of 58% was extracted in a single-step NaOH-EDTA procedure. The extracts contained a broad range of P forms, including phosphomonoesters (averaging 24% of the total soil P), phosphodiesters (averaging 10% of total P), phosphonates (up to 4% of total P), and both pyrophosphate and long-chain polyphosphates (together averaging 6% of total P). Soil P composition was found to be dependant upon two key biogeochemical properties: organic matter content and pH. For example, stereoisomers of inositol hexakisphosphate were detected exclusively in acidic soils with high mineral content, while phosphonates were detected in soils from a broad range of vegetation and hydrogeomorphic types but only under acidic conditions. Conversely inorganic polyphosphates occurred in a broad range of wetland soils, and their abundance appears to reflect more broadly that of a "substantial" and presumably active microbial community with a significant relationship between total inorganic polyphosphates and microbial biomass P. We conclude that soil P composition varies markedly among freshwater wetlands but can be predicted by fundamental soil properties.

Forms of organic phosphorus in wetland soils

NASA Astrophysics Data System (ADS)

Cheesman, A. W.; Turner, B. L.; Reddy, K. R.

2014-06-01

Phosphorus (P) cycling in freshwater wetlands is dominated by biological mechanisms, yet there has been no comprehensive examination of the forms of biogenic P (i.e. forms derived from biological activity) in wetland soils. We used solution 31P NMR spectroscopy to identify and quantify P forms in surface soils of 28 palustrine wetlands spanning a range of climatic, hydro-geomorphic and vegetation types. Total P concentrations ranged between 51 and 3516 μg P g

Estimation of wetland methane emissions in a biogeochemical model integrated in CESM: sensitivity analysis and comparison against surface and atmospheric measurements

NASA Astrophysics Data System (ADS)

Meng, L.; Mahowald, N. M.; Hess, P. G.; Yavitt, J. B.; Riley, W. J.; Subin, Z. M.; Lawrence, D. M.; Swenson, S. C.; Jauhiainen, J.; Fuka, D. R.

2012-12-01

Methane emissions from natural wetlands and rice paddies constitute a large proportion of atmospheric methane, but the magnitude and year-to-year variation of these methane sources is still unpredictable. Here we describe and evaluate the integration of a methane biogeochemical model (CLM4Me; Riley et al. 2011) into the Community Land Model 4.0 (CLM4CN) in order to better explain spatial and temporal variations in methane emissions. We test new functions for soil pH and redox potential that impact microbial methane production in soils. We also constrain aerenchyma in plants in always-inundated areas in order to better represent wetland vegetation. Satellite inundated fraction is explicitly prescribed in the model because there are large differences between simulated fractional inundation and satellite observations and thus we do not use CLM4 simulated inundated area. The model is evaluated at the site level with vegetation cover and water table prescribed from measurements. Explicit site level evaluations of simulated methane emissions are quite different than evaluating the grid cell averaged emissions against available measurements. Using a baseline set of parameter values, our model-estimated average global wetland emissions for the period 1993-2004 were 256 Tg CH4 y-1 (including the soil sink). Tropical wetlands contributed 201 Tg CH4 y-1, or 78% of the global wetland flux. Northern latitude (>50N) systems contributed 12 Tg CH4 y-1. Our sensitivity studies show a large range (150-346 Tg CH4 y-1) in predicted global methane emissions. In order to evaluate our methane emissions on the regional and global scales against atmospheric measurements, we conducted simulations with the Community Atmospheric Model with chemistry (CAM-chem) forced with our baseline simulation of wetland and rice paddy emissions along with other methane sources (e.g. anthropogenic, fire, and termite emissions) and compared model simulations against measured atmospheric concentrations obtained from the World Data Centre for Greenhouse Gases (WDCGG) at http://ds.data.jma.go.jp/gmd/wdcgg/. Overall, using our estimated wetland and rice paddy emissions, CAM-chem model can produce seasonal and interannual variations of observed atmospheric concentration performs well. Thus, within the current level of uncertainty, our emissions appear to be reasonable.

Soil color indicates carbon and wetlands: developing a color-proxy for soil organic carbon and wetland boundaries on sandy coastal plains in South Africa.

PubMed

Pretorius, M L; Van Huyssteen, C W; Brown, L R

2017-10-13

A relationship between soil organic carbon and soil color is acknowledged-albeit not a direct one. Since heightened carbon contents can be an indicator of wetlands, a quantifiable relationship between color and carbon might assist in determining wetland boundaries by rapid, field-based appraisal. The overarching aim of this initial study was to determine the potential of top soil color to indicate soil organic carbon, and by extension wetland boundaries, on a sandy coastal plain in South Africa. Data were collected from four wetland types in northern KwaZulu-Natal in South Africa. Soil samples were taken to a depth of 300 mm in three transects in each wetland type and analyzed for soil organic carbon. The matrix color was described using a Munsell soil color chart. Various color indices were correlated with soil organic carbon. The relationship between color and carbon were further elucidated using segmented quantile regression. This showed that potentially maximal carbon contents will occur at values of low color indices, and predictably minimal carbon contents will occur at values of low or high color indices. Threshold values can thus be used to make deductions such as "when the sum of dry and wet Value and Chroma values is 9 or more, carbon content will be 4.79% and less." These threshold values can then be used to differentiate between wetland and non-wetland sites with a 70 to 100% certainty. This study successfully developed a quantifiable correlation between color and carbon and showed that wetland boundaries can be determined based thereon.

The influence of managed versus natural hydrologic regimes on the hydrochemical patterns in a constructed wetland in the Athabasca oil sands region, Canada.

NASA Astrophysics Data System (ADS)

Biagi, K.; Oswald, C.; Nicholls, E.; Carey, S.

2017-12-01

Bitumen extraction via surface mining in the Athabasca Oil Sands Region (AOSR) results in permanent alteration of the landscape once rich in boreal forest and wetlands. As part of their legal requirements, oil companies must reclaim disturbed landscapes into functioning ecosystems, and to date only two pilot wetland-peatland systems have been constructed. Peatland reclamation is challenging as they must be completely reconstructed with few guidelines or previous work in this region. Furthermore, the variable sub-humid climate and salinity of waste-materials are obstacles to the success of peatland creation. In 2012, Syncrude Canada Ltd. constructed a 52 ha upland-wetland system, the Sandhill Fen Watershed (SFW), which was designed with a pump and underdrain system to provide freshwater and enhance drainage to limit salinization from underlying waste materials that have elevated electrical conductivity (EC) and Na+. The objective of this research is to understand the hydrochemical response of a constructed wetland to variations in hydrological management with respect to sources, flow pathways and major chemical transformations of water in the three years following commissioning. EC, major ions and stable isotopes were collected using a combination of high frequency and discrete water sampling from 2013-2015. Results indicate that high activity of both inflow and outflow pumps in 2013 kept the EC relatively low, with most wetland sites <1000 µS/cm. Ca+2 was the dominant cation in 2013, averaging 105 mg/L in the wetland while Na+ averaged 56 mg/L. With limited pump activity in 2014 and 2015, the EC and ion concentrations increased considerably with EC in the wetland >1000 µS/cm in 2014 and >2000 µS/cm in 2015. Most wetland sites remained Ca+2 dominant where Ca+2 and Na+ averaged 200 and 130 mg/L, respectively. However, the most notable change in 2014 and 2015 was the emergence of several Na+ "hotspots" in the margins where Na+ concentrations averaged 450 mg/L while Ca+2 averaged 250 mg/L. Stable isotope data confirm that the "hotspots" match the underlying waste water and provide evidence of its upward transport and seepage under a natural hydrologic regime. Minimizing salinization is critical for reclamation in the AOSR, and lessons learned from SFW will guide both current and future peatland creation efforts.

The Rise of GNSS Reflectometry for Earth Remote Sensing

NASA Technical Reports Server (NTRS)

Zuffada, Cinzia; Li, Zhijin; Nghiem, Son V.; Lowe, Steve; Shah, Rashmi; Clarizia, Maria Paola; Cardellach, Estel

2015-01-01

The Global Navigation Satellite System (GNSS) reflectometry, i.e. GNSS-R, is a novel remote-sensing technique first published in that uses GNSS signals reflected from the Earth's surface to infer its surface properties such as sea surface height (SSH), ocean winds, sea-ice coverage, vegetation, wetlands and soil moisture, to name a few. This communication discusses the scientific value of GNSS-R to (a) furthering our understanding of ocean mesoscale circulation toward scales finer than those that existing nadir altimeters can resolve, and (b) mapping vegetated wetlands, an emerging application that might open up new avenues to map and monitor the planet's wetlands for methane emission assessments. Such applications are expected to be demonstrated by the availability of data from GEROS-ISS, an ESA experiment currently in phase A, and CyGNSS [3], a NASA mission currently in development. In particular, the paper details the expected error characteristics and the role of filtering played in the assimilation of these data to reduce the altimetric error (when averaging many measurements).

Landscape ecological assessment and eco-tourism development in the South Dongting Lake Wetland, China.

PubMed

He, Ping; Wang, Bao-zhong

2003-03-01

As an important resource and the living environment of mankind, wetland has become gradually a highlight, strongly concerned and intensively studied by scientists and sociologists. The governments in the world and the whole society have been paying more and more attention on it. The Dongting Lake of China is regarded as an internationally important wetland. For a rational development and protection of the wetland, an investigation and studied on its resources and its value to tourism in the South Dongting Lake was conducted, to create an assessment system of the ecological landscapes, and to evaluate qualitatively and quantitatively the value of wetland landscape to the ecotourism. The results showed that the scenic value of the South Dongting Lake Wetland satisfied the criterion of AAAA grade of China national scenic attraction. The eco-tourism value of the landscape cultures in the South Dongting Lake Wetland was discussed with emphasis. It were formulated that a principle and frame of sustainable exploitation of the wetland landscapes and it was proposed as well that establishing a Wetland Park and developing eco-tourism in the South Dongting Lake Wetland is a fragile ecosystem with low resistance to the impact of the exploitation. Thus, we must pay intensively attention to the influence of exploitation on the landscape, take the ecological risk in account to employ a right countermeasure and avoid the negative affection.

The Beaver Creek story

USGS Publications Warehouse

Doyle, W.H.; Whitworth, B.G.; Smith, G.F.; Byl, T.D.

1996-01-01

Beaver Creek watershed in West Tennessee includes about 95,000 acres of the Nation's most productive farmland and most highly erodible soils. In 1989 the U.S. Geological Survey, in cooperation with the Tennessee Department of Agriculture, began a study to evaluate the effect of agricultural activities on water quality in the watershed and for best management practices designed to reduce agricultural nonpoint-source pollution. Agrichemical monitoring included testing the soils, ground water, and streams at four farm sites ranging from 27 to 420 acres. Monitoring stations were operated downstream to gain a better understanding of the water chemistry as runoff moved from small ditches into larger streams to the outlet of the Beaver Creek watershed. Prior to the implementation of best management practices at one of the farm study sites, some storms produced an average suspended-sediment concentration of 70,000 milligrams per liter. After the implementation of BMP's, however, the average value never exceeded 7,000 milligrams per liter. No-till crop production was the most effective best management practice for conserving soil on the farm fields tested. A natural bottomland hardwood wetland and a constructed wetland were evaluated as instream resource-management systems. The wetlands improved water quality downstream by acting as a filter and removing a significant amount of nonpoint-source pollution from the agricultural runoff. The constructed wetland reduced the sediment, pesticide, and nutrient load by approximately 50 percent over a 4-month period. The results of the Beaver Creek watershed study have increased the understanding of the effects of agriculture on water resources. Study results also demonstrated that BMP's do protect and improve water quality.

Valuing ecosystem services from wetlands restoration in the Mississippi Alluvial Valley

USGS Publications Warehouse

Jenkins, W.A.; Murray, B.C.; Kramer, R.A.; Faulkner, S.P.

2010-01-01

This study assesses the value of restoring forested wetlands via the U.S. government's Wetlands Reserve Program (WRP) in the Mississippi Alluvial Valley by quantifying and monetizing ecosystem services. The three focal services are greenhouse gas (GHG) mitigation, nitrogen mitigation, and waterfowl recreation. Site- and region-level measurements of these ecosystem services are combined with process models to quantify their production on agricultural land, which serves as the baseline, and on restored wetlands. We adjust and transform these measures into per-hectare, valuation-ready units and monetize them with prices from emerging ecosystem markets and the environmental economics literature. By valuing three of the many ecosystem services produced, we generate lower bound estimates for the total ecosystem value of the wetlands restoration. Social welfare value is found to be between $1435 and $1486/ha/year, with GHG mitigation valued in the range of $171 to $222, nitrogen mitigation at $1248, and waterfowl recreation at $16. Limited to existing markets, the estimate for annual market value is merely $70/ha, but when fully accounting for potential markets, this estimate rises to $1035/ha. The estimated social value surpasses the public expenditure or social cost of wetlands restoration in only 1 year, indicating that the return on public investment is very attractive for the WRP. Moreover, the potential market value is substantially greater than landowner opportunity costs, showing that payments to private landowners to restore wetlands could also be profitable for individual landowners. ?? 2009 Elsevier B.V.

The Impacts of wetland restoration on Fish Productivity in Nigeria

NASA Astrophysics Data System (ADS)

Ayorinde, O. A.; Okunade, K. M.; Agboola, D. M.; Adesokan, Z. A.

2016-02-01

Wetland is one of the resources of high value which has been exposed to indiscriminate use. It is an important ecosystem to fish and loss or degradation of wetland will have a direct consequence on sustainable fisheries. This paper reviewed the term "wetland", its functions and values, importance to fish production in Nigeria and threats to its sustainability. The term "wetland" has been defined by various researchers especially based on their profession and their needs but up till today there is no single definition accepted by all users. In Nigeria, the most commonly adopted is that of RAMSAR convention. Wetland has both marketed and non-marketed functions and values. They provide essential link in the life cycle of 75 percent of the fish and shell fish commercially harvested in the world and are vital to fish health. Despite the importance, there have been exceptional losses of wetlands. Lagos state alone has witnessed more than 96 percent loss. Major threats to wetlands are: agriculture, development, pollution and climate change. Therefore proper management of the wetland ecosystem is important in other to ensure continuous fish production.

Efficiencies of freshwater and estuarine constructed wetlands for phenolic endocrine disruptor removal in Taiwan.

PubMed

Hsieh, Chi-Ying; Yang, Lei; Kuo, Wen-Chien; Zen, Yi-Peng

2013-10-01

We examined the distribution and removal efficiencies of phenolic endocrine disruptors (EDs), namely nonylphenol diethoxylates (NP2EO), nonylphenol monoethoxylates (NP1EO), nonylphenol (NP), and octylphenol (OP), in wastewater treated by estuarine and freshwater constructed wetland systems in Dapeng Bay National Scenic Area (DBNSA) and along the Dahan River in Taiwan. Water samples were taken bimonthly at 30 sites in three estuarine constructed wetlands (Datan, Pengcun and Linbian right bank (A and B)) in DBNSA, for eight sampling campaigns. The average removal efficiencies were in the range of 3.13-97.3% for wetlands in DBNSA. The highest average removal occurred in the east inlet to the outlet of the Tatan wetland. The most frequently detected compound was OP (57.7%), whose concentration was up to 1458.7 ng/L in DBNSA. NP was seen in only 20.5% of the samples. The temporal variation of EDs showed a decrease across seasons, where summer>spring>winter>autumn in these constructed wetlands. The removal efficiencies of EDs by estuarine wetlands, in decreasing order, were Datan>Pengcun>Linbian right bank in DBNSA. Water samples collected at 18 sites in three freshwater constructed wetlands (Daniaopi, Hsin-Hai I, and Hsin-Hai II) along the riparian area of Dahan River. NP2EO was the most abundant compound, with a concentration of up to 11,200 ng/L. Removal efficiencies ranged from 55% to 91% for NP1EO, NP2EO, and NP in Hsin-Hai I. The average removal potential of EDs in freshwater constructed wetlands, in decreasing order, was Hsin-Hai II>Daniaopi>Hsin-Hai I constructed wetlands. The lowest concentrations of the selected compounds were observed in the winter. The highest removal efficiency of the selected phenolic endocrine disruptors was achieved by Hsin-Hai I wetland. The calculated risk quotients used to evaluate the ecological risk were up to 30 times higher in the freshwater wetlands along Dahan River than in the estuarine (DBNSA) constructed wetlands, indicating that existing concentrations of these EDs in wetland systems pose a high ecological risk to aquatic organisms. The decreasing risk quotient from influent to effluent indicates that phenolic endocrine disruptors can be treated in these constructed wetlands. Our results of this research can serve as a preliminary understanding on the ED removal efficiencies in different types of constructed wetlands. Copyright © 2013 Elsevier B.V. All rights reserved.

Wetland Resiliency: How does multi-year water table level decline and recovery influence carbon dioxide and methane fluxes?

NASA Astrophysics Data System (ADS)

Pugh, C.; Reed, D. E.; Desai, A. R.; Sulman, B. N.

2016-12-01

Wetlands play a disproportionately large role in the global carbon budget, and individual wetlands can fluctuate between carbon sinks and sources depending on factors such as hydrology, biogeochemistry, and land use. Although much research has been done on wetland biogeochemical cycles, there is a lack of experimental evidence concerning how changes in wetland hydrology influence these cycles over interannual timescales. Over a seven-year period, Sulman et al. (2009) found that a drought-induced declining water table at a shrub wetland in northern Wisconsin coincided with increased ecosystem respiration (ER) and gross ecosystem productivity (GEP) (Sulman et al. 2009). Since then, however, the average water table level at this site has begun to increase, thus allowing a unique opportunity to explore how wetland carbon storage is impacted by water table recovery. With the addition of three more years of eddy covariance observations post recovery and new methane flux observations, we found that water table level no longer had a significant correlation with GEP, ER, or methane flux. Air temperature, however, had a strong correlation with all three. Average methane flux stayed relatively constant under 14 °C, before increasing an order of magnitude from 3.7 nmol m-2 s-1 in April to 36 nmol m-2 s-1 in July. These results suggest that, over decadal timescales, temperature, rather than water level, is a stronger limiting factor for both aerobic and anaerobic respiration in shrub fen wetlands. Wetlands play a disproportionately large role in the global carbon budget, and individual wetlands can fluctuate between carbon sinks and sources depending on factors such as hydrology, biogeochemistry, and land use. Although much research has been done on wetland biogeochemical cycles, there is a lack of experimental evidence concerning how changes in wetland hydrology influence these cycles over interannual timescales. Over a seven-year period, Sulman et al. (2009) found that a drought-induced declining water table at a shrub wetland in northern Wisconsin coincided with increased ecosystem respiration (ER) and gross ecosystem productivity (GEP) (Sulman et al. 2009). Since then, however, the average water table level at this site has begun to increase, thus allowing a unique opportunity to explore how wetland carbon storage is impacted by water table recovery. With the addition of three more years of eddy covariance observations post recovery and new methane flux observations, we found that water table level no longer had a significant correlation with GEP, ER, or methane flux. Air temperature, however, had a strong correlation with all three. Average methane flux stayed relatively constant under 14 °C, before increasing an order of magnitude from 3.7 nmol m-2 s-1 in April to 36 nmol m-2 s-1 in July. These results suggest that, over decadal timescales, temperature, rather than water level, is a stronger limiting factor for both aerobic and anaerobic respiration in shrub fen wetlands.

7 CFR 1467.4 - Program requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... that promote the restoration, protection, enhancement, maintenance, and management of wetland functions... successful restoration of wetland functions and values when considering the cost of acquiring the easement...) The likelihood of the successful restoration of such land and the resultant wetland values merit...

7 CFR 623.9 - Easement priority.

Code of Federal Regulations, 2011 CFR

2011-01-01

... restored, (e) Wetland function or values, (f) Likelihood of successful restoration of wetland values, (g... AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS RESERVE PROGRAM § 623.9 Easement priority. The State... government expenditure on restoration and easement purchase. The factors for determining the priority for...

Freshwater Wetlands: A Citizen's Primer.

ERIC Educational Resources Information Center

Catskill Center for Conservation and Development, Inc., Hobart, NY.

The purpose of this "primer" for the general public is to describe the general characteristics of wetlands and how wetland alteration adversely affects the well-being of humans. Particular emphasis is placed on wetlands in New York State and the northeast. Topics discussed include wetland values, destruction of wetlands, the costs of…

A case study examining the efficacy of drainage setbacks for limiting effects to wetlands in the Prairie Pothole Region, USA

USGS Publications Warehouse

Tangen, Brian; Finocchiaro, Raymond

2017-01-01

The enhancement of agricultural lands through the use of artificial drainage systems is a common practice throughout the United States, and recently the use of this practice has expanded in the Prairie Pothole Region. Many wetlands are afforded protection from the direct effects of drainage through regulation or legal agreements, and drainage setback distances typically are used to provide a buffer between wetlands and drainage systems. A field study was initiated to assess the potential for subsurface drainage to affect wetland surface-water characteristics through a reduction in precipitation runoff, and to examine the efficacy of current U.S. Department of Agriculture drainage setback distances for limiting these effects. Surface-water levels, along with primary components of the catchment water balance, were monitored over 3 y at four seasonal wetland catchments situated in a high-relief terrain (7–11% slopes). During the second year of the study, subsurface drainage systems were installed in two of the catchments using drainage setbacks, and the drainage discharge volumes were monitored. A catchment water-balance model was used to assess the potential effect of subsurface drainage on wetland hydrology and to assess the efficacy of drainage setbacks for mitigating these effects. Results suggest that overland precipitation runoff can be an important component of the seasonal water balance of Prairie Pothole Region wetlands, accounting on average for 34% (19–49%) or 45% (39–49%) of the annual (includes snowmelt runoff) or seasonal (does not include snowmelt) input volumes, respectively. Seasonal (2014–2015) discharge volumes from the localized drainage systems averaged 81 m3 (31–199 m3), and were small when compared with average combined inputs of 3,745 m3 (1,214–6,993 m3) from snowmelt runoff, direct precipitation, and precipitation runoff. Model simulations of reduced precipitation runoff volumes as a result of subsurface drainage systems showed that ponded wetland surface areas were reduced by an average of 590 m2 (141–1,787 m2), or 24% (3–46%), when no setbacks were used (drainage systems located directly adjacent to wetland). Likewise, wetland surface areas were reduced by an average of 141 m2 (23–464 m2), or 7% (1–28%), when drainage setbacks (buffer) were used. In totality, the field data and model simulations suggest that the drainage setbacks should reduce, but not eliminate, impacts to the water balance of the four wetlands monitored in this study that were located in a high-relief terrain. However, further study is required to assess the validity of these conclusions outside of the limited parameters (e.g., terrain, weather, soils) of this study and to examine potential ecological effects of altered wetland hydrology.

Polychlorinated biphenyls (PCBs) in sediments/soils of different wetlands along 100-year coastal reclamation chronosequence in the Pearl River Estuary, China.

PubMed

Zhao, Qingqing; Bai, Junhong; Lu, Qiongqiong; Gao, Zhaoqin; Jia, Jia; Cui, Baoshan; Liu, Xinhui

2016-06-01

PCBs (polychlorinated biphenyls) were determined in sediment/soil profiles to a depth of 30 cm from three different wetlands (i.e., ditch wetlands, riparian wetlands and reclaimed wetlands) of the Pearl River Estuary to elucidate their levels, distribution and toxic risks along a 100-year chronosequence of reclamation. All detected PCB congeners and the total 15 PCBs (∑15 PCBs) decreased with depth along sediment/soil profiles in these three wetlands. The ∑15 PCBs concentrations ranged from 17.68 to 169.26 ng/g in surface sediments/soils. Generally, old wetlands tended to have higher PCB concentrations than younger ones. The dominant PCB congeners at all sampling sites were light PCB homologues (i.e., tetra-CBs and tri-CBs). According to the sediment quality guideline, the average PCB concentrations exceeded the threshold effects level (TEL, 21.6 ng/g) at most of the sampling sites, exhibiting possible adverse biological effects, which were dominantly caused by light PCB congeners. The total toxic equivalent (TEQ) concentrations of 10 dioxin-like PCBs (DL-PCBs) detected at all sampling sites ranged from 0.04 to 852.7 (10(-3) ng/g), mainly affected by PCB126. Only DL-PCB concentrations in ditch and riparian wetland sediments with 40-year reclamation histories (i.e., D40 and Ri40) exhibited moderate adverse biological effects according to SQGQ values. Principal component analysis indicated that PCBs in three wetland sediments/soils mainly originated from Aroclor 1016, 1242, and 1248. Correlation analysis showed that sediment/soil organic carbon content had a significant correlation with the concentrations of several PCB congeners (P < 0.05), whereas no significant correlations were observed between any PCBs congeners and grain size or aggregate content (P > 0.05). Copyright © 2016 Elsevier Ltd. All rights reserved.

Remotely sensed MODIS wetland components for assessing the variability of methane emissions in Indian tropical/subtropical wetlands

NASA Astrophysics Data System (ADS)

Bansal, Sangeeta; Katyal, Deeksha; Saluja, Ridhi; Chakraborty, Monojit; Garg, J. K.

2018-02-01

Temperature and area fluctuations in wetlands greatly influence its various physico-chemical characteristics, nutrients dynamic, rates of biomass generation and decomposition, floral and faunal composition which in turn influence methane (CH4) emission rates. In view of this, the present study attempts to up-scale point CH4 flux from the wetlands of Uttar Pradesh (UP) by modifying two-factor empirical process based CH4 emission model for tropical wetlands by incorporating MODIS derived wetland components viz. wetland areal extent and corresponding temperature factors (Ft). This study further focuses on the utility of remotely sensed temperature response of CH4 emission in terms of Ft. Ft is generated using MODIS land surface temperature products and provides an important semi-empirical input for up-scaling CH4 emissions in wetlands. Results reveal that annual mean Ft values for UP wetlands vary from 0.69 (2010-2011) to 0.71(2011-2012). The total estimated area-wise CH4 emissions from the wetlands of UP varies from 66.47 Gg yr-1with wetland areal extent and Ft value of 2564.04 km2 and 0.69 respectively in 2010-2011 to 88.39 Gg yr-1with wetland areal extent and Ft value of 2720.16 km2 and 0.71 respectively in 2011-2012. Temporal analysis of estimated CH4 emissions showed that in monsoon season estimated CH4 emissions are more sensitive to wetland areal extent while in summer season sensitivity of estimated CH4 emissions is chiefly controlled by augmented methanogenic activities at high wetland surface temperatures.

Environmental assessment of potential toxic trace element contents in the inundated floodplain area of Tablas de Daimiel wetland (Spain).

PubMed

Jiménez-Ballesta, R; García-Navarro, F J; Bravo, S; Amorós, J A; Pérez-de-Los-Reyes, C; Mejías, M

2017-10-01

Contamination of aquatic systems with potentially toxic trace elements (PTEs) is a major problem throughout the world. The National Park Tablas de Daimiel (NPTD) is considered to make up one of the two most important wetlands in the Biosphere Reserve called "Wet Spot." Since PTEs are good indicator of the prevailing environmental conditions and possible contamination, soil samples collected from 43 sites were analyzed in order to investigate the levels and its distribution of these elements, in the inundated floodplain area of the NPTD wetland. In addition, some physicochemical parameters such as pH, electrical conductivity and organic matter were measured. The total concentrations of 32 trace elements were determined by X-ray fluorescence. The results show that there was accumulation of lead (Pb), tin (Sn), selenium (Se), antimony (Sb), copper (Cu), vanadium (V), nickel (Ni), zinc (Zn), arsenic (As), strontium (Sr) and zirconium (Zr)-in some cases at high concentrations. The interpolated maps showed that the distributions of some of these elements and in some cases the trend in spatial variability are pronounced and decrease from the inlet to the outlet. The values for some elements are higher than the reference values, which is consistent with contamination (some values are higher by a factor of more than 10 compared to the reference). In the case of iodine (I), the levels at some sample points are significantly more than ten times the reference; Se appears in the range from 1.0 to 9.8 mg/kg, with an average value of 3.1 mg/kg, and these can be considered as seleniferous soils. The concentrations found are consistent with the introduction in the wetland of pollution by human activities, such as agricultural non-point sources, uncontrolled fertilization over many years, treatment with urban wastewater and other possible sources.

Water quality of small seasonal wetlands in the Piedmont ecoregion, South Carolina, USA: Effects of land use and hydrological connectivity.

PubMed

Yu, Xubiao; Hawley-Howard, Joanna; Pitt, Amber L; Wang, Jun-Jian; Baldwin, Robert F; Chow, Alex T

2015-04-15

Small, shallow, seasonal wetlands with short hydroperiod (2-4 months) play an important role in the entrapment of organic matter and nutrients and, due to their wide distribution, in determining the water quality of watersheds. In order to explain the temporal, spatial and compositional variation of water quality of seasonal wetlands, we collected water quality data from forty seasonal wetlands in the lower Blue Ridge and upper Piedmont ecoregions of South Carolina, USA during the wet season of February to April 2011. Results indicated that the surficial hydrological connectivity and surrounding land-use were two key factors controlling variation in dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) in these seasonal wetlands. In the sites without obvious land use changes (average developed area <0.1%), the DOC (p < 0.001, t-test) and TDN (p < 0.05, t-test) of isolated wetlands were significantly higher than that of connected wetlands. However, this phenomenon can be reversed as a result of land use changes. The connected wetlands in more urbanized areas (average developed area = 12.3%) showed higher concentrations of dissolved organic matter (DOM) (DOC: 11.76 ± 6.09 mg L(-1), TDN: 0.74 ± 0.22 mg L(-1), mean ± standard error) compared to those in isolated wetlands (DOC: 7.20 ± 0.62 mg L(-1), TDN: 0.20 ± 0.08 mg L(-1)). The optical parameters derived from UV and fluorescence also confirmed significant portions of protein-like fractions likely originating from land use changes such as wastewater treatment and livestock pastures. The average of C/N molar ratios of all the wetlands decreased from 77.82 ± 6.72 (mean ± standard error) in February to 15.14 ± 1.58 in April, indicating that the decomposition of organic matter increased with the temperature. Results of this study demonstrate that the water quality of small, seasonal wetlands has a direct and close association with the surrounding environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Michigan Wetlands: Yours To Protect. A Citizen's Guide to Local Involvement in Wetland Protection. Second Edition.

ERIC Educational Resources Information Center

Cwikiel, Wilfred

This guidebook is designed to assist concerned Michigan citizens, local governments, conservation organizations, landowners, and others in their efforts to initiate wetlands protection activities. Chapter 1 focuses on wetland functions, values, losses, and the urgent need to protect wetland resources. Chapter 2 discusses wetland identification and…

[Protection value evaluation of national wetland parks in Hunan Province, China].

PubMed

Wu, Hou Jian; Dan, Xin Qiu; Liu, Shi Hao; Huang, Yan; Shu, Yong; Cao, Hong; Wu, Zhao Bai

2017-01-01

This paper put forward an evaluation index system which included 5 aspects such as ecological location and representation, biodiversity, species rarity, naturality, scale and partition suitability as well as 15 indicators to assess the protection values of 60 national wetland parks in Hunan Province, China. Analytic hierarchy process (AHP) and entropy method were used in this evaluation index system. There were 37 national wetland parks (accounting for 61.7%) keeping high protection values with scores of greater than or equal to 67.64 points, and 12 national wetland parks (accounting for 20.0%) keeping very high protection values with scores of greater than or equal to 77.72 points. Although there was a discrete and rare regularity of the inter-annual variation, these values still showed a decreasing trend in general. From the space point of view, 70 points isogram divided the national wetland parks of Hunan Province into two high score areas and three high score points in the west and east area, and one low score area and four low score points in the middle. Ecological location, resource endowment and scale were the decisive factors for the conservation va-lues of national wetland parks in Hunan Province.

Floristic quality assessment of one natural and three restored wetland complexes in North Dakota, USA

USGS Publications Warehouse

Mushet, David M.; Euliss, Ned H.; Shaffer, Terry L.

2002-01-01

Floristic quality assessment is potentially an important tool for conservation efforts in the northern Great Plains of North America, but it has received little rigorous evaluation. Floristic quality assessments rely on coefficients assigned to each plant species of a region’s flora based on the conservatism of each species relative to others in the region. These “coefficients of conservatism” (C values) are assigned by a panel of experts familiar with a region’s flora. The floristic quality assessment method has faced some criticism due to the subjective nature of these assignments. To evaluate the effect of this subjectivity on floristic quality assessments, we performed separate evaluations of the native plant communities in a natural wetland complex and three restored wetland complexes. In our first assessment, we used C values assigned “subjectively” by the Northern Great Plains Floristic Quality Assessment Panel. We then performed an independent assessment using the observed distributions of species among a group of wetlands that ranged from highly disturbed to largely undisturbed (data-generated C values). Using the panel-assigned C values, mean C values (C¯">C¯C¯) of the restored wetlands rarely exceeded 3.4 and never exceeded 3.9, with the highest values occurring in the oldest restored complex; all but two wetlands in the natural wetland complex had a C¯">C¯C¯ greater than 3.9. Floristic quality indices (FQI) for the restored wetlands rarely exceeded 22 and usually reached maximums closer to 19, with higher values occurring again in the oldest restored complex; only two wetlands in the natural complex had an FQI less than 22. We observed that 95% confidence limits for species richness and percent natives overlapped greatly among wetland complexes, whereas confidence limits for both C¯">C¯C¯ and FQI overlapped little. C¯">C¯C¯ and FQI values were consistently greater when we used the datagenerated C values than when we used the panel-assigned C values; nonetheless, conclusions reached based on these two independent assessment techniques were virtually identical. Our results are consistent with the opinion that coefficients assigned subjectively by expert botanists familiar with a region’s flora provide adequate information to perform accurate floristic quality assessments.

Eddy Covariance Measurements of CO2 and CH4 before and after a Wetland Restoration, Tomago NSW, Australia: A Blue Carbon Investigation

NASA Astrophysics Data System (ADS)

Macsween, K.; Edwards, G. C.; Saintilan, N.; Negandhi, K.; Kelleway, J.; Rogers, K.; Safari, D.; Tewari, K.

2017-12-01

Australia holds 33% of the world's tidal marsh area. Scientific and policy interest has recently turned to the value of coastal wetlands for carbon sequestration ("Blue Carbon"). These coastal mangrove and saltmarsh restorations are now at the forefront of developments for ecosystem-based climate change mitigation and adaptation. The Tomago wetland located near Newcastle, NSW, Australia is undergoing rehabilitation restoring tidal inundation to a previously leveed floodplain. It is hypothesised that the restoration of tidal inundation would convert a methane source into a sink as a consequence of soil salinization. At Tomago a Before-After-Control-Impact experimental design has been undertaken to measure the impact of tidal reinstatement on wetland floodplain accretion and gas flux. Prior to tidal reinstatement, eddy covariance towers (CO2 and CH4) were installed as well as surface elevation tables, and continuous water level and water quality loggers. Hydrodynamic modelling identified the sites within the wetland predicted to remain disconnected from tidal flow. Concurrent with the micrometeorological energy balance and gas flux measurements environmental variables such as soil water salinity, inundation regime, and soil microbial communities were undertaken. This comprehensive set of data facilitated the predictive power to explain variation in greenhouse gas flux. Results showed the average CO2 and CH4 fluxes before tidal reinstatement to be -22.70 and 0.25 mg m-2 hr-1 respectively and after tidal reinstatement to be 6.41 and 0.16 mg m-2 hr-1. Over the year the average CO2 and CH4 fluxes were -3.29 and 0.20 mg m-2 hr-1. Results showed CO2 is driving the system in terms of net carbon. Two extreme precipitation events during the measurement period had significant influence on the carbon pool. It was shown that it is possible to regulate CH4 flux through management of water and salinity levels.

Spring-migration ecology of Northern Pintails in south-central Nebraska

USGS Publications Warehouse

Pearse, A.T.; Krapu, G.L.; Cox, R.R.; Davis, B.E.

2011-01-01

Spring-migration ecology of staging Northern Pintails, Anas acuta, was investigated in south-central Nebraska, USA. Habitat associations, local movements, settling patterns, arrival dates, residency times and survival were estimated from 71 radiomarked pintails during spring 2001, 2003 and 2004, and diet determined from 130 females collected during spring 1998 and 1999. Seventy-two percent of pintail diurnal locations were in palustrine wetlands, 7% in riverine wetlands, 3% in lacustrine wetlands, 6% in municipal sewage lagoons and irrigation reuse pits and 10.5% in croplands. Emergent wetlands with hemi-marsh conditions were used diurnally more often than wetlands with either open or closed vegetation structures. Evening foraging flights averaged 4.3 km (SE = 0.6) and 72% were to cornfields. In accord with these findings, 87% of 93 pintails collected during spring 1998 and 1999 returning to evening roosts consumed corn, which represented 84% dry mass of all foods. Pintails collected on non-cropped wetlands ingested invertebrates and seeds from wetland plants more frequently than birds returning to roost. Radiomarked pintails arrived in Nebraska on 7 March 2003 and 18 February 2004; average arrival date was six days earlier during 2004 compared to 2003. Residency time for individuals varied greatly (1-40 days) yet yearly means were similar and averaged 9.5 days within the region. No mortality was detected for 71 birds monitored over 829 exposure days. Conservation planners linking population dynamics and habitat conditions at spring-staging areas need to focus on pintail body condition during spring and its connection with reproductive success and survival during the breeding season.

Spring-migration ecology of Northern Pintails in south-central Nebraska

USGS Publications Warehouse

Pearse, Aaron T.; Krapu, Gary L.; Cox, Robert R.; Davis, Bruce E.

2011-01-01

Spring-migration ecology of staging Northern Pintails, Anas acuta, was investigated in south-central Nebraska, USA. Habitat associations, local movements, settling patterns, arrival dates, residency times and survival were estimated from 71 radiomarked pintails during spring 2001, 2003 and 2004, and diet determined from 130 females collected during spring 1998 and 1999. Seventy-two percent of pintail diurnal locations were in palustrine wetlands, 7% in riverine wetlands, 3% in lacustrine wetlands, 6% in municipal sewage lagoons and irrigation reuse pits and 10.5% in croplands. Emergent wetlands with hemi-marsh conditions were used diurnally more often than wetlands with either open or closed vegetation structures. Evening foraging flights averaged 4.3 km (SE = 0.6) and 72% were to cornfields. In accord with these findings, 87% of 93 pintails collected during spring 1998 and 1999 returning to evening roosts consumed corn, which represented 84% dry mass of all foods. Pintails collected on non-cropped wetlands ingested invertebrates and seeds from wetland plants more frequently than birds returning to roost. Radiomarked pintails arrived in Nebraska on 7 March 2003 and 18 February 2004; average arrival date was six days earlier during 2004 compared to 2003. Residency time for individuals varied greatly (1–40 days) yet yearly means were similar and averaged 9.5 days within the region. No mortality was detected for 71 birds monitored over 829 exposure days. Conservation planners linking population dynamics and habitat conditions at spring-staging areas need to focus on pintail body condition during spring and its connection with reproductive success and survival during the breeding season.

Waterfowl nesting on small man-made islands in prairie wetlands

USGS Publications Warehouse

Johnson, R.F.; Woodward, R.O.; Kirsch, L.M.

1978-01-01

Small islands constructed in prairie wetlands were attractive nesting sites for mallards (Anas platyrhynchos) and Canada geese (Branta canadensis). Nest densities of mallards on islands averaged 135 per ha compared to 0.03 per ha on adjacent upland habitats. Construction time averaged 2 hours per island and cost $50. No maintenance was required during the first 10 years.

A comparison of methane emissions following rice paddies conversion to crab-fish farming wetlands in southeast China.

PubMed

Hu, Zhiqiang; Wu, Shuang; Ji, Cheng; Zou, Jianwen; Zhou, Quansuo; Liu, Shuwei

2016-01-01

Rice paddies and aquaculture wetlands are typical agricultural wetlands that constitute one of the important sources of atmospheric methane (CH4). Traditional transplanted rice paddies have been experiencing conversion to pond aquaculture wetlands for pursuing higher economic benefits over the past decades in southeast China. A parallel field experiment was carried out to compare CH4 emissions from a transplanted rice paddy and its converted crab-fish farming wetland in southeast China. Over the rice-growing season, CH4 fluxes averaged 1.86 mg m(-2) h(-1) from rice paddies, and 1.14 and 0.50 mg m(-2) h(-1) for the treatments with or without aquatic vegetation present in the crab-fish farming wetlands, respectively. When averaged across the treatments, seasonal CH4 emissions from crab-fish framing wetlands were 52% lower than those from rice paddies. The CH4 fluxes were negatively related to water dissolved oxygen (DO) concentration but positively related to soil/sediment dissolved organic carbon (DOC) content in crab-fish farming wetlands. Dependence of CH4 fluxes on DO or DOC was intensified by the aquatic vegetation presence. By extrapolating the present CH4 emission rate with the current rice paddy-converted aquaculture cultivation area, the seasonal CH4 emissions from inland aquaculture wetlands during the critical farming stage (20 June to 18 October) were estimated to be 33.6 Gg ha(-1) in southeast China in 2012. Rice paddies conversion to crab-fish farming wetlands might have reduced CH4 emissions by 22-54% in mainland China. Results of this study suggest that the conversion of transplanted rice paddies to crab-fish aquaculture wetlands for higher economic benefits would also lead to a lower ecosystem CH4 release rate.

Solute transport and storage mechanisms in wetlands of the Everglades, south Florida

USGS Publications Warehouse

Harvey, Judson W.; Saiers, James E.; Newlin, Jessica T.

2005-01-01

Solute transport and storage processes in wetlands play an important role in biogeochemical cycling and in wetland water quality functions. In the wetlands of the Everglades, there are few data or guidelines to characterize transport through the heterogeneous flow environment. Our goal was to conduct a tracer study to help quantify solute exchange between the relatively fast flowing water in the open part of the water column and much more slowly moving water in thick floating vegetation and in the pore water of the underlying peat. We performed a tracer experiment that consisted of a constant‐rate injection of a sodium bromide (NaBr) solution for 22 hours into a 3 m wide, open‐ended flume channel in Everglades National Park. Arrival of the bromide tracer was monitored at an array of surface water and subsurface samplers for 48 hours at a distance of 6.8 m downstream of the injection. A one‐dimensional transport model was used in combination with an optimization code to identify the values of transport parameters that best explained the tracer observations. Parameters included dimensions and mass transfer coefficients describing exchange with both short (hours) and longer (tens of hours) storage zones as well as the average rates of advection and longitudinal dispersion in the open part of the water column (referred to as the “main flow zone”). Comparison with a more detailed set of tracer measurements tested how well the model's storage zones approximated the average characteristics of tracer movement into and out of the layer of thick floating vegetation and the pore water in the underlying peat. The rate at which the relatively fast moving water in the open water column was exchanged with slowly moving water in the layer of floating vegetation and in sediment pore water amounted to 50 and 3% h−1, respectively. Storage processes decreased the depth‐averaged velocity of surface water by 50% relative to the water velocity in the open part of the water column. As a result, flow measurements made with other methods that only work in the open part of the water column (e.g., acoustic Doppler) would have overestimated the true depth‐averaged velocity by a factor of 2. We hypothesize that solute exchange and storage in zones of floating vegetation and peat pore water increase contact time of solutes with biogeochemically active surfaces in this heterogeneous wetland environment.

Trace Element and Cu Isotopic Tracers of Subsurface Flow and Transport in Wastewater Irrigated Soils

NASA Astrophysics Data System (ADS)

Carte, J.; Fantle, M. S.

2017-12-01

An understanding of subsurface flow paths is critical for quantifying the fate of contaminants in wastewater irrigation systems. This study investigates the subsurface flow of wastewater by quantifying the distribution of trace contaminants in wastewater irrigated soils. Soil samples were collected from the upper 1m of two wetlands at Penn State University's wastewater irrigation site, at which all effluent from the University's wastewater treatment plant has been sprayed since 1983. Major and trace element and Cu isotopic composition were determined for these samples, in addition to wastewater effluent and bedrock samples. The upper 20 cm of each wetland shows an enrichment of Bi, Cd, Cr, Cu, Mo, Ni, Pb, and Zn concentrations relative to deep (>1m) soils at the site by a factor of 1.7-3.5. Each wetland also has a subsurface clay rich horizon with Bi, Cu, Li, Ni, Pb, and Zn concentrations enriched by a factor of 1.4 to 5 relative to deep soils. These subsurface horizons directly underlie intervals that could facilitate preferential effluent flow: a gravel layer in one wetland, and a silty loam with visible mottling, an indication of dynamic water saturation, in the other. Trace metal concentrations in other horizons from both wetlands fall in the range of the deep soils. Significant variability in Cu isotopic composition is present in soils from both wetlands, with δ65Cu values ranging from 0.74‰ to 5.09‰. Soil δ65Cu correlates well with Cu concentrations, with lighter δ65Cu associated with higher concentrations. The Cu isotopic composition of the zones of metal enrichment are comparable to the ostensible average wastewater effluent δ65Cu value (0.61‰), while other horizons have considerably heavier δ65Cu values. We hypothesize that wastewater is the source of the metal enrichments, as each of the enriched elements are present as contaminants in wastewater, and the enrichments are located in clay-rich horizons conducive to trace metal immobilization due to adsorption. This hypothesis will be further tested by modeling with the reactive transport code CrunchTope. This study provides evidence that trace element and isotopic composition of soils can be useful tracers of subsurface hydrologic pathways and elemental fate and transport.

The spatial distribution of soil organic carbon in tidal wetland soils of the continental United States.

PubMed

Hinson, Audra L; Feagin, Rusty A; Eriksson, Marian; Najjar, Raymond G; Herrmann, Maria; Bianchi, Thomas S; Kemp, Michael; Hutchings, Jack A; Crooks, Steve; Boutton, Thomas

2017-12-01

Tidal wetlands contain large reservoirs of carbon in their soils and can sequester carbon dioxide (CO 2 ) at a greater rate per unit area than nearly any other ecosystem. The spatial distribution of this carbon influences climate and wetland policy. To assist with international accords such as the Paris Climate Agreement, national-level assessments such as the United States (U.S.) National Greenhouse Gas Inventory, and regional, state, local, and project-level evaluation of CO 2 sequestration credits, we developed a geodatabase (CoBluCarb) and high-resolution maps of soil organic carbon (SOC) distribution by linking National Wetlands Inventory data with the U.S. Soil Survey Geographic Database. For over 600,000 wetlands, the total carbon stock and organic carbon density was calculated at 5-cm vertical resolution from 0 to 300 cm of depth. Across the continental United States, there are 1,153-1,359 Tg of SOC in the upper 0-100 cm of soils across a total of 24 945.9 km 2 of tidal wetland area, twice as much carbon as the most recent national estimate. Approximately 75% of this carbon was found in estuarine emergent wetlands with freshwater tidal wetlands holding about 19%. The greatest pool of SOC was found within the Atchafalaya/Vermilion Bay complex in Louisiana, containing about 10% of the U.S. total. The average density across all tidal wetlands was 0.071 g cm -3 across 0-15 cm, 0.055 g cm -3 across 0-100 cm, and 0.040 g cm -3 at the 100 cm depth. There is inherent variability between and within individual wetlands; however, we conclude that it is possible to use standardized values at a range of 0-100 cm of the soil profile, to provide first-order quantification and to evaluate future changes in carbon stocks in response to environmental perturbations. This Tier 2-oriented carbon stock assessment provides a scientific method that can be copied by other nations in support of international requirements. © 2017 John Wiley & Sons Ltd.

Nitrogen management in reservoir catchments through constructed wetland systems.

PubMed

Tunçiper, B; Ayaz, S C; Akça, L; Samsunlu, A

2005-01-01

In this study, nitrogen removal was investigated in pilot-scale subsurface flow (SSF) and in free water surface flow (FWS) constructed wetlands installed in the campus of TUBITAK-Marmara Research Center, Gebze, near Istanbul, Turkey. The main purposes of this study are to apply constructed wetlands for the protection of water reservoirs and to reuse wastewater. Experiments were carried out at continuous flow reactors. The effects of the type of plants on the removal were investigated by using emergent (Canna, Cyperus, Typhia spp., Phragmites spp., Juncus, Poaceae, Paspalum and Iris.), submerged (Elodea, Egeria) and floating (Pistia, Salvina and Lemna) marsh plants at different conditions. During the study period HLRs were 30, 50, 70, 80 and 120 L m(2)d(-1) respectively. The average annual NH4-N, NO(3)-N, organic N and TN treatment efficiencies in SSF and FWS wetlands are 81% and 68%, 37% and 49%, 75% and 68%, 47% and 53%, respectively. Nitrification, denitrification and ammonification rate constant (k20) values in SSF and FNS systems have been found as 0.898 d(-1) and 0.541 d(-1), 0.488 d(-1) and 0.502 d(-1), 0.986 d(-1) and 0.908 respectively. Two types of the models (first-order plug flow and multiple regression) were tried to estimate the system performances.

Elimination of veterinary antibiotics and antibiotic resistance genes from swine wastewater in the vertical flow constructed wetlands.

PubMed

Liu, Lin; Liu, Chaoxiang; Zheng, Jiayu; Huang, Xu; Wang, Zhen; Liu, Yuhong; Zhu, Gefu

2013-05-01

This paper investigated the efficiency of two vertical flow constructed wetlands characterized by volcanic (CW1) and zeolite (CW2) respectively, at removing three common antibiotics (ciprofloxacin HCl, oxytetracycline HCl, and sulfamethazine) and tetracycline resistance (tet) genes (tetM, tetO, and tetW) from swine wastewater. The result indicated that the two systems could significantly reduce the wastewater antibiotics content, and elimination rates were in the following sequence: oxytetracycline HCl>ciprofloxacin HCl>sulfamethazine. The zeolite-medium system was superior to that of the volcanic-medium system vis-à-vis removal, perhaps because of the differing pH values and average pore sizes of the respective media. A higher concentration of antibiotics accumulated in the soil than in the media and vegetation, indicating that soil plays the main role in antibiotics removal from wastewater in vertical flow constructed wetlands. The characteristics of the wetland medium may also affect the antibiotic resistance gene removal capability of the system; the total absolute abundances of three tet genes and of 16S rRNA were reduced by 50% in CW1, and by almost one order of magnitude in CW2. However, the relative abundances of target tet genes tended to increase following CW1 treatment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Projected wetland densities under climate change: Habitat loss but little geographic shift in conservation strategy

USGS Publications Warehouse

Sofaer, Helen R.; Skagen, Susan K.; Barsugli, Joseph J.; Rashford, Benjamin S.; Reese, Gordon C.; Hoeting, Jennifer A.; Wood, Andrew W.; Noon, Barry R.

2016-01-01

Climate change poses major challenges for conservation and management because it alters the area, quality, and spatial distribution of habitat for natural populations. To assess species’ vulnerability to climate change and target ongoing conservation investments, researchers and managers often consider the effects of projected changes in climate and land use on future habitat availability and quality and the uncertainty associated with these projections. Here, we draw on tools from hydrology and climate science to project the impact of climate change on the density of wetlands in the Prairie Pothole Region of the USA, a critical area for breeding waterfowl and other wetland-dependent species. We evaluate the potential for a trade-off in the value of conservation investments under current and future climatic conditions and consider the joint effects of climate and land use. We use an integrated set of hydrological and climatological projections that provide physically based measures of water balance under historical and projected future climatic conditions. In addition, we use historical projections derived from ten general circulation models (GCMs) as a baseline from which to assess climate change impacts, rather than historical climate data. This method isolates the impact of greenhouse gas emissions and ensures that modeling errors are incorporated into the baseline rather than attributed to climate change. Our work shows that, on average, densities of wetlands (here defined as wetland basins holding water) are projected to decline across the U.S. Prairie Pothole Region, but that GCMs differ in both the magnitude and the direction of projected impacts. However, we found little evidence for a shift in the locations expected to provide the highest wetland densities under current vs. projected climatic conditions. This result was robust to the inclusion of projected changes in land use under climate change. We suggest that targeting conservation towards wetland complexes containing both small and relatively large wetland basins, which is an ongoing conservation strategy, may also act to hedge against uncertainty in the effects of climate change.

Sebkhet Karkura: an example of a semi-arid Mediterranean wetland rich in biotic sediments

NASA Astrophysics Data System (ADS)

Abdulsamad, Esam O.; Elbabour, Mansour M.

2014-05-01

Habitat wetlands in Libya may be grouped into several distinct varieties, according to climate, water supply, soils, and biotic diversity. They include coastal Sebkhas (salt marshes), karst lakes, Wadi estuaries, below sea-level desert lakes, and balat flats (playas) where the soil is saturated part of some rainy seasons forming a kind of ephemeral, shallow lakes in pre-desert areas. The most prominent, however, are the extensive coastal salt marshes. These have either organic or inorganic soils, or both, depending on their location and climate conditions. Soils common to most coastal wetlands are composed largely of inorganic material in the form of sand, silt, or clay; in addition to organic material formed by decayed plants and various biotic sediments. For the purpose of the present poster, however, Sebkhet Karkura, an extensive stretch of about 50 km square (20 km long by an average width of 2.5 km) of Sebkha/wetland formation, located about 80 km southwest of Benghazi, will serve as an example of coastal Sebkhas. Here, the sediments are consisting mostly of dark earth brown sandy silt with salt and gypsum. Pure-salt deposits are normally extracted for salt processing in the area. Loams, silt, gravel, and calcareous sand are also present. At the surface of the wetland, calcarenites are fairly common but sand-beach and sand-dunes are representing the major sediments along the coastal wetland area. The recent biotal components of these sediments are described and a number of recent small-sized benthic seashells, belonging to phylum mollusca, have been investigated along the seaside of Sabkhet Karkura and several species have been identified. It is worth noting that Sebkhet Karkura, as well as other similar coastal wetlands, currently face serious threats due to human action, especially over exploitation of their resources, urban encroachments, dredging, and solid waste dumping. Increased awareness on the part of the general public of wetland ecological values and functions is essential as a preventive measure against such threats.

Comparative Hydrology, Water Quality, and Ecology of Selected Natural and Augmented Freshwater Wetlands in West-Central Florida

USGS Publications Warehouse

Lee, T.M.; Haag, K.H.; Metz, P.A.; Sacks, L.A.

2009-01-01

Comparing altered wetlands to natural wetlands in the same region improves the ability to interpret the gradual and cumulative effects of human development on freshwater wetlands. Hydrologic differences require explicit attention because they affect nearly all wetland functions and are an overriding influence on other comparisons involving wetland water quality and ecology. This study adopts several new approaches to quantify wetland hydrologic characteristics and then describes and compares the hydrology, water quality, and ecology of 10 isolated freshwater marsh and cypress wetlands in the mantled karst landscape of central Florida. Four of the wetlands are natural, and the other six have water levels indirectly lowered by ground-water withdrawals on municipally owned well fields. For several decades, the water levels in four of these altered wetlands have been raised by adding ground water in a mitigation process called augmentation. The two wetlands left unaugmented were impaired because their water levels were lowered. Multifaceted comparisons between the altered and natural wetlands are used to examine differences between marshes and cypress wetlands and to describe the effects of augmentation practices on the wetland ecosystems. In the karstic geologic setting, both natural and altered wetlands predominantly lost water to the surficial aquifer. Water leaking out of the wetlands created water-table mounds below the wetlands. The smallest mounds radiated only slightly beyond the vegetated area of the wetlands. The largest and steepest mounds occurred below two of the augmented wetlands. There, rapid leakage rates regenerated a largely absent surficial aquifer and mounds encompassed areas 7-8 times as large as the wetlands. Wetland leakage rates, estimated using a daily water-budget analysis applied over multiple years and normalized as inches per day, varied thirtyfold from the slowest leaking natural wetland to the fastest leaking augmented wetland. Leakage rates increased as the size of the flooded area decreased and as the downward head difference between the wetland and the underlying Upper Floridan aquifer increased. Allowing one of the augmented wetlands to dry up for about 2.5 months in the spring of 2004, and then refilling it, generated a net savings of augmentation water despite the amount of water required to recreate the water-table mound beneath the wetland. Runoff from the surrounding uplands was an important component of the water budget in all of the unaugmented wetlands and two of the augmented wetlands. At a minimum, runoff contributed from half (45 percent) to twice (182 percent) as much water as direct rainfall at individual wetlands. Wetland flooded areas, derived using wetland water levels and bathymetric data and presented as a percentage of total wetland area, were used to compare and contrast hydrologic conditions among the 10 wetlands. The percentages of the natural wetland areas that flooded during the study were comparable, despite differences in the sizes of the wetlands. The percent flooded area in each wetland was calculated daily over the study period and monthly for up to 16 years using historical water-level data. Historical flooding in the natural wetlands spanned a greater range in area and had more pronounced seasonality than historical flooding at either the impaired or augmented wetlands. Flooding in the impaired and natural wetlands was similar, however, during 2 years of the study with substantially reduced well-field pumping and above average rainfall. Comparisons indicated several hydrologic differences between the marsh and cypress wetlands in this study. The natural and impaired marshes leaked at about half the rate of the natural and impaired cypress wetlands, and the marshes collectively were underlain by geologic material with lower vertical leakance values than the cypress wetlands. The natural marshes had higher evaporation rates compared to cypress

Agricultural drainage and wetland management in Ontario.

PubMed

Walters, Dan; Shrubsole, Dan

2003-12-01

Land drainage is recognized as an integral part of agricultural activity throughout the world. However, the increase in agricultural production has resulted in the loss of wetland functions and values. Therefore, wetland management and agricultural drainage illustrate the conflict between economic development and natural values. This research assesses the approval process for agricultural land drainage in Ontario, Canada, to determine how the benefits of increased agricultural production are balanced against the loss of wetland values. A permit review of drainage applications was conducted from 1978 to 1997 in Zorra Township, Ontario, Canada. Data collection also included the document reviews, interviews with government agencies and wetland evaluation files. The selected criteria include efficiency, equity, consistency and adequacy. The results indicate that while the process is efficient, fundamental problems remain with the bargaining process.

Interagency Coastal Wetlands Workgroup: Statement of purpose and goals

USGS Publications Warehouse

,

2017-01-01

Purpose The Interagency Coastal Wetlands Workgroup (ICWWG) helps to address coastal wetland loss by bringing together seven federal agencies with programs and authorities that support protection and management of coastal wetlands. Background Wetlands in coastal watersheds of the U.S. were lost at an average rate of 80,000 acres per year between 2004 and 2009. This is an increase from 59,000 acres per year between 1998 and 2004 as documented by the U.S. Fish and Wildlife Service (FWS) and National Oceanic and Atmospheric Administration (NOAA) in their reports on the Status and Trends of Wetlands in the Coastal Watersheds. The ICWWG was formed in 2009 in response to these loss trends. Coastal wetlands include saltwater and freshwater wetlands located within coastal watersheds — specifically USGS 8-digit watersheds which drain into the Atlantic, Pacific, or Gulf of Mexico.

Artificial wetlands to augment use by estuarine birds

USGS Publications Warehouse

Zedler, Joy B.; Kus, Barbara E.

1996-01-01

The value of natural wetlands to bird populations is well-recognized, and declines in waterfowl numbers are often attributed to losses in wetland area. if the destruction of wetland reduces bird populations, then adding wetland habitats might improve the situation. This idea was tested in Tijuana Estuary in the late 1980s.

North American prairie wetlands are important nonforested land-based carbon storage sites

USGS Publications Warehouse

Euliss, N.H.; Gleason, R.A.; Olness, A.; McDougal, R.L.; Murkin, H.R.; Robarts, R.D.; Bourbonniere, R.A.; Warner, B.G.

2006-01-01

We evaluated the potential of prairie wetlands in North America as carbon sinks. Agricultural conversion has resulted in the average loss of 10.1 Mg ha- 1 of soil organic carbon on over 16 million ha of wetlands in this region. Wetland restoration has potential to sequester 378 Tg of organic carbon over a 10-year period. Wetlands can sequester over twice the organic carbon as no-till cropland on only about 17% of the total land area in the region. We estimate that wetland restoration has potential to offset 2.4% of the annual fossil CO2 emission reported for North America in 1990. ?? 2005 Elsevier B.V. All rights reserved.

Distribution of carbon, nitrogen and phosphorus in coastal wetland soil related land use in the Modern Yellow River Delta

PubMed Central

Yu, Junbao; Zhan, Chao; Li, Yunzhao; Zhou, Di; Fu, Yuqin; Chu, Xiaojing; Xing, Qinghui; Han, Guangxuan; Wang, Guangmei; Guan, Bo; Wang, Qing

2016-01-01

The delivery and distribution of nutrients in coastal wetland ecosystems is much related to the land use. The spatial variations of TOC, TN, NH4+-N, NO3−-N and TP and associated soil salinity with depth in 9 kinds land uses in coastal zone of the modern Yellow River Delta (YRD) was evaluated based on monitoring data in field from 2009 to 2015. The results showed that the average contents of soil TOC, TN, NO3−-N, NH4+-N and TP were 4.21 ± 2.40 g kg−1, 375.91 ± 213.44, 5.36 ± 9.59 and 7.20 ± 5.58 and 591.27 ± 91.16 mg kg−1, respectively. The high N and C contents were found in cropland in southern part and low values in natural wetland, while TP was relatively stable both in profiles and in different land uses. The land use, land formation age and salinity were important factors influencing distributions of TOC and N. Higher contents of TOC and N were observed in older formation age lands in whole study region, while the opposite regulation were found in new-born natural wetland, indicating that the anthropogenic activities could greatly alter the original distribution regulations of nutrients in coastal natural wetlands by changing the regional land use. PMID:27892492

Derivative spectra matching for wetland vegetation identification and classification by hyperspectral image

NASA Astrophysics Data System (ADS)

Wang, Jinnian; Zheng, Lanfen; Tong, Qingxi

1998-08-01

In this paper, we reported some research result in applying hyperspectral remote sensing data in identification and classification of wetland plant species and associations. Hyperspectral data were acquired by Modular Airborne Imaging Spectrometer (MAIS) over Poyang Lake wetland, China. A derivative spectral matching algorithm was used in hyperspectral vegetation analysis. The field measurement spectra were as reference for derivative spectral matching. In the study area, seven wetland plant associations were identified and classified with overall average accuracy is 84.03%.

[Accumulation, distribution and pollution assessment of heavy metals in surface sediment of Caohai plateau wetland, Guizhou province].

PubMed

Zhang, Qing-Hai; Lin, Chang-Hu; Tan, Hong; Lin, Shao-Xia; Yang, Hong-Bo

2013-03-01

The objective of this paper is to investigate the concentrations and distribution characteristics of heavy metals in surface sediments of different areas in the Caohai plateau wetland. 16 samples of surface sediments were collected and 7 heavy metals were analyzed. Heavy metal pollution in surface sediments of different areas in the Caohai plateau wetland was estimated by the Tomlinson Pollution Load Index (PLI) method. The analyzed results indicated that the average contents of Cd, Hg, As, Pb, Cr, Cu, Zn were 0.985, 0.345, 15.8, 38.9, 38.6, 22.8 and 384 mg x kg(-1), respectively. The heavy metal distributions varied with regional environment changes, the order of average contents of Cd and Hg in different regions was E (the eastern region) > S (the southern region) > N (the northern region), the order of the average content of Pb was N > E > S, and that of Zn was S > E > N. The results also suggested a medium heavy metal pollution level in the surface sediment of the Caohai plateau wetland with the PLI(zone) reaching 1.17. The order of pollution level in surface sediments of different regions was E > S > N. The results showed medium pollution levels in E and Hg which reached the extreme intensity pollution level were also the major polluted elements in surface sediments of the Caohai plateau wetland. And also, results showed medium pollution levels of Cd and Pb in surface sediments of Caohai plateau wetland. Cluster analysis results showed similar pollution sources of Cd, Zn, Pb and Hg, which should be attached great importance in terms of the prevention of the Caohai plateau wetland.

ANNUAL WATER BUDGETS FOR A FORESTED SINKHOLE WETLAND

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, Dr. Andrew Jason; Neary, Vincent S

2012-01-01

Annual water budgets spanning two years, 2004 and 2005, are constructed for a sinkhole wetland in the Tennessee Highland Rim following conversion of 13 % of its watershed to impervious surfaces. The effect of watershed development on the hydrology of the study wetland was significant. Surface runoff was the dominant input, with a contribution of 61.4 % of the total. An average of 18.9 % of gross precipitation was intercepted by the canopy and evaporated. Seepage from the surface water body to the local groundwater system accounted for 83.1 % of the total outflow. Deep recharge varied from 43.2 %more » (2004) to 12.1 % (2005) of total outflow. Overall, evapotranspiration accounted for 72.4 % of the total losses, with an average of 65.7 % lost from soil profile storage. The annual water budgets indicate that deep recharge is a significant hydrologic function performed by isolated sinkhole wetlands, or karst pans, on the Tennessee Highland Rim. Continued hydrologic monitoring of sinkhole wetlands are needed to evaluate hydrologic function and response to anthropogenic impacts. The regression technique developed to estimate surface runoff entering the wetland is shown to provide reasonable annual runoff estimates, but further testing is needed.« less

A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands.

PubMed

Turetsky, Merritt R; Kotowska, Agnieszka; Bubier, Jill; Dise, Nancy B; Crill, Patrick; Hornibrook, Ed R C; Minkkinen, Kari; Moore, Tim R; Myers-Smith, Isla H; Nykänen, Hannu; Olefeldt, David; Rinne, Janne; Saarnio, Sanna; Shurpali, Narasinha; Tuittila, Eeva-Stiina; Waddington, J Michael; White, Jeffrey R; Wickland, Kimberly P; Wilmking, Martin

2014-07-01

Wetlands are the largest natural source of atmospheric methane. Here, we assess controls on methane flux using a database of approximately 19 000 instantaneous measurements from 71 wetland sites located across subtropical, temperate, and northern high latitude regions. Our analyses confirm general controls on wetland methane emissions from soil temperature, water table, and vegetation, but also show that these relationships are modified depending on wetland type (bog, fen, or swamp), region (subarctic to temperate), and disturbance. Fen methane flux was more sensitive to vegetation and less sensitive to temperature than bog or swamp fluxes. The optimal water table for methane flux was consistently below the peat surface in bogs, close to the peat surface in poor fens, and above the peat surface in rich fens. However, the largest flux in bogs occurred when dry 30-day averaged antecedent conditions were followed by wet conditions, while in fens and swamps, the largest flux occurred when both 30-day averaged antecedent and current conditions were wet. Drained wetlands exhibited distinct characteristics, e.g. the absence of large flux following wet and warm conditions, suggesting that the same functional relationships between methane flux and environmental conditions cannot be used across pristine and disturbed wetlands. Together, our results suggest that water table and temperature are dominant controls on methane flux in pristine bogs and swamps, while other processes, such as vascular transport in pristine fens, have the potential to partially override the effect of these controls in other wetland types. Because wetland types vary in methane emissions and have distinct controls, these ecosystems need to be considered separately to yield reliable estimates of global wetland methane release. © 2014 John Wiley & Sons Ltd.

A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands

USGS Publications Warehouse

Turetsky, Merritt R.; Kotowska, Agnieszka; Bubier, Jill; Dise, Nancy B.; Crill, Patrick; Hornibrook, Ed R.C.; Minkkinen, Kari; Moore, Tim R.; Myers-Smith, Isla H.; Nykanen, Hannu; Olefeldt, David; Rinne, Janne; Saarnio, Sanna; Shurpali, Narasinha; Tuittila, Eeva-Stiina; Waddington, J. Michael; White, Jeffrey R.; Wickland, Kimberly P.; Wilmking, Martin

2014-01-01

Wetlands are the largest natural source of atmospheric methane. Here, we assess controls on methane flux using a database of approximately 19 000 instantaneous measurements from 71 wetland sites located across subtropical, temperate, and northern high latitude regions. Our analyses confirm general controls on wetland methane emissions from soil temperature, water table, and vegetation, but also show that these relationships are modified depending on wetland type (bog, fen, or swamp), region (subarctic to temperate), and disturbance. Fen methane flux was more sensitive to vegetation and less sensitive to temperature than bog or swamp fluxes. The optimal water table for methane flux was consistently below the peat surface in bogs, close to the peat surface in poor fens, and above the peat surface in rich fens. However, the largest flux in bogs occurred when dry 30-day averaged antecedent conditions were followed by wet conditions, while in fens and swamps, the largest flux occurred when both 30-day averaged antecedent and current conditions were wet. Drained wetlands exhibited distinct characteristics, e.g. the absence of large flux following wet and warm conditions, suggesting that the same functional relationships between methane flux and environmental conditions cannot be used across pristine and disturbed wetlands. Together, our results suggest that water table and temperature are dominant controls on methane flux in pristine bogs and swamps, while other processes, such as vascular transport in pristine fens, have the potential to partially override the effect of these controls in other wetland types. Because wetland types vary in methane emissions and have distinct controls, these ecosystems need to be considered separately to yield reliable estimates of global wetland methane release.

7 CFR 1467.3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Conservation Service or the person delegated authority to act for the Chief. Commenced conversion wetland means... protection of wetland functions and values, including necessary activities, as set forth in the Wetlands... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.3 Definitions. The...

7 CFR 1467.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Conservation Service or the person delegated authority to act for the Chief. Commenced conversion wetland means... protection of wetland functions and values, including necessary activities, as set forth in the Wetlands... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.3 Definitions. The...

7 CFR 1467.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Conservation Service or the person delegated authority to act for the Chief. Commenced conversion wetland means... protection of wetland functions and values, including necessary activities, as set forth in the Wetlands... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.3 Definitions. The...

On-site wastewater treatment using subsurface flow constructed wetlands in Ireland.

PubMed

Gill, Laurence W; O'Luanaigh, Niall; Johnston, Paul M

2011-01-01

The results from an Irish EPA-funded project on the effectiveness of using constructed wetlands for treating wastewater from single households is presented, which has contributed to the design guidelines included in the new EPA Code of Practice. Three subsurface flow gravel-filled wetlands were constructed on separate sites--one to provide secondary treatment and the other two to provide tertiary treatment stages for the domestic effluent. A comprehensive analysis over three years was then conducted to provide a robust characterization of the internal dynamics of the systems, particularly with respect to N and P removal as well as evaluating the temporal water balance across the different seasons. The removal of Total N was only 29% and 30% in the secondary and tertiary treatment wetlands, respectively; particularly disappointing for the tertiary treatment process, which was receiving nitrified effluent. Studies on the (15)N stable isotope confirmed that 35% of the ammonium from the septic tank was passing straight through the process without taking part in any biogeochemical processes. However, influent N in the wetlands was shown to be biologically assimilated into organic nitrogen and then released again as soluble ammonium--so-called nitrogen "spiraling." Removal of Total P in the wetlands averaged from 28% to 45% with higher P removals measured during summer periods, although the effluent concentrations were still found to be high (> 5 mg/l on average). The phosphorus in the plant material was also analysed revealing that the annual above-ground stem matter only accounted for 1.3% to 8.4% of the annual total P-load in the wetlands. Finally, the water balance analyses showed that the mean flow discharging from both the secondary and tertiary treatment wetlands was slightly greater than the mean flow to the reed bed over the trial period, with rainfall acting to increase flows by 13% and 5%, respectively, on average in winter while just about balancing evapotranspiration in the summer.

[Methane fluxes and controlling factors in the intertidal zone of the Yellow River estuary in autumn].

PubMed

Jiang, Huan-Huan; Sun, Zhi-Gao; Wang, Ling-Ling; Mou, Xiao-Jie; Sun, Wan-Long; Song, Hong-Li; Sun, Wen-Guang

2012-02-01

The characteristics of methane (CH4) fluxes from tidal wetlands of the Yellow River estuary were observed in situ with static-chamber and GC methods in September and October 2009, and the key factors affecting CH4 fluxes were discussed. From the aspect of space, the CH4 flux ranges in high tidal wetland, middle tidal wetland, low tidal wetland, bare flat are - 0.206-1.264, -0.197-0.431, -0.125-0.659 and -0.742-1.767 mg x (m2 x h)(-1), the day average fluxes are 0.089, 0.038, 0.197 and 0.169 mg x (m2 x h)(-1), respectively, indicating that the tidal wetlands are the sources of CH4 and the source function of CH4 differed among the four study sites, in the order of low tidal wetland > bare flat > high tidal wetland > middle tidal wetland. From the aspect of time, the ranges of CH4 fluxes from the tidal wetland ecosystems are -0.444-1.767 and - 0.742- 1.264 mg x (m2 x h)(-1), and the day average fluxes are 0.218 and 0.028 mg x (m2 x h)(-1) in September and October, respectively. The CH4 fluxes in each tidal wetland in September are higher than those in October except that the high tidal wetland acts as weak sink in September. Further studies indicate that the changes of environmental factors in the Yellow River estuary are complicated, and the CH4 fluxes are affected by multiple factors. The differences of CH4 fluxes characteristics among different tidal wetlands in autumn are probably related to temperature (especially atmospheric temperature) and vegetation growth status, while the effects of water or salinity condition and tide status on the CH4 flux characteristics might not be ignored.

Economic valuation of flood mitigation services: A case study from the Otter Creek, VT.

NASA Astrophysics Data System (ADS)

Galford, G. L.; Ricketts, T.; Bryan, K. L.; ONeil-Dunne, J.; Polasky, S.

2014-12-01

The ecosystem services provided by wetlands are widely recognized but difficult to quantify. In particular, estimating the effect of landcover and land use on downstream flood outcomes remains challenging, but is increasingly important in light of climate change predictions of increased precipitation in many areas. Economic valuation can help incorporate ecosystem services into decisions and enable communities to plan for climate and flood resiliency. Here we estimate the economic value of Otter Creek wetlands for Middlebury, VT in mitigating the flood that followed Tropical Storm Irene, as well as for ten historic floods. Observationally, hydrographs above and below the wetlands in the case of each storm indicated the wetlands functioned as a temporary reservoir, slowing the delivery of water to Middlebury. We compare observed floods, based on Middlebury's hydrograph, with simulated floods for scenarios without wetlands. To simulate these "without wetlands" scenarios, we assume the same volume of water was delivered to Middlebury, but in a shorter time pulse similar to a hydrograph upstream of the wetlands. For scenarios with and without wetlands, we map the spatial extent of flooding using LiDAR digital elevation data. We then estimate flood depth at each affected building, and calculate monetary losses as a function of the flood depth and house value using established depth damage relationships. For example, we expect damages equal to 20% of the houses value for a flood depth of two feet in a two-story home with a basement. We define the value of flood mitigation services as the difference in damages between the with and without wetlands scenario, and find that the Otter Creek wetlands reduced flood damage in Middlebury by 88% following Hurricane Irene. Using the 10 additional historic floods, we estimate an ongoing mean value of $400,000 in avoided damages per year. Economic impacts of this magnitude stress the importance of wetland conservation and warrant the consideration of ecosystem services in land use decisions. Our study indicates that here and elsewhere, green infrastructure may have to potential to increase the resilience of communities to projected changes in climate.

[Distribution of soil organic carbon storage and carbon density in Gahai Wetland ecosystem].

PubMed

Ma, Wei-Wei; Wang, Hui; Huang, Rong; Li, Jun-Zhen; Li, De-Yu

2014-03-01

The profile distribution and accumulation characteristics of organic carbon of four typical marshes (herbaceous peat, marsh wetland, mountain wetland, subalpine meadow) were studied in Gahai Wetlands of Gannan in July 2011. The results showed that the soil bulk densities of the four typical marshes ranged from 0.22 to 1.29 g x cm(-3). The content of soil organic carbon in the herbaceous peat was higher than in other types, with its average content of organic carbon (286. 80 g x kg(-1)) being about 2.91, 4.99, 7.31 times as much as that of the marsh wetland, mountain wetland and subalpine meadow, respectively. The average organic carbon densities were in order of herbaceous peat > subalpine meadow > marsh wetland > mountain wetland, with the highest in the 0-10 cm layer. The change of organic carbon density along the soil profile was basically in accordance with the organic carbon content in the four typical marshes, but fluctuated with soil depth. There were obviously two carbon storage layers (0-10 and 20-40 cm, respectively) in the four typical marshes. The amounts of organic carbon stored in the 0-60 cm layer of the four typical marshes were 369.46, 278.83, 276.16, 292.23 t x hm(-2), respectively. The total amount of organic carbon stored in the 0-60 cm of the four typical marshes was about 9.50 x 10(6) t.

Economic valuation of selected direct and indirect use values of the Makgadikgadi wetland system, Botswana

NASA Astrophysics Data System (ADS)

Setlhogile, Tshepo; Arntzen, Jaap; Mabiza, Collin; Mano, Reneth

Economic valuation of wetlands aims to investigate public preferences for changes in the state of the wetland and the natural resources it constitutes in monetary terms. It provides a means of quantifying the direct and indirect benefits that people derive from wetlands. In addition, it informs management planning and practice about resource options, optimal allocation and also provides information for conservation of the resource. The Makgadikgadi wetland is a unique system that mostly consists of dry pans during most of the year. This study aimed at estimating the value of groundwater recharge and community-based natural resource management (CBNRM) activities within the Makgadikgadi wetland and how these goods and services contribute to the local and national economy. The study used the Total Economic Valuation approach, which considers both the direct and indirect use values of the resource. In essence, the study concentrated on one direct use value (use of resources through CBNRM) and one indirect use value (groundwater recharge). With regard to CBNRM, three community-based organisations (CBOs) were selected for the study and static and dynamic cost-benefit models for these CBOs were developed. The groundwater recharge value was largely determined through desktop review and interviews with stakeholders. The results indicate a small positive contribution of CBOs towards the economy of Botswana and a high potential for communities to derive substantial benefits from the projects because currently benefits realised by communities are limited. CBOs involved in joint venture partnerships with tourism and hunting enterprises benefit more from utilising the wetland’s resources. Groundwater recharge often occurs in areas away from the physical location of the wetland and may not be easily attributable to the wetland. However, the study assessed the value taking into consideration the various sectors which rely on the groundwater resource. The groundwater recharge value is significant (BWP 9-10 million) but lower when compared with the value generated by the Okavango delta (BWP 16 million). Given future increases in water demands, groundwater abstraction will exceed recharge, thus hampering the availability of the resource for the future generations and maintenance of the environment.

How efficient are constructed wetlands in removing pharmaceuticals from untreated and treated urban wastewaters? A review.

PubMed

Verlicchi, Paola; Zambello, Elena

2014-02-01

This review presents and discusses the data from 47 peer-reviewed journal articles on the occurrence of 137 pharmaceutical compounds in the effluent from various types of constructed wetlands treating urban wastewater. We analyse the observed removal efficiencies of the investigated compounds in order to identify the type of constructed wetland that best removes those most frequently detected. The literature reviewed details experimental investigations carried out on 136 treatment plants, including free water surface systems, as well as horizontal and vertical subsurface flow beds (pilot or full-scale) acting as primary, secondary or tertiary treatments. The occurrence of selected pharmaceuticals in sediments and gravel and their uptake by common macrophytes are also presented and discussed. We analyse the main removal mechanisms for the selected compounds and investigate the influence of the main design parameters, as well as operational and environmental conditions of the treatment systems on removal efficiency. We also report on previous attempts to correlate observed removal values with the chemical structure and chemical-physical properties (mainly pKa and LogKow) of pharmaceutical compounds. We then use the literature data to calculate the average pharmaceutical mass loadings in the effluent from constructed wetlands, comparing the ability of such systems to remove selected pharmaceuticals with the corresponding conventional secondary and tertiary treatments. Finally, the environmental risk posed by pharmaceutical residues in effluents from constructed wetlands acting as secondary and tertiary treatment steps is calculated in the form of the risk quotient ratio. This approach enabled us to provide a ranking of the most critical compounds for the two scenarios, to discuss the ramifications of the adoption of constructed wetlands for removing such persistent organic compounds, and to propose avenues of future research. © 2013.

Hydrodynamic modelling of a tidal delta wetland using an enhanced quasi-2D model

NASA Astrophysics Data System (ADS)

Wester, Sjoerd J.; Grimson, Rafael; Minotti, Priscilla G.; Booija, Martijn J.; Brugnach, Marcela

2018-04-01

Knowledge about the hydrological regime of wetlands is key to understand their physical and biological properties. Modelling hydrological and hydrodynamic processes within a wetland is therefore becoming increasingly important. 3D models have successfully modelled wetland dynamics but depend on very detailed bathymetry and land topography. Many 1D and 2D models of river deltas highly simplify the interaction between the river and wetland area or simply neglect the wetland area. This study proposes an enhanced quasi-2D modelling strategy that captures the interaction between river discharge and moon tides and the resulting hydrodynamics, while using the scarce data available. The water flow equations are discretised with an interconnected irregular cell scheme, in which a simplification of the 1D Saint-Venant equations is used to define the water flow between cells. The spatial structure of wetlands is based on the ecogeomorphology in complex estuarine deltas. The islands within the delta are modelled with levee cells, creek cells and an interior cell representing a shallow marsh wetland. The model is calibrated for an average year and the model performance is evaluated for another average year and additionally an extreme dry three-month period and an extreme wet three-month period. The calibration and evaluation are done based on two water level measurement stations and two discharge measurement stations, all located in the main rivers. Additional calibration is carried out with field water level measurements in a wetland area. Accurate simulations are obtained for both calibration and evaluation with high correlations between observed and simulated water levels and simulated discharges in the same order of magnitude as observed discharges. Calibration against field measurements showed that the model can successfully simulate the overflow mechanism in wetland areas. A sensitivity analysis for several wetland parameters showed that these parameters are all influencing the water level fluctuation within the wetlands to varying degrees. The enhanced quasi-2D model has the potential to accurately simulate river and wetland dynamics for large wetland areas and help to understand their hydrodynamics.

An overview of wetlands of Saudi Arabia: Values, threats, and perspectives.

PubMed

Al-Obaid, Sami; Samraoui, Boudjéma; Thomas, Jacob; El-Serehy, Hamed A; Alfarhan, Ahmed H; Schneider, Wolfgang; O'Connell, Mark

2017-02-01

The wetlands of Saudi Arabia are located in a water-stressed region that is highly vulnerable to climate and other global changes. Sebkhas, mudflats, mangroves, and wadis are the dominant wetlands in the arid regions of North Africa and the Arabian Peninsula. These unique wetlands are recognized as a sanctuary for biodiversity and for their economic services generated from mineral extraction, agriculture, and grazing. Despite their ecological values and societal services, the long-term permanence of Saudi Arabia's wetlands faces strong challenges resulting from human activities associated with sustained population growth, habitat degradation, and coastal development. This paper consolidates a literature review of Saudi Arabia's wetlands from local to global importance, highlights their biodiversity, and identifies threats and evolution of these vulnerable ecosystems in the arid Arabian Peninsula by focusing on the status of key freshwater taxa (Odonata, freshwater fishes, amphibians, and waterbirds) and documenting changes affecting important wetlands.

A wetland aquifer interaction test

NASA Astrophysics Data System (ADS)

Wise, W. R.; Annable, M. D.; Walser, J. A. E.; Switt, R. S.; Shaw, D. T.

2000-01-01

An understanding of the hydraulic connectivity between an isolated wetland and its underlying groundwater is required to help assess the ecological impact that changes in the groundwater level may induce. Literature values for the hydraulic conductivity of peat vary up to ten orders of magnitude, indicating the absolute necessity of obtaining site-specific information. Horizontal and vertical variability in peat layers makes the process of extrapolating point-based measurements to predict system-level behavior difficult. By inducing or augmenting a flow up from the underlying aquifer into the wetland through a rapid lowering of wetland water level, the system-level hydraulic connectivity of a wetland to the groundwater may be directly measured. At a study site, a small, seasonally flooded depression mash wetland in Florida, the method and subsequent analysis yielded a value for the hydraulic resistance of the organic layer of 6 days, indicating a significant connection between the wetland and the aquifer.

Capturing and Explaining Preference Heterogeneity for Wetland Management Options in the Kilombero Valley, Tanzania

NASA Astrophysics Data System (ADS)

Speelman, Stijn; Mombo, Felister; Vandermeulen, Valerie; Phillip, Damas; Van Huylenbroeck, Guido

2015-01-01

Wetland degradation has recently received considerable research attention. Although wetlands are valuable ecosystems, their actual value is difficult to measure because the services they provide often do not have market values. The current study seeks to investigate the preferences for wetland management options in the Kilombero Valley, central Tanzania using choice modeling. The results show that both respondents from the Kilombero Valley and Morogoro Municipality desire improvements in the condition of the wetlands. This indicates that the ongoing degradation is not socially optimal. A second finding is that the preferences for wetland conservation are heterogeneous and can be linked to livelihood characteristics. Communities living in the area, for example, are highly dependent on the wetland for their livelihood and would be impacted by conservation measures. Therefore, in order to reduce the pressure on wetlands, it is necessary and imperative to explore the options for alternative income-generating activities or to focus, for example, on technologies to improve efficiency and effectiveness in crop production.

Spatially-explicit valuation of coastal wetlands for cyclone mitigation in Australia and China.

PubMed

Ouyang, Xiaoguang; Lee, Shing Yip; Connolly, Rod M; Kainz, Martin J

2018-02-14

Coastal wetlands are increasingly recognised for their pivotal role in mitigating the growing threats from cyclones (including hurricanes) in a changing climate. There is, however, insufficient information about the economic value of coastal wetlands for cyclone mitigation, particularly at regional scales. Analysis of data from 1990-2012 shows that the variation of cyclone frequencies is related to EI Niño strength in the Pacific Ocean adjacent to Australia, but not China. Among the cyclones hitting the two countries, there are significant relationships between the ratio of total economic damage to gross domestic production (TD/GDP) and wetland area within cyclone swaths in Australia, and wetland area plus minimum cyclone pressure despite a weak relationship in China. The TD/GDP ratio is significantly higher in China than in Australia. Despite their extensive and growing occurrence, seawalls in China appear not to play a critical role in cyclone mitigation, and cannot replace coastal wetlands, which provide other efficient ecosystem services. The economic values of coastal wetlands in Australia and China are respectively estimated at US$52.88 billion and 198.67 billion yr -1 for cyclone mitigation, albeit with large within-country geographic variation. This study highlights the urgency to integrate this value into existing valuations of coastal wetlands.

Metrics for determining hydrophytic vegetation in wetland delineation: a clarification on the prevalence index

Treesearch

Diane De Steven

2015-01-01

A recent publication and an article in Wetland Science & Practice (Lichvar and Gillrich 2014b, 2014a) discuss two metrics for determining if vegetation is hydrophytic for purposes of U.S. wetland delineations, the Prevalence Index (PI) and a proposed Hydrophytic Cover Index (HCI). Based on Wentworth et al. (1988), the PI is a weighted average of ordinal scores (1-5...

Study on the techniques of valuation of ecosystem services based on remote sensing in Anxin County

NASA Astrophysics Data System (ADS)

Wang, Hongyan; Li, Zengyuan; Gao, Zhihai; Wang, Bengyu; Bai, Lina; Wu, Junjun; Sun, Bin; Wang, Zhibo

2014-05-01

The farmland ecosystem is an important component of terrestrial ecosystems and has a fundamental role in the human life. The wetland is an unique and versatile ecological system. It is important for rational development and sustainable utilization of farmland and wetland resources to study on the measurement of valuation of farmland and wetland ecosystem services. It also has important significance for improving productivity. With the rapid development of remote sensing technology, it has become a powerful tool for evaluation of the value of ecosystem services. The land cover types in Anxin County mainly was farmland and wetland, the indicator system for ecosystem services valuation was brought up based on the remote sensing data of high spatial resolution ratio(Landsat-5 TM data and SPOT-5 data), the technology system for measurement of ecosystem services value was established. The study results show that the total ecosystem services value in 2009 in Anxin was 4.216 billion yuan, and the unit area value was between 8489 yuan/hm2 and 329535 yuan/hm2. The value of natural resources, water conservation value in farmland ecosystem and eco-tourism value in wetland ecosystem were higher than the other, total of the three values reached 2.858 billion yuan, and the percentage of the total ecosystem services values in Anxin was 67.79%. Through the statistics in the nine towns and three villages of Anxin County, the juantou town has the highest services value, reached 0.736 billion yuan. Scientific and comprehensive evaluation of the ecosystem services can conducive to promoting the understanding of the importance of the ecosystem. The research results had significance to ensure the sustainable use of wetland resources and the guidance of ecological construction in Anxin County.

Wetlands: Science, Politics, and Geographical Relationships. Pathways in Geography Series, Title No. 9.

ERIC Educational Resources Information Center

Benhart, John E.; Margin, Alex

This teacher's guide focuses on the value and functions of wetlands by integrating science and the politics of wetlands into a geographic framework. Wetlands are highly dynamic, diverse, and prolific ecosystems. The volume advocates a need for mutual understanding and harmony of effort in order to deal with the complex issues of the wetlands. The…

Relations Among River Stage, Rainfall, Ground-Water Levels, and Stage at Two Missouri River Flood-Plain Wetlands

USGS Publications Warehouse

Kelly, Brian P.

2001-01-01

The source of water is important to the ecological function of Missouri River flood-plain wetlands. There are four potential sources of water to flood-plain wetlands: direct flow from the river channel during high river stage, ground-water movement into the wetlands in response to river-stage changes and aquifer recharge, direct precipitation, and runoff from surrounding uplands. Concurrent measurements of river stage, rainfall, ground-water level, and wetland stage were compared for two Missouri River flood-plain wetlands located near Rocheport, Missouri, to characterize the spatial and temporal relations between river stage, rainfall, ground-water levels and wetland stage, determine the source of water to each wetland, and compare measured and estimated stage and ground-water levels at each site. The two sites chosen for this study were wetland NC-5, a non-connected, 50 feet deep scour constantly filled with water, formed during the flood of 1993, and wetland TC-1, a shallow, temporary wetland intermittently filled with water. Because these two wetlands bracket a range of wetland types of the Missouri River flood plain, the responses of other Missouri River wetlands to changes in river stage, rainfall, and runoff should be similar to the responses exhibited by wetlands NC-5 and TC-1. For wetlands deep enough to intersect the ground-water table in the alluvial aquifer, such as wetland NC-5, the ground-water response factor can estimate flood-plain wetland stage changes in response to known river-stage changes. Measured maximum stage and ground-water-level changes at NC-5 fall within the range of estimated changes using the ground-water response factor. Measured maximum ground-water-level changes at TC-1 are similar to, but consistently greater than the estimated values, and are most likely the result of alluvial deposits with higher than average hydraulic conductivity located between wetland TC-1 and the Missouri River. Similarity between ground-water level and stage hydrography at wetland NC-5 indicate that ground-water-level fluctuations caused by river-stage changes control the stage of wetland NC-5. A 2-day lag time exists between river-stage changes and ground water and stage changes at wetland NC-5. The lack of a measurable response of wetland NC-5 stage to rainfall indicate that rainfall is not a large source of water to wetland NC-5. Stage in wetland TC-1 only increased at high river stage in June and July 1999, and from runoff caused by local rainfall during the winter. The 2-day lag time between peak stages at wetland TC-1 and peak Missouri River stages compared to the 1-day lag time between Missouri River stage and ground-water peaks at wetland TC-1 indicates ground-water flow does not directly affect wetland stage at TC-1, but surface-water flow does affect wetland stage at TC-1 during high river stage. Comparing wetland TC-1 stage to potential water sources indicates the most likely explanation for the rise in stage at wetland TC-1 is surface runoff supplied via seepage through the levees and upward flow of ground water through alluvial deposits of higher hydraulic conductivity during high river stage. The rate of decrease in wetland TC-1 stage was limited by the rate at which ground-water level decreased. Stage response to rainfall at wetland TC-1 during the winter months and no response to greater rainfall amounts during spring and summer months indicate that evapotranspiration may limit the affect of rainfall on stage at wetland TC-1 during the growing season.

7 CFR 633.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... wetlands and is considered essential for the protection of the wetland or for the nesting, breeding, or feeding of migratory waterfowl. Adjacent land need not be contiguous to the land designated as wetland... payment means the payment made by the NRCS to achieve the protection of the wetland functions and values...

7 CFR 633.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... wetlands and is considered essential for the protection of the wetland or for the nesting, breeding, or feeding of migratory waterfowl. Adjacent land need not be contiguous to the land designated as wetland... payment means the payment made by the NRCS to achieve the protection of the wetland functions and values...

7 CFR 633.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... wetlands and is considered essential for the protection of the wetland or for the nesting, breeding, or feeding of migratory waterfowl. Adjacent land need not be contiguous to the land designated as wetland... payment means the payment made by the NRCS to achieve the protection of the wetland functions and values...

A Physically-based Model for Predicting Soil Moisture Dynamics in Wetlands

NASA Astrophysics Data System (ADS)

Kalin, L.; Rezaeianzadeh, M.; Hantush, M. M.

2017-12-01

Wetlands are promoted as green infrastructures because of their characteristics in retaining and filtering water. In wetlands going through wetting/drying cycles, simulation of nutrient processes and biogeochemical reactions in both ponded and unsaturated wetland zones are needed for an improved understanding of wetland functioning for water quality improvement. The physically-based WetQual model can simulate the hydrology and nutrient and sediment cycles in natural and constructed wetlands. WetQual can be used in continuously flooded environments or in wetlands going through wetting/drying cycles. Currently, WetQual relies on 1-D Richards' Equation (RE) to simulate soil moisture dynamics in unponded parts of the wetlands. This is unnecessarily complex because as a lumped model, WetQual only requires average moisture contents. In this paper, we present a depth-averaged solution to the 1-D RE, called DARE, to simulate the average moisture content of the root zone and the layer below it in unsaturated parts of wetlands. DARE converts the PDE of the RE into ODEs; thus it is computationally more efficient. This method takes into account the plant uptake and groundwater table fluctuations, which are commonly overlooked in hydrologic models dealing with wetlands undergoing wetting and drying cycles. For verification purposes, DARE solutions were compared to Hydrus-1D model, which uses full RE, under gravity drainage only assumption and full-term equations. Model verifications were carried out under various top boundary conditions: no ponding at all, ponding at some point, and no rain. Through hypothetical scenarios and actual atmospheric data, the utility of DARE was demonstrated. Gravity drainage version of DARE worked well in comparison to Hydrus-1D, under all the assigned atmospheric boundary conditions of varying fluxes for all examined soil types (sandy loam, loam, sandy clay loam, and sand). The full-term version of DARE offers reasonable accuracy compared to the full RE solutions from Hydrus-1D, with a significant reduction in computational time. The full-term version of DARE estimated the moisture content with better accuracy for the root zone by considering zero pressure head at a fixed groundwater depth as the bottom boundary condition. The accuracy of this model is lower for the second layer.

Dynamics of water-table fluctuations in an upland between two prairie-pothole wetlands in North Dakota

USGS Publications Warehouse

Rosenberry, Donald O.; Winter, Thomas C.

1997-01-01

Data from a string of instrumented wells located on an upland of 55 m width between two wetlands in central North Dakota, USA, indicated frequent changes in water-table configuration following wet and dry periods during 5 years of investigation. A seasonal wetland is situated about 1.5 m higher than a nearby semipermanent wetland, suggesting an average ground water-table gradient of 0.02. However, water had the potential to flow as ground water from the upper to the lower wetland during only a few instances. A water-table trough adjacent to the lower semipermanent wetland was the most common water-table configuration during the first 4 years of the study, but it is likely that severe drought during those years contributed to the longevity and extent of the water-table trough. Water-table mounds that formed in response to rainfall events caused reversals of direction of flow that frequently modified the more dominant water-table trough during the severe drought. Rapid and large water-table rise to near land surface in response to intense rainfall was aided by the thick capillary fringe. One of the wettest summers on record ended the severe drought during the last year of the study, and caused a larger-scale water-table mound to form between the two wetlands. The mound was short in duration because it was overwhelmed by rising stage of the higher seasonal wetland which spilled into the lower wetland. Evapotranspiration was responsible for generating the water-table trough that formed between the two wetlands. Estimation of evapotranspiration based on diurnal fluctuations in wells yielded rates that averaged 3–5 mm day−1. On many occasions water levels in wells closer to the semipermanent wetland indicated a direction of flow that was different from the direction indicated by water levels in wells farther from the wetland. Misinterpretation of direction and magnitude of gradients between ground water and wetlands could result from poorly placed or too few observation wells, and also from infrequent measurement of water levels in wells.

Extreme dissolved oxygen variability in urbanised tropical wetlands: The need for detailed monitoring to protect nursery ground values

NASA Astrophysics Data System (ADS)

Dubuc, Alexia; Waltham, Nathan; Malerba, Martino; Sheaves, Marcus

2017-11-01

Little is known about levels of dissolved oxygen fish are exposed to daily in typical urbanised tropical wetlands found along the Great Barrier Reef coastline. This study investigates diel dissolved oxygen (DO) dynamics in one of these typical urbanised wetlands, in tropical North Queensland, Australia. High frequency data loggers (DO, temperature, depth) were deployed for several days over the summer months in different tidal pools and channels that fish use as temporal or permanent refuges. DO was extremely variable over a 24 h cycle, and across the small-scale wetland. The high spatial and temporal DO variability measured was affected by time of day and tidal factors, namely water depth, tidal range and tidal direction (flood vs ebb). For the duration of the logging time, DO was mainly above the adopted threshold for hypoxia (50% saturation), however, for around 11% of the time, and on almost every logging day, DO values fell below the threshold, including a severe hypoxic event (<5% saturation) that continued for several hours. Fish still use this wetland intensively, so must be able to cope with low DO periods. Despite the ability of fish to tolerate extreme conditions, continuing urban expansion is likely to lead to further water quality degradation and so potential loss of nursery ground value. There is a substantial discontinuity between the recommended DO values in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality and the values observed in this wetland, highlighting the limited value of these guidelines for management purposes. Local and regional high frequency data monitoring programs, in conjunction with local exposure risk studies are needed to underpin the development of the management that will ensure the sustainability of coastal wetlands.

Model parameters for representative wetland plant functional groups

USGS Publications Warehouse

Williams, Amber S.; Kiniry, James R.; Mushet, David M.; Smith, Loren M.; McMurry, Scott T.; Attebury, Kelly; Lang, Megan; McCarty, Gregory W.; Shaffer, Jill A.; Effland, William R.; Johnson, Mari-Vaughn V.

2017-01-01

Wetlands provide a wide variety of ecosystem services including water quality remediation, biodiversity refugia, groundwater recharge, and floodwater storage. Realistic estimation of ecosystem service benefits associated with wetlands requires reasonable simulation of the hydrology of each site and realistic simulation of the upland and wetland plant growth cycles. Objectives of this study were to quantify leaf area index (LAI), light extinction coefficient (k), and plant nitrogen (N), phosphorus (P), and potassium (K) concentrations in natural stands of representative plant species for some major plant functional groups in the United States. Functional groups in this study were based on these parameters and plant growth types to enable process-based modeling. We collected data at four locations representing some of the main wetland regions of the United States. At each site, we collected on-the-ground measurements of fraction of light intercepted, LAI, and dry matter within the 2013–2015 growing seasons. Maximum LAI and k variables showed noticeable variations among sites and years, while overall averages and functional group averages give useful estimates for multisite simulation modeling. Variation within each species gives an indication of what can be expected in such natural ecosystems. For P and K, the concentrations from highest to lowest were spikerush (Eleocharis macrostachya), reed canary grass (Phalaris arundinacea), smartweed (Polygonum spp.), cattail (Typha spp.), and hardstem bulrush (Schoenoplectus acutus). Spikerush had the highest N concentration, followed by smartweed, bulrush, reed canary grass, and then cattail. These parameters will be useful for the actual wetland species measured and for the wetland plant functional groups they represent. These parameters and the associated process-based models offer promise as valuable tools for evaluating environmental benefits of wetlands and for evaluating impacts of various agronomic practices in adjacent areas as they affect wetlands.

Baldcypress, an important wetland tree species: ecological value, management and mensuration

Treesearch

Bernard R. Parresol

2002-01-01

China has the largest area of wetlands in Asia and the fourth largest amount worldwide. Wetlands include marshes, swamps, salt marshes, parts of streams, shorelines, and flood plains. It is estimated that wetlands in China cover over 25 million ha, 80% being of the fresh water variety, or 2.6% of the land base (Lu 1990). However, it is recognized that existing wetland...

Seasonal and spatial variabilities in the water chemistry of prairie pothole wetlands influence the photoproduction of reactive intermediates.

PubMed

McCabe, Andrew J; Arnold, William A

2016-07-01

The hydrology and water chemistry of prairie pothole wetlands vary spatially and temporally, on annual and decadal timescales. Pesticide contamination of wetlands arising from agricultural activities is a foremost concern. Photochemical reactions are important in the natural attenuation of pesticides and may be important in limiting ecological and human exposure. Little is known, however, about the variable influence of wetland water chemistry on indirect photochemistry. In this study, seasonal water samples were collected from seven sites throughout the prairie pothole region over three years to understand the spatiotemporal dynamics of reactive intermediate photoproduction. Samples were classified by the season in which they were collected (spring, summer, or fall) and the typical hydroperiod of the wetland surface water (temporary or semi-permanent). Under photostable conditions, steady-state concentrations and apparent quantum yields or quantum yield coefficients were measured for triplet excited states of dissolved organic matter, singlet oxygen, hydroxyl radical, and carbonate radical under simulated sunlight. Steady-state concentrations and quantum yields increased on average by 15% and 40% from spring to fall, respectively. Temporary wetlands had 40% higher steady-state concentrations of reactive intermediates than semi-permanent wetlands, but 50% lower quantum yields. Computed quantum yields for reactive intermediate formation were used to predict the indirect photochemical half-lives of seven pesticides in average temporary and semi-permanent prairie pothole wetlands. As a first approximation, the predictions agree to within two orders of magnitude of previously reported half-lives. Copyright © 2016 Elsevier Ltd. All rights reserved.

Environmental evolution records reflected by radionuclides in the sediment of coastal wetlands: A case study in the Yellow River Estuary wetland.

PubMed

Wang, Qidong; Song, Jinming; Li, Xuegang; Yuan, Huamao; Li, Ning; Cao, Lei

2016-10-01

Vertical profiles of environmental radionuclides ( 210 Pb, 137 Cs, 238 U, 232 Th, 226 Ra and 4 0 K) in a sediment core (Y1) of the Yellow River Estuary wetland were investigated to assess whether environmental evolutions in the coastal wetland could be recorded by the distributions of radionuclides. Based on 210 Pb and 137 Cs dating, the average sedimentation rate of core Y1 was estimated to be 1.0 cm y -1 . Vertical distributions of natural radionuclides ( 238 U, 232 Th, 226 Ra and 40 K) changed dramatically, reflecting great changes in sediment input. Concentrations of 238 U, 232 Th, 226 Ra and 40 K all had significant positive relationships with organic matter and clay content, but their distributions were determined by different factors. Factor analysis showed that 238 U was determined by the river sediment input while 226 Ra was mainly affected by the seawater erosion. Environmental changes such as river channel migrations and sediment discharge variations could always cause changes in the concentrations of radionuclides. High concentrations of 238 U and 226 Ra were consistent with high accretion rate. Frequent seawater intrusion decreased the concentration of 226 Ra significantly. The value of 238 U/ 226 Ra tended to be higher when the sedimentation rate was low and tide intrusion was frequent. In summary, environmental evolutions in the estuary coastal wetland could be recorded by the vertical profiles of natural radionuclides. Copyright © 2016 Elsevier Ltd. All rights reserved.

Estuarine wetland evolution including sea-level rise and infrastructure effects.

NASA Astrophysics Data System (ADS)

Rodriguez, Jose Fernando; Trivisonno, Franco; Rojas, Steven Sandi; Riccardi, Gerardo; Stenta, Hernan; Saco, Patricia Mabel

2015-04-01

Estuarine wetlands are an extremely valuable resource in terms of biotic diversity, flood attenuation, storm surge protection, groundwater recharge, filtering of surface flows and carbon sequestration. On a large scale the survival of these systems depends on the slope of the land and a balance between the rates of accretion and sea-level rise, but local man-made flow disturbances can have comparable effects. Climate change predictions for most of Australia include an accelerated sea level rise, which may challenge the survival of estuarine wetlands. Furthermore, coastal infrastructure poses an additional constraint on the adaptive capacity of these ecosystems. Numerical models are increasingly being used to assess wetland dynamics and to help manage some of these situations. We present results of a wetland evolution model that is based on computed values of hydroperiod and tidal range that drive vegetation preference. Our first application simulates the long term evolution of an Australian wetland heavily constricted by infrastructure that is undergoing the effects of predicted accelerated sea level rise. The wetland presents a vegetation zonation sequence mudflats - mangrove - saltmarsh from the seaward margin and up the topographic gradient but is also affected by compartmentalization due to internal road embankments and culverts that effectively attenuates tidal input to the upstream compartments. For this reason, the evolution model includes a 2D hydrodynamic module which is able to handle man-made flow controls and spatially varying roughness. It continually simulates tidal inputs into the wetland and computes annual values of hydroperiod and tidal range to update vegetation distribution based on preference to hydrodynamic conditions of the different vegetation types. It also computes soil accretion rates and updates roughness coefficient values according to evolving vegetation types. In order to explore in more detail the magnitude of flow attenuation due to roughness and its effects on the computation of tidal range and hydroperiod, we performed numerical experiments simulating floodplain flow on the side of a tidal creek using different roughness values. Even though the values of roughness that produce appreciable changes in hydroperiod and tidal range are relatively high, they are within the range expected for some of the wetland vegetation. Both applications of the model show that flow attenuation can play a major role in wetland hydrodynamics and that its effects must be considered when predicting wetland evolution under climate change scenarios, particularly in situations where existing infrastructure affects the flow.

Study of Wetland Ecosystem Vegetation Using Satellite Data

NASA Astrophysics Data System (ADS)

Dyukarev, E. A.; Alekseeva, M. N.; Golovatskaya, E. A.

2017-12-01

The normalized difference vegetation index (NDVI) is used to estimate the aboveground net production (ANP) of wetland ecosystems for the key area at the South Taiga zone of West Siberia. The vegetation index and aboveground production are related by linear dependence and are specific for each wetland ecosystem. The NDVI grows with an increase in the ANP at wooded oligotrophic ecosystems. Open oligotrophic bogs and eutrophic wetlands are characterized by an opposite relation. Maps of aboveground production for wetland ecosystems are constructed for each study year and for the whole period of studies. The average aboveground production for all wetland ecosystems of the key area, which was estimated with consideration for the area they occupy and using the data of satellite measurements of the vegetation index, is 305 g C/m2/yr. The total annual carbon accumulation in aboveground wetland vegetation in the key area is 794600 t.

The contribution of wetlands to stream nitrogen load in the Loch Vale Watershed, Colorado, USA

USGS Publications Warehouse

Jian-hui, Huang; Baron, Jill S.; Binkley, Dan

1996-01-01

We explored the difference between the concentrations of different N forms and other chemical properties between stream water and riparian zone wetland soil water in the Loch Vale Watershed which is located on the eastern slope of the Continental Divide in Rocky Mountain National Park, Colorado, USA. The nitrate N concentration in stream water were significantly higher than in soil water of the three wetlands, while no significant difference appeared in ammonium N. The pH values were higher and conductivity values were lower in stream water than in wetland soil water. However, significant difference also appeared between nitrate N concentrations, pH and conductivity values in the water sampled from different positions of streams. The stream tributary water had higher nitrate N concentrations, higher pH and higher conducitity values. We also conducted experiments to compare the difference between the productivity, total N concentrations in biomass and soil of upper layers. At the end, we concluded that the wetlands distributed along the streams in Loch Vale Watershed had little effect on the nitrogen load of the stream water there.

Simulating the water budget of a Prairie Potholes complex from LiDAR and hydrological models in North Dakota, USA

USGS Publications Warehouse

Huang, Shengli; Young, Claudia; Abdul-Aziz, Omar I.; Dahal, Devendra; Feng, Min; Liu, Shuguang

2013-01-01

Hydrological processes of the wetland complex in the Prairie Pothole Region (PPR) are difficult to model, partly due to a lack of wetland morphology data. We used Light Detection And Ranging (LiDAR) data sets to derive wetland features; we then modelled rainfall, snowfall, snowmelt, runoff, evaporation, the “fill-and-spill” mechanism, shallow groundwater loss, and the effect of wet and dry conditions. For large wetlands with a volume greater than thousands of cubic metres (e.g. about 3000 m3), the modelled water volume agreed fairly well with observations; however, it did not succeed for small wetlands (e.g. volume less than 450 m3). Despite the failure for small wetlands, the modelled water area of the wetland complex coincided well with interpretation of aerial photographs, showing a linear regression with R2 of around 0.80 and a mean average error of around 0.55 km2. The next step is to improve the water budget modelling for small wetlands.

Effect of vegetation type on treatment performance and bioelectric production of constructed wetland modules combined with microbial fuel cell (CW-MFC) treating synthetic wastewater.

PubMed

Saz, Çağdaş; Türe, Cengiz; Türker, Onur Can; Yakar, Anıl

2018-03-01

An operation of microcosm-constructed wetland modules combined with microbial fuel cell device (CW-MFC) was assessed for wastewater treatment and bioelectric generation. One of the crucial aims of the present experiment is also to determine effect of vegetation on wastewater treatment process and bioelectric production in wetland matrix with microbial fuel cell. Accordingly, CW-MFC modules with vegetation had higher treatment efficiency compared to unplanted wetland module, and average COD, NH 4 + , and TP removal efficiency in vegetated wetland modules were ranged from 85 to 88%, 95 to 97%, and 95 to 97%, respectively. However, the highest NO 3 - removal (63%) was achieved by unplanted control module during the experiment period. The maximum average output voltage, power density, and Coulombic efficiency were obtained in wetland module vegetated with Typha angustifolia for 1.01 ± 0.14 V, 7.47 ± 13.7 mWatt/m 2 , and 8.28 ± 10.4%, respectively. The results suggest that the presence of Typha angustifolia vegetation in the CW-MFC matrix provides the benefits for treatment efficiency and bioelectric production; thus, it increases microbial activities which are responsible for biodegradation of organic compounds and catalyzed to electron flow from anode to cathode. Consequently, we suggest that engineers can use vegetated wetland matrix with Typha angustifolia in CW-MFC module in order to maximize treatment efficiency and bioelectric production.

Vegetation Sampling for Wetland Delineation: A Review and Synthesis of Methods and Sampling Issues

DTIC Science & Technology

2010-07-01

different combination of characteristics. Wetlands may exhibit sharp boundaries between plant communities ( ecotones ), a gradual boundary (ecocline), or...and weighted averages as a component of assessment. Wetlands 13(3): 185–193. Attrill, M. J., and S. D. Rundle. 2002. Ecotone or ecocline...Gammon, and M. K. Garrett. 1994. Ecotone dynamics and boundary determination in the Great Dismal Swamp. Ecological Applications 4(1): 189– 203. ERDC

Projected wetland densities under climate change: habitat loss but little geographic shift in conservation strategy.

PubMed

Sofaer, Helen R; Skagen, Susan K; Barsugli, Joseph J; Rashford, Benjamin S; Reese, Gordon C; Hoeting, Jennifer A; Wood, Andrew W; Noon, Barry R

2016-09-01

Climate change poses major challenges for conservation and management because it alters the area, quality, and spatial distribution of habitat for natural populations. To assess species' vulnerability to climate change and target ongoing conservation investments, researchers and managers often consider the effects of projected changes in climate and land use on future habitat availability and quality and the uncertainty associated with these projections. Here, we draw on tools from hydrology and climate science to project the impact of climate change on the density of wetlands in the Prairie Pothole Region of the USA, a critical area for breeding waterfowl and other wetland-dependent species. We evaluate the potential for a trade-off in the value of conservation investments under current and future climatic conditions and consider the joint effects of climate and land use. We use an integrated set of hydrological and climatological projections that provide physically based measures of water balance under historical and projected future climatic conditions. In addition, we use historical projections derived from ten general circulation models (GCMs) as a baseline from which to assess climate change impacts, rather than historical climate data. This method isolates the impact of greenhouse gas emissions and ensures that modeling errors are incorporated into the baseline rather than attributed to climate change. Our work shows that, on average, densities of wetlands (here defined as wetland basins holding water) are projected to decline across the U.S. Prairie Pothole Region, but that GCMs differ in both the magnitude and the direction of projected impacts. However, we found little evidence for a shift in the locations expected to provide the highest wetland densities under current vs. projected climatic conditions. This result was robust to the inclusion of projected changes in land use under climate change. We suggest that targeting conservation towards wetland complexes containing both small and relatively large wetland basins, which is an ongoing conservation strategy, may also act to hedge against uncertainty in the effects of climate change. © 2016 by the Ecological Society of America.

[Research progress on wetland ecotourism].

PubMed

Wang, Li-Long; Lu, Lin

2009-06-01

Wetland is rich in biodiversity and cultural diversity, possessing higher tourism value and environmental education and community participation functions. Wetland ecotourism reflects the sustainable development of tourism economy and wetland protection, having received great concern from governments and scholars at home and abroad. This paper summarized the related theories and practices, discussed the research advances in wetland ecotourism from the aspects of significance, progress, contents, methods and results, and pointed out the important research fields in the future, aimed to accelerate the development of wetland ecotourism research and to provide reference about the resources exploitation, environment protection, and scientific administration of wetland and related scenic areas.

Risk Assessment as an Environmental Management Tool: Considerations for Freshwater Wetlands

Treesearch

A. Dennis Lemly

1997-01-01

This paper presents a foundation for improving the risk assessment process for freshwater wetlands. Integrating wetland science, i.e., use of an ecosystem-based approach, is the key concept. Each biotic and abiotic wetland component should be identified and its contribution to ecosystem functions and societal values determined when deciding whether a stressor poses an...

Multi-temporal RADARSAT-1 and ERS backscattering signatures of coastal wetlands in southeastern Louisiana

USGS Publications Warehouse

Kwoun, Oh-Ig; Lu, Z.

2009-01-01

Using multi-temporal European Remote-sensing Satellites (ERS-1/-2) and Canadian Radar Satellite (RADARSAT-1) synthetic aperture radar (SAR) data over the Louisiana coastal zone, we characterize seasonal variations of radar backscat-tering according to vegetation type. Our main findings are as follows. First, ERS-1/-2 and RADARSAT-1 require careful radiometric calibration to perform multi-temporal backscattering analysis for wetland mapping. We use SAR backscattering signals from cities for the relative calibration. Second, using seasonally averaged backscattering coefficients from ERS-1/-2 and RADARSAT-1, we can differentiate most forests (bottomland and swamp forests) and marshes (freshwater, intermediate, brackish, and saline marshes) in coastal wetlands. The student t-test results support the usefulness of season-averaged backscatter data for classification. Third, combining SAR backscattering coefficients and an optical-sensor-based normalized difference vegetation index can provide further insight into vegetation type and enhance the separation between forests and marshes. Our study demonstrates that SAR can provide necessary information to characterize coastal wetlands and monitor their changes.

Effects of land use changes on the ecosystem service values of coastal wetlands.

PubMed

Camacho-Valdez, Vera; Ruiz-Luna, Arturo; Ghermandi, Andrea; Berlanga-Robles, César A; Nunes, Paulo A L D

2014-10-01

Changes in the coastal landscape of Southern Sinaloa (Mexico), between 2000 and 2010, were analyzed to relate spatial variations in wetlands extent with the provision and economic value of the ecosystem services (ES). Remote sensing techniques applied to Landsat TM imagery were used to evaluate land use/land cover changes while the value transfer method was used to assess the value of ES by land cover category. Five wetland types and other four land covers were found as representative of the coastal landscape. Findings reveal a 14 % decrease in the saltmarsh/forested mangrove area and a 12 % increase in the area of shrimp pond aquaculture (artificial wetland) during the study period. ES valuation shows that the total value flow increased by 9 % from $215 to $233 million (2007 USD) during the 10-year period. This increase is explained as result of the high value worldwide assigned to saltmarsh. We recognize limitations in the transfer-based approach in quantifying and mapping ES values in the region, but this method provides with value estimates spatially defined, and also provides some guidance in the preliminary screening of policies and projected development in the context of data-scarce regions.

Patterns and drivers for wetland connections in the Prairie Pothole Region, United States

USGS Publications Warehouse

Vanderhoof, Melanie; Christensen, Jay R.; Alexander, Laurie C.

2017-01-01

Ecosystem function in rivers, lakes and coastal waters depends on the functioning of upstream aquatic ecosystems, necessitating an improved understanding of watershed-scale interactions including variable surface-water flows between wetlands and streams. As surface water in the Prairie Pothole Region expands in wet years, surface-water connections occur between many depressional wetlands and streams. Minimal research has explored the spatial patterns and drivers for the abundance of these connections, despite their potential to inform resource management and regulatory programs including the U.S. Clean Water Act. In this study, wetlands were identified that did not intersect the stream network, but were shown with Landsat images (1990–2011) to become merged with the stream network as surface water expanded. Wetlands were found to spill into or consolidate with other wetlands within both small (2–10 wetlands) and large (>100 wetlands) wetland clusters, eventually intersecting a stream channel, most often via a riparian wetland. These surface-water connections occurred over a wide range of wetland distances from streams (averaging 90–1400 m in different ecoregions). Differences in the spatial abundance of wetlands that show a variable surface-water connection to a stream were best explained by smaller wetland-to-wetland distances, greater wetland abundance, and maximum surface-water extent. This analysis demonstrated that wetland arrangement and surface water expansion are important mechanisms for depressional wetlands to connect to streams and provides a first step to understanding the frequency and abundance of these surface-water connections across the Prairie Pothole Region.

Accumulation rates of airborne heavy metals in wetlands

USGS Publications Warehouse

Souch, C.J.; Filippelli, G.M.; Dollar, N.; Perkins, S.; Mastalerz, Maria

2002-01-01

Accumulation rates of heavy metals (Cd, Cr, Cu, Mn, Pb, and Zn) retained in wetland sediments in northwest Indiana-downwind of the Chicago-Gary-Hammond industrial area-are quantified to assess anthropogenic influences on atmospheric fluxes. Metal concentrations for 22 sediment cores are determined by ICP-AES after ashing and strong acid extraction. Relations between organic content and metal concentrations at depth are used to separate natural and anthropogenic sources. Accumulation rates over the lifetime of the wetlands (???4500 years) have averaged 0.2 (Cd), 1.4 (Cu), 1.7 (Cr), 13.4 (Mn), 4.8 (Pb), and 18.7 (Zn) mg m-2 y-1. Rates for the last 100 years have increased on average by factors of 6 (Cd), 8 (Cu), 10 (Mn), 15 (Pb), and 30 (Zn), remaining effectively constant for Cr. Where the wetlands have been drained, metals have been lost from the sediments, owing to changes in organic content and local hydrochemistry (exposure to acidic rainfall). Sediment-based accumulation rates at the undrained sites are higher, though generally consistent, with measured and modeled atmospheric fluxes documented by short-term studies conducted over the last three decades. The fraction of the total metals in the wetlands estimated to be of anthropogenic origin ranges from approximately 3% for Cr, up to approximately 35% for Pb, and 70% for Zn. This historic legacy of contamination must be considered in land management decisions, particularly when wetlands are drained.

Experimental and numerical study of the relation between flow paths and fate of a pesticide in a riparian wetland

NASA Astrophysics Data System (ADS)

Kidmose, Jacob; Dahl, Mette; Engesgaard, Peter; Nilsson, Bertel; Christensen, Britt S. B.; Andersen, Stine; Hoffmann, Carl Christian

2010-05-01

SummaryA field-scale pulse-injection experiment with the herbicide Isoproturon was conducted in a Danish riparian wetland. A non-reactive tracer (bromide) experiment was also carried out to characterize the physical transport system. Groundwater flow and reactive transport modelling was used to simulate flow paths, residence times, as well as bromide and Isoproturon distributions. The wetland can be characterized by two distinct riparian flow paths; one flow path discharges 2/3 of the incoming groundwater directly to the free water surface of the wetland near the foot of the hillslope with an average residence time of 205 days, and another flow path diffusively discharging the remaining 1/3 of the incoming groundwater to the stream with an average residence time of 425 days. The reactive transport simulations reveal that Isoproturon is retarded by a factor of 2-4, which is explained by the high organic content in the peat layer of the wetland. Isoproturon was found to be aerobically degraded with a half-life in the order of 12-80 days. Based on the quantification of flow paths, residence times and half-lives it is estimated that about 2/3 of the injected Isoproturon is removed in the wetland. Thus, close to 1/3 may find its way to the stream through overland flow. It is also possible that high concentrations of metabolites will reach the stream.

Research access to privately owned wetland basins in the prairie pothole region of the United States

USGS Publications Warehouse

Fellows, David P.; Buhl, Thomas K.

1995-01-01

We describe efforts to obtain access for research to 81 wetland basins on 69 farms in four zones of the Prairie Pothole Region of North Dakota, South Dakota, and Minnesota. Access was obtained to 54% of the farms in areas where land was intensively cropped and 87% of farms in areas of low cropping intensity. On average, 1.35 operators had to be contacted and 1.70 interviews were required to obtain a decision on access to a farm. On 77% of the farms, cooperators placed at least one restriction on access, most commonly requiring walking access only or notification before nighttime work. Cost of obtaining access averaged $265/farm in wages and travel expenses. No cooperators were willing to sign written access agreements. Operators rescinded access to four farms and drained three wetland basins during the first year; six of the seven sites lost were in the intensively cropped portion of a low-wetland-density zone. The difficulty of obtaining and retaining research access to privately owned wetland basins in intensively cropped areas may be related to landowner attitudes towards wetlands. Researchers may have to rely on remote sensing or consider payment for access to secure representative research sites in such areas. Unwillingness of cooperators to sign access agreements may jeopardize research by the newly formed National Biological Service and other resource management agencies.

A STORMWATER CONSTRUCTED WETLAND USING RENEWABLE AND RECYCLABLE MATERIALS AND NATIVE WETLAND PLANTS

EPA Science Inventory

To complete the first objective, we installed a weather station within the storm water drainage area that measured air temperature, relative humidity, solar radiation, wind speed, and rainfall. Measurements were taken every 30 minutes and included the average temperature, rela...

Watershed-scale effects of isolated wetlands on downstream hydrology: modeling approaches

EPA Science Inventory

Geographically isolated wetlands (GIWs) are depressional features on an eroding landscape that are entirely surrounded by uplands. These wetlands are purported to provide an array of ecological and watershed values and functions, including increasing biodiversity, modifying water...

Greenhouse gas emissions and carbon sequestration potential in restored freshwater marshes in the Sacramento San-Joaquin Delta, California

NASA Astrophysics Data System (ADS)

Knox, S. H.; Sturtevant, C. S.; Oikawa, P. Y.; Matthes, J. H.; Dronova, I.; Anderson, F. E.; Verfaillie, J. G.; Baldocchi, D. D.

2015-12-01

Wetlands can be effective carbon sinks due to limited decomposition rates in anaerobic soil. As such there is a growing interest in the use of restored wetlands as biological carbon sequestration projects for greenhouse gas (GHG) emission reduction programs. However, using wetlands to offset emissions requires accurate accounting of both carbon dioxide (CO2) and methane (CH4) exchange since wetlands are also sources of CH4. To date few studies have quantified CO2 and CH4 exchange from restored wetlands or assessed how these fluxes vary during ecosystem development. In this study, we report on multiple years of eddy covariance measurements of CO2 and CH4 fluxes from two restored freshwater marshes of differing ages (one restored in 1997 and the other in 2010) in the Sacramento-San Joaquin Delta, CA. Measurements at the younger restored wetland started in October 2010 and began in April 2011 at the older site. The younger restored wetland showed considerable year-to-year variability in the first 4 years following restoration, with CO2 uptake ranging from 12 to 420 g C-CO2 m-2 yr-1. Net CO2 uptake at the older wetland was overall greater than at the younger site, ranging from 292 to 585 g C-CO2 m-2 yr-1. Methane emissions were on average higher at the younger wetland (46 g C-CH4 m-2 yr-1) relative to the older one (33 g C-CH4 m-2 yr-1). In terms of the GHG budgets (assuming a global warming potential of 34), the younger wetland was consistently a GHG source, emitting on average 1439 g CO2 eq m-2 yr-1, while the older wetland was a GHG sink in two of the years of measurement (sequestering 651 and 780 g CO2 eq m-2 yr-1 in 2012 and 2013, respectively) and a source of 750 g CO2 eq m-2 yr-1 in 2014. This study highlights how dynamic CO2 and CH4 fluxes are in the first years following wetland restoration and suggests that restored wetlands have the potential to act as GHG sinks but this may depend on time since restoration.

Wetlands in The Netherlands and New Zealand: optimising biodiversity and carbon sequestration during urbanisation.

PubMed

van Roon, Marjorie R

2012-06-30

The halting of biodiversity decline of wetlands necessitates ecosystem protection, restoration and re-creation of all wetland types preferably in all suitable landscapes. As peat wetlands (bogs and fens) are superior as carbon stores, and because of their rarity they have a higher biodiversity value relative to other wetland types, they need to be prioritised for protection and restoration. The hydrological, pH, and nutrient conditions essential to each type of wetland that need to be understood and provided for during development are discussed for The Netherlands' and New Zealand. Case studies describe freshwater wetland management and challenges during urbanisation in the Stad van de Zon and Blauwestad in The Netherlands, and in the Styx valley and Pegasus in Christchurch, New Zealand. A summary of the history of urbanisation and wetland destruction, and of biodiversity management for each country provides a context for the case studies. These case studies demonstrate the degree to which the relative values of bogs, fens and swamps, with respect to biodiversity and carbon sequestration, are understood and managed using diverse protection measures, within the boundaries of new urban developments and in adjacent ecological corridors. Copyright © 2012 Elsevier Ltd. All rights reserved.

[Ecosystem services valuation of Qinghai Lake].

PubMed

Jiang, Bo; Zhang, Lu; Ouyang, Zhi-yun

2015-10-01

Qinghai Lake is the largest inland and salt water lake in China, and provides important ecosystem services to beneficiaries. Economic valuation of wetland ecosystem services from Qinghai Lake can reveal the direct contribution of lake ecosystems to beneficiaries using economic data, which can advance the incorporation of wetland protection of Qinghai Lake into economic tradeoffs and decision analyses. In this paper, we established a final ecosystem services valuation system based on the underlying ecological mechanisms and regional socio-economic conditions. We then evaluated the eco-economic value provided by the wetlands at Qinghai Lake to beneficiaries in 2012 using the market value method, replacement cost method, zonal travel cost method, and contingent valuation method. According to the valuation result, the total economic values of the final ecosystem services provided by the wetlands at Qinghai Lake were estimated to be 6749.08 x 10(8) yuan RMB in 2012, among which the value of water storage service and climate regulation service were 4797.57 x 10(8) and 1929.34 x 10(8) yuan RMB, accounting for 71.1% and 28.6% of the total value, respectively. The economic value of the 8 final ecosystem services was ranked from greatest to lowest as: water storage service > climate regulation service > recreation and tourism service > non-use value > oxygen release service > raw material production service > carbon sequestration service > food production service. The evaluation result of this paper reflects the substantial value that the wetlands of Qinghai Lake provide to beneficiaries using monetary values, which has the potential to help increase wetland protection awareness among the public and decision-makers, and inform managers about ways to create ecological compensation incentives. The final ecosystem service evaluation system presented in this paper will offer guidance on separating intermediate services and final services, and establishing monitoring programs for dynamic ecosystem services valuation with the aim of helping improve management outcomes.

Sedimentation of prairie wetlands

USGS Publications Warehouse

Gleason, Robert A.; Euliss, Ned H.

1998-01-01

Many wetlands in the prairie pothole region are embedded within an agricultural landscape where they are subject to varying degrees of siltation. Cultivation of wetland catchment areas has exacerbated soil erosion; wetlands in agricultural fields receive more sediment from upland areas than wetlands in grassland landscapes and hence are subject to premature filling (i.e., they have shorter topographic lives). Associated impacts from increased turbidity, sediment deposition, and increased surface water input likely have impaired natural wetland functions. Although trapping of sediments by wetlands is often cited as a water quality benefit, sediment input from agricultural fields has potential to completely fill wetlands and shorten their effective life-span. Thus, the value placed on wetlands to trap sediments is in conflict with maximizing the effective topographic life of wetlands. Herein, we provide an overview of sedimentation, identify associated impacts on wetlands, and suggest remedial management strategies. We also highlight the need to evaluate the impact of agricultural practices on wetland functions from an interdisciplinary approach to facilitate development of best management practices that benefit both wetland and agricultural interests.

Effects of energy development on wetland plants and macroinvertebrate communities in Prairie Pothole Region wetlands

USGS Publications Warehouse

Preston, Todd M.; Ray, Andrew M.

2016-01-01

Energy production in the Williston Basin, USA, results in the coproduction of highly saline, sodium chloride-dominated water (brine). The Prairie Pothole Region (PPR) overlies the northeastern portion of the Williston Basin. Although PPR wetlands span a range of salinity, the dominant salt is sodium sulfate, and salinities are much lower than brine. Introduction of brine to wetlands can result in pronounced water-quality changes; however, the ecological effects of such contamination are poorly understood. We examined the effects of brine contamination on primary productivity, emergent macrophyte tissue chemistry, and invertebrate communities from 10 wetlands in the PPR. Based on a recognized Contamination Index (CI) used to identify brine contamination in the PPR, water-quality samples indicated that six wetlands were uncontaminated while four were contaminated. Across this gradient, we observed a significant decrease in above-ground biomass and a significant increase in tissue chloride concentrations of hardstem bulrush (Schoenoplectus acutus) with increased CI values. Additionally, a significant decrease in macroinvertebrate taxonomic richness with increased CI values was observed. These findings provide needed insight on the biological effects of brine contamination on PPR wetlands.

Measurements of an Anomalous Global Methane Increase During 1998

NASA Technical Reports Server (NTRS)

Dlugokencky, E. J.; Walter, B. P.; Masarie, K. A.; Lang, P. M.; Kasischke, E. S.; Hansen, James E. (Technical Monitor)

2001-01-01

Measurements of atmospheric methane from a globally distributed network of air sampling sites indicate that the globally averaged CH4 growth rate increased from an average of 3.9 ppb/yr during 1995-1997 to 12.7 +/- 0.6 ppb in 1998. The global growth rate then decreased to 2.6 +/- 0.6 ppb during 1999, indicating that the large increase in 1998 was an anomaly and not a return to the larger growth rates observed during the late 1970s and early 1980s. The increased growth rate represents an anomalous increase in the imbalance between CH4 sources and sinks equal to approximately 24 Tg CH4 during 1998. Wetlands and boreal biomass burning are sources that may have contributed to the anomaly. During 1998, the globally averaged temperature anomaly was +0.67 C, the largest temperature anomaly in the modern record. A regression model based on temperature and precipitation anomalies was used to calculate emission anomalies of 11.6 Tg CH4 from wetlands north of 30 N and 13 Tg CH4 for tropical wetlands during 1998 compared to average emissions calculated for 1982-1993. In 1999, calculated wetland emission anomalies were negative for high northern latitudes and the tropics, contributing to the low growth rate observed in 1999. Also 1998 was a severe fire year in boreal regions where approximately 1.3x10(exp 5) sq km of forest and peat land burned releasing an estimated 5.7 Tg CH4

7 CFR 1467.13 - Modifications.

Code of Federal Regulations, 2011 CFR

2011-01-01

... must meet WRP regulations and program objectives, comply with the definition of wetland restoration as... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.13 Modifications. (a... the program so long as the modification will not adversely affect the wetland functions and values for...

18 CFR 725.7 - Regional or river basin planning.

Code of Federal Regulations, 2011 CFR

2011-04-01

... preservation and restoration of natural and beneficial floodplain values; (4) Where avoidance of wetlands... IMPLEMENTATION OF EXECUTIVE ORDERS 11988, FLOODPLAIN MANAGEMENT AND 11990, PROTECTION OF WETLANDS... whether proposed activities would be located in floodplains or wetlands, or, even if located outside of...

An Inventory and Classification of Coastal Wetlands of the Laurentian Great Lakes

EPA Science Inventory

This inventory and classification of DRM/riverine coastal wetlands is needed for doing a probability based selection for assessments of this valued aquatic resource across large areas, e.g., by states for 305B reports of coastal wetland condition.

Wetlands with greater degree of urbanization improve PM2.5 removal efficiency.

PubMed

Liu, Jiakai; Yan, Guoxin; Wu, Yanan; Wang, Yu; Zhang, Zhenming; Zhang, Mingxiang

2018-09-01

In recent decades, China has experienced both rapid urbanization and heavy air pollution and the rapid urbanization trend would be continue in the next decade. Wetlands have been shown to be efficient in particle removal, primarily through dry deposition and leaf accumulation. Thus, a more comprehensive understanding of PM2.5 removal by wetlands during urbanization processes could inform urban planning. In the current study, three wetland plots, Cuihu Lake Park (CL), Summer Palace (SP), and Olympic Park (OP), were selected as low, medium, and highly degrees of urbanization site respectively based on the proportions of building and traffic district areas to compare the removal efficiencies. Results show the average dry deposition velocity in OP was significantly higher than CL and SP. Dry deposition is mainly influenced by meteorological conditions. Buildings and other infrastructure make the meteorological conditions conducive to deposition, resulting in higher wind velocity, higher temperature, and more intense turbulence between buildings. Variation in leaf accumulation was not statistically significant between the three plots, and plant species was the major factor affecting the amount of accumulation. The dry deposition contribution to particle removal increases with degree of urbanization. The average dry deposition accounted for 39.74%, 52.55%, and 62.75% at low, middle and high level respectively. Therefore, Wetlands with greater degree of urbanization improve PM2.5 removal efficiency primarily by accelerating the dry deposition process. The result emphasizes the importance of wetlands in particle removal in highly urbanized areas and thus more wetlands should be preserved and/or created during urban expansion. Copyright © 2018 Elsevier Ltd. All rights reserved.

Research of the diurnal soil respiration dynamic in two typical vegetation communities in Tianjin estuarine wetland

NASA Astrophysics Data System (ADS)

Zhang, Q.; Meng, W. Q.; Li, H. Y.

2016-08-01

Understanding the differences and diurnal variations of soil respiration in different vegetation communities in coastal wetland is to provide basic reliable scientific evidence for the carbon "source" function of wetland ecosystems in Tianjin.Measured soil respiration rate which changed during a day between two typical vegetation communities (Phragmites australis, Suaeda salsa) in coastal wetland in October, 2015. Soil temperature and moisture were measured at the same time. Each of the diurnal curves of soil temperature in two communities had a single peak value, and the diurnal variations of soil moisture showed a "two peak-one valley" trend. The diurnal dynamic of soil respiration under the two communities had obvious volatility which showed a single peak form with its maximum between 12:00-14:00 and minimum during 18:00. The diurnal average of soil respiration rate in Phragmites australis communities was 3.37 times of that in Suaeda salsa communities. Significant relationships were found by regression analysis among soil temperature, soil moisture and soil respiration rate in Suaeda salsa communities. There could be well described by exponential models which was y = -0.245e0.105t between soil respiration rate and soil temperature, by quadratic models which was y = -0.276×2 + 15.277× - 209.566 between soil respiration rate and soil moisture. But the results of this study showed that there were no significant correlations between soil respiration and soil temperature and soil moisture in Phragmites australis communities (P > 0.05). Therefore, under the specific wetland environment conditions in Tianjin, soil temperature and moisture were not main factors influencing the diurnal variations of soil respiration rate in Phragmites australis communities.

Controls on ecosystem and root respiration across a permafrost and wetland gradient in interior Alaska

USGS Publications Warehouse

McConnell, Nicole A.; Turetsky, Merritt R.; McGuire, A. David; Kane, Evan S.; Waldrop, Mark P.; Harden, Jennifer W.

2013-01-01

Permafrost is common to many northern wetlands given the insulation of thick organic soil layers, although soil saturation in wetlands can lead to warmer soils and increased thaw depth. We analyzed five years of soil CO2 fluxes along a wetland gradient that varied in permafrost and soil moisture conditions. We predicted that communities with permafrost would have reduced ecosystem respiration (ER) but greater temperature sensitivity than communities without permafrost. These predictions were partially supported. The colder communities underlain by shallow permafrost had lower ecosystem respiration (ER) than communities with greater active layer thickness. However, the apparent Q10 of monthly averaged ER was similar in most of the vegetation communities except the rich fen, which had smaller Q10 values. Across the gradient there was a negative relationship between water table position and apparent Q10, showing that ER was more temperature sensitive under drier soil conditions. We explored whether root respiration could account for differences in ER between two adjacent communities (sedge marsh and rich fen), which corresponded to the highest and lowest ER, respectively. Despite differences in root respiration rates, roots contributed equally (~40%) to ER in both communities. Also, despite similar plant biomass, ER in the rich fen was positively related to root biomass, while ER in the sedge marsh appeared to be related more to vascular green area. Our results suggest that ER across this wetland gradient was temperature-limited, until conditions became so wet that respiration became oxygen-limited and influenced less by temperature. But even in sites with similar hydrology and thaw depth, ER varied significantly likely based on factors such as soil redox status and vegetation composition.

LANDSAT applications to wetlands classification in the upper Mississippi River Valley. Ph.D. Thesis. Final Report

NASA Technical Reports Server (NTRS)

Lillesand, T. M.; Werth, L. F. (Principal Investigator)

1980-01-01

A 25% improvement in average classification accuracy was realized by processing double-date vs. single-date data. Under the spectrally and spatially complex site conditions characterizing the geographical area used, further improvement in wetland classification accuracy is apparently precluded by the spectral and spatial resolution restrictions of the LANDSAT MSS. Full scene analysis of scanning densitometer data extracted from scale infrared photography failed to permit discrimination of many wetland and nonwetland cover types. When classification of photographic data was limited to wetland areas only, much more detailed and accurate classification could be made. The integration of conventional image interpretation (to simply delineate wetland boundaries) and machine assisted classification (to discriminate among cover types present within the wetland areas) appears to warrant further research to study the feasibility and cost of extending this methodology over a large area using LANDSAT and/or small scale photography.

The utility of state parks as a conservation tool for isolated and ephemeral wetlands: A case study from the southern Blue Ridge

NASA Astrophysics Data System (ADS)

Howard, J. H.; Baldwin, R.; Pitt, A. L.; Baldwin, E. D.

2013-12-01

Biodiversity management has been historically confined to parks and protected areas and these types of formally-protected areas may help to mitigate the effects of climate change and habitat loss by preventing further fragmentation, degradation and the spread of invasive species. Much research has demonstrated the importance of parks and other such protected areas for their ecological, conservational, and socio-cultural benefits. Protected areas constitute ~ 12% of the earth's land surface and are described as an essential core unit for for in situ conservation. State parks provide a type of a priori conservation, allowing areas which are identified as ecologically important within state park boundaries to be more rapidly prioritized for conservation and management. The development of South Carolina's state parks strongly contributed to cultural, social and ecological improvement across the state and we demonstrate that this network of protected areas can also help scientists to better locate, study and conserve cryptic or unprotected habitats. Our goals for this study were to use the SC state park system to 1) examine the structural and functional differences between wetlands located inside versus outside the state park system, and 2) suggest a conservation framework for small wetlands incorporating both state parks and adjacent areas with variable ownership status. At each wetland, we variables at the within-pond and local (5 m buffer around pool) scales. We visited each study wetland (N = 41, park pool = 19, non-park pools = 22) 5 times during both 2010 and 2011; collected water quality data and recorded the presence and activity of mammals, reptiles, amphibians, benthic invertebrates, zooplankton, phytoplankton and benthic algae. We hypothesized that wetlands within state parks would have better water quality and higher species richness compared to non-park wetlands. Our case study revealed that wetlands outside of state parks exhibited less variable depths and were deeper on average than park pools. We found significant differences in total taxonomic richness, invertebrate tolerance values and wetland depth between park and non-park wetlands. We relied heavily on local ecological knowledge (LEK) for identification and information on wetlands within parks. Furthermore, state parks played a vital role in the development of this project and our study was enriched as a result of utilizing state park personnel and their LEK. We were also able to interact with the public during our site visits and this two-way dialogue between scientists and the general public was useful for educating citizens about the importance of isolated/ephemeral wetlands and helped us better understand public perceptions of wetlands. State parks provided a number of study sites, various personnel who were knowledgeable about the locations and dynamics of wetlands and an a priori framework for conservation at the local scale which can help bolster conservation efforts at larger scales. We posit that state parks are an under-utilized but extremely important resource for filling the gaps in conservation.

SURVEY AND ASSESSMENT OF CRITICAL WETLANDS IN LA PLATA COUNTY, COLORADO

EPA Science Inventory

The Products of this study will be to: 1) identify high-quality examples, and the corresponding natural heritage value, of all types of wetland/riparian areas in San Juan County (using CNHP's Comprehensive Statewide Wetland Classification); 2) coordinate efforts with the propose...

Fringe benefit: Value of restoring coastal wetlands for Great Lakes fisheries

EPA Science Inventory

Fishery support is recognized as a valuable ecosystem service provided by Great Lakes coastal wetlands, but it is challenging to quantify because multiple species and habitats are involved. Recent studies indicate that coastal wetland area is proportional to fishery harvest among...

10 CFR 1022.4 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... ENERGY (GENERAL PROVISIONS) COMPLIANCE WITH FLOODPLAIN AND WETLAND ENVIRONMENTAL REVIEW REQUIREMENTS... DOE action in a wetland that is also within the floodplain, subject to the exclusions specified at § 1022.5(c) and (d) of this part. Floodplain and wetland values means the qualities of or functions...

Factors affecting coastal wetland loss and restoration

USGS Publications Warehouse

Cahoon, D.R.; Phillips, S.W.

2007-01-01

Opening paragraph: Tidal and nontidal wetlands in the Chesapeake Bay watershed provide vital hydrologic, water-quality, and ecological functions. Situated at the interface of land and water, these valuable habitats are vulnerable to alteration and loss by human activities including direct conversion to non-wetland habitat by dredge-and-fill activities from land development, and to the effects of excessive nutrients, altered hydrology and runoff, contaminants, prescribed fire management, and invasive species. Processes such as sea-level rise and climate change also impact wetlands. Although local, State, and Federal regulations provide for protection of wetland resources, the conversion and loss of wetland habitats continue in the Bay watershed. Given the critical values of wetlands, the Chesapeake 2000 Agreement has a goal to achieve a net gain in wetlands by restoring 25,000 acres of tidal and nontidal wetlands by 2010. The USGS has synthesized findings on three topics: (1) sea-level rise and wetland loss, (2) wetland restoration, and (3) factors affecting wetland diversity.

Measurement and simulation of evapotranspiration at a wetland site in the New Jersey Pinelands

USGS Publications Warehouse

Sumner, David M.; Nicholson, Robert S.; Clark, Kenneth L.

2012-01-01

Evapotranspiration (ET) was monitored above a wetland forest canopy dominated by pitch-pine in the New Jersey Pinelands during November 10, 2004-February 20, 2007, using an eddy-covariance method. Twelve-month ET totals ranged from 786 to 821 millimeters (mm). Minimum and maximum ET rates occurred during December-February and in July, respectively. Relations between ET and several environmental variables (incoming solar radiation, air temperature, relative humidity, soil moisture, and net radiation) were explored. Net radiation (r = 0.72) and air temperature (r = 0.73) were the dominant explanatory variables for daily ET. Air temperature was the dominant control on evaporative fraction with relatively more radiant energy used for ET at higher temperatures. Soil moisture was shown to limit ET during extended dry periods. With volumetric soil moisture below a threshold of about 0.15, the evaporative fraction decreased until rain ended the dry period, and the evaporative fraction sharply recovered. A modified Hargreaves ET model, requiring only easily obtainable daily temperature data, was shown to be effective at simulating measured ET values and has the potential for estimating historical or real-time ET at the wetland site. The average annual ET measured at the wetland site during 2005-06 (801 mm/yr) is about 32 percent higher than previously reported ET for three nearby upland sites during 2005-09. Periodic disturbance by fire and insect defoliation at the upland sites reduced ET. When only undisturbed periods were considered, the wetland ET was 17 percent higher than the undisturbed upland ET. Interannual variability in wetlands ET may be lower than that of uplands ET because the upland stands are more susceptible to periodic drought conditions, disturbance by fire, and insect defoliation. Precipitation during the study period at the nearby Indian Mills weather station was slightly higher than the long-term (1902-2011) annual mean of 1,173 millimeters (mm), with 1,325 and 1,396 mm of precipitation in 2005 and 2006, respectively.

Dynamics of the wetland vegetation in large lakes of the Yangtze Plain in response to both fertilizer consumption and climatic changes

NASA Astrophysics Data System (ADS)

Hou, Xuejiao; Feng, Lian; Chen, Xiaoling; Zhang, Yunlin

2018-07-01

Using moderate-resolution imaging spectroradiometer (MODIS) data that cover the 15-year period from 2000 to 2014 and a phenology-based classification method, the long-term changes in the wetland vegetation of 25 large lakes on the Yangtze Plain were obtained. The classification method was developed based on the phenological information extracted from time series of MODIS observations, which demonstrated mean user's/producer's accuracies of 76.17% and 84.58%, respectively. The first comprehensive record of the spatial distribution and temporal dynamics of wetland vegetation in the large lakes on the Yangtze Plain was created. Of the 25 lakes examined, 17 showed a decreasing trend of vegetation area percentages (VAPs) during the study period, and 7 were statistically significant (p < 0.05). The same number of lakes was found to display decreasing trends in vegetation greenness over this 15-year period, and these decreasing trends were statistically significant (p < 0.05) for 11 of the lakes. Substantially fewer lakes showed increases in either their VAPs or their vegetation greenness values. Analysis using a multiple general linear model revealed that the amounts of chemical fertilizer used for farmlands surrounding the lakes, precipitation, daily sunshine hours, temperature and water turbidity played the most important roles in regulating the interannual changes in vegetation greenness in 40% (10/25), 12% (3/25), 4% (1/25), 20% (5/25) and 12% (3/25) of the lake wetlands, respectively. On average, the combined effects of these five driving factors above explained 89.08 ± 7.89% of the variation in greenness over this 15-year period for the 25 lakes. This wetland vegetation environmental data record (EDR) of large lakes in Yangtze Plain demonstration will provide a crucial baseline information for the wetland environment conservation and restoration.

Tampa Bay coastal wetlands: nineteenth to twentieth century tidal marsh-to-mangrove conversion

USGS Publications Warehouse

Raabe, Ellen A.; Roy, Laura C.; McIvor, Carole C.

2012-01-01

Currently, mangroves dominate the tidal wetlands of Tampa Bay, Florida, but an examination of historic navigation charts revealed dominance of tidal marshes with a mangrove fringe in the 1870s. This study's objective was to conduct a new assessment of wetland change in Tampa Bay by digitizing nineteenth century topographic and public land surveys and comparing these to modern coastal features at four locations. We differentiate between wetland loss, wetland gain through marine transgression, and a wetland conversion from marsh to mangrove. Wetland loss was greatest at study sites to the east and north. Expansion of the intertidal zone through marine transgression, across adjacent low-lying land, was documented primarily near the mouth of the bay. Generally, the bay-wide marsh-to-mangrove ratio reversed from 86:14 to 25:75 in 125 years. Conversion of marsh to mangrove wetlands averaged 72 % at the four sites, ranging from 52 % at Old Tampa Bay to 95 % at Feather Sound. In addition to latitudinal influences, intact wetlands and areas with greater freshwater influence exhibited a lower rate of marsh-to-mangrove conversion. Two sources for nineteenth century coastal landscape were in close agreement, providing an unprecedented view of historic conditions in Tampa Bay.

Hydrologic response in karstic-ridge wetlands to rainfall and evapotranspiration, central Florida, 2001-2003

USGS Publications Warehouse

Knowles, Leel; Phelps, G.G.; Kinnaman, Sandra L.; German, Edward R.

2005-01-01

Two internally drained karstic wetlands in central Florida-Boggy Marsh at the Hilochee Wildlife Management Area and a large unnamed wetland at the Lyonia Preserve-were studied during 2001-03 to gain a better understanding of the net-recharge function that these wetlands provide, the significance of exchanges with ground water with regard to wetland water budgets, and the variability in wetland hydrologic response to a range of climate conditions. These natural, relatively remote and unaltered wetlands were selected to provide a baseline of natural wetland hydrologic variability to which anthropogenic influences on wetland hydrology could be compared. Large departures from normal rainfall during the study were fortuitous, and allowed monitoring of hydrologic processes over a wide range of climate conditions. Wetland responses varied greatly as a result of climate conditions that ranged from moderate drought to extremely moist. Anthropogenic activities influenced water levels at both study sites; however, because these activities were brief relative to the duration of the study, sufficient data were collected during unimpacted periods to allow for the following conclusions to be made. Water budgets developed for Boggy Marsh and the Lyonia large wetland showed strong similarity between the flux terms of rainfall, evaporation, net change in storage, and the net ground-water exchange residual. Runoff was assumed to be negligible. Of the total annual flux at Boggy Marsh, rainfall accounted for 45 percent; evaporation accounted for 25 percent; net change in storage accounted for 25 percent; and the net residual accounted for 5 percent. At the Lyonia large wetland, rainfall accounted for 44 percent; evaporation accounted for 29 percent; net change in storage accounted for 21 percent; and the net residual accounted for 6 percent of the total annual flux. Wetland storage and ground-water exchange were important when compared to the total water budget at both wetlands. Even though rainfall was far above average during the study, wetland evaporation volumetrically exceeded rainfall. Ground-water inflow was effective in partially offsetting the negative residual between rainfall and evaporation, thus adding to wetland storage. Ground-water inflow was most common at both wetlands when rainfall continued for days or weeks, or during a week with more than about 2.5 inches of rainfall. Large decreases in wetland storage were associated with large negative fluxes of evaporation and ground-water exchange. The response of wetland water levels to rainfall showed a strong and similar relation at both study sites; however, the greater variability in the relation of wetland water-level change to rainfall at higher rainfall rates indicated that hydrologic processes other than rainfall became more important in the response of the wetland. Changes in wetland water levels seemed to be related more to vertical gradients than to lateral gradients. The largest wetland water-level rises were associated mostly with lower vertical gradients, when vertical head differences were below the 18-month average; however, at the Lyonia large wetland, extremely large lateral gradients toward the wetland during late June 2002 may have contributed to substantial gains in wetland water. During the remainder of the study, wetland water-level rises were associated mostly with decreasing vertical gradients and highly variable lateral gradients. Conversely, wetland water-level decreases were associated mostly with increasing vertical gradients and lateral gradients away from the wetland, particularly during the dry season. The potential for lateral ground-water exchange with the wetlands varied substantially more than that for vertical exchange. Potential for vertical losses of wetland water to ground water was highest during a dry period from December 2001 to June 2002, during the wet season of 2002, and for several months into the following dry season. Lateral he

Adsorption, sedimentation, and inactivation of E. coli within wastewater treatment wetlands.

PubMed

Boutilier, L; Jamieson, R; Gordon, R; Lake, C; Hart, W

2009-09-01

Bacteria fate and transport within constructed wetlands must be understood if engineered wetlands are to become a reliable form of wastewater treatment. This study investigated the relative importance of microbial treatment mechanisms in constructed wetlands treating both domestic and agricultural wastewater. Escherichia coli (E. coli) inactivation, adsorption, and settling rates were measured in the lab within two types of wastewater (dairy wastewater lagoon effluent and domestic septic tank effluent). In situ E. coli inactivation was also measured within a domestic wastewater treatment wetland and the adsorption of E. coli was also measured within the wetland effluent. Inactivation of E. coli appears to be the most significant contributor to E. coli removal within the wastewaters and wetland environments examined in this study. E. coli survived longer within the dairy wastewater (DW) compared to the domestic wastewater treatment wetland water (WW). First order rate constants for E. coli inactivation within the WW in the lab ranged from 0.09 day(-1) (d(-1)) at 7.6 degrees C to 0.18d(-1) at 22.8 degrees C. The average in situ rate constant observed within the domestic wetland ranged from 0.02 d(-1) to 0.03 d(-1) at an average water temperature of 17 degrees C. First order rate constants for E. coli inactivation within the DW ranged from 0.01 d(-1) at 7.7 degrees C to 0.04 d(-1) at 24.6 degrees C. Calculated distribution coefficients (K(d)) were 19,000 mL g(-1), 324,000 mL g(-1), and 293 mL g(-1) for E. coli with domestic septic tank effluent (STE), treated wetland effluent (WLE), and DW, respectively. Approximately 50%, 20%, and 90% of E. coli were "free floating" or associated with particles <5 microm in size within the STE, WLE, and DW respectively. Although 10-50% of E. coli were found to associate with particles >5 microm within both the STE and DW, settling did not appear to contribute to E. coli removal within sedimentation experiments, indicating that the particles the bacteria were associated with had very small settling velocities. The results of this study highlight the importance of wastewater characterization when designing a treatment wetland system for bacterial removal. This study illustrated the level of variability in E. coli removal processes that can be observed within different wastewater, and wetland environments.

Silica in invasive wetland plant species of lagoons, Côte d'Ivoire: Spatio-temporal patterns

NASA Astrophysics Data System (ADS)

José-mathieu Koné, Yéfanlan; Schoelynck, Jonas

2017-04-01

Tropical wetlands are known to accumulate a large quantity of Biogenic Silica (BSi) produced by wetland plant species (Struyf et al., 2015), and approximately 70-80% of the total supply of Dissolved Si (DSi) to the coastal zone occurs in (sub) tropical river systems (Jennerjahn et al. 2006). However, the data at these latitudes are limited. Here, we present the BSi concentration from eleven invasive macrophyte species randomly collected in three small ( 800ha) lagoons of Côte d'Ivoire during 12 months. Our data showed a large spatio-temporal variability of BSi in the three lagoons with no consistent trends. In general, the BSi concentrations obtained were high and values ranged from 0 to 54 mg g-1 through the entire sampling period, with the highest values found in Acroceras zizaniodes (emergent species of Poaceae). In general, free floating species had significantly less BSi than emergent species (P<0.0001) which corroborates with the earlier findings of Schoelynck and Struyf (2016). However, the concentrations of BSi found in Salvinia molesta (a free floating species of fern, Salviniaceae) at the young stage were similar to those found in the emergent species. Based on yearly averages, highest BSi values were observed in Kodjoboué lagoon, and the lowest in the Ono lagoon that is 80% covered by macrophytes. Moreover, the dissolved silica (DSi) concentrations were systematically higher in Ono Lagoon than in Kodjoboué Lagoon. We conclude that in an eutrophic system Si accumulating in aquatic macrophytes is not related to Si availability but to other environmental factors. Jennerjahn, T.C., Knoppers, B.A., de Souze, W.F.L., Brunskill, G.J., Silva, E.I.L., Adi, S. et al., 2006. Factors controlling dissolved silica in tropical rivers. In: Ittekot, V. (ed) The silicon cycle. Island Press, Washington, D. C, pp 29-51 Schoelynck J and Struyf E, 2016. Silicon in aquatic vegetation. Functional Ecology. 30: 1323-1330. Struyf, E., Mosimane, K., Van Pelt, D., Murray-Hudson, M., Meire, P., Frings, P., Wolski, P., Schaller, J., Gondwe, M.J., Schoelynck, J. and Conley, D.J., 2015. The role of vegetation in the Okavango Delta silica sink. Wetlands, 5: 171-181.

Quantifying home range habitat requirements for bobcats (Lynx rufus) in Vermont, USA

USGS Publications Warehouse

Donovan, Therese; Freeman, Mark; Abouelezz, Hanem; Royar, Kim; Howard, Alan D.; Mickey, R.

2011-01-01

We demonstrate how home range and habitat use analysis can inform landscape-scale conservation planning for the bobcat, Lynx rufus, in Vermont USA. From 2005 to 2008, we outfitted fourteen bobcats with GPS collars that collected spatially explicit locations from individuals every 4 h for 3–4 months. Kernel home range techniques were used to estimate home range size and boundaries, and to quantify the utilization distribution (UD), which is a spatially explicit, topographic mapping of how different areas within the home range are used. We then used GIS methods to quantify both biotic (e.g. habitat types, stream density) and abiotic (e.g. slope) resources within each bobcat’s home range. Across bobcats, upper 20th UD percentiles (core areas) had 18% less agriculture, 42% less development, 26% more bobcat habitat (shrub, deciduous, coniferous forest, and wetland cover types), and 33% lower road density than lower UD percentiles (UD valleys). For each bobcat, we used Akaike’s Information Criterion (AIC) to evaluate and compare 24 alternative Resource Utilization Functions (hypotheses) that could explain the topology of the individual’s UD. A model-averaged population-level Resource Utilization Function suggested positive responses to shrub, deciduous, coniferous forest, and wetland cover types within 1 km of a location, and negative responses to roads and mixed forest cover types within 1 km of a location. Applying this model-averaged function to each pixel in the study area revealed habitat suitability for bobcats across the entire study area, with suitability scores ranging between −1.69 and 1.44, where higher values were assumed to represent higher quality habitat. The southern Champlain Valley, which contained ample wetland and shrub habitat, was a concentrated area of highly suitable habitat, while areas at higher elevation areas were less suitable. Female bobcat home ranges, on average, had an average habitat suitability score of near 0, indicating that home ranges consisted of both beneficial and detrimental habitat types. We discuss the application of habitat suitability mapping and home range requirements for bobcat conservation and landscape scale management.

Quantifying home range habitat requirements for bobcats (Lynx rufus) in Vermont, USA

USGS Publications Warehouse

Donovan, T.M.; Freeman, M.; Abouelezz, H.; Royar, Kim; Howard, A.; Mickey, R.

2011-01-01

We demonstrate how home range and habitat use analysis can inform landscape-scale conservation planning for the bobcat, Lynx rufus, in Vermont USA. From 2005 to 2008, we outfitted fourteen bobcats with GPS collars that collected spatially explicit locations from individuals every 4. h for 3-4. months. Kernel home range techniques were used to estimate home range size and boundaries, and to quantify the utilization distribution (UD), which is a spatially explicit, topographic mapping of how different areas within the home range are used. We then used GIS methods to quantify both biotic (e.g. habitat types, stream density) and abiotic (e.g. slope) resources within each bobcat's home range. Across bobcats, upper 20th UD percentiles (core areas) had 18% less agriculture, 42% less development, 26% more bobcat habitat (shrub, deciduous, coniferous forest, and wetland cover types), and 33% lower road density than lower UD percentiles (UD valleys). For each bobcat, we used Akaike's Information Criterion (AIC) to evaluate and compare 24 alternative Resource Utilization Functions (hypotheses) that could explain the topology of the individual's UD. A model-averaged population-level Resource Utilization Function suggested positive responses to shrub, deciduous, coniferous forest, and wetland cover types within 1. km of a location, and negative responses to roads and mixed forest cover types within 1. km of a location. Applying this model-averaged function to each pixel in the study area revealed habitat suitability for bobcats across the entire study area, with suitability scores ranging between -1.69 and 1.44, where higher values were assumed to represent higher quality habitat. The southern Champlain Valley, which contained ample wetland and shrub habitat, was a concentrated area of highly suitable habitat, while areas at higher elevation areas were less suitable. Female bobcat home ranges, on average, had an average habitat suitability score of near 0, indicating that home ranges consisted of both beneficial and detrimental habitat types. We discuss the application of habitat suitability mapping and home range requirements for bobcat conservation and landscape scale management. ?? 2011.

Foreword: function, classification and management of Asian wetlands

USGS Publications Warehouse

Turnipseed, D. Phil; Middleton, Beth A.

2014-01-01

Asian wetland conservation is critical for future environmental protection in the region, but these wetlands are understudied. In particular, there is a lack of research studies published in English due to the limited access of Asian researchers to western scientific journals. This special feature of Wetlands showcases primary research conducted in Asian wetlands and was sponsored by various agencies of the U.S. and Chinese governments including the U.S. Geological Survey, U.S. Department of State, and The State Forestry Administration of the People’s Republic of China. The featured articles should be of great value to wetland scientists, managers and policy-makers with an interest in the conservation of Asian wetlands.

Structural and Functional Loss in Restored Wetland Ecosystems

PubMed Central

Moreno-Mateos, David; Power, Mary E.; Comín, Francisco A.; Yockteng, Roxana

2012-01-01

Wetlands are among the most productive and economically valuable ecosystems in the world. However, because of human activities, over half of the wetland ecosystems existing in North America, Europe, Australia, and China in the early 20th century have been lost. Ecological restoration to recover critical ecosystem services has been widely attempted, but the degree of actual recovery of ecosystem functioning and structure from these efforts remains uncertain. Our results from a meta-analysis of 621 wetland sites from throughout the world show that even a century after restoration efforts, biological structure (driven mostly by plant assemblages), and biogeochemical functioning (driven primarily by the storage of carbon in wetland soils), remained on average 26% and 23% lower, respectively, than in reference sites. Either recovery has been very slow, or postdisturbance systems have moved towards alternative states that differ from reference conditions. We also found significant effects of environmental settings on the rate and degree of recovery. Large wetland areas (>100 ha) and wetlands restored in warm (temperate and tropical) climates recovered more rapidly than smaller wetlands and wetlands restored in cold climates. Also, wetlands experiencing more (riverine and tidal) hydrologic exchange recovered more rapidly than depressional wetlands. Restoration performance is limited: current restoration practice fails to recover original levels of wetland ecosystem functions, even after many decades. If restoration as currently practiced is used to justify further degradation, global loss of wetland ecosystem function and structure will spread. PMID:22291572

Does human perception of wetland aesthetics and healthiness relate to ecological functioning?

PubMed

Cottet, Marylise; Piégay, Hervé; Bornette, Gudrun

2013-10-15

Wetland management usually aims at preserving or restoring desirable ecological characteristics or functions. It is now well-recognized that some social criteria should also be included. Involving lay-people in wetland preservation or restoration projects may mean broadening project objectives to fit various and potentially competing requirements that relate to ecology, aesthetics, recreation, etc. In addition, perceived value depends both upon expertise and objectives, both of which vary from one stakeholder population to another. Perceived value and ecological functioning have to be reconciled in order to make a project successful. Understanding the perceptions of lay-people as well as their opinions about ecological value is a critical part of the development of sustainable management plans. Characterizing the environment in a way that adequately describes ecological function while also being consistent with lay perception may help reach such objectives. This goal has been addressed in a case study relating to wetlands of the Ain River (France). A photo-questionnaire presenting a sample of photographs of riverine wetlands distributed along the Ain River was submitted to 403 lay-people and self-identified experts. Two objectives were defined: (1) to identify the different parameters, whether visual or ecological, influencing the perception regarding the value of these ecosystems; (2) to compare the perceptions of self-identified experts and lay-people. Four criteria appear to strongly influence peoples' perceptions of ecological and aesthetical values: water transparency and colour, the presence and appearance of aquatic vegetation, the presence of sediments, and finally, trophic status. In our study, we observed only a few differences in perception. The differences primarily related to the value assigned to oligotrophic wetlands but even here, the differences between lay and expert populations were minimal. These results support the idea that it is possible to implement an integrated and participative management program for ecosystems. Our approach can provide a shared view of environmental value facilitating the work of managers in defining comprehensive goals for wetland preservation or restoration projects. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ecological restoration and effect investigation of a river wetland in a semi-arid region, China

NASA Astrophysics Data System (ADS)

Xu, S.; Jiang, X.; Liu, Y.; Fu, Y.; Zhao, Q.

2015-05-01

River wetlands are heavily impacted by human intervention. The degradation and loss of river wetlands has made the restoration of river ecosystems a top priority. How to rehabilitate rivers and their services has been a research focus. The main goal of it is to restore the river wetland ecosystems with ecological methods. The Gudong River was selected as a study site in Chaoyang city in this study. Based on the analysis of interference factors in the river wetland degradation, a set of restoration techniques were proposed and designed for regional water level control, including submerged dikes, ecological embankments, revegetation and dredging. The restoration engineering has produced good results in water quality, eco-environment, and landscape. Monthly reports of the Daling River show that the water quality of Gudong River was better than Grade III in April 2013 compared with Grade V in May 2012. The economic benefit after restoration construction is 1.71 million RMB per year, about 1.89 times that before. The ratio of economic value, social value and eco-environmental value is 1:4:23.

[Research on the influence of urban land use structure and pattern on nitrogen, phosphorus of wetland water environment in Xianlin New Town of Nanjing].

PubMed

Cai, Chun-Xiao; Liu, Hong-Yu; Li, Yu-Feng; Wang, Cong; Hou, Ming-Hang

2014-08-01

The 10 typical wetlands in Xianlin New Townof Nanjing were classified into three categories, including rural wetland, suburban wetland, and urban wetland according to the influence of urbanization as well as the characteristics of wetland and LUCC of catchment regions. RDA was used to analyse the relationships between nitrogen and phosphorus in urban wetland and various types and patterns of land use. It was found that the water quality of the urban wetlands presented to be worse than that from rural wetlands, followed by sub urban wetlands. Secondly, according to all investigated wetlands, TP and TN turned out to be higher during the wet seasons than dry seasons. In addition, significant differences of TP were observed between wet and dry seasons for rural and suburban wetlands, and it was not so obvious for urban wetlands. However, the differences of TN was opposite to that of TP. Thirdly, factors affecting the water quality of wetlands were comprised of types and patterns of land use, and thus significant positive relationships were found between the concentrations of TN and TP and the impervious land, while negative correlations for meadows, woodlands and wetlands. What's more, higher remarkable differences were found in wetlands than those from meadows and woodlands. Regarding to patterns of land use, TP, TN concentrations were negatively correlated with the average patch shape in the dry and wet seasons, whereas positively relationships were observed for patch density and diversity index; furthermore, with refer to the impact of adjacent landscape, significant relationships were found between the content of TN and the patterns of land use and thus, a negative correlation in the wet season and a positive correlation in the dry season were observed, respectively.

Nitrogen source tracking with δ15N content of coastal wetland plants in Hawaii

Treesearch

Gregory L. Bruland; Richard A. Mackenzie

2010-01-01

Inter- and intra-site comparisons of the nitrogen (N) stable isotope composition of wetland plant species have been used to identify sources of N in coastal areas. In this study, we compared δ15N values from different herbaceous wetland plants across 34 different coastal wetlands from the five main Hawaiian Islands and investigated relationships of δ15N with...

Soil recovery across a chronosequence of restored wetlands in the Florida Everglades

NASA Astrophysics Data System (ADS)

Wang, Qibing; Li, Yuncong; Zhang, Min

2015-12-01

The restoration project in the Hole-in-the-Donut of Everglades National Park in Florida, USA is to reestablish native wetlands by complete removal of the invasive plants and the associated soil. However, there is little information available about changes in properties of the newly formed Marl soils in restored wetlands. In this study, we measured soil physicochemical properties, soil enzymatic activities, and stable isotopes of carbon (δ13C) in plants and soil organic carbon (SOC) in an undisturbed natural wetland (UNW) and three wetlands restored respectively in 1989, 1996 and 1999 (WR89, WR96 and WR99). The older restored wetlands (WR89 and WR96) are characterized by greater SOC and mineral nitrogen. The values of soil dehydrogenase and phosphatase activities in the four wetlands follow the order: UNW > WR89 > WR96 > WR99, and are consistent with changes in vegetation coverage. The principal component analysis shows that dehydrogenase and phosphatase activities are the vital variables contributing to the soil of UNW. The similar δ13C values of SOC and plants in the restored wetlands suggest the formation of SOC during restoration is mainly derived from the associated plants. These results indicate that the newly restored soils develop toward the soil in the UNW with time since restoration.

Soil recovery across a chronosequence of restored wetlands in the Florida Everglades.

PubMed

Wang, Qibing; Li, Yuncong; Zhang, Min

2015-12-01

The restoration project in the Hole-in-the-Donut of Everglades National Park in Florida, USA is to reestablish native wetlands by complete removal of the invasive plants and the associated soil. However, there is little information available about changes in properties of the newly formed Marl soils in restored wetlands. In this study, we measured soil physicochemical properties, soil enzymatic activities, and stable isotopes of carbon (δ(13)C) in plants and soil organic carbon (SOC) in an undisturbed natural wetland (UNW) and three wetlands restored respectively in 1989, 1996 and 1999 (WR89, WR96 and WR99). The older restored wetlands (WR89 and WR96) are characterized by greater SOC and mineral nitrogen. The values of soil dehydrogenase and phosphatase activities in the four wetlands follow the order: UNW > WR89 > WR96 > WR99, and are consistent with changes in vegetation coverage. The principal component analysis shows that dehydrogenase and phosphatase activities are the vital variables contributing to the soil of UNW. The similar δ(13)C values of SOC and plants in the restored wetlands suggest the formation of SOC during restoration is mainly derived from the associated plants. These results indicate that the newly restored soils develop toward the soil in the UNW with time since restoration.

Functional values of Great Lakes coastal wetlands: What we know and what we can be working towards

EPA Science Inventory

Water quality improvement, shoreline protection, carbon sequestration, and lake productivity subsidy are among the functional values commonly attributed to Great Lakes coastal wetlands (GLCWs). There is much less information concerning these than there is concerning habitat and f...

Diversity of wetland plants used traditionally in China: a literature review.

PubMed

Zhang, Yin; Xu, Hualin; Chen, Hui; Wang, Fei; Huai, Huyin

2014-10-15

In comparison with terrestrial plants, those growing in wetlands have been rarely studied ethnobotanically, including in China, yet people living in or near wetlands can accumulate much knowledge of the uses of local wetland plants. A characteristic of wetlands, cutting across climatic zones, is that many species are widely distributed, providing opportunities for studying general patterns of knowledge of the uses of plants across extensive areas, in the present case China. There is urgency in undertaking such studies, given the rapid rates of loss of traditional knowledge of wetland plants as is now occurring. There have been very few studies specifically on the traditional knowledge of wetland plants in China. However, much information on such knowledge does exist, but dispersed through a wide body of literature that is not specifically ethnobotanical, such as regional Floras. We have undertaken an extensive study of such literature to determine which species of wetland plants have been used traditionally and the main factors influencing patterns shown by such knowledge. Quantitative techniques have been used to evaluate the relative usefulness of different types of wetland plants and regression analyses to determine the extent to which different quantitative indices give similar results. 350 wetland plant species, belonging to 66 families and 187 genera, were found to have been used traditionally in China for a wide range of purposes. The top ten families used, in terms of numbers of species, were Poaceae, Polygonaceae, Cyperaceae, Lamiaceae, Asteraceae, Ranunculaceae, Hydrocharitaceae, Potamogetonaceae, Fabaceae, and Brassicaceae, in total accounting for 58.6% of all species used. These families often dominate wetland vegetation in China. The three most widely used genera were Polygonum, Potamogeton and Cyperus. The main uses of wetlands plants, in terms of numbers of species, were for medicine, food, and forage. Three different ways of assigning an importance value to species (Relative Frequency of Citation RFC; Cultural Importance CI; Cultural Value Index CV) all gave similar results. A diverse range of wetland plants, in terms of both taxonomic affiliation and type of use, have been used traditionally in China. Medicine, forage and food are the three most important categories of use, the plants providing basic resources used by local people in their everyday lives. Local availability is the main factor influencing which species are used. Quantitative indexes, especially Cultural Value Index, proved very useful for evaluating the usefulness of plants as recorded in the literature.

Cumulative effects of wetland drainage on watershed-scale subsurface hydrologic connectivity

NASA Astrophysics Data System (ADS)

Creed, I. F.; Ameli, A.

2017-12-01

Subsurface hydrologic connectivity influences hydrological, biogeochemical and ecological responses within watersheds. However, information about the location, duration, and frequency of subsurface hydrologic connections within wetlandscapes and between wetlandscapes and streams is often not available. This leads to a lack of understanding of the potential effects of human modifications of the landscape, including wetland degradation and removal, on subsurface hydrologic connectivity and therefore watershed responses. Herein, we develop a computationally efficient, physically-based subsurface hydrologic connectivity model that explicitly characterizes the effects of wetland degradation and removal on the distribution, length, and timing of subsurface hydrologic connectivity within a wetland-dominated watershed in the Prairie Pothole Region of North America. We run the model using a time series of wetland inventories that reflect incremental wetland loss from 1962, to 1993, and to 2009. We also consider a potential future wetland loss scenario based on removal of all wetlands outside of the protected areas of the watershed. Our findings suggest that wetland degradation and removal over this period increased the average length, transit time, and frequency of subsurface hydrologic connections to the regional surface waters, resulting in decreased baseflow in the major river network. This study provides important insights that can be used by wetland managers and policy makers to support watershed-scale wetland protection and restoration plans to improve water resource management.

St. Louis River fish migrations: Gains and losses of ecosystem ...

EPA Pesticide Factsheets

The Twin Ports fishery has undergone change from a migratory fish-based fishery to a Lake Superior-based fishery, and is now returning to a diverse fishery that includes fish of both life histories. These changes reflect past disturbances to the Great Lakes ecosystem as well as recent water quality improvement and efforts to restore habitat in the St. Louis River. Migratory fishes are an important ecosystem service for the St. Louis River, and improvements to the ecosystem quality within the St. Louis River Area of Concern has benefited migratory fishes. The coastal wetlands within the lower river provide direct support to a variety of high-value, recreationally-important fish species, including walleye, northern pike, and bass. Moreover, these wetlands serve as nursery habitat for a broader suite of high-value, commercially-important species. Restoration has likely improved the value of these coastal wetlands because low-value rough species tend to be more prevalent in degraded coastal wetlands, whereas high-value commercial and game fishes are more prevalent in high-quality coastal wetlands. There have been losses in ecosystem services, as well. Owing to legacy contamination of mercury and PCBs, migratory fishes in the St. Louis River have sufficiently high contaminant burdens to warrant consumption advisories, and recent movement research demonstrates that there is a positive relationship between increased use of St. Louis River habitat (versus Lake Superior)

[Effects of Three Gorges Reservoir impoundment on the wetland ecosystem service value of Dongting Lake, South-central China].

PubMed

Li, Jing-Bao; Dai, Yong; Yin, Ri-Xin; Yang, Yan; Li, Yu-dan; Wang, Ke-ying

2013-03-01

Based on the field investigation and measurement, and by using the monetary method, this paper estimated the wetland ecosystem service value of Dongting Lake before and after the impoundment of Three Gorges Reservoir (in 1996 and 2010, respectively). After the impoundment, the total ecosystem service value increased from 156.69x10(8) yuan in 1996 to 177.11x10(8) yuan in 2010. The main services value in 1996 was in the order of flood storage and regulation > water storage and supply > air regulation > scientific research and education, while that in 2010 was leisure tourism > shipping transportation > air regulation > water storage and supply. In the total service value of the wetland ecosystem, the direct value associated with water decreased from 110. 85x10(8) in 1996 to 27.47x10(8) in 2010, with a decrement of 75.2%. Though the proportion of the direct value in the production and supply of material products had somewhat increase, the indirect value in ecological environment regulation and maintenance and in culture and society still maintained at about 80% of the total value. In addition to climate factors, the impoundment of Three Gorges Reservoir and the reduction of water and sediment from Yangtze River to the Lake were the crucial reasons leading to the changes of the wetland ecosystem service value of Dongting Lake.

10 CFR 1022.13 - Floodplain or wetland assessment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... negative, direct and indirect, and long- and short-term effects of the proposed action on the floodplain... wetland values (§ 1022.4) appropriate to the location under evaluation. In addition, the effects of a..., the effects on the survival, quality, and function of the wetland shall be evaluated. (3) Alternatives...

LANDSCAPE ECOLOGY APPROACHES FOR DETECTING, MAPPING, AND ASSESSING THE VULNERABILITY OF DEPRESSIONAL WETLANDS

EPA Science Inventory

U.S. EPA is using a landscape ecology approach to assess the ecological/hydrologic functions and related human values of depressional wetlands along coastal Texas, considered to be vulnerable to human disturbance. Many of those wetlands may be at high risk because of recent court...

7 CFR 623.4 - Eligible land.

Code of Federal Regulations, 2011 CFR

2011-01-01

... restored on the land under a CRP contract, or under a Federal or State wetland restoration program with an... AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS RESERVE PROGRAM § 623.4 Eligible land. (a) Except as otherwise... condition and repairing related floodwater control systems; (3) Is likely to have its wetland value restored...

Ecological Risk Assessment of Metals Contamination in the Sediments of Natural Urban Wetlands in Dry Tropical Climate.

PubMed

Rana, Vivek; Maiti, Subodh Kumar; Jagadevan, Sheeja

2016-09-01

The pollution load due to metal contamination in the sediments of urban wetlands (Dhanbad, India) due to illegal release of domestic and industrial wastewater was studied by using various geochemical indices, such as contamination factor (Cf), degree of contamination (Cd), modified degree of contamination (mCd), pollution load index (PLI) and geoaccumulation index (Igeo) for Cu, Co, Cd, Cr and Mn. Cluster analysis (CA) and Principal component analysis (PCA) of metals present in wetland sediments were carried out to assess their origin and relationship with each other. The Cf values for different metals in the wetlands under investigation indicated low to very high level of pollution (Cf ranged between 0.02 and 14.15) with highest Cf (14.15) for Cd. The wetland receiving both domestic and industrial wastewater had the highest values of Cd, mCd and PLI as 17.48, 3.49 and 1.03 respectively.

A FRAMEWORK FOR THE ASSESSMENT OF WILDLIFE HABITAT VALUE OF NEW ENGLAND SALT MARSHES

EPA Science Inventory

Resource managers are frequently asked to make decisions that affect the protection and restoration of wetland habitats. The desire is often to base at least some part of this decision process on an assessment of wildlife habitat value, an acknowledged and important wetland func...

Remote Sensing and Wetland Ecology: a South African Case Study.

PubMed

De Roeck, Els R; Verhoest, Niko E C; Miya, Mtemi H; Lievens, Hans; Batelaan, Okke; Thomas, Abraham; Brendonck, Luc

2008-05-26

Remote sensing offers a cost efficient means for identifying and monitoring wetlands over a large area and at different moments in time. In this study, we aim at providing ecologically relevant information on characteristics of temporary and permanent isolated open water wetlands, obtained by standard techniques and relatively cheap imagery. The number, surface area, nearest distance, and dynamics of isolated temporary and permanent wetlands were determined for the Western Cape, South Africa. Open water bodies (wetlands) were mapped from seven Landsat images (acquired during 1987 - 2002) using supervised maximum likelihood classification. The number of wetlands fluctuated over time. Most wetlands were detected in the winter of 2000 and 2002, probably related to road constructions. Imagery acquired in summer contained fewer wetlands than in winter. Most wetlands identified from Landsat images were smaller than one hectare. The average distance to the nearest wetland was larger in summer. In comparison to temporary wetlands, fewer, but larger permanent wetlands were detected. In addition, classification of non-vegetated wetlands on an Envisat ASAR radar image (acquired in June 2005) was evaluated. The number of detected small wetlands was lower for radar imagery than optical imagery (acquired in June 2002), probably because of deterioration of the spatial information content due the extensive pre-processing requirements of the radar image. Both optical and radar classifications allow to assess wetland characteristics that potentially influence plant and animal metacommunity structure. Envisat imagery, however, was less suitable than Landsat imagery for the extraction of detailed ecological information, as only large wetlands can be detected. This study has indicated that ecologically relevant data can be generated for the larger wetlands through relatively cheap imagery and standard techniques, despite the relatively low resolution of Landsat and Envisat imagery. For the characterisation of very small wetlands, high spatial resolution optical or radar images are needed. This study exemplifies the benefits of integrating remote sensing and ecology and hence stimulates interdisciplinary research of isolated wetlands.

Environmental concerns and future oil and gas developments in Coastal Wetlands of Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

John, C.J.; Harder, B.J.; Groat, C.G.

1993-09-01

Recent studies have confirmed that much oil and natural gas have been overlooked and increases in future recoverable reserves will come from drilling in these areas. Increased production will result from identifying unexploited compartmentalized reservoirs, new infield reservoirs, and bypassed reservoirs, and by using enhanced recovery technologies for hydrocarbon recovery in incompletely drained reservoirs previously left unproduced for economic reasons. Most of southern Louisiana's hydrocarbon reserves underlie coastal wetland areas of the state. Major environmental concerns associated with the future development of existing reserves are canal dredging and destruction of wildlife habitat, use and disposal of oil-based muds, mitigation formore » wetland damage, and the recent emerging issue of surface contamination by naturally occurring radioactive materials with potential liabilities and future remedial regulation. To reduce wetland environmental damage caused by access canals to drilling sites, the Coastal Management Division of the Louisiana Department of Natural Resources instituted a geologic reviews program to review drilling permit application in the coastal wetlands. This process provides a mechanism for state and federal agencies to comment on the requested drilling permit. As a result of this process, the total average wetland disturbed area has been reduced from 767 ac per year in 1982 to approximately 76 ac per year in 1991. Average lengths of access canals also have been reduced by approximately 78% during the period. Oil and gas companies are becoming increasingly aware of the environmental consequences of drilling in wetlands and are considering them in planning for development activities. In the current climate of increasing public consciousness about the environment, addressing environmental concerns in the planning state will go a long way in helping alleviate future environmental problems.« less

Influence of environmental variables on the structure and composition of soil bacterial communities in natural and constructed wetlands.

PubMed

Arroyo, Paula; Sáenz de Miera, Luis E; Ansola, Gemma

2015-02-15

Bacteria are key players in wetland ecosystems, however many essential aspects regarding the ecology of wetland bacterial communities remain unknown. The present study characterizes soil bacterial communities from natural and constructed wetlands through the pyrosequencing of 16S rDNA genes in order to evaluate the influence of wetland variables on bacterial community composition and structure. The results show that the composition of soil bacterial communities was significantly associated with the wetland type (natural or constructed wetland), the type of environment (lagoon, Typha or Salix) and three continuous parameters (SOM, COD and TKN). However, no clear associations were observed with soil pH. Bacterial diversity values were significantly lower in the constructed wetland with the highest inlet nutrient concentrations. The abundances of particular metabolic groups were also related to wetland characteristics. Copyright © 2014 Elsevier B.V. All rights reserved.

Improved wetland remote sensing in Yellowstone National Park using classification trees to combine TM imagery and ancillary environmental data

USGS Publications Warehouse

Wright, C.; Gallant, Alisa L.

2007-01-01

The U.S. Fish and Wildlife Service uses the term palustrine wetland to describe vegetated wetlands traditionally identified as marsh, bog, fen, swamp, or wet meadow. Landsat TM imagery was combined with image texture and ancillary environmental data to model probabilities of palustrine wetland occurrence in Yellowstone National Park using classification trees. Model training and test locations were identified from National Wetlands Inventory maps, and classification trees were built for seven years spanning a range of annual precipitation. At a coarse level, palustrine wetland was separated from upland. At a finer level, five palustrine wetland types were discriminated: aquatic bed (PAB), emergent (PEM), forested (PFO), scrub–shrub (PSS), and unconsolidated shore (PUS). TM-derived variables alone were relatively accurate at separating wetland from upland, but model error rates dropped incrementally as image texture, DEM-derived terrain variables, and other ancillary GIS layers were added. For classification trees making use of all available predictors, average overall test error rates were 7.8% for palustrine wetland/upland models and 17.0% for palustrine wetland type models, with consistent accuracies across years. However, models were prone to wetland over-prediction. While the predominant PEM class was classified with omission and commission error rates less than 14%, we had difficulty identifying the PAB and PSS classes. Ancillary vegetation information greatly improved PSS classification and moderately improved PFO discrimination. Association with geothermal areas distinguished PUS wetlands. Wetland over-prediction was exacerbated by class imbalance in likely combination with spatial and spectral limitations of the TM sensor. Wetland probability surfaces may be more informative than hard classification, and appear to respond to climate-driven wetland variability. The developed method is portable, relatively easy to implement, and should be applicable in other settings and over larger extents.

Louisiana wetland water level monitoring using retracked TOPEX/POSEIDON altimetry

USGS Publications Warehouse

Lee, H.; Shum, C.K.; Yi, Y.; Ibaraki, M.; Kim, J.-W.; Braun, Andreas; Kuo, C.-Y.; Lu, Z.

2009-01-01

Previous studies using satellite radar altimetry to observe inland river and wetland water level changes usually spatially average high-rate (10-Hz for TOPEX, 18-Hz for Envisat) measurements. Here we develop a technique to apply retracking of TOPEX waveforms by optimizing the estimated retracked gate positions using the Offset Center of Gravity retracker. This study, for the first time, utilizes stacking of retracked TOPEX data over Louisiana wetland and concludes that the water level observed by each of 10-Hz data with along-track sampling of ∼660 m exhibit variations, indicating detection of wetland dynamics. After further validations using nearby river gauges, we conclude that TOPEX is capable of measuring accurate water level changes beneath heavy-vegetation canopy region (swamp forest), and that it revealed wetland dynamic flow characteristics along track with spatial scale of 660 m or longer.

Defining restoration targets for water depth and salinity in wind-dominated Spartina patens (Ait.) Muhl. coastal marshes

USGS Publications Warehouse

Nyman, J.A.; LaPeyre, Megan K.; Caldwell, Andral W.; Piazza, Sarai C.; Thom, C.; Winslow, C.

2009-01-01

Coastal wetlands provide valued ecosystem functions but the sustainability of those functions often is threatened by artificial hydrologic conditions. It is widely recognized that increased flooding and salinity can stress emergent plants, but there are few measurements to guide restoration, management, and mitigation. Marsh flooding can be estimated over large areas with few data where winds have little effect on water levels, but quantifying flooding requires hourly measurements over long time periods where tides are wind-dominated such as the northern Gulf of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly observations of water depth and 521,561 hourly observations of water salinity from 14 sites in Louisiana coastal marshes dominated by Spartina patens (Ait.) Muhl. Unlike predicted water levels, observed water levels varied monthly and annually. We attributed those observed variations to variations in river runoff and winds. In stable marshes with slow wetland loss rates, we found that marsh elevation averaged 1 cm above mean high water, 15 cm above mean water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt during April, May, and June, and 5.4 ppt during July, August, and September. The daily, seasonal, and annual variation in water levels and salinity that were evident would support the contention that such variation be retained when designing and operating coastal wetland management and restoration projects. Our findings might be of interest to scientists, engineers, and managers involved in restoration, management, and restoration in other regions where S. patens or similar species are common but local data are unavailable.

Defining restoration targets for water depth and salinity in wind-dominated Spartina patens (Ait.) Muhl. coastal marshes

USGS Publications Warehouse

Nyman, J.A.; La Peyre, M.K.; Caldwell, A.; Piazza, S.; Thom, C.; Winslow, C.

2009-01-01

Coastal wetlands provide valued ecosystem functions but the sustainability of those functions often is threatened by artificial hydrologic conditions. It is widely recognized that increased flooding and salinity can stress emergent plants, but there are few measurements to guide restoration, management, and mitigation. Marsh flooding can be estimated over large areas with few data where winds have little effect on water levels, but quantifying flooding requires hourly measurements over long time periods where tides are wind-dominated such as the northern Gulf of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly observations of water depth and 521,561 hourly observations of water salinity from 14 sites in Louisiana coastal marshes dominated by Spartina patens (Ait.) Muhl. Unlike predicted water levels, observed water levels varied monthly and annually. We attributed those observed variations to variations in river runoff and winds. In stable marshes with slow wetland loss rates, we found that marsh elevation averaged 1 cm above mean high water, 15 cm above mean water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt during April, May, and June, and 5.4 ppt during July, August, and September. The daily, seasonal, and annual variation in water levels and salinity that were evident would support the contention that such variation be retained when designing and operating coastal wetland management and restoration projects. Our findings might be of interest to scientists, engineers, and managers involved in restoration, management, and restoration in other regions where S. patens or similar species are common but local data are unavailable. ?? 2009 Elsevier B.V.

Annotated Bibliography: Value of Environmental Protection and Restoration

DTIC Science & Technology

1993-02-01

approach. Ecological Economics, 3, 1-24. Key Words: wetlands, ecotechnology A simulation model is developed to predict the efficiency and economics of an...application of ecotechnology using a created wetland to receive and treat coal mine drainage. The model examines the role of loading rates of iron on...shows that the use of ecotechnology such as wetland trt- "’nt systems can provide low-cost solutions to some expensive pollution problems. Wetland

An Assessment of Long-Term Compliance with Performance Standards in Compensatory Mitigation Wetlands.

PubMed

Van den Bosch, Kyle; Matthews, Jeffrey W

2017-04-01

Under the US Clean Water Act, wetland restoration is used to compensate for adverse impacts to wetlands. Following construction, compensation wetlands are monitored for approximately 5 years to determine if they comply with project-specific performance standards. Once a compensation site complies with performance standards, it is assumed that the site will continue to meet standards indefinitely. However, there have been few assessments of long-term compliance. We surveyed, in 2012, 30 compensation sites 8-20 years after restoration to determine whether projects continued to meet performance standards. Additionally, we compared floristic quality of compensation sites to the quality of adjacent natural wetlands to determine whether wetland condition in compensation sites could be predicted based on the condition of nearby wetlands. Compensation sites met, on average, 65% of standards during the final year of monitoring and 53% of standards in 2012, a significant decrease in compliance. Although forested wetlands often failed to meet standards for planted tree survival, the temporal decrease in compliance was driven by increasing dominance by invasive plants in emergent wetlands. The presumption of continued compliance with performance standards after a 5-year monitoring period was not supported. Wetlands restored near better quality natural wetlands achieved and maintained greater floristic quality, suggesting that landscape context was an important determinant of long-term restoration outcomes. Based on our findings, we recommend that compensation wetlands should be monitored for longer time periods, and we suggest that nearby or adjacent natural wetlands provide good examples of reasonably achievable restoration outcomes in a particular landscape.

Temperature and hydrology affect methane emissions from Prairie Pothole Wetlands

USGS Publications Warehouse

Bansal, Sheel; Tangen, Brian; Finocchiaro, Raymond

2016-01-01

The Prairie Pothole Region (PPR) in central North America consists of millions of depressional wetlands that each have considerable potential to emit methane (CH4). Changes in temperature and hydrology in the PPR from climate change may affect methane fluxes from these wetlands. To assess the potential effects of changes in climate on methane emissions, we examined the relationships between flux rates and temperature or water depth using six years of bi-weekly flux measurements during the snow-free period from six temporarily ponded and six permanently ponded wetlands in North Dakota, USA. Methane flux rates were among the highest reported for freshwater wetlands, and had considerable spatial and temporal variation. Methane flux rates increased with increasing temperature and water depth, and were especially high when conditions were warmer and wetter than average (163 ± 28 mg CH4 m−2 h−1) compared to warmer and drier (37 ± 7 mg CH4 m−2 h−1). Methane emission rates from permanent wetlands were less sensitive to changes in temperature and water depth compared to temporary wetlands, likely due to higher sulfate concentrations in permanent wetlands. While the predicted increase in temperature with climate change will likely increase methane emission rates from PPR wetlands, drier conditions could moderate these increases.

Long-term effects of wetland harvesting practices on productivity and carbon pools

Treesearch

Scott McKee; Mike Aust; John Seiler; Brian Strahm

2012-01-01

Forested wetlands are valued for social and ecological benefits including filtering sediments, uptake of nutrients, carbon storage, reduction of flood depths, protection of shorelines and streambanks, and provision of terrestrial and aquatic wildlife habitat (Walbridge 1993, Kellison and Young 1997, Brady and Weil 2002). Although the importance of wetland functions are...

Tracing Nitrogen through Landscapes to Coastal Wetlands using d15N of Larval Fish

EPA Science Inventory

Our objective was to evaluate the use of the nitrogen stable isotope value (d15N) of larval fish as an indicator of incipient anthropogenic nitrogen loading to coastal wetlands in the Great Lakes. We sampled coastal wetlands in five Lake Superior south shore tributaries that had ...

Global carbon sequestration in tidal, saline wetland soils

USGS Publications Warehouse

Chmura, G.L.; Anisfeld, S.C.; Cahoon, D.R.; Lynch, J.C.

2003-01-01

Wetlands represent the largest component of the terrestrial biological carbon pool and thus play an important role in global carbon cycles. Most global carbon budgets, however, have focused on dry land ecosystems that extend over large areas and have not accounted for the many small, scattered carbon-storing ecosystems such as tidal saline wetlands. We compiled data for 154 sites in mangroves and salt marshes from the western and eastern Atlantic and Pacific coasts, as well as the Indian Ocean, Mediterranean Ocean, and Gulf of Mexico. The set of sites spans a latitudinal range from 22.4??S in the Indian Ocean to 55.5??N in the northeastern Atlantic. The average soil carbon density of mangrove swamps (0.055 ?? 0.004 g cm-3) is significantly higher than the salt marsh average (0.039 ?? 0.003 g cm-3). Soil carbon density in mangrove swamps and Spartina patens marshes declines with increasing average annual temperature, probably due to increased decay rates at higher temperatures. In contrast, carbon sequestration rates were not significantly different between mangrove swamps and salt marshes. Variability in sediment accumulation rates within marshes is a major control of carbon sequestration rates masking any relationship with climatic parameters. Globally, these combined wetlands store at least 44.6 Tg C yr-1 and probably more, as detailed areal inventories are not available for salt marshes in China and South America. Much attention has been given to the role of freshwater wetlands, particularly northern peatlands, as carbon sinks. In contrast to peatlands, salt marshes and mangroves release negligible amounts of greenhouse gases and store more carbon per unit area. Copyright 2003 by the American Geophysical Union.

Effects of a constructed wetland and pond system upon shallow groundwater quality

Treesearch

Ying Ouyang

2013-01-01

Constructed wetland (CW) and constructed pond (CP) are commonly utilized for removal of excess nutrients and certain pollutants from stormwater. This study characterized shallow groundwater quality for pre- and post-CW and CP system conditions using data from monitoring wells. Results showed that the average concentrations of groundwater phosphorus (P) decreased from...

Carbon Storage in US Wetlands. | Science Inventory | US EPA

EPA Pesticide Factsheets

Background/Question/Methods Wetland soils contain some of the highest stores of soil carbon in the biosphere. However, there is little understanding of the quantity and distribution of carbon stored in US wetlands or of the potential effects of human disturbance on these stocks. We provide unbiased estimates of soil carbon stocks for wetlands at regional and national scales and describe how soil carbon stocks vary by anthropogenic disturbance to the wetland. To estimate the quantity and distribution of carbon stocks in wetlands of the conterminous US, we used data gathered in the field as part of the 2011 National Wetland Condition Assessment (NWCA) conducted by USEPA. During the growing season, field crews collected soil samples by horizon from 120-cm deep soil pits at 967 randomly selected wetland sites. Soil samples were analyzed for bulk density and organic carbon. We applied site carbon stock averages by soil depth back to the national population of wetlands and to several subpopulations, including five geographic areas and anthropogenic disturbance level. Disturbance levels were categorized by the NWCA as least, intermediately, or most disturbed using a priori defined physical, chemical, and biological indicators that were observable at the time of the site visit.Results/Conclusions We find that wetlands in the conterminous US store a total of 11.52 PgC – roughly equivalent to four years of annual carbon emissions by the US, with the greatest soil ca

Approaches to the conservation of coastal wetlands in the Western Hemisphere

USGS Publications Warehouse

Bildstein, K.L.; Bancroft, G.T.; Dugan, P.J.; Gordon, D.H.; Erwin, R.M.; Nol, E.; Payne, L.X.; Senner, Stanley E.

1991-01-01

Coastal wetlands rank among the most productive and ecologically valuable natural ecosystems on Earth. Unfortunately, they are also some of the most disturbed. Because they are productive and can serve as transportation arteries, coastal wetlands have long attracted human settlement. More than half of the U.S. population currently lives within 80 km of its coasts, and one estimate places 70% of all humanity in the coastal zone. Human impacts to coastal wetlands include physical alteration of hydrological processes; the introduction of toxic materials, nutrients, heat, and exotic species; and the unsustainable harvest of native species. Between 1950 and 1970, coastal wetland losses in the U.S. averaged 8 100 ha/year. In Central and South America, development pressures along the coastal zone rank among the most serious natural resource problems in the region..... Here, we (1) briefly describe coastal wetland avifauna, (2) discuss the threat of global warming on coastal wetlands, (3) use several Western Hemisphere wetlands as site-specific examples of development pressures facing these habitats, and (4) provide synopses of nongovernmental and governmental approaches to wetland conservation. Overall, we provide a socio-economic context for conservation of coastal wetlands in the Western Hemisphere. We suggest that efforts aimed at conserving sites of particular importance for their biological diversity should be pursued within a framework of wise use that addresses the broader issues of human population growth and economic development.

[Connotation characterization and evaluation of ecological well-being based on ecosystem service theory.

PubMed

Zang, Zheng; Zou, Xin- Qing

2016-04-22

China is advocating ecological civilization construction nowadays. Further researches on the relation between ecosystem service and humanity well-being are full of theoretical and practical significance. Combining related researches, this paper defined the concept and connotation of ecological well-being based on ecosystem service theory. Referencing theory of national economic accounting and relative researches, the evaluation indicators of ecological well-being supply and consumption were established. The quantitative characterization and evaluation method of red line of regional ecological well-being was proposed on the basis of location quotient. Then the evaluation of ecological well-being in mainland China in 2012 was set as an example for empirical research. The results showed that the net product values of 6 ecosystems, includingcultivated land, forest land, grassland, wetland, water area and unused land, were respectively 1481.925, 8194.806, 4176.277, 4245.760, 3177.084 and 133.762 billion CNY. Spatial heterogeneity of ecosystem net product in different provinces was distinct. Ecological well-being per capita of forest land, grassland, wetland, cultivated land and unused land in eastern and middle provinces were under the red line and less than the national average. The spatial distribution of 9 kinds of ecological well-being per capita split at Hu's line with high value in northwest and low value in southeast, and was aggravated by differences in density of population and land resources gift.

Select state inland wetland protection laws. A review of the state laws and their natural resource data requirements

NASA Technical Reports Server (NTRS)

Klein, S. B.

1980-01-01

Although many states afford some measure of protection for wetland areas through flood-plain regulations or through programs for coastal areas, shorelands, scenic and wild rivers or pollution control, few states have programs that adequately deal with conservation of wetlands. Only 16 states have legislation specifically regulating development or use of wetlands. Most of the wetland acts apply only to coastal wetlands, several to inland wetlands and three acts apply to both. Many other states are still regulating wetland use through the dredge and fill and/or critical area program. Several offer tax incentives to property owners to encourage protection of wetlands or broader open spaces. Many states have acquired wetlands for park and wildlife purposes and a large measure of wetland protection is achieved by the very restrictive controls applied to floodways areas. Direct floodplain or floodway regulations or state standards for local regulations were adopted in 24 states but protection of ecological values of wetlands is rarely an explicit objective of these programs. Scenic and wild river programs adopted in one half of the states provide some protection for wetland areas.

Uranium fate in wetland mesocosms: Effects of plants at two iron loadings with different pH values

EPA Science Inventory

Small-scale continuous flow wetland mesocosms (~0.8 L) were used to evaluate how plant roots under different iron loadings affect uranium (U) mobility. When significant concentrations of ferrous iron (Fe) were present at circumneutral pH values, U concentrations in root exposed ...

Nesting and foraging behavior of red-winged blackbirds in stormwater wetlands

USGS Publications Warehouse

Sparling, D.W.; Eisemann, J.; Kuenzel, W.

2007-01-01

Stormwater wetlands are a common part of urban and suburban landscapes. These constructed wetlands provide first-order treatment of effluent from roads, parking lots, lawns and other surfaces. They also provide habitat for wetland-associated birds. Thus, there is a concern that birds may be attracted to potentially toxic habitats. This study assesses nesting success and forging behavior of Red-winged Blackbirds (Agelaius phoeniceus) in retention stormwater wetlands based on drainage type. Drainage categories included residential, commercial, and highway sites. Commercial sites had the lowest nesting success and the lowest diversity of invertebrate foods. Mean nest success values for all three types of wetlands, especially for highway drainages, were comparable to published values from natural wetlands. Over two years of study highway ponds collectively served as source populations whereas residential and commercial sites were population sinks in one year and sources in the other. Red-wings using highway sites had the highest foraging efficiency as determined by the frequency and duration of forays. Residential sites had the greatest human disturbance and generally had intermediate-quality habitat and nesting success. We conclude that while stormwater wetlands collect run off and accompanying pollutants, they can still be valuable habitats for nesting birds in urban and suburban areas. We recommend a few management strategies that can increase avian use of these habitats. ?? Springer Science+Business Media, LLC 2007.

Valuing the Recreational Benefits of Wetland Adaptation to Climate Change: A Trade-off Between Species' Abundance and Diversity

NASA Astrophysics Data System (ADS)

Faccioli, Michela; Riera Font, Antoni; Torres Figuerola, Catalina M.

2015-03-01

Climate change will further exacerbate wetland deterioration, especially in the Mediterranean region. On the one side, it will accelerate the decline in the populations and species of plants and animals, this resulting in an impoverishment of biological abundance. On the other one, it will also promote biotic homogenization, resulting in a loss of species' diversity. In this context, different climate change adaptation policies can be designed: those oriented to recovering species' abundance and those aimed at restoring species' diversity. Based on the awareness that knowledge about visitors' preferences is crucial to better inform policy makers and secure wetlands' public use and conservation, this paper assesses the recreational benefits of different adaptation options through a choice experiment study carried out in S'Albufera wetland (Mallorca). Results show that visitors display positive preferences for an increase in both species' abundance and diversity, although they assign a higher value to the latter, thus suggesting a higher social acceptability of policies pursuing wetlands' differentiation. This finding acquires special relevance not only for adaptation management in wetlands but also for tourism planning, as most visitors to S'Albufera are tourists. Thus, given the growing competition to attract visitors and the increasing demand for high environmental quality and unique experiences, promoting wetlands' differentiation could be a good strategy to gain competitive advantage over other wetland areas and tourism destinations.

Contribution of recent hurricanes to wetland sedimentation in coastal Louisiana

NASA Astrophysics Data System (ADS)

Liu, Kam-biu; Bianchette, Thomas; Zou, Lei; Qiang, Yi; Lam, Nina

2017-04-01

Hurricanes are important agents of sediment deposition in the wetlands of coastal Louisiana. Since Hurricanes Katrina and Rita of 2005, coastal Louisiana has been impacted by Hurricanes Gustav (2008), Ike (2008), and Isaac (2012). By employing the principles and methods of paleotempestology we have identified the storm deposits attributed to the three most recent hurricanes in several coastal lakes and swamps in Louisiana. However, the spatial distribution and volume of these storm depositions cannot be easily inferred from stratigraphic data derived from a few locations. Here we report on results from a GIS study to analyze the spatial and temporal patterns of storm deposition based on data extracted from the voluminous CRMS (Coastal Reference Monitoring System) database, which contains vertical accretion rate measurements obtained from 390 wetland sites over various time intervals during the past decade. Wetland accretion rates averaged about 2.89 cm/yr from stations sampled before Hurricane Isaac, 4.04 cm/yr during the 7-month period encompassing Isaac, and 2.38 cm/yr from sites established and sampled after Isaac. Generally, the wetland accretion rates attributable to the Isaac effects were 40% and 70% greater than before and after the event, respectively. Accretion rates associated with Isaac were highest at wetland sites along the Mississippi River and its tributaries instead of along the path of the hurricane, suggesting that freshwater flooding from fluvial channels, enhanced by the storm surge from the sea, is the main mechanism responsible for increased accretion in the wetlands. Our GIS work has recently been expanded to include other recent hurricanes. Preliminary results indicate that, for non-storm periods, the average wetland accretion rates between Katrina/Rita and Gustav/Ike was 2.58 cm/yr; that between Gustav/Ike and Isaac was 1.95 cm/yr; and that after Isaac was 2.37 cm/yr. In contrast, the accretion rates attributable to the effects of Gustav/Ike and Isaac were 4.41 cm/yr and 3.52 cm/yr, respectively. These results show that hurricane-related accretion rates in wetlands are 50 - 225% higher than the normal rates typical of non-storm periods.

Placing prairie pothole wetlands along spatial and temporal continua to improve integration of wetland function in ecological investigations

USGS Publications Warehouse

Euliss, Ned H.; Mushet, David M.; Newton, Wesley E.; Otto, Clint R.V.; Nelson, Richard D.; LaBaugh, James W.; Scherff, Eric J.; Rosenberry, Donald O.

2014-01-01

We evaluated the efficacy of using chemical characteristics to rank wetland relation to surface and groundwater along a hydrologic continuum ranging from groundwater recharge to groundwater discharge. We used 27 years (1974–2002) of water chemistry data from 15 prairie pothole wetlands and known hydrologic connections of these wetlands to groundwater to evaluate spatial and temporal patterns in chemical characteristics that correspond to the unique ecosystem functions each wetland performed. Due to the mineral content and the low permeability rate of glacial till and soils, salinity of wetland waters increased along a continuum of wetland relation to groundwater recharge, flow-through or discharge. Mean inter-annual specific conductance (a proxy for salinity) increased along this continuum from wetlands that recharge groundwater being fresh to wetlands that receive groundwater discharge being the most saline, and wetlands that both recharge and discharge to groundwater (i.e., groundwater flow-through wetlands) being of intermediate salinity. The primary axis from a principal component analysis revealed that specific conductance (and major ions affecting conductance) explained 71% of the variation in wetland chemistry over the 27 years of this investigation. We found that long-term averages from this axis were useful to identify a wetland’s long-term relation to surface and groundwater. Yearly or seasonal measurements of specific conductance can be less definitive because of highly dynamic inter- and intra-annual climate cycles that affect water volumes and the interaction of groundwater and geologic materials, and thereby influence the chemical composition of wetland waters. The influence of wetland relation to surface and groundwater on water chemistry has application in many scientific disciplines and is especially needed to improve ecological understanding in wetland investigations. We suggest ways that monitoring in situ wetland conditions could be linked with evolving remote sensing technology to improve our ability to better inform decisions affecting wetland sustainability and provide periodic inventories of wetland ecosystem services to document temporal trends in wetland function and how they respond to contemporary land-use change.

Potential effects of restoration on biogeochemical functions of bottom land hardwood ecosystems

Treesearch

Graeme Lockaby; John A. Stanturf

2000-01-01

The concept of wetland restoration carries multiple meanings and implications. The scientific usage of the term connotes re-establishment of wetland functions, and often it is the functions, which society deems most valuable, that receive highest focus. Arguably, among key wetland functions, the highest societal value may be linked with the biogeochemical...

Erosion and restoration of two headwater wetlands following an extreme wildfire

Treesearch

Jonathan Long; Javis Davis

2016-01-01

Wildfire can damage headwater wetlands, yet the value of post-fire restoration treatments in channels has been contested. Staff from the White Mountain Apache Tribe, students from the local Cibecue Community School, and researchers from the U.S. Forest Service collaboratively recorded channel responses over 13 years at two headwater wetlands lying within watersheds...

Dietary use and conservation concern of edible wetland plants at Indo-Burma hotspot: a case study from Northeast India.

PubMed

Jain, A; Sundriyal, M; Roshnibala, S; Kotoky, R; Kanjilal, P B; Singh, H B; Sundriyal, R C

2011-10-04

The wetlands of the North East India fall among the global hotspots of biodiversity. However, they have received very little attention with relation to their intrinsic values to human kind; therefore their conservation is hardly addressed. These wetlands are critical for the sustenance of the tribal communities. Field research was conducted during 2003 to 2006 in seven major wetlands of four districts of Manipur state, Northeast India (viz. Imphal-East, Imphal-West, Thoubal, and Bishnupur). A total of 224 wetland-plant-collectors were interviewed for the use and economics of species using semi-structured questionnaires and interview schedules. Imphal, Bishenpur and Thoubal markets were investigated in detail for influx and consumption pattern of these plants. The collectors were also inquired for medicinal use of wetland species. Nutritive values of 21 species were analyzed in laboratory. The vouchers were collected for all the species and deposited in the CSIR-NEIST (Formerly Regional Research Laboratory), Substation, Lamphelpat, Imphal, Manipur, India. We recorded 51 edible wetland species used by indigenous people for food and medicinal purposes. Thirty eight species had high medicinal values and used in the traditional system to treat over 22 diseases. At least 27 species were traded in three markets studied (i.e. Imphal, Thoubal and Bishenpur), involving an annual turnover of 113 tons of wetland edible plants and a gross revenue of Rs. 907, 770/- (US$1 = Rs. 45/-). The Imphal market alone supplies 60% of the total business. Eighty per cent of the above mentioned species are very often used by the community. The community has a general opinion that the availability of 45% species has depleted in recent times, 15 species need consideration for conservation while another 7 species deserved immediate protection measures. The nutrient analysis showed that these species contribute to the dietary balance of tribal communities. Considering the importance of wild wetland plants in local sustenance, it is suggested to protect their habitats, develop domestication protocols of selected species, and build programs for the long-term management of wetland areas by involving local people. Some medicinal plants may also be used to develop into modern medicines.

Environmental Assessment: Construction of Consolidated Fuel Overhaul and Repair Facility at Tinker Air Force Base, Oklahoma

DTIC Science & Technology

2007-10-01

ofbuildings owned, leased, privatized, or otherwise occupied, managed, or controlled by or for the DoD. A 0.83 acre wetland currently exists at the...require displacement of this existing wetland . Therefore, as part of the proposed action, a , wetland habitat of equal or greater value would be...Buildings. However, the new building and parking lot would completely displace the existing wetland on the north side of the site. (EA Section 2.2, Page

Environmental Assessment: Construction of Consolidated Fuel Overhaul and Repair Facility at Tinker Air Force Base, Oklahoma

DTIC Science & Technology

2007-10-01

buildings owned, leased, privatized, or otherwise occupied, managed, or controlled by or for the DoD. A 0.83 acre wetland currently exists at the...would require displacement of this existing wetland . Therefore, as part of the proposed action, a wetland habitat of equal or greater value would be...Buildings. However, the new building and parking lot would completely displace the existing wetland on the north side of the site. (EA Section 2.2, Page

The importance of hydrology in restoration of bottomland hardwood wetland functions

USGS Publications Warehouse

Hunter, R.G.; Faulkner, S.P.; Gibson, K.A.

2008-01-01

Bottomland hardwood (BLH) forests have important biogeochemical functions and it is well known that certain structural components, including pulsed hydrology, hydric soils, and hydrophytic vegetation, enhance these functions. It is unclear, however, how functions of restored BLH wetlands compare to mature, undisturbed wetlands. We measured a suite of structural and functional attributes in replicated natural BLH wetlands (NAT), restored BLH wetlands with hydrology re-established (RWH), and restored BLH wetlands without hydrology re-established (RWOH) in this study. Trees were replanted in all restored wetlands at least four years prior to the study and those wetlands with hydrology re-established had flashboard risers placed in drainage ditches to allow seasonal surface flooding. Vegetation, soils, and selected biogeochemical functions were characterized at each site. There was a marked difference in woody vegetation among the wetlands that was due primarily to site age. There was also a difference in herbaceous vegetation among the restored sites that may have been related to differences in age or hydrology. Water table fluctuations of the RWH wetlands were comparable to those of the NAT wetlands. Thus, placing flashboard risers in existing drainage ditches, along with proper management, can produce a hydroperiod that is similar to that of a relatively undisturbed BLH. Average length of saturation within the upper 15 cm of soils was 37, 104, and 97 days for RWOH, RWH, and NAT, respectively. Soil moisture, denitrification potential, and soluble organic carbon concentrations differed among wetland sites, but soil carbon and nitrogen concentrations, heterotrophic microbial activity, and readily mineralizable carbon concentrations did not. Significant linear relationships were also found between soil moisture and heterotrophic microbial activity, readily mineralizable carbon, and soluble organic carbon. In addition, sedimentation rates were higher in NAT and RWH wetlands than in RWOH sites. Results of this study suggest that reconnection of bottomland hardwood wetlands to their surrounding watershed through the restoration of surface hydrology is necessary to restore wetland functions important to nutrient and sediment removal. ?? 2008 The Society of Wetland Scientists.

Evapotranspiration from drained wetlands: drivers, modeling, storage functions, and restoration implications

NASA Astrophysics Data System (ADS)

Shukla, S.; Wu, C. L.; Shrestha, N.

2017-12-01

Abstract Evapotranspiration (ET) is a major component of wetland and watershed water budgets. The effect of wetland drainage on ET is not well understood. We tested whether the current understanding of insignificant effect of drainage on ET in the temperate region wetlands applies to those in the sub-tropics. Eddy covariance (EC) based ET measurements were made for two years at two previously drained and geographically close wetlands in the Everglades region of Florida. One wetland was significantly drained with 97% of its storage capacity lost. The other was a more functional wetland with 42% of storage capacity lost. Annual average ET at the significantly drained wetland was 836 mm, 34% less than the function wetland (1271 mm) and the difference was statistically significant (p = 0.001). Such differences in wetland ET in the same climatic region have not been observed. The difference in ET was mainly due to drainage driven differences in inundation and associated effects on net radiation (Rn) and local relative humidity. Two daily ET models, a regression (r2 = 0.80) and a Relevance Vector Machine (RVM) model (r2 = 0.84), were developed with the latter being more robust. These models, when used in conjunction with hydrologic models, improved ET predictions for drained wetlands. Predictions from an integrated model showed that more intensely drained wetlands at higher elevation should be targeted for restoration of downstream flows (flooding) because they have the ability to loose higher water volume through ET which increases available water storage capacity of wetlands. Daily ET models can predict changes in ET for improved evaluation of basin-scale effects of restoration programs and climate change scenarios.

The integration of constructed wetlands into a treatment system for airport runoff.

PubMed

Revitt, D M; Worral, P; Brewer, D

2001-01-01

A new surface runoff treatment system has been designed for London Heathrow Airport, which incorporates separate floating constructed wetlands or reedbeds and sub-surface flow constructed wetlands as major pollutant removal systems. The primary requirement of the newly developed treatment system is to control the concentrations of glycols following their use as de-icers and anti-icers within the airport. The ability of reedbeds to contribute to this treatment role was fully tested through pilot scale, on-site experiments over a 2 year period. The average reductions in runoff BOD concentrations achieved by pilot scale surface flow and sub-surface flow reedbeds were 30.9% and 32.9%, respectively. The corresponding average glycol removal efficiencies were 54.2% and 78.3%, following shock dosing inputs. These treatment performances are used to predict the required full scale constructed wetland surface areas needed to attain the desired effluent water quality. The treatment system also incorporates aeration, storage and, combined with reedbed technology, has been designed to reduce a mixed inlet BOD concentration of 240 mg/l to less than 40 mg/l for water temperatures varying between 6 degrees C and 20 degrees C.

Avian utilization of subsidence wetlands

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nawrot, J.R.; Conley, P.S.; Smout, C.L.

1995-09-01

Diverse and productive wetlands have resulted from coal mining in the midwest. The trend from surface to underground mining has increased the potential for subsidence. Planned subsidence of longwall mining areas provides increased opportunities for wetland habitat establishment. Planned subsidence over a 180 meter (590 foot) deep longwall mine in southern Illinois during 1984 to 1986 produced three subsidence wetlands totaling 15 hectares (38 acres). The resulting palustrine emergent wetlands enhanced habitat diversity within the surrounding palustrine forested unsubsided area. Habitat assessments and evaluations of avian utilization of the subsidence wetlands were conducted during February 1990 through October 1991. Avianmore » utilization was greatest within the subsided wetlands. Fifty-three bird species representing seven foraging guilds utilized the subsidence wetlands. Wading/fishing, dabbling waterfowl, and insectivorous avian guilds dominated the subsidence wetlands. The subsidence wetlands represented ideal habitat for wood ducks and great blue herons which utilized snags adjacent to and within the wetlands for nesting (19 great blue heron nests produced 25 young). Dense cover and a rich supply of macroinvertebrates provide excellent brood habitat for wood ducks, while herpetofauna and ichthyofauna provided abundant forage in shallow water zones for great blue herons and other wetland wading birds. The diversity of game and non-game avifauna utilizing the subsidence areas demonstrated the unique value of these wetlands. Preplanned subsidence wetlands can help mitigate loss of wetland habitats in the midwest.« less

Quantitative assessment of urban wetland dynamics using high spatial resolution satellite imagery between 2000 and 2013.

PubMed

Hu, Tangao; Liu, Jiahong; Zheng, Gang; Li, Yao; Xie, Bin

2018-05-09

Accurate and timely information describing urban wetland resources and their changes over time, especially in rapidly urbanizing areas, is becoming more important. We applied an object-based image analysis and nearest neighbour classifier to map and monitor changes in land use/cover using multi-temporal high spatial resolution satellite imagery in an urban wetland area (Hangzhou Xixi Wetland) from 2000, 2005, 2007, 2009 and 2013. The overall eight-class classification accuracies averaged 84.47% for the five years. The maps showed that between 2000 and 2013 the amount of non-wetland (urban) area increased by approximately 100%. Herbaceous (32.22%), forest (29.57%) and pond (23.85%) are the main land-cover types that changed to non-wetland, followed by cropland (6.97%), marsh (4.04%) and river (3.35%). In addition, the maps of change patterns showed that urban wetland loss is mainly distributed west and southeast of the study area due to real estate development, and the greatest loss of urban wetlands occurred from 2007 to 2013. The results demonstrate the advantages of using multi-temporal high spatial resolution satellite imagery to provide an accurate, economical means to map and analyse changes in land use/cover over time and the ability to use the results as inputs to urban wetland management and policy decisions.

The role of protected area wetlands in waterfowl habitat conservation: implications for protected area network design

USGS Publications Warehouse

Beatty, William S.; Kesler, Dylan C.; Webb, Elisabeth B.; Raedeke, Andrew H.; Naylor, Luke W.; Humburg, Dale D.

2014-01-01

The principal goal of protected area networks is biodiversity preservation, but efficacy of such networks is directly linked to animal movement within and outside area boundaries. We examined wetland selection patterns of mallards (Anas platyrhynchos) during non-breeding periods from 2010 to 2012 to evaluate the utility of protected areas to migratory waterfowl in North America. We tracked 33 adult females using global positioning system (GPS) satellite transmitters and implemented a use-availability resource selection design to examine mallard use of wetlands under varying degrees of protection. Specifically, we examined effects of proximities to National Wildlife Refuges, private land, state wildlife management areas, Wetland Reserve Program easements (WRP), and waterfowl sanctuaries on mallard wetland selection. In addition, we included landscape-level variables that measured areas of sanctuary and WRP within the surrounding landscape of each used and available wetland. We developed 8 wetland selection models according to season (autumn migration, winter, spring migration), hunting season (present, absent), and time period (diurnal, nocturnal). Model averaged parameter estimates indicated wetland selection patterns varied across seasons and time periods, but ducks consistently selected wetlands with greater areas of sanctuary and WRP in the surrounding landscape. Consequently, WRP has the potential to supplement protected area networks in the midcontinent region. Additionally, seasonal variation in wetland selection patterns indicated considering the effects of habitat management and anthropogenic disturbances on migratory waterfowl during the non-breeding period is essential in designing protected area networks.

Healthy Wetlands: Valuing Both the Wet and the Dry

ERIC Educational Resources Information Center

Jenkins, Kim; Panizzon, Debra

2009-01-01

February 2nd of each year is World Wetlands Day. It commemorates the signing of the Ramsar Convention in Iran in 1971 and the crucial role wetlands play in terms of ecological health. Not only do they provide essential habitats for many aquatic species of organisms but they are used by many terrestrial animals as temporary havens for food, or…

Vascular and non-vascular plant community response to silvicultural practices and resultant microtopography creation in a forested wetland

Treesearch

Heidi M. Anderson; Margeret R. Gale; Martin F. Jurgensen; Carl C. Trettin

2007-01-01

Forested wetlands are important ecosystems valued for their indigenous plant communities, spatial heterogeneity, wildlife habitat, water quality, and timber resources. When harvested for timber, plant composition in these wetlands may change due to alteration in microsite habitats. Harvest severity also may affect plant composition. In this study, a mineral conifer...

Modelling methane emissions from natural wetlands by development and application of the TRIPLEX-GHG model

USGS Publications Warehouse

Zhu, Qing; Liu, Jinxun; Peng, C.; Chen, H.; Fang, X.; Jiang, H.; Yang, G.; Zhu, D.; Wang, W.; Zhou, X.

2014-01-01

A new process-based model TRIPLEX-GHG was developed based on the Integrated Biosphere Simulator (IBIS), coupled with a new methane (CH4) biogeochemistry module (incorporating CH4 production, oxidation, and transportation processes) and a water table module to investigate CH4 emission processes and dynamics that occur in natural wetlands. Sensitivity analysis indicates that the most sensitive parameters to evaluate CH4 emission processes from wetlands are r (defined as the CH4 to CO2 release ratio) and Q10 in the CH4 production process. These two parameters were subsequently calibrated to data obtained from 19 sites collected from approximately 35 studies across different wetlands globally. Being heterogeneously spatially distributed, r ranged from 0.1 to 0.7 with a mean value of 0.23, and the Q10 for CH4 production ranged from 1.6 to 4.5 with a mean value of 2.48. The model performed well when simulating magnitude and capturing temporal patterns in CH4 emissions from natural wetlands. Results suggest that the model is able to be applied to different wetlands under varying conditions and is also applicable for global-scale simulations.

Sources of mercury to San Francisco Bay surface sediment as revealed by mercury stable isotopes

USGS Publications Warehouse

Gehrke, Gretchen E.; Blum, Joel D.; Marvin-DePasquale, Mark

2011-01-01

Mercury (Hg) concentrations and isotopic compositions were examined in shallow-water surface sediment (0–2 cm) from San Francisco (SF) Bay to determine the extent to which historic Hg mining contributes to current Hg contamination in SF Bay, and to assess the use of Hg isotopes to trace sources of contamination in estuaries. Inter-tidal and wetland sediment had total Hg (HgT) concentrations ranging from 161 to 1529 ng/g with no simple gradients of spatial variation. In contrast, inter-tidal and wetland sediment displayed a geographic gradient of δ202Hg values, ranging from -0.30% in the southern-most part of SF Bay (draining the New Almaden Hg District) to -0.99% in the northern-most part of SF Bay near the Sacramento–San Joaquin River Delta. Similar to SF Bay inter-tidal sediment, surface sediment from the Alviso Slough channel draining into South SF Bay had a δ202Hg value of -0.29%, while surface sediment from the Cosumnes River and Sacramento–San Joaquin River Delta draining into north SF Bay had lower average δ202Hg values of -0.90% and -0.75%, respectively. This isotopic trend suggests that Hg-contaminated sediment from the New Almaden Hg District mixes with Hg-contaminated sediment from a low δ202Hg source north of SF Bay. Tailings and thermally decomposed ore (calcine) from the New Idria Hg mine in the California Coast Range had average δ202Hg values of -0.37 and +0.03%, respectively, showing that Hg calcination fractionates Hg isotopes resulting in Hg contamination from Hg(II) mine waste products with higher δ202Hg values than metallic Hg(0) produced from Hg mines. Thus, there is evidence for at least two distinct isotopic signals for Hg contamination in SF Bay: Hg associated with calcine waste materials at Hg mines in the Coast Range, such as New Almaden and New Idria; and Hg(0) produced from these mines and used in placer gold mines and/or in other industrial processes in the Sierra Nevada region and SF Bay area.

Development of a "Hydrologic Equivalent Wetland" Concept for Modeling Cumulative Effects of Wetlands on Watershed Hydrology

NASA Astrophysics Data System (ADS)

Wang, X.; Liu, T.; Li, R.; Yang, X.; Duan, L.; Luo, Y.

2012-12-01

Wetlands are one of the most important watershed microtopographic features that affect, in combination rather than individually, hydrologic processes (e.g., routing) and the fate and transport of constituents (e.g., sediment and nutrients). Efforts to conserve existing wetlands and/or to restore lost wetlands require that watershed-level effects of wetlands on water quantity and water quality be quantified. Because monitoring approaches are usually cost or logistics prohibitive at watershed scale, distributed watershed models, such as the Soil and Water Assessment Tool (SWAT), can be a best resort if wetlands can be appropriately represented in the models. However, the exact method that should be used to incorporate wetlands into hydrologic models is the subject of much disagreement in the literature. In addition, there is a serious lack of information about how to model wetland conservation-restoration effects using such kind of integrated modeling approach. The objectives of this study were to: 1) develop a "hydrologic equivalent wetland" (HEW) concept; and 2) demonstrate how to use the HEW concept in SWAT to assess effects of wetland restoration within the Broughton's Creek watershed located in southwestern Manitoba of Canada, and of wetland conservation within the upper portion of the Otter Tail River watershed located in northwestern Minnesota of the United States. The HEWs were defined in terms of six calibrated parameters: the fraction of the subbasin area that drains into wetlands (WET_FR), the volume of water stored in the wetlands when filled to their normal water level (WET_NVOL), the volume of water stored in the wetlands when filled to their maximum water level (WET_MXVOL), the longest tributary channel length in the subbasin (CH_L1), Manning's n value for the tributary channels (CH_N1), and Manning's n value for the main channel (CH_N2). The results indicated that the HEW concept allows the nonlinear functional relations between watershed processes and wetland characteristics (e.g., size and morphology) to be accurately represented in the models. The loss of the first 10 to 20% of the wetlands in the Minnesota study area would drastically increase the peak discharge and loadings of sediment, total phosphorus (TP), and total nitrogen (TN). On the other hand, the justifiable reductions of the peak discharge and loadings of sediment, TP, and TN in the Manitoba study area may require that 50 to 80% of the lost wetlands be restored. Further, the comparison between the predicted restoration and conservation effects revealed that wetland conservation seems to deserve a higher priority while both wetland conservation and restoration may be equally important. Moreover, although SWAT was used in this study, the HEW concept is generic and can also be applied with any other hydrologic models.

[Changes in vegetation and soil characteristics under tourism disturbance in lakeside wetland of northwest Yunnan Plateau, Southwest China].

PubMed

Tang, Ming-Yan; Yang, Yong-Xing

2014-05-01

The characteristics of vegetation and soil were investigated in Bita Lake and Shudu Lake wetlands in northwest Yunnan Plateau under tourism disturbance. The 22 typical plots in the wetlands were classified into 4 types by TWINSPAN, including primary wetland, light degradation, moderate degradation, and severe degradation. Along the degradation gradient, the plant community density, coverage, species number and Shannon diversity index increased and the plant height decreased in Bita Lake and Shudu Lake wetlands, and Whittaker diversity index increased in Bita Lake wetland. Plant species number, soil organic matter, total nitrogen, porosity, available nitrogen, available phosphorus and available potassium contents were higher in Shudu Lake wetland than in Bita Lake wetland, but the plant density, height, soil total potassium and pH were opposite. Canonical correspondence analysis (CCA) by importance values of 42 plants and 11 soil variables showed that soil organic matter, total nitrogen and total potassium were the key factors on plant species distribution in Bita Lake and Shudu Lake wetlands under tourism disturbance. TWINSPAN classification and analysis of vegetation-soil characteristics indicated the effects of tourism disturbance in Bita Lake wetland were larger than in Shudu Lake wetland.

(226) RA AND (228) RA ACTIVITIES ASSOCIATED WITH AGRICULTURAL DRAINAGE PONDS AND WETLAND PONDS IN THE KANKAKEE WATERSHED, IL-IN, USA

EPA Science Inventory

Background radioactivity is elevated in many agricultural drainage ponds and also constructed wetland ponds in the Kankakee watershed. During 1995-1999, gross-a and -B activities were measured up to 455 and 1650 mBq L-1, respectively. 226Ra and 228Ra averaged 139 and 192 mBq L-01...

Profound and pervasive degradation of Madagascar's freshwater wetlands and links with biodiversity.

PubMed

Bamford, Andrew J; Razafindrajao, Felix; Young, Richard P; Hilton, Geoff M

2017-01-01

Reflecting a global trend, freshwater wetlands in Madagascar have received little conservation or research attention. Madagascar is a global conservation priority due to its high level of species endemism but most work has focused on protecting forests. For the first time, we investigated the state of wetlands across the country to determine the effects of human disturbance. We conducted a rapid survey of 37 wetlands, using waterbirds and benthic invertebrates as ecological indicators. We recorded nine variables relating to human disturbance, revealing widespread wetland destruction. Principal Components Analysis reduced the nine variables to a single Principal Component (PC) that explained 50% of the dataset variance, demonstrating that different forms of human disturbance are ubiquitous and inseparable. The disturbance PC provides an index of how pristine a lake is and in Generalized Linear Models (GLMs) was significantly inversely related to the number of waterbird species present and the density of Chironomidae. The disturbance PC was estimated for every wetland in a GIS-derived dataset of wetland locations in Madagascar, giving a country-wide frequency distribution of disturbance. To validate the estimated PC values, we used the GLMs to predict the number of endemic bird species at an independent sample of 22 lakes. The predicted values correlated with the observed number of species, demonstrating that our procedure can identify lakes with high biodiversity value. The disturbance PC provides a convenient method for ranking sites, and a country-wide ranking demonstrates that the only near-pristine lakes in Madagascar are small sites that have been preserved by remoteness from human activity and not conservation management. The strategy of conserving high biodiversity remnants is insufficient because existing remnants suffer some degree of degradation and only support small populations of threatened species. Large-scale restoration of degraded wetlands is required for the long-term conservation of Madagascar's freshwater biodiversity.

Profound and pervasive degradation of Madagascar’s freshwater wetlands and links with biodiversity

PubMed Central

Razafindrajao, Felix; Young, Richard P.; Hilton, Geoff M.

2017-01-01

Reflecting a global trend, freshwater wetlands in Madagascar have received little conservation or research attention. Madagascar is a global conservation priority due to its high level of species endemism but most work has focused on protecting forests. For the first time, we investigated the state of wetlands across the country to determine the effects of human disturbance. We conducted a rapid survey of 37 wetlands, using waterbirds and benthic invertebrates as ecological indicators. We recorded nine variables relating to human disturbance, revealing widespread wetland destruction. Principal Components Analysis reduced the nine variables to a single Principal Component (PC) that explained 50% of the dataset variance, demonstrating that different forms of human disturbance are ubiquitous and inseparable. The disturbance PC provides an index of how pristine a lake is and in Generalized Linear Models (GLMs) was significantly inversely related to the number of waterbird species present and the density of Chironomidae. The disturbance PC was estimated for every wetland in a GIS-derived dataset of wetland locations in Madagascar, giving a country-wide frequency distribution of disturbance. To validate the estimated PC values, we used the GLMs to predict the number of endemic bird species at an independent sample of 22 lakes. The predicted values correlated with the observed number of species, demonstrating that our procedure can identify lakes with high biodiversity value. The disturbance PC provides a convenient method for ranking sites, and a country-wide ranking demonstrates that the only near-pristine lakes in Madagascar are small sites that have been preserved by remoteness from human activity and not conservation management. The strategy of conserving high biodiversity remnants is insufficient because existing remnants suffer some degree of degradation and only support small populations of threatened species. Large-scale restoration of degraded wetlands is required for the long-term conservation of Madagascar’s freshwater biodiversity. PMID:28792516

Magnetic susceptibility for use in delineating hydric soils

USGS Publications Warehouse

Grimley, D.A.; Vepraskas, M.J.

2000-01-01

Field indicators are used to identify hydric soil boundaries and to delineate wetlands. The most common field indicators may not be seen in some soils with thick, dark, mollic epipedons, and do not form in Fe-poor soils. This study evaluated magnetic susceptibility (MS) meter as a field tool to determine hydric soil boundaries. Five Mollisoldominated sites formed in glacial deposits in Illinois were evaluated along with one Ultisol-dominated site formed in Coastal Plain sediments of North Carolina. Measurements of volumetric MS were made along transects at each site that extended from wetland into upland areas. One created wetland was evaluated. Field indicators were used to identify the hydric soils. Results showed that volumetric MS values were significantly (P 0.15) differences in MS were found for Coastal Plain hydric and nonhydric soils where MS values were low (<10 ?? 10-5 SI). Critical MS values that separated hydric and nonhydric soils varied between 20 ?? 10-5 and 30 ?? 10-5 SI for the loessal soils evaluated in Illinois. Such critical values will have to be determined on site using field indicators until specific values can be defined for hydric soils within a given parent material. With a critical MS value in hand, a wetland delineator can make MS measurements along transects perpendicular to the envisioned hydric soil boundary to quickly and quantitatively identify it.

Elevated CO2 facilitates C and N accumulation in a rice paddy ecosystem.

PubMed

Guo, Jia; Zhang, Mingqian; Wang, Xiaowen; Zhang, Weijian

2015-03-01

Elevated CO2 can stimulate wetland carbon (C) and nitrogen (N) exports through gaseous and dissolved pathways, however, the consequent influences on the C and N pools are still not fully known. Therefore, we set up a free-air CO2 enrichment experiment in a paddy field in Eastern China. After five year fumigation, we studied C and N in the plant-water-soil system. The results showed: (1) elevated CO2 stimulated rice aboveground biomass and N accumulations by 19.1% and 12.5%, respectively. (2) Elevated CO2 significantly increased paddy soil TOC and TN contents by 12.5% and 15.5%, respectively in the 0-15 cm layer, and 22.7% and 26.0% in the 15-30 cm soil layer. (3) Averaged across the rice growing period, elevated CO2 greatly increased TOC and TN contents in the surface water by 7.6% and 11.4%, respectively. (4) The TOC/TN ratio and natural δ15N value in the surface soil showed a decreasing trend under elevated CO2. The above results indicate that elevated CO2 can benefit C and N accumulation in paddy fields. Given the similarity between the paddies and natural wetlands, our results also suggest a great potential for long-term C and N accumulation in natural wetlands under future climate patterns. Copyright © 2015. Published by Elsevier B.V.

Potential increase in coastal wetland vulnerability to sea-level rise suggested by considering hydrodynamic attenuation effects

PubMed Central

Rodríguez, José F.; Saco, Patricia M.; Sandi, Steven; Saintilan, Neil; Riccardi, Gerardo

2017-01-01

The future of coastal wetlands and their ecological value depend on their capacity to adapt to the interacting effects of human impacts and sea-level rise. Even though extensive wetland loss due to submergence is a possible scenario, its magnitude is highly uncertain due to limited understanding of hydrodynamic and bio-geomorphic interactions over time. In particular, the effect of man-made drainage modifications on hydrodynamic attenuation and consequent wetland evolution is poorly understood. Predictions are further complicated by the presence of a number of vegetation types that change over time and also contribute to flow attenuation. Here, we show that flow attenuation affects wetland vegetation by modifying its wetting-drying regime and inundation depth, increasing its vulnerability to sea-level rise. Our simulations for an Australian subtropical wetland predict much faster wetland loss than commonly used models that do not consider flow attenuation. PMID:28703130

Drainage investment and wetland loss: an analysis of the national resources inventory data

USGS Publications Warehouse

Douglas, Aaron J.; Johnson, Richard L.

1994-01-01

The United States Soil Conservation Service (SCS) conducts a survey for the purpose of establishing an agricultural land use database. This survey is called the National Resources Inventory (NRI) database. The complex NRI land classification system, in conjunction with the quantitative information gathered by the survey, has numerous applications. The current paper uses the wetland area data gathered by the NRI in 1982 and 1987 to examine empirically the factors that generate wetland loss in the United States. The cross-section regression models listed here use the quantity of wetlands, the stock of drainage capital, the realty value of farmland and drainage costs to explain most of the cross-state variation in wetland loss rates. Wetlands preservation efforts by federal agencies assume that pecuniary economic factors play a decisive role in wetland drainage. The empirical models tested in the present paper validate this assumption.

Potential increase in coastal wetland vulnerability to sea-level rise suggested by considering hydrodynamic attenuation effects

NASA Astrophysics Data System (ADS)

Rodríguez, José F.; Saco, Patricia M.; Sandi, Steven; Saintilan, Neil; Riccardi, Gerardo

2017-07-01

The future of coastal wetlands and their ecological value depend on their capacity to adapt to the interacting effects of human impacts and sea-level rise. Even though extensive wetland loss due to submergence is a possible scenario, its magnitude is highly uncertain due to limited understanding of hydrodynamic and bio-geomorphic interactions over time. In particular, the effect of man-made drainage modifications on hydrodynamic attenuation and consequent wetland evolution is poorly understood. Predictions are further complicated by the presence of a number of vegetation types that change over time and also contribute to flow attenuation. Here, we show that flow attenuation affects wetland vegetation by modifying its wetting-drying regime and inundation depth, increasing its vulnerability to sea-level rise. Our simulations for an Australian subtropical wetland predict much faster wetland loss than commonly used models that do not consider flow attenuation.

Using stable isotopes to understand hydrochemical processes in and around a Prairie Pothole wetland in the Northern Great Plains, USA

USGS Publications Warehouse

Mills, Christopher T.; Goldhaber, Martin B.; Stricker, Craig A.; Holloway, JoAnn M.; Morrison, Jean M.; Ellefsen, Karl J.; Rosenberry, Donald O.; Thurston, Roland S.

2011-01-01

Millions of internally drained wetland systems in the Prairie Potholes region of the northern Great Plains (USA and Canada) provide indispensable habitat for waterfowl and a host of other ecosystem services. The hydrochemistry of these systems is complex and a crucial control on wetland function, flora and fauna. Wetland waters can have high concentrations of SO2-4 due to the oxidation of large amounts of pyrite in glacial till that is in part derived from the Pierre shale. Water chemistry including δ18OH2O, δ2HH2O, and δ34SSO4 values, was determined for groundwater, soil pore water, and wetland surface water in and around a discharge wetland in North Dakota. The isotopic data for the first time trace the interaction of processes that affect wetland chemistry, including open water evaporation, plant transpiration, and microbial SO4 reduction.

Determining Hydroperiod for Boreal and Prairie Pothole Wetlands using SAR, Optical and LiDAR Remote Sensing Data Fusion

NASA Astrophysics Data System (ADS)

Montgomery, J. S.; Hopkinson, C.; Brisco, B.; Patterson, S.; Chasmer, L.; Mahoney, C.

2017-12-01

Cultivation, irrigation networks, and infrastructure have all greatly impacted the ecology and hydrology of the Prairie Pothole and Boreal regions of western Canada. Due to sub-humid climate and high potential evaporation, many wetlands in these natural regions are seldom continuously occupied by water, and are often confined to local depressions. In the Boreal region, wetlands may be difficult to monitor due to their remote location, whereas prairie wetlands have highly varying degrees of surface water and soil saturation throughout the year. This study examines how high-resolution Lidar, Synthetic Aperture Radar (SAR), and optical data can be utilized in spatial-temporal studies to classify wetlands based on water extent, riparian vegetation, and topographic characteristics. An intensity (dB) threshold routine was used to extract open surface water extent to determine hydroperiod. Digital Elevation Models (DEM) are used with a topographic position index to infer local depressions, while Digital Surface Models (DSMs) are used to characterise vegetation structural characteristics within and proximal to wetlands. The proposed framework provides an index of wetland permanence and wetland class, where permanence varies seasonally and annually. Boreal wetland hydroperiod is less variable than that found in prairie pothole wetlands, most notably the semi-permanent class, varying by only 2%, compared to >50% in prairie pothole wetlands. For years studied, prairie pothole wetlands reached maximum water extent following major rainfall events. Seasonal and semi-permanent wetlands were found to have greater change in surface water between years than temporary wetlands (75.3% and 59.1% from average respectively). The lowest frequency of water pixel inundation for seasonal and semi-permanent wetlands was found to be in the year with the most precipitation during the growing season (2013, 384mm), compared to 2014 (289mm), and 2015 (310mm). A combination of statistical analyses and ground validation of the output classes is used to evaluate the data fusion approach (overall accuracies >80%, RMSE <4). The decision-tree modeling approach provides insight into dynamic wetland surface water changes that are important for wetland monitoring, conservation and land use development within western Canada.

[Influence of land use change on dissolved organic carbon export in Naoli River watershed. Northeast China].

PubMed

Yin, Xiao-min; Lyu, Xian-guo; Liu, Xing-tu; Xue, Zhen-shan

2015-12-01

The present study was conducted to evaluate the influence of land use change on dissolved organic carbon (DOC) export in Naoli River watershed, Northeast China. Seasonal variation of DOC concentrations of the river water and its relationship with land use in the whole watershed and 100 m riparian zone at the annual average scale were analyzed using the method of field sampling, laboratory analysis, GIS and statistics analysis. The results showed that the concentrations of DOC under base flow conditions in spring and summer were significantly higher than that in fall in the study watershed. The seasonal trend of DOC concentrations in wetland-watersheds was similar to that in all the sub-watersheds, while significantly different from that in non-wetland watersheds. On the annual average scale, percentage of wetland in the whole watershed and paddy field in the 100 m riparian zone had positive relationship with the DOC concentration in the river water, while percentage of forest in the whole watershed had negative relationship with it (P < 0.05). It indicated that wetland in the sub-watershed played a significant role in the seasonal variation of DOC in river water of Naoli River watershed. Wetland in the watershed and paddy field in the 100 m riparian zone significantly promoted DOC export, while forest alleviated it. Land use change in the watershed in the past few decades dramatically changed the DOC balance of river water.

Anthropogenic Black Carbon Emission Increase during the Last 150 Years at Coastal Jiangsu, China

PubMed Central

Bao, Kunshan; Shen, Ji; Wang, Guoping; Gao, Chuanyu

2015-01-01

Black carbon (BC) is one of the major drivers of climate change and a useful indicator of environmental pollution from industrialization, and thus it is essential to reconstruct the historical trend in BC flux to better understand its impact. The Yancheng coastal wetland reserve in Jiangsu province is an area sensitive to global sea level change and is also located in the most developed as well as most polluted region of China. We investigated the concentration and historical flux of BC over the past 150 years through geochemical analysis of two 210Pb-dated sediment cores from Yancheng coastal wetland. Measured BC contents ranged from 0.24 mg g-1 to 1.41 mg g-1 with average values of 0.51mg g-1-0.69 mg g-1, and BC fluxes ranged from 0.69 g m-2 yr-1 to 11.80 g m-2 yr-1 with averages of 2.94g m-2 yr-1-3.79 g m-2 yr-1. These values are consistent with other records worldwide. Both BC content and flux show a gradual and continuous increase over time and clearly reflect increased emissions from anthropogenic activities. The BC records have a significant peak in recent years (from 2000 to 2007), which is accompanied by the sharp increase of energy consumption and total carbon emission in the region. It is reasonable to conclude that changes in BC from increasing human activities have controlled BC fluxes during the last 150 years. Industrial contamination, especially BC emission, in the coastal region of eastern China should be taken into account when developing management strategies for protecting the natural environment. PMID:26200665

Resilience of Socio-Hydrological Systems in Canadian Prairies to Agricultural Drainage: Policy Analysis and Modelling Approach

NASA Astrophysics Data System (ADS)

Wheater, H. S.; Xu, L.; Gober, P.; Pomeroy, J. W.; Wong, J.

2017-12-01

Extensive agricultural drainage of lakes and wetlands in the Canadian Prairies has led to benefits for agricultural production, but has had a substantial influence on hydrological regimes and wetland extent. There is need for the potential impacts of current policy in changing the socio-hydrological resilience of prairie wetland basins in response to agricultural drainage to be examined. Whilst wetland drainage can increase agricultural productivity, it can also reduce stocks of natural capital and decrease ecosystem services, such as pollutant retention, habitat for waterfowls, carbon sequestration, and downstream flood attenuation. Effective policies that balance drainage benefits and negative externalities have to consider pricing. This is explored here using the Cold Regions Hydrological Model for hydrological simulations and the Inclusive Wealth approach for modelling in support of cost-benefit analysis. Inclusive wealth aggregates the value of natural, human, and technological assets used to produce social welfare. A shadow price, defined as the marginal change in social value for a marginal change in the current stock quantity, is used to valuate assets that contribute to social welfare. The shadow price of each asset is estimated by taking into account the social and economic benefits and external losses of wetland services caused by wetland drainage. The coupled model was applied to the Smith Creek Research Basin in south-eastern Saskatchewan, Canada where wetland drainage has caused major alterations of the hydrological regime including increased peak flows, discharge volumes and duration of streamflow. Changes in depressional storage in wetlands was used to calculate the corresponding changes of inclusive wealth over a 30-year period under the impacts from the limitation proposed in the Agricultural Water Management Strategy of Saskatchewan. The adjusted societal values of drainage demonstrate the dynamics between changes in hydrological conditions of wetland basins and social welfare, which help to evaluate potential impacts of the current policy on the resilience and sustainability of socio-hydrological systems. The results also help determine effective goals for management to maximize the societal benefits of drainage and minimize its negative impacts on ecosystem functions.

Midcontinent Prairie-Pothole wetlands and climate change: An Introduction to the Supplemental Issue

USGS Publications Warehouse

Mushet, David M.

2016-01-01

The multitude of wetlands in the Prairie Pothole Region of North America forms one of Earth’s largest wetland complexes. The midcontinent location exposes this ecologically and economically important wetland system to a highly variable climate, markedly influencing ponded-water levels, hydroperiods, chemical characteristics, and biota of individual basins. Given their dominance on the landscape and recognized value, great interest in how projected future changes in climate will affect prairie-pothole wetlands has developed and spawned much scientific research. On June 2, 2015, a special symposium, “Midcontinent Prairie-Pothole Wetlands: Influence of a Changed Climate,” was held at the annual meeting of the Society of Wetland Scientists in Providence, Rhode Island, USA. The symposium’s twelve presenters covered a wide range of relevant topics delivered to a standing-room-only audience. Following the symposium, the presenters recognized the need to publish their presented papers as a combined product to facilitate widespread distribution. The need for additional papers to more fully cover the topic of prairie-pothole wetlands and climate change was also identified. This supplemental issue of Wetlands is the realization of that vision.

Remote Sensing Monitoring of Wetland of Sanya and Lingshui in Hainan Province, Based on gf Data

NASA Astrophysics Data System (ADS)

Guo, Y.; Li, L.

2018-04-01

Wetland is an important land and natural resources with many functions. It is closely related to the survival, reproduction and development of human beings, as well as one of the most important living environments of human beings. Hainan Province, which is located in the northern edge of the tropics with the tropical monsoon climate and covers a variety of wetland types. In this paper, in order to investigate the change of wetland distribution and the variations of area in study region, the remote sensing data of GF-1 and GF-2 from 2009 to 2015 were used. The method used in this study was automatic information extraction and human-computer interaction. The wetland types in study area mainly was divided into three level-1 classes, including coastal wetland, river wetland and lake wetland, and was also divided into eight level-2 classes at the same time. The results showed that the total area of wetland increased 9.13 km2 in study area from 2009 to 2015, in which the area of constructed wetland increased 6.29 km2, the natural wetland increased only 2.83 km2. The area of natural wetland has not changed much, but its proportion has been reduced. This reflected that the wetland in the research area has been more artificially intervened since 2009, which caused the increasing of the area of constructed wetland. As the wetland resources can coordinate the sustainable benefit of the society, the protection of natural wetland should be strengthened and valued.

Dietary use and conservation concern of edible wetland plants at indo-burma hotspot: a case study from northeast India

PubMed Central

2011-01-01

Background The wetlands of the North East India fall among the global hotspots of biodiversity. However, they have received very little attention with relation to their intrinsic values to human kind; therefore their conservation is hardly addressed. These wetlands are critical for the sustenance of the tribal communities. Methods Field research was conducted during 2003 to 2006 in seven major wetlands of four districts of Manipur state, Northeast India (viz. Imphal-East, Imphal-West, Thoubal, and Bishnupur). A total of 224 wetland-plant-collectors were interviewed for the use and economics of species using semi-structured questionnaires and interview schedules. Imphal, Bishenpur and Thoubal markets were investigated in detail for influx and consumption pattern of these plants. The collectors were also inquired for medicinal use of wetland species. Nutritive values of 21 species were analyzed in laboratory. The vouchers were collected for all the species and deposited in the CSIR-NEIST (Formerly Regional Research Laboratory), Substation, Lamphelpat, Imphal, Manipur, India. Results We recorded 51 edible wetland species used by indigenous people for food and medicinal purposes. Thirty eight species had high medicinal values and used in the traditional system to treat over 22 diseases. At least 27 species were traded in three markets studied (i.e. Imphal, Thoubal and Bishenpur), involving an annual turnover of 113 tons of wetland edible plants and a gross revenue of Rs. 907, 770/- (US$1 = Rs. 45/-). The Imphal market alone supplies 60% of the total business. Eighty per cent of the above mentioned species are very often used by the community. The community has a general opinion that the availability of 45% species has depleted in recent times, 15 species need consideration for conservation while another 7 species deserved immediate protection measures. The nutrient analysis showed that these species contribute to the dietary balance of tribal communities. Conclusions Considering the importance of wild wetland plants in local sustenance, it is suggested to protect their habitats, develop domestication protocols of selected species, and build programs for the long-term management of wetland areas by involving local people. Some medicinal plants may also be used to develop into modern medicines. PMID:21970571

Fish community structure in freshwater karstic water bodies of the Sian Ka'an Reserve in the Yucatan peninsula, Mexico

USGS Publications Warehouse

Zambrano, L.; Vazquez-Dominguez, E.; Garcia-Bedoya, D.; Loftus, W.F.; Trexler, J.C.

2006-01-01

We evaluated the relationship between limnetic characteristics and fish community structure (based on species richness, abundance and individual size) in contrasting but interconnected inland aquatic habitats of freshwater karstic wetlands in the Yucatan peninsula, Mexico. In the western hemisphere, freshwater karstic wetlands are found in south-eastern Mexico, northern Belize, western Cuba, Andros Island, Bahamas and the Everglades of southern Florida. Only in the Everglades have fish communities been well described. Karstic wetlands are typically oligotrophic because calcium carbonate binds phosphorus, making it relatively unavailable for plants. Fourteen permanent and seasonally flooded water bodies were sampled in both wet and dry seasons in Sian Ka'an Biosphere Reserve, in the Mexican state of Quintana Roo. Water systems were divided by morphology in four groups: cenotes with vegetation (CWV), cenotes without vegetation (CNV), wetlands (WTL), and temporal cenotes (TPC). Discriminant analysis based on physical characteristics such as turbidity, temperature, depth and oxygen confirmed that these habitats differed in characteristics known to influence fish communities. A sample-based rarefaction test showed that species richness was significantly different between water systems groups, showing that WTL and CWV had higher richness values than CNV and TPC. The most abundant fish families, Poeciliidae, Cichlidae and Characidae, differed significantly in average size among habitats and seasons. Seasonal and inter-annual variation, reflecting temporal variation in rainfall, strongly influenced the environmental differences between shallow and deep habitats, which could be linked to fish size and life cycles. Five new records of species were found for the reserve, and one new record for Quintana Roo state. ?? 2006 by Verlag Dr. Friedrich Pfeil.

Challenges and Conundrums in Modeling Global Methane Emissions from Wetlands: An Empiricist's Viewpoint

NASA Astrophysics Data System (ADS)

Bridgham, S. D.

2015-12-01

Wetlands emit a third to half of the global CH4 flux and have the largest uncertainty of any emission source. Moreover, wetlands have provided an important radiative feedback to climate in the geologic and recent past. A number of largescale wetland CH4 models have been developed recently, but intermodel comparisons show wide discrepancies in their predictions. I present an empiricist's overview of the current limitations and challenges of more accurately modeling wetland CH4 emissions. One of the largest limitations is simply the poor knowledge of wetland area, with estimated global values varying by a more than a factor of three. The areas of seasonal and tropical wetlands are particularly poorly constrained. There are also few wetlands with complete, multi-year datasets for all of the input variables for many models, and this lack of data is particularly alarming in tropical wetlands given that they are arguably the single largest natural or anthropogenic global CH4 source. Almost all largescale CH4 models have little biogeochemical mechanistic detail and treat anaerobic carbon cycling in a highly simplified manner. The CH4:CO2 ratio in anaerobic carbon mineralization is a central parameter in many models, but is at most set at a few values with no mechanistic underpinning. However, empirical data show that this ratio varies by five orders of magnitude in different wetlands, and tropical wetlands appear to be particularly methanogenic, all for reasons that are very poorly understood. The predominance of the acetoclastic pathway of methanogenesis appears to be related to total CH4 production, but different methanogenesis pathways are generally not incorporated into models. Other important anaerobic processes such as humic substances acting as terminal electron acceptors, fermentation, homoacetogenesis, and anaerobic CH4 oxidation are also not included in most models despite evidence of their importance in empirical studies. Moreover, there has been an explosion of microbial studies in wetlands using high-throughput molecular techniques, but microbial community and functional parameters are largely missing from models. However, recently developed trait-based models show promise for reducing the multivariate complexity of this data into manageable parameters for large-scale CH4 models.

Realizing ecosystem services: wetland hydrologic function along a gradient of ecosystem condition.

PubMed

McLaughlin, Daniel L; Cohen, Matthew J

2013-10-01

Wetlands provide numerous ecosystem services, from habitat provision to pollutant removal, floodwater storage, and microclimate regulation. Delivery of particular services relies on specific ecological functions, and thus to varying degree on wetland ecological condition, commonly quantified as departure from minimally impacted reference sites. Condition assessments are widely adopted as regulatory indicators of ecosystem function, and for some services (e.g., habitat) links between condition and function are often direct. For others, however, links are more tenuous, and using condition alone to enumerate ecosystem value (e.g., for compensatory mitigation) may underestimate important services. Hydrologic function affects many services cited in support of wetland protection both directly (floodwater retention, microclimate regulation) and indirectly (biogeochemical cycling, pollutant removal). We investigated links between condition and hydrologic function to test the hypothesis, embedded in regulatory assessment of wetland value, that condition predicts function. Condition was assessed using rapid and intensive approaches, including Florida's official wetland assessment tool, in 11 isolated forested wetlands in north Florida (USA) spanning a land use intensity gradient. Hydrologic function was assessed using hydrologic regime (mean, variance, and rates of change of water depth), and measurements of groundwater exchange and evapotranspiration (ET). Despite a wide range in condition, no systematic variation in hydrologic regime was observed; indeed reference sites spanned the full range of variation. In contrast, ET was affected by land use, with higher rates in intensive (agriculture and urban) landscapes in response to higher leaf area. ET determines latent heat exchange, which regulates microclimate, a valuable service in urban heat islands. Higher ET also indicates higher productivity and thus carbon cycling. Groundwater exchange regularly reversed flow direction at all sites in response to rainfall. This buffering effect on regional aquifer levels, an underappreciated service of isolated wetlands, was provided regardless of condition. Intensive landscapes may benefit most from the hydrologic services that wetlands provide because that is where certain services (floodwater storage, microclimate regulation) are realized. While the portfolio of wetland services clearly changes with disturbance, our results support a revised approach to wetland valuation that recognizes the services that accrue from sustained or enhanced functions in these "working wetlands."

Hindcasting Historical Breeding Conditions for an Endangered Salamander in Ephemeral Wetlands of the Southeastern USA: Implications of Climate Change.

PubMed

Chandler, Houston C; Rypel, Andrew L; Jiao, Yan; Haas, Carola A; Gorman, Thomas A

2016-01-01

The hydroperiod of ephemeral wetlands is often the most important characteristic determining amphibian breeding success, especially for species with long development times. In mesic and wet pine flatwoods of the southeastern United States, ephemeral wetlands were a common landscape feature. Reticulated flatwoods salamanders (Ambystoma bishopi), a federally endangered species, depend exclusively on ephemeral wetlands and require at least 11 weeks to successfully metamorphose into terrestrial adults. We empirically modeled hydroperiod of 17 A. bishopi breeding wetlands by combining downscaled historical climate-model data with a recent 9-year record (2006-2014) of observed water levels. Empirical models were subsequently used to reconstruct wetland hydrologic conditions from 1896-2014 using the downscaled historical climate datasets. Reconstructed hydroperiods for the 17 wetlands were highly variable through time but were frequently unfavorable for A. bishopi reproduction (e.g., only 61% of years, using a conservative estimate of development time [12 weeks], were conducive to larval development and metamorphosis). Using change-point analysis, we identified significant shifts in average hydroperiod over the last century in all 17 wetlands. Mean hydroperiods were shorter in recent years than at any other point since 1896, and thus less suitable for A. bishopi reproduction. We suggest that climate change will continue to impact the reproductive success of flatwoods salamanders and other ephemeral wetland breeders by reducing the number of years these wetlands have suitable hydroperiods. Consequently, we emphasize the importance of conservation and management for mitigating other forms of habitat degradation, especially maintenance of high quality breeding sites where reproduction can occur during appropriate environmental conditions.

Macrobenthic diversity in protected, disturbed, and newly formed intertidal wetlands of a subtropical estuary in China.

PubMed

Lv, Weiwei; Ma, Chang-An; Huang, Youhui; Yang, Yang; Yu, Ji; Zhang, Mingqing; Zhao, Yunlong

2014-12-15

In this study, intertidal macrobenthic diversity in protected, disturbed, and newly formed wetlands of Yangtze estuary was assessed using PRIMER 5.2 based on species diversity and species relatedness. We observed high diversity in nature reserves and low diversity in adjacent disturbed and newly formed wetlands. These diversity data were then integrated with historical data to detect the variation in macrobenthic diversity over the past two decades. The integrated data indicated that the intertidal macrobenthic diversity sharply decreased in heavy reclamation tidal flats whereas markedly increased in non-disturbed nature reserve and newly formed wetland. Benthic health was observed with the departure degree of average taxonomic distinctness (Δ(+)) and variation in taxonomic distinctness (Λ(+)) from the simulated 95% confidence funnel. All the habitats were subjected to different levels of human interference, except Jiuduansha and Beigangbeisha. The degradation of intertidal wetland in Yangtze estuary was mainly attributed to land reclamation, overgrazing, and overfishing. Copyright © 2014 Elsevier Ltd. All rights reserved.

Diurnal variation of methane emissions from an alpine wetland on the eastern edge of Qinghai-Tibetan Plateau.

PubMed

Chen, Huai; Wu, Ning; Yao, Shouping; Gao, Yongheng; Wang, Yanfen; Tian, Jianqing; Yuan, Xingzhong

2010-05-01

Alpine wetland is a source for CH(4), but little is known about methane emission from such wetland, especially about its diurnal pattern. In this study we tried to probe the diurnal variation in methane emission from alpine wetland vegetation. The average methane emission rate was 9.6 +/- 3.4 mg CH(4) m(-2) h(-1). There was an apparent diurnal variation pattern in methane emission with one minor peak at 06:00 and a major one at 15:00. The sunrise peak was consistent with a two-way transport mechanism for plants (convective at daytime and diffusive at night-time). CH(4) emission was found significantly correlated with redox potentials. The afternoon peak could not be explained by diurnal variation in soil temperature, but could be attributable to changes in CH(4) oxidation and production driven by plant gas transport mechanism. The results have important implications for sampling and scaling strategies for estimating methane emission from alpine wetlands.

Performance and cost evaluation of constructed wetland for domestic waste water treatment.

PubMed

Deeptha, V T; Sudarsan, J S; Baskar, G

2015-09-01

Root zone treatment through constructed wetlands is an engineered method of purifying wastewater. The aim of the present research was to study the potential of wetland plants Phragmites and Typha in treatment of wastewater and to compare the cost of constructed wetlands with that of conventional treatment systems. A pilot wetland unit of size 2x1x0.9 m was constructed in the campus. 3x3 rows of plants were transplanted into the pilot unit and subjected to wastewater from the hostels and other campus buildings. The raw wastewater and treated wastewater were collected periodically and tested for Total nitrogen (TN),Total Phosphorous (TP), Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD). It was observed that this pilot unit reduced the concentrations of TN, TP, BOD and COD by 76, 73, 83 and 86%, respectively, on an average. Root zone system achieved standards for tertiary treatment with low operating costs, low maintenance costs, enhance the landscape, provide a natural habitat for birds, and did not emit any odour.

Mid term monitoring of heavy metals content in soils of Mediterranean coastal wetlands. La Albufera de Valencia Natural Park, Spain

NASA Astrophysics Data System (ADS)

Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Gimeno-García, Eugenia

2014-05-01

Coastal wetlands, in general, and Mediterranean ones, in particular, suffer from differente anthropogenic pressures that may affect their intrinsic environmental and ecological functions. Most, if not all, Mediterranean wetlands are not natural spaces were preservation of habitat and wildlife is the only management policy achieved, bur rather their terriroty is a combination of land units with different activities and influences, such as farming, environmental protection and connectivities with urban and industrial areas. Therefore, the need of periodical monitoring is required whenever pressures and environmental health of wetlands is assessed, particularly of those processes that affect the interconnection of environmental compartiments involving water, soils and biota. In agro-ecological protected wetlands soils play and important role because they are potential sources of pollutants due to farming practices. In this case, presence of heavy metals in soils is and indicator of both environmental health and anthtopogenic direct (farming activities) and indirect (neighbour urban areas) pressures. In this work a mid term (17 year) monitoring of seven heavy metals (Cd, Co, Cr, Cu, Pb, Ni and Zn) in soils of coastal Mediterranean wetlands (La Albufera Natural Park, Spain) are analyzed. Two monitoring campaings were achieved in 1991 and 2008. In both cases the same 20 points were visited which were distributed in the natural park according two four different sectors of potential anthropogenic pressure and land use. At each point two soil samples were collected at differente depths (0 to 20 cm and 20 to 40 cm). The selected metals were analyzed to determine its total and extractable fractions by treatment with EDTA. Atomic Absorption Spectrometry, using graphite furnace when necessary, was used for the determination of metals. In general, there is a reduction of metal contents in the study area in both dates. The trend of metals according to average concentration (mg/kg) in 1991 and 2008 were Zn (60.38) > Pb (47.50) > Ni (29.10) > Cu (25.82) > Cr (16.04) > Co (11.40) > Cd (0.50) and Zn (68.82) > Cr (48.12) > Cu (34.93) > Pb (24.60) > Ni (22.49) > Co (6.58) > Cd (0.42), respectively. Average increments were found in Zn, Cr and Cu, which are related with high point (indiviudal location and/or sector) values rather than a general trend in the area. Maximum concentrations were obtained for Zn (120.38 mg/kg and 230.05 mg/kg in 1991 and 2008 respectively), Pb (72.31 mg/kg and 64.90 mg/kg), Ni (43.07. mg/kg and 43.74 mg/kg), Cu (55.83 mg/kg and 109.91 mg/kg) and Cr (36.10 mg/kg and 254.93 mg/kg). There is a clear spatial trend in the distribution of heavy metals in both dates, higher values where found in the northern sector of the Natural Park, which is a neighbour sector of the large city of Valencia, and in points close (less than 500 m) to main roads, suggestin the influence of external factors in the distribution of pollutants. Acknowledgements This work was supported by the Spanish Ministry of Science and Innovation through the project CONSOLIDER-INGENIO 2010 (CSD2009) and by the Ministry and the European Regional Development Fund (ERDF) (projects CGL2011-29703-C02-00, CGL2011-29703-C02-01, CGL2011-29703-C02-02).

Water selenium speciation and sediment fractionation in a California flow-through wetland system

USGS Publications Warehouse

Gao, S.; Tanii, K.K.; Peters, D.W.; Herbel, M.J.

2000-01-01

A flow-through wetland system was established in the Tulare Lake Drainage District (TLDD) in California to determine if selenium (Se) from saline irrigation drainage can be removed prior to impoundment in evaporation basins to reduce potential toxicity to waterbirds. The objective of this research was to evaluate Se speciation, accumulation, and fractionation in the waters and sediments of the newly developed wetland system. The inlet water was dominated by selenate [Se(VI), 92%], with smaller percentages of selenite [Se(IV), 5%] and organic Se [org-Se(-II), 3%]. For the outflow water, the average percentage of Se(VI) was 72% in November 1997 and 59% in February 1999. This change may be due to an increase in either residence time and/or accumulation of organic detrital matter, which may enhance Se(VI) reduction processes. Selenium accumulation, transformation, and incorporation with the solid phase were all intensified in the surface sediment (<20 cm). The highest total Se concentrations in the sediments were found in the top 5 cm and concentrations dramatically decreased with depth. Elemental Se [Se(0)], as extracted by Na2SO3, was the largest fraction (average of 46%) of the total sediment Se, followed by organic matter-associated Se (OM-Se) extracted by NaOH (average of 34%). Soluble, adsorbed, and carbonate-associated Se, as extracted by KCl, K2HPO4 (pH 8.0), and NaOAc (pH 5.0), were about 3, 10, and 3% of the total sediment Se, respectively. After establishing the wetland for 2 yr, significant Se removal from the flowing water was observed. The major sink mechanisms in the sediment are reduction to Se(0) and immobilization into the organic phase.A flow-through wetland system was established in the Tulare Lake Drainage District (TLDD) in California to determine if selenium (Se) from saline irrigation drainage can be removed prior to impoundment in evaporation basins to reduce potential toxicity to waterbirds. The objective of this research was to evaluate Se speciation, accumulation, and fractionation in the waters and sediments of the newly developed wetland system. The inlet water was dominated by selenate [Se(VI), 92%], with smaller percentages of selenite [Se(IV), 5%] and organic Se [org-Se(-II), 3%]. For the outflow water, the average percentage of Se(VI) was 72% in November 1997 and 59% in February 1999. This change may be due to an increase in either residence time and/or accumulation of organic detrital matter, which may enhance Se(VI) reduction processes. Selenium accumulation, transformation, and incorporation with the solid phase were all intensified in the surface sediment (<20 cm). The highest total Se concentrations in the sediments were found in the top 5 cm and concentrations dramatically decreased with depth. Elemental Se [Se(0)], as extracted by Na2SO3, was the largest fraction (average of 46%) of the total sediment Se, followed by organic matter-associated Se (OM-Se) extracted by NaOH (average of 34%). Soluble, adsorbed, and carbonate-associated Se, as extracted by KCl, K2HPO4 (pH 8.0), and NaOAc (pH 5.0), were about 3, 10, and 3% of the total sediment Se, respectively. After establishing the wetland for 2 yr, significant Se removal from the flowing water was observed. The major sink mechanisms in the sediment are reduction to Se(0) and immobilization into the organic phase.

An approach to hydrogeological modeling of a large system of groundwater-fed lakes and wetlands in the Nebraska Sand Hills, USA

NASA Astrophysics Data System (ADS)

Rossman, Nathan R.; Zlotnik, Vitaly A.; Rowe, Clinton M.

2018-05-01

The feasibility of a hydrogeological modeling approach to simulate several thousand shallow groundwater-fed lakes and wetlands without explicitly considering their connection with groundwater is investigated at the regional scale ( 40,000 km2) through an application in the semi-arid Nebraska Sand Hills (NSH), USA. Hydraulic heads are compared to local land-surface elevations from a digital elevation model (DEM) within a geographic information system to assess locations of lakes and wetlands. The water bodies are inferred where hydraulic heads exceed, or are above a certain depth below, the land surface. Numbers of lakes and/or wetlands are determined via image cluster analysis applied to the same 30-m grid as the DEM after interpolating both simulated and estimated heads. The regional water-table map was used for groundwater model calibration, considering MODIS-based net groundwater recharge data. Resulting values of simulated total baseflow to interior streams are within 1% of observed values. Locations, areas, and numbers of simulated lakes and wetlands are compared with Landsat 2005 survey data and with areas of lakes from a 1979-1980 Landsat survey and the National Hydrography Dataset. This simplified process-based modeling approach avoids the need for field-based morphology or water-budget data from individual lakes or wetlands, or determination of lake-groundwater exchanges, yet it reproduces observed lake-wetland characteristics at regional groundwater management scales. A better understanding of the NSH hydrogeology is attained, and the approach shows promise for use in simulations of groundwater-fed lake and wetland characteristics in other large groundwater systems.

Effects of acidic precipitation on waterbirds in Maine

USGS Publications Warehouse

Longcore, J.R.; McAuley, D.G.; Stromborg, K.L.; Hensler, G.L.

1985-01-01

During 1982-84 waterbird use and numbers of waterbird broods were recorded for 29 wetlands on two study areas (25 and 77 km2) in east-central Maine underlain with bedrock having low, acid-neutralizing capacity (ANC). Twenty-nine wetlands over bedrock with high ANC (Class 3) and 31 wetlands over bedrock of low ANC (Class 1) were evaluated as predictors of wetland pH and alkalinity. Using the alkalinity value of 25 times was greater (P< ..0001) for downstream (84%) versus headwater (16%) wetlands during 1982-84. Avian use was similar when wetlands were classified either as beaver-created or glacial in origin. Headwater wetlands, which are most vulnerable to acidification within the low ANC areas, are used mostly by common goldeneye (Bucephala clangula), and common loon (Gavia immer). Common merganser (Mergus merganser), spotted sandpiper (Actitis macularia), and chimney swift (Chaetura pelagica) were associated with headwater wetlands about equally. The majority of species (16), including dabbling ducks, used, almost exclusively, wetlands classified as downstream or beaver-created. For all years, 87% of the 246 broods observed was on wetlands classified as either downstream or beaver-created. Our data suggest that avian use of wetlands is influenced more by the morphometric and vegetative characteristics of the wetland basin rather than by the wetland water chemistry. Nevertheless, large numbers of a variety of avian species are associated with wetlands underlain with bedrock that has little or no capacity to neutralize acidic depositions.

[Wetlands of priority restoration in Northeast China based on spatial analysis].

PubMed

Dong, Zhang-Yu; Liu, Dian-Wei; Wang, Zong-Ming; Ren, Chun-Ying; Tang, Xu-Guang; Jia, Ming-Ming; Wang, Yan

2013-01-01

By using GIS/RS technology, and from the aspects of landscape structure, river- and road densities, wetness index, geomorphology, and cultivated land productivity, a spatial analysis was made on the potentiality of wetland restoration in Northeast China, with the regions of priority and secondary priority restoration wetlands determined. Then, by using the coordinated development index of crop production and wetland as well as the landscape indices, the wetland restoration effect was verified. In Northeast China, the wetland area of priority restoration was 1.78 x 10(6) hm2, among which, farmland and grassland were the main types for restoration, accounting for 96.7% of the total, and mainly located in the Sanjiang Plain in the northeastern part and the Songnen Plain in the central part of Northeast China. The wetland area of secondary priority restoration was 1.03 x 10(6) hm2. After the restoration of the wetlands, the wetland area in Northeast China would be increased by 37.4%, compared with the present wetland area, and the value of the coordinated development index of crop production and wetland would increase from 0.539 before restoration to 0.733 after restoration. The landscape pattern would be more benefit to the performance of the ecological functions of the wetlands. This study revealed that the restoration scheme of the wetlands in Northeast China based on spatial analysis was practicable, which could provide data support for the implement of wetland restoration and the improvement of ecological environment in Northeast China.

Long-term change in limnology and invertebrates in Alaskan boreal wetlands

USGS Publications Warehouse

Corcoran, R.M.; Lovvorn, J.R.; Heglund, P.J.

2009-01-01

Climate change is more pronounced at high northern latitudes, and may be affecting the physical, chemical, and biological attributes of the abundant wetlands in boreal forests. On the Yukon Flats, located in the boreal forest of northeast Alaska, wetlands originally sampled during 1985-1989 were re-sampled for water chemistry and macroinvertebrates in summer 2001-2003. Wetlands sampled lost on average 19% surface water area between these periods. Total nitrogen and most metal cations (Na, Mg, and Ca, but not K) increased between these periods, whereas total phosphorus and chlorophyll a (Chl a) declined. These changes were greater in wetlands that had experienced more drying (decreased surface area). Compared with 1985-1989, densities of cladocerans, copepods, and ostracods in both June and August were much higher in 2002-2003, whereas densities of amphipods, gastropods, and chironomid larvae were generally lower. In comparisons among wetlands in 2002-2003 only, amphipod biomass was lower in wetlands with lower Chl a, which might help explain the decline of amphipods since the late 1980s when Chl a was higher. The decline in Chl a corresponded to greatly increased zooplankton density in June, suggesting a shift in carbon flow from scrapers and deposit-feeders to water-column grazers. Declines in benthic and epibenthic deposit-feeding invertebrates suggest important food web effects of climate change in otherwise pristine wetlands of the boreal forest. ?? 2008 Springer Science+Business Media B.V.

Contaminant exposure and effects in Red-Winged Blackbirds inhabiting stormwater retention ponds

USGS Publications Warehouse

Sparling, D.W.; Eisemann, J.D.; Kuenzel, W.J.

2004-01-01

Stormwater wetlands are created to retain water from storms and snow melt to reduce sediment, nutrient, and contaminant pollution of natural waterways in metropolitan areas. However, they are often a source of attractive habitat to wetland-associated wildlife. In this study of 12 stormwater wetlands and a larger, older reference site, elevated concentrations of zinc and copper were found in sediments and carcasses of 8-day-old red-winged blackbird (Agelaius phoeniceus) nestlings inhabiting stormwater sites. Although nesting success in the stormwater wetlands was comparable to national averages, sediment zinc concentrations correlated with clutch size, hatching success, fledgling success, and Mayfield nest success, suggesting that the nestlings may have been stressed and impaired by elevated zinc. This stress may have been direct on the nestlings or indirect through effects on the availability of food organisms.

Contaminant exposure and effects in red-winged blackbirds inhabiting stormwater retention ponds.

PubMed

Sparling, Donald W; Eisemann, John D; Kuenzel, Wayne

2004-05-01

Stormwater wetlands are created to retain water from storms and snow melt to reduce sediment, nutrient, and contaminant pollution of natural waterways in metropolitan areas. However, they are often a source of attractive habitat to wetland-associated wildlife. In this study of 12 stormwater wetlands and a larger, older reference site, elevated concentrations of zinc and copper were found in sediments and carcasses of 8-day-old red-winged blackbird (Agelaius phoeniceus) nestlings inhabiting stormwater sites. Although nesting success in the stormwater wetlands was comparable to national averages, sediment zinc concentrations correlated with clutch size, hatching success, fledgling success, and Mayfield nest success, suggesting that the nestlings may have been stressed and impaired by elevated zinc. This stress may have been direct on the nestlings or indirect through effects on the availability of food organisms.

Pre-Construction Biogeochemical Analysis of Mercury in Wetlands Bordering the Hamilton Army Airfield (HAAF) Wetlands Restoration Site. Part 2

DTIC Science & Technology

2007-09-01

2004). Hydrophobic organic contaminants ( petroleum hydrocarbons , polynuclear aromatic hydrocarbons , and polychlorinated biphenyls) dissolved in the...Effect of 3.4% GAC contact on the 56-d bioaccumulation of THg and MeHg in Nereis virens...wetland restoration project. The bioaccumulation factor (BAF) values were greater for MeHg than for THg. The THg and MeHg body burdens of Nereis

Ecosystem development after mangrove wetland creation: plant-soil change across a 20-year chronosequence

USGS Publications Warehouse

Osland, Michael J.; Spivak, Amanda C.; Nestlerode, Janet A.; Lessmann, Jeannine M.; Almario, Alejandro E.; Heitmuller, Paul T.; Russell, Marc J.; Krauss, Ken W.; Alvarez, Federico; Dantin, Darrin D.; Harvey, James E.; From, Andrew S.; Cormier, Nicole; Stagg, Camille L.

2012-01-01

Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland losses. However, ecosystem development and functional equivalence in restored and created mangrove wetlands are poorly understood. We compared a 20-year chronosequence of created tidal wetland sites in Tampa Bay, Florida (USA) to natural reference mangrove wetlands. Across the chronosequence, our sites represent the succession from salt marsh to mangrove forest communities. Our results identify important soil and plant structural differences between the created and natural reference wetland sites; however, they also depict a positive developmental trajectory for the created wetland sites that reflects tightly coupled plant-soil development. Because upland soils and/or dredge spoils were used to create the new mangrove habitats, the soils at younger created sites and at lower depths (10-30 cm) had higher bulk densities, higher sand content, lower soil organic matter (SOM), lower total carbon (TC), and lower total nitrogen (TN) than did natural reference wetland soils. However, in the upper soil layer (0-10 cm), SOM, TC, and TN increased with created wetland site age simultaneously with mangrove forest growth. The rate of created wetland soil C accumulation was comparable to literature values for natural mangrove wetlands. Notably, the time to equivalence for the upper soil layer of created mangrove wetlands appears to be faster than for many other wetland ecosystem types. Collectively, our findings characterize the rate and trajectory of above- and below-ground changes associated with ecosystem development in created mangrove wetlands; this is valuable information for environmental managers planning to sustain existing mangrove wetlands or mitigate for mangrove wetland losses.

Estimating pothole wetland connectivity to Pipestem Creek ...

EPA Pesticide Factsheets

Understanding hydrologic connectivity between wetlands and perennial streams is critical to understanding how reliant stream flow is on wetlands within their watershed. We used the isotopic evaporation signal in water to examine wetland-stream hydrologic connectivity within the Pipestem Creek watershed, North Dakota, a watershed dominated by prairie-pothole wetlands. During a wetter-than-normal decade, Pipestem Creek exhibited an evaporated-water signal that had approximately half the isotopic-enrichment signal found in most evaporatively enriched pothole wetlands. If evaporation was mainly occurring within the stream, we expected the evaporation signal to increase from upstream towards downstream. However, the signal either remained similar or decreased downstream over the two years of sampling. Groundwater measured at the water table adjacent to Pipestem Creek had isotopic values that indicated recharge from winter precipitation and had no significant evaporative enrichment. Using isotopic theory and discharge data, we estimated the surface area of open water necessary to generate the evaporation signal found within Pipestem Creek over time. The range of evaporating surface-area estimates was highly dynamic, spanning from 35 to 2380 ha of open water contributing to streamflow over time, and varied primarily with the amount of discharge. The median value (417 ha) was well above the surface area of the Pipestem Creek network (245 ha), and only two periods

Edaphic Conditions Regulate Denitrification Directly and Indirectly by Altering Denitrifier Abundance in Wetlands along the Han River, China.

PubMed

Xiong, Ziqian; Guo, Laodong; Zhang, Quanfa; Liu, Guihua; Liu, Wenzhi

2017-05-16

Riparian wetlands play a critical role in retaining nitrogen (N) from upland runoff and improving river water quality, mainly through biological processes such as soil denitrification. However, the relative contribution of abiotic and biotic factors to riparian denitrification capacity remains elusive. Here we report the spatiotemporal dynamics of potential and unamended soil denitrification rates in 20 wetlands along the Han River, an important water source in central China. We also quantified the abundance of soil denitrifying microorganisms using nirK and nirS genes. Results showed that soil denitrification rates were significantly different between riparian and reservoir shoreline wetlands, but not between mountain and lowland wetlands. In addition, soil denitrification rates showed strong seasonality, with higher values in August (summer) and April (spring) but lower values in January (winter). The potential and unamended denitrification rates were positively correlated with edaphic conditions (moisture and carbon concentration), denitrifier abundance, and plant species richness. Path analysis further revealed that edaphic conditions could regulate denitrification rates both directly and indirectly through their effects on denitrifier abundance. Our findings highlight that not only environmental factors, but also biotic factors including denitrifying microorganisms and standing vegetation, play an important role in regulating denitrification rate and N removal capacity in riparian wetlands.

Hydrogeochemical investigation of Küçük Menderes River coastal wetland, Selçuk-Izmir, Turkey

NASA Astrophysics Data System (ADS)

Somay, A. Melis; Gemici, Ünsal; Filiz, Sevki

2008-07-01

Küçük Menderes River forms a rich coastal wetland inside in the Selçuk plain. Three saline/brackish lakes, one swamp and Küçük Menderes River are these wetlands’ components. Alkaline-slightly alkaline type lakes are recharged from precipitation and karstic springs that discharge from marble-schist and marble-alluvium contacts in the northern and southern parts of the study area. Water types of the wetland are Na-Cl and Na-Ca-Mg-HCO3-Cl in both rainy and dry seasons. Both seawater intrusion and evaporation, as being the sources of the ions, justify the presence of Na-Cl, Na-SO4 and Cl-SO4, in the wetland water. Environmental isotopes were used to identify the relationship between wetland and groundwater in the Selçuk plain. The δ18O and δD composition of wetland area samples have changed between -6.42 to -4.56‰, and -36.40 to -23.80‰, respectively. The lakes and rivers are plotted on the mixing line by slope of 5.2 and these data indicate that wetland is affected from seawater intrusion. The recharge area that was sampled in order to compare the wetland has Ca-HCO3 water type with a neutral-slightly alkaline pH values and the main hydrogeochemical process is weathering the different types of silicates. Iron, manganese and selenium are the dominant minor ions due to the high biological activities and organic matters in the lakes. There are two contamination risks for this wetland: (1) waste disposal site and (2) water treatment plant where the purified waters are released into the river. EC, Al, As, Cd, Cu, Fe and Zn values exceed those of aquatic life standards. In the near future these sites will pose a danger for wetland wild life and surrounding irrigation water suppliers.

The Transition of Benthic Nutrient Sources after Planned Levee Breaches Adjacent to Upper Klamath and Agency Lakes, Oregon

USGS Publications Warehouse

Kuwabara, James S.; Topping, Brent R.; Carter, James L.; Parcheso, Francis; Cameron, Jason M.; Asbill, Jessica R.; Fend, Steven V.; Duff, John H.; Engelstad, Anita C.

2010-01-01

Four sampling trips were coordinated after planned levee breaches that hydrologically reconnected both Upper Klamath Lake and Agency Lake, Oregon, to adjacent wetlands. Sets of nonmetallic pore-water profilers were deployed during these trips in November 2007, June 2008, May 2009, and July 2009. Deployments temporally spanned the annual cyanophyte bloom of Aphanizomenon flos-aquae (AFA) and spatially involved three lake and four wetland sites. Profilers, typically deployed in triplicate at each lake or wetland site, provided high-resolution (centimeter-scale) estimates of the vertical concentration gradients for diffusive-flux determinations. Estimates based on molecular diffusion may underestimate benthic flux because solute transport across the sediment-water interface can be enhanced by processes including bioturbation, bioirrigation and groundwater advection. Water-column and benthic samples were also collected to help interpret spatial and temporal trends in diffusive-flux estimates. Data from these samples complement taxonomic and geochemical analyses of bottom-sediments taken from Upper Klamath Lake (UKL) in prior studies. This ongoing study provides information necessary for developing process-interdependent solute-transport models for the watershed (that is, models integrating physical, geochemical, and biological processes) and supports efforts to evaluate remediation or load-allocation strategies. To augment studies funded by the U.S. Bureau of Reclamation (USBR), the Department of the Interior supported an additional full deployment of pore-water profilers in November 2007 and July 2009, immediately following the levee breaches and after the crash of the annual summer AFA bloom. As observed consistently since 2006, benthic flux of 0.2-micron filtered, soluble reactive phosphorus (that is, biologically available phosphorus, primarily as orthophosphate; SRP) was consistently positive (that is, out of the sediment into the overlying water column) and ranged from a negligible value (-0.19?0.91 milligrams per square meter per day; mg m-2 d-1) within wetlands of the Upper Klamath National Wildlife Refuge to 74?48 mg m-2 d-1 at the newly restored wetland site removed from the levee breach (TNC1); both observed in May 2009 before the annual AFA bloom. When areally averaged (13 km2 for the newly restored wetlands), an SRP flux to the overlying water column is determined of approximately 87,000 kilograms (kg) over the 3-month AFA bloom season that exceeds the magnitude of riverine inputs (42,000 kg for the season). Elevated SRP benthic flux at TNC1 relative to all other lake and wetland sites (including TNC2 near the breached levee) in 2009 suggests that the restored wetlands, at least chemically, remain in a transition period after engineered blasts on October 30, 2007, restored hydrologic connectivity between lake and wetland environments. As reported in previous lake studies, ammonium fluxes to the water column were consistently positive, with the exception of two measurements at the restored wetland sites (TNC1 and TNC2) immediately following the levee breaches in November 2007. The flux of ammonia, particularly at elevated pH in the overlying water column, has toxicological implications for endangered fish populations in both lake and wetland environments. For dissolved nitrate, with the exception of a single positive flux measurement at TNC1 in June 2008 (0.16?0.02 mg m-2 d-1), consistently negative (consumed by the sediment) or undetectable nitrate-flux values were observed (-21?12 mg m-2 d-1 to undetectable fluxes due to concentrations for dissolved nitrate <0.03 milligrams per liter (mg L-1) in both porewaters and overlying waters near the sediment-water interface). Such negative fluxes for dissolved nitrate are typical of microbial transformations, such as dinitrification (dissimilatory nitrate reduction), that benthically consume nitrate from the water column. The diffusive-flux measurements reported herei

Phosphorus and nitrogen legacy in a restoration wetland, upper Klamath lake, Oregon

USGS Publications Warehouse

Duff, J.H.; Carpenter, K.D.; Snyder, D.T.; Lee, Karl K.; Avanzino, R.J.; Triska, F.J.

2009-01-01

The effects of sediment, ground-water, and surface-water processes on the timing, quantity, and mechanisms of N and P fluxes were investigated in the Wood River Wetland 57 years after agricultural practices ceased and seasonal and permanent wetland hydrologies were restored. Nutrient concentrations in standing water largely reflected ground water in winter, the largest annual water source in the closed-basin wetland. High concentrations of total P (22 mg L -1) and total N (30 mg L-1) accumulated in summer when water temperature, air temperature, and evapotranspiration were highest. High positive benthic fluxes of soluble reactive P and ammonium (NH4-N) were measured in two sections of the study area in June and August, averaging 46 and 24 mg m-2 d-1, respectively. Nonetheless, a wetland mass balance simultaneously indicated a net loss of P and N by assimilation, denitrification (1.110.1 mg N m-2 h-1), or solute repartitioning. High nutrient concentrations pose a risk for water quality management. Shifts in the timing and magnitude of water inflows and outflows may improve biogeochemical function and water quality by optimizing seed germination and aquatic plant distribution, which would be especially important if the Wood River Wetland was reconnected with hyper-eutrophic Agency Lake. ?? 2009, The Society of Wetland Scientists.

Grey water characteristics and treatment options for rural areas in Jordan.

PubMed

Halalsheh, M; Dalahmeh, S; Sayed, M; Suleiman, W; Shareef, M; Mansour, M; Safi, M

2008-09-01

Low water consumption in rural areas in Jordan had resulted in the production of concentrated grey water. Average COD, BOD and TSS values were 2568mg/l, 1056mg/l and 845mg/l, respectively. The average grey water generation was measured to be 14L/c.d. Three different treatment options were selected based on certain criterions, and discussed in this article. The examined treatment systems are septic tank followed by intermittent sand filter; septic tank followed by wetlands; and UASB-hybrid reactor. Advantages and disadvantages of each system are presented. It was concluded that UASB-hybrid reactor would be the most suitable treatment option in terms of compactness and simplicity in operation. The volume of UASB-hybrid reactor was calculated to be 0.268m(3) with a surface area of 0.138m(2) for each house having 10 inhabitants on average. Produced effluent is expected to meet Jordanian standards set for reclaimed water reuse in irrigating fruit trees.

Hydrology, vegetation, and soils of four north Florida River flood plains with an evaluation of state and federal wetland determinations

USGS Publications Warehouse

Light, H.M.; Darst, M.R.; MacLaughlin, M.T.; Sprecher, S.W.

1993-01-01

A study of hydrologic conditions, vegetation, and soils was made in wetland forests of four north Florida streams from 1987 to 1990. The study was conducted by the U.S. Geological Survey in cooperation with the Florida Department of Environmental Regulation to support State and Federal efforts to improve wetland delineation methodology in flood plains. Plant communities and soils were described and related to topographic position and long-term hydrologic conditions at 10 study plots located on 4 streams. Detailed appendixes give average duration, frequency, and depth of flooding; canopy, subcanopy, and ground-cover vegetation; and taxonomic classification, series, and profile descriptions of soils for each plot. Topographic relief, range in stage, and depth of flooding were greatest on the alluvial flood plain of the Ochlockonee River, the largest of the four streams. Soils were silty in the lower elevations of the flood plain, and tree communities were distinctly different in each topographic zone. The Aucilla River flood plain was dominated by levees and terraces with very few depressions or low backwater areas. Oaks dominated the canopy of both lower and upper terraces of the Aucilla flood plain. Telogia Creek is a blackwater stream that is a major tributary of the Ochlockonee River. Its low, wet flood plain was dominated by Wyssa ogeche (Ogeechee tupelo) trees, had soils with mucky horizons, and was inundated by frequent floods of very short duration. The St. Marks River, a spring-fed stream with high base flow, had the least topographic relief and lowest range in stage of the four streams. St. Marks soils had a higher clay content than the other streams, and limestone bedrock was relatively close to the surface. Wetland determinations of the study plots based on State and Federal regulatory criteria were evaluated. Most State and Federal wetland determinations are based primarily on vegetation and soil characteristics because hydrologic records are usually not available. In this study, plots were located near long-term gaging stations, thus wetland determinations based on plant and soil characteristics could be evaluated at sites where long-term hydrologic conditions were known. Inconsistencies among hydrology, vegetation, and soil determinations were greatest on levee communities of the Ochlockonee and Aucilla River flood plains. Duration of average annual longest flood was almost 2 weeks for both plots. The wetland species list currently used (1991) by the State lacks many ground-cover species common to forested flood plains of north Florida rivers. There were 102 ground-cover species considered upland plants by the State that were present on the nine annually flooded plots of this study. Among them were 34 species that grew in areas continuously flooded for an average of 5 weeks or more each year. Common flood-plain species considered upland plants by the State were: Hypoxis leptocarpa (yellow star-grass), and two woody vines, Brunnichia ovata (ladies' eardrops) and Campsis radicans (trumpet-creeper), which were common in areas flooded continuously for 6 to 9 weeks a year; Sebastiania fruticosa (Sebastian-bush), Chasmanthium laxum (spikegrass), and Panicum dichotomum (panic grass), which typically grew in areas flooded an average of 2 to 3 weeks or more per year; Vitis rotundifolia (muscadine) and Toxicodendron radicans (poison-ivy), usually occurring in areas flooded an average of 1 to 2 weeks a year; and Quercus virginiana (live oak) present most often in areas flooded approximately 1 week a year. Federal wetland regulations (1989) limited wetland jurisdiction to only those areas that are inundated or saturated during the growing season. However, year-round hydrologic records were chosen in this report to describe the influence of hydrology on vegetation, because saturation, inundation, or flowing water can have a variety of both beneficial and adverse effects on flood-plain vegetation at any time of the

Nitrous oxide and methane emission in an artificial wetland treating polluted runoff from an agricultural catchment

NASA Astrophysics Data System (ADS)

Mander, Ülo; Tournebize, Julien; Soosaar, Kaido; Chaumont, Cedric; Hansen, Raili; Muhel, Mart; Teemusk, Alar; Vincent, Bernard

2015-04-01

An artificial wetland built in 2010 to reduce water pollution in a drained agricultural watershed showed real potential for pesticide and nitrate removal. The 1.2 ha off-shore wetland with a depth of from 0.1 to 1 m intercepts drainage water from a 450 ha watershed located near the village of Rampillon (03°03'37.3'' E, 48°32'16.7'' N, 70 km south-east of Paris, France). A sluice gate installed at the inlet makes it possible to close the wetland during the winter months (December - March), when no pesticides are applied and rainfall events are more frequent. The flow entering the wetland fluctuates from 0 to 120 L/s. The wetland is partially covered by Carex spp., Phragmites australis, Juncus conglomeratus, Typha latifolia and philamentous algae. Since 2011, an automatic water quality monitoring system measures water discharge, temperature, dissolved O2, conductivity pH, NO3- and DOC in both inlet and outlet. In May 2014, an automatic weather station and Campbell Irgason system for the measurement of CO2 and H2O fluxes were installed in the middle of the wetland. In May and November 2014 one-week high frequency measurement campaigns were conducted to study N2O and CH4 fluxes using 6 manually operated opaque floating static chambers and 12 floating automatic dynamic chambers. The latter were operated via multiplexer and had an incubation time of 5 minutes, whereas the gas flow was continuously measured using the Aerodyne TILDAS quantum cascade laser system. During the campaign, the reduction of NO3- concentration was measured in nine reactor pipes. Also, water samples were collected for N2O and N2 isotope analysis, and sediments were collected for potential N2 emission measurements. In May, the hydraulic retention time (HRT) was 30 days, and the average NO3- concentration decreased from 24 in the inflow to 0 mg/L in the outflow. Methane flux was relatively high (average 1446, variation 0.2-113990 μg CH4-C m-2 h-1), while about 2/3 was emitted via ebullition. Nitrous oxide flux was low (average 1.1, variation from -25 to 63 μg N2O-N m-2 h-1) and showed consumption during the daytime. Similarly to CH4, most of the N2O emission originated from ebullition. The potential N2 flux from sediments was high (990-1920 μg N m-2 h-1). In November, with HRT at about 3 days, the average NO3- concentration decreased from 45 to 20 mg/L. Methane flux was 2-3 times lower and N2O emission about 2 times higher than in May. This is related to the lower water temperature (20°C in May and 10°C in November) and shorter HRT in November. However, in situ pipe reactors showed a 90% NO3- removal potential in both periods. Offshore artificial wetlands can efficiently remove NO3- without significant N2O emission, although CH4 flux can be high during the first 5 years after establishment.

Population estimates of Hyla cinerea (Schneider) (Green Tree frog) in an urban environment

USGS Publications Warehouse

Pham, L.; Boudreaux, S.; Karhbet, S.; Price, B.; Ackleh, A.S.; Carter, J.; Pal, N.

2007-01-01

Hyla cinerea (Green Treefrog) is a common wetlands species in the southeastern US. To better understand its population dynamics, we followed a relatively isolated population of Green Treefrogs from June 2004 through October 2004 at a federal office complex in Lafayette, LA. Weekly, Green Treefrogs were caught, measured, marked with VIE tags, and released. The data were used to estimate population size. The time frame was split into two periods: before and after August 17, 2004. Before August 17, 2004, the average estimated population size was 143, and after August 24, 2005, this value jumped to 446, an increase possibly due to tadpoles metamorphosing into adults.

Limnology of Jagatpur wetland, Bhagalpur (Bihar), India.

PubMed

Kumar, Brajnandan

2011-10-01

The water quality in Jagatpur wetland was assessed in terms of physico - chemical characteristics for two years, between August 2003-July 2005. The variations in different physico-chemical parameters have been discussed in this paper in relation to fluctuating climatic condition. The wetland is experiencing racing eutrophication as evidenced by pH was acidic to alkaline, total hardness was considerably high, bicarbonate was in moderate amount, phosphate-phosphorus content was in a range of medium to high and higher values of COD. The present status of the quality of water of Jagatpur wetland is delineated in this paper.

Hydrologic Linkages Between Floodplain Wetlands and Adjacent Agricultural Lands

NASA Astrophysics Data System (ADS)

Matteson, C.; Jackson, C. R.; Wilde, S. B.; Batzer, D.; Shelton, J.; Jeffers, J. B.

2017-12-01

Depending on wetland position relative to dominant flow pathways, wetlands can provide biogeochemical processing and water quality improvement in agricultural settings, particularly with respect to nutrients. Here we evaluate field-to-stream water quality gradients across a forested alluvial swamp and through a ditched wetland swale on the same site. During 2016 and 2017, water samples collected on a farm from shallow piezometers and surface water were analyzed for total oxidized nitrogen (TOxN), total phosphorus (TP), and microbial abundance. A 54-acre alluvial swamp borders the northern side of the study farm. Toeslope nutrient concentrations in shallow groundwater and surfacewater are elevated relative to background levels, with median values of 13.25 mg/l/TOxN and 47.60 µg/l/TP. Shallow groundwater and surfacewater concentrations are substantially lower only a few meters into the floodplain wetland and lower still (0.13 mg/l/TOxN and 29.67 µg/l/TP) at discharge points to an adjacent creek. Across the farm, an 18-acre wetland swale has been ditched, drained, and cropped. TOxN levels entering and exiting the ditched swale do not mitigate as efficiently, median values of 3.91 mg/l/TOxN reduce to 1.45 mg/l/TOxN, while TP input and reduction exceed the alluvial swamp by starting at 141.67 µg/l/TP at the inflow and discharging into a large river at 57.40 µg/l/TP. Microbial communities in seeps and surfacewater also vary systematically with geographic position. Higher proportions of Cyanobacteria, Turbidity indicators, and Diatom communities are observed in the ditched swale, and input areas of the alluvial swamp. ANOVA tests of TOxN (P<0.001) and TP (P=0.9) change across the alluvial swamp suggest effective processing of TOxN. While P values for TOxN and TP in the ditched swale, yield P=0.9 for TOxN and P=1.0 for TP indicating reduced efficiency of mitigation. Though values of both TOxN and TP do decrease before discharge into the river, they are not statistically significant and still greater values than the alluvial swamp. Dissipation of microbial indicators shows pollution mitigation further into the alluvial swamp. Though pollutant additions have been similar into both wetland types, water quality improvements are distinct in the alluvial swamp.

Research: The Effect of Wetland Mitigation Banking on the Achievement of No-Net-Loss.

PubMed

BROWN; LANT

1999-04-01

/ This study determines whether the 68 wetland mitigation banks in existence in the United States through 1 January 1996 are achieving no-net-loss of wetland acreage nationally and regionally. Although 74% of the individual banks achieve no-net-loss by acreage, overall, wetland mitigation banks are projected to result in a net loss of 21,328 acres of wetlands nationally, 52% of the acreage in banks, as already credited wetland acreages are converted to otheruses. While most wetland mitigation banks are using appropriate compensation methods and ratios, several of the largest banks use preservation or enhancement, instead of restoration or creation. Most of these preservation/enhancement banks use minimum mitigation ratios of 1:1, which is much lower than ratios given in current guidelines. Assuming that mitigation occurs in these banks as preservation at the minimum allowable ratio, ten of these banks, concentrated in the western Gulf Coast region, will account for over 99% of projected net wetland acreage loss associated with banks. We conclude that wetland mitigation banking is a conceptually sound environmental policy and planning tool, but only if applied according to recently issued guidelines that ensure no-net-loss of wetland functions and values. Wetland mitigation banking inevitably leads to geographic relocation of wetlands, and therefore changes, either positively or negatively, the functions they perform and ecosystem services they provide. KEY WORDS: Mitigation banking; Wetlands; Army Corps of Engineers; No-net-loss

Response of ecosystem services to land use change in Xiamen Island

NASA Astrophysics Data System (ADS)

Gao, L.

2009-12-01

: Land use change was a major factor affecting ecosystem services. Taken Xiamen Island as an example, by integrating remote sensing data to examine land use patterns from 1950 to 2007, the regional ecosystem services of Xiamen Island were evaluated based on two revised methods aiming to identify the stress effects and mechanisms of land use change on ecosystem services. The results showed that during 1950~2007, in general, Xiamen Island’s land use intensity had been annually rising. The trends of Xiamen Island’s ecosystem services value acquired by two methods were both consistent with decreasing along with the growth of land use intensity. Before 1987, the ecosystem service value of Xiamen Island had increased by 1.07 million yuan, due to the expanding of 12.87 km2 water and wetland. After the establishment of Xiamen special economic zone in 1984, the rapid urbanization has resulted a sharp decline in ecosystem service value, the average annual loss reached by 619,773 yuan after 1987. As the utilization of land reaching saturation and the launching of ecological projects, such as the Xiamen Eastern Sea Comprehensive Improvement Project, it could be predicted that the decreasing trend of ecosystem services value was going to be slowed down in the near future. The first revised method referencing four eco-system services solved the problem of overestimated value caused by the second revised method based on provisioning service alone. By applying the ESV total correction method, the problem of over counting service value by correction made from a single aspect could be solved.Equivalent value per unit area of ecosystem services in China 2007 and revised value by second method Note: The modified coefficient of crop, orchard & forest, wetland and inland water provisioning ESV revised by the second method is 2.858, 2.405, 1.523, 1.843 respectively; for regulating, ultural and supporting ESV, the coefficient is 2.339, 15.339, 2.339 respectively.

Treatment of domestic wastewater by subsurface flow constructed wetlands filled with gravel and tire chip media.

PubMed

Richter, A Y; Weaver, R W

2003-12-01

Subsurface flow constructed wetlands (SFCWs) are becoming increasingly common in on-site treatment of wastewater. Gravel is the most popular form of wetland fill medium, but tire chips provide more porosity, are less dense, and less expensive. This study determines the treatment efficiency of SFCWs filled with gravel or tire chip media to treat domestic wastewater. The influent and effluent of six SFCWs filled with tire chip medium and six SFCWs filled with gravel were monitored for 5 to 16 consecutive months. Parameters measured included pH, biochemical oxygen demand (BOD5), total and volatile suspended solids, NH4, P, and fecal and total coliforms. The only clear difference between medium types in wetland performance was for P. Soluble P in the effluent averaged 1.6 +/- 1.0 mg l(-1) in the tire chip-filled wetlands and 4.8 +/- 3.2 mg l(-1) in the gravel-filled wetlands. Most likely, Fe from exposed wires in shredded steel-belted tires complexed with P to create an insoluble compound. Tire chips may be a better fill medium for SFCWs than gravel because of higher porosity, lower cost, and greater reduction of P in effluent.

Climate and land-use change in wetlands: A dedication

USGS Publications Warehouse

Middleton, Beth A.

2017-01-01

Future climate and land-use change may wreak havoc on wetlands, with the potential to erode their values as harbors for biota and providers of human services. Wetlands are important to protect, particularly because these provide a variety of ecosystem services including wildlife habitat, water purification, flood storage, and storm protection (Mitsch, Bernal, and Hernandez 2015). Without healthy wetlands, future generations may become increasingly less in harmony with the sustainability of the Earth. To this end, the thematic feature on climate and land-use change in wetlands explores the critical role of wetlands in the overall health and well-being of humans and our planet. Our special feature contributes to the understanding of the idea that the health of natural ecosystems and humans are linked and potentially stressed by climate change and land-use change (Horton and Lo 2015; McDonald 2015). In particular, this special issue considers the important role of wetlands in the environment, and how land-use and environmental change might affect them in the future.

Effect of recirculation on organic matter removal in a hybrid constructed wetland system.

PubMed

Ayaz, S C; Findik, N; Akça, L; Erdoğan, N; Kinaci, C

2011-01-01

This research project aimed to determine the technologically feasible and applicable wastewater treatment systems which will be constructed to solve environmental problems caused by small communities in Turkey. Pilot-scale treatment of a small community's wastewater was performed over a period of more than 2 years in order to show applicability of these systems. The present study involves removal of organic matter and suspended solids in serially operated horizontal (HFCW) and vertical (VFCW) sub-surface flow constructed wetlands. The pilot-scale wetland was constructed downstream of anaerobic reactors at the campus of TUBITAK-MRC. Anaerobically pretreated wastewater was introduced into this hybrid two-stage sub-surface flow wetland system (TSCW). Wastewater was first introduced into the horizontal sub-surface flow system and then the vertical flow system before being discharged. Recirculation of the effluent was tested in the system. When the recirculation ratio was 100%, average removal efficiencies for TSCW were 91 +/- 4% for COD, 83 +/- 10% for BOD and 96 +/- 3% for suspended solids with average effluent concentrations of 9 +/- 5 mg/L COD, 6 +/- 3 mg/L BOD and 1 mg/L for suspended solids. Comparing non-recirculation and recirculation periods, the lowest effluent concentrations were obtained with a 100% recirculation ratio. The effluent concentrations met the Turkish regulations for discharge limits of COD, BOD and TSS in each case. The study showed that a hybrid constructed wetland system with recirculation is a very effective method of obtaining very low effluent organic matter and suspended solids concentrations downstream of anaerobic pretreatment of domestic wastewaters in small communities.

Dynamic use of wetlands by black ducks and mallards: evidence against competitive exclusion

USGS Publications Warehouse

McAuley, D.G.; Clugston, D.A.; Longcore, J.R.

2004-01-01

The decline of the American black duck (Anas rubripes) has been attributed to competition from mallards (A. platyrhynchos) that led to exclusive use of fertile wetlands by mallards. Data from annual breeding waterfowl surveys provide instantaneous, single observations of breeding pairs, which are used to estimate breeding population size and evaluate the condition of habitat. Data from these surveys have been used to document habitat use by black ducks and mallards. We used quiet-observation surveys from elevated platforms to study sympatric black ducks and mallards in northern Maine during the breeding season. Our objectives were to document occupancy of wetlands by breeding black ducks and mallards throughout the day during prenesting and early nesting periods to determine whether 1) wetlands were occupied by only a single species, 2) pairs of the same species occupied wetlands throughout the period, and 3) single observations of short duration adequately determine numbers and species using a wetland. We observed ducks at 5-minute intervals from elevated platforms on wetland margins to determine numbers and species of indicated pairs using each wetland over time. We visited 80% of the wetlands >2 times, with mean total time per wetland averaging 267 minutes. For each wetland we determined the most frequently observed grouping of black ducks and mallards from all combinations recorded during all intervals (e.g., 1 black duck [BO] pair during 9 intervals; 2 mallard [MA] pairs and 1 BO pair during 22 intervals; 0 pairs during 3 intervals). A single pair, a lone male, or no ducks were recorded during 34% of the 5-minute intervals. For wetlands with >2 hours of observations (n=65), all but 2 were used by >2 different combinations of ducks. On most wetlands, the most frequent grouping was observed during 2 hours were used by both species, random visits detected both species on only 27 wetlands. Our data do not support assertions that the mallard has caused the decline of black ducks through interspecific competition for habitat, or that wetlands are occupied continuously by single pairs that aggressively exclude conspecifics. Our data indicated that single, short-duration visits with disturbance to wetlands are unreliable and inappropriate to document seasonal use of wetlands by breeding black ducks and mallards.

Hindcasting Historical Breeding Conditions for an Endangered Salamander in Ephemeral Wetlands of the Southeastern USA: Implications of Climate Change

PubMed Central

Chandler, Houston C.; Rypel, Andrew L.; Jiao, Yan; Haas, Carola A.; Gorman, Thomas A.

2016-01-01

The hydroperiod of ephemeral wetlands is often the most important characteristic determining amphibian breeding success, especially for species with long development times. In mesic and wet pine flatwoods of the southeastern United States, ephemeral wetlands were a common landscape feature. Reticulated flatwoods salamanders (Ambystoma bishopi), a federally endangered species, depend exclusively on ephemeral wetlands and require at least 11 weeks to successfully metamorphose into terrestrial adults. We empirically modeled hydroperiod of 17 A. bishopi breeding wetlands by combining downscaled historical climate-model data with a recent 9-year record (2006–2014) of observed water levels. Empirical models were subsequently used to reconstruct wetland hydrologic conditions from 1896–2014 using the downscaled historical climate datasets. Reconstructed hydroperiods for the 17 wetlands were highly variable through time but were frequently unfavorable for A. bishopi reproduction (e.g., only 61% of years, using a conservative estimate of development time [12 weeks], were conducive to larval development and metamorphosis). Using change-point analysis, we identified significant shifts in average hydroperiod over the last century in all 17 wetlands. Mean hydroperiods were shorter in recent years than at any other point since 1896, and thus less suitable for A. bishopi reproduction. We suggest that climate change will continue to impact the reproductive success of flatwoods salamanders and other ephemeral wetland breeders by reducing the number of years these wetlands have suitable hydroperiods. Consequently, we emphasize the importance of conservation and management for mitigating other forms of habitat degradation, especially maintenance of high quality breeding sites where reproduction can occur during appropriate environmental conditions. PMID:26910245

Evaluation of a market in wetland credits: entrepreneurial wetland banking in Chicago.

PubMed

Robertson, Morgan; Hayden, Nicholas

2008-06-01

With the rise of market-led approaches to environmental policy, compensation for permitted discharge of dredge or fill material into wetlands under Section 404 of the U.S. Clean Water Act has been purchased increasingly from entrepreneurial third-party providers. The growth of this practice (i.e., entrepreneurial wetland banking) has resolved many challenges associated with wetland compensation. But it has also produced (1) quantifiable temporal loss of wetland ecological functions, (2) spatial redistribution of wetland area, and (3) a degree of regulatory instability that may pose a threat to entrepreneurial compensation as a sustainable component of wetland-compensation policy. We used achieved compensation ratios, lapse between bank credit sale and the attainment of performance standards, distance between impact and bank site, and changes in bank market area to examine these 3 factors. We analyzed data from a census of all such transactions in the Chicago District of the U.S. Army Corps of Engineers, compiled from site visits, Corps databases, and contacts with consultants and Section 404 permittees. Entrepreneurial banking provided compensation at a lower overall ratio than nonbank forms of compensation. Approximately 60% of bank credits were sold after site-protection standards were met but before ecological performance standards were met at the bank site. The average distance between bank and impact site was approximately 26 km. The area of markets within which established banks can sell wetland credits has fluctuated considerably over the study period. Comparing these data with similar data for other compensation mechanisms will assist in evaluating banking as an element of conservation policy. Data characterizing the performance of entrepreneurial wetland banks in actual regulatory environments are scarce, even though it is the most established of similar markets that have become instrumental to federal policy in administering several major environmental protection laws.

Keeping agricultural soil out of rivers: evidence of sediment and nutrient accumulation within field wetlands in the UK.

PubMed

Ockenden, Mary C; Deasy, Clare; Quinton, John N; Surridge, Ben; Stoate, Chris

2014-03-15

Intensification of agriculture has resulted in increased soil degradation and erosion, with associated pollution of surface waters. Small field wetlands, constructed along runoff pathways, offer one option for slowing down and storing runoff in order to allow more time for sedimentation and for nutrients to be taken up by plants or micro-organisms. This paper describes research to provide quantitative evidence for the effectiveness of small field wetlands in the UK landscape. Ten wetlands were built on four farms in Cumbria and Leicestershire, UK. Annual surveys of sediment and nutrient accumulation in 2010, 2011 and 2012 indicated that most sediment was trapped at a sandy site (70 tonnes over 3 years), compared to a silty site (40 tonnes over 3 years) and a clay site (2 tonnes over 3 years). The timing of rainfall was more important than total annual rainfall for sediment accumulation, with most sediment transported in a few intense rainfall events, especially when these coincided with bare soil or poor crop cover. Nutrient concentration within sediments was inversely related to median particle size, but the total mass of nutrients trapped was dependent on the total mass of sediment trapped. Ratios of nutrient elements in the wetland sediments were consistent between sites, despite different catchment characteristics across the individual wetlands. The nutrient value of sediment collected from the wetlands was similar to that of soil in the surrounding fields; dredged sediment was considered to have value as soil replacement but not as fertiliser. Overall, small field wetlands can make a valuable contribution to keeping soil out of rivers. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Impact of hydraulic and carbon loading rates of constructed wetlands on contaminants of emerging concern (CECs) removal.

PubMed

Sharif, Fariya; Westerhoff, Paul; Herckes, Pierre

2014-02-01

Constructed wetlands remove trace organic contaminants via synergistic processes involving plant biomass that include hydrolysis, volatilization, sorption, biodegradation, and photolysis. Wetland design conditions, such as hydraulic loading rates (HLRs) and carbon loading rates (CLRs), influence these processes. Contaminant of emerging concern (CEC) removal by wetland plants was investigated at varying HLRs and CLRs. Rate constants and parameters obtained from batch-scale studies were used in a mechanistic model to evaluate the effect of these two loading rates on CEC removal. CLR significantly influenced CEC removal when wetlands were operated at HLR >5 cm/d. High values of CLR increased removal of estradiol and carbamazepine but lowered that of testosterone and atrazine. Without increasing the cumulative HLR, operating two wetlands in series with varying CLRs could be a way to improve CEC removal. Copyright © 2013 Elsevier Ltd. All rights reserved.

Wetland Feature Extraction in Poyang Lake from Muti-Sensor and Multi-Temporal Images

NASA Astrophysics Data System (ADS)

Zhang, Li; Desnos, Yves-Louis; Wang, Yeqiao; Chen, Xiaoling; Zmuda, Andy; Yesou, Herve

2016-08-01

Under the high dynamic hydrological variations and impacts from human activities, the nature wetlands of Poyang Lake face major challenges in biodiversity decline and wetland degradation. Variations of Poyang Lake wetlands are difficult to map by a single source or one time remote sensing imagery because the landscape is dominated by herbaceous vegetation and aquatic macrophytes which are altered and controlled by the water level. This study selected and combined time series NDVI, Green Ratio Vegetation Index (GRVI) and Modified Normalized Different Water Index (MNDWI), Backscattering coefficients(σ0) (VV&VH mode), Shannon Entropy (SE) and H/α wishart classification value derived from Sentinel 1A and Sentinel 2A to investigate the spatial-temporal variation of wetlands in autumn and spring growing season with discussions about the possibility of monitoring the wetland vegetation by C-band dual-pol datasets.

Winter Tourism and mountain wetland management and restoration

NASA Astrophysics Data System (ADS)

Gaucherand, S.; Mauz, I.

2012-04-01

The degradation and loss of wetlands is more rapid than that of other ecosystems (MEA 2005). In mountains area, wetlands are small and scattered and particularly sensitive to global change. The development of ski resorts can lead to the destruction or the deterioration of mountain wetlands because of hydrologic interferences, fill in, soil compression and erosion, etc. Since 2008, we have studied a high altitude wetland complex in the ski resort of Val Thorens. The aim of our study was to identify the impacts of mountain tourism development (winter and summer tourism) on wetland functioning and to produce an action plan designed to protect, rehabilitate and value the wetlands. We chose an approach based on multi-stakeholder participatory process at every stage, from information gathering to technical choices and monitoring. In this presentation, we show how such an approach can efficiently improve the consideration of wetlands in the development of a ski resort, but also the bottlenecks that need to be overcome. We will also discuss some of the ecological engineering techniques used to rehabilitate or restore high altitude degraded wetlands. Finally, this work has contributed to the creation in 2012 of a mountain wetland observatory coordinated by the conservatory of Haute-Savoie. The objective of this observatory is to estimate ecosystem services furnished by mountain wetlands and to find restoration strategies adapted to the local socio-economical context (mountain agriculture and mountain tourism).

Determination of the health of Lunyangwa wetland using Wetland Classification and Risk Assessment Index

NASA Astrophysics Data System (ADS)

Wanda, Elijah M. M.; Mamba, Bhekie B.; Msagati, Titus A. M.; Msilimba, Golden

2016-04-01

Wetlands are major sources of various ecological goods and services including storage and distribution of water in space and time which help in ensuring the availability of surface and groundwater throughout the year. However, there still remains a poor understanding of the range of values of water quality parameters that occur in wetlands either in its impacted state or under natural conditions. It was thus imperative to determine the health of Lunyangwa wetland in Mzuzu City in Malawi in order to classify and determine its state. This study used the Escom's Wetland Classification and Risk Assessment Index Field Guide to determine the overall characteristics of Lunyangwa wetland and to calculate its combined Wetland Index Score. Data on site information, field measurements (i.e. EC, pH, temperature and DO) and physical characteristics of Lunyangwa wetland were collected from March, 2013 to February, 2014. Results indicate that Lunyangwa wetland is a largely open water zone which is dominated by free-floating plants on the water surface, beneath surface and emergent in substrate. Furthermore, the wetland can be classified as of a C ecological category (score = 60-80%), which has been moderately modified with moderate risks of the losses and changes occurring in the natural habitat and biota in the wetland. It was observed that the moderate modification and risk were largely because of industrial, agricultural, urban/social catchment stressors on the wetland. This study recommends an integrated and sustainable management approach coupled with continuous monitoring and evaluation of the health of the wetland for all stakeholders in Mzuzu City. This would help to maintain the health of Lunyangwa wetland which is currently at risk of being further modified due to the identified catchment stressors.

7 CFR 623.1 - Purpose and scope.

Code of Federal Regulations, 2014 CFR

2014-01-01

... improvement, flood water retention, floodway enhancement, ground water recharge, open space, aesthetic values... AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS RESERVE PROGRAM § 623.1 Purpose and scope. (a) The regulations... wetland characteristics, such as hydrologic conditions of inundation or saturation of the soil and...

7 CFR 623.1 - Purpose and scope.

Code of Federal Regulations, 2012 CFR

2012-01-01

... improvement, flood water retention, floodway enhancement, ground water recharge, open space, aesthetic values... AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS RESERVE PROGRAM § 623.1 Purpose and scope. (a) The regulations... wetland characteristics, such as hydrologic conditions of inundation or saturation of the soil and...

7 CFR 623.1 - Purpose and scope.

Code of Federal Regulations, 2013 CFR

2013-01-01

... improvement, flood water retention, floodway enhancement, ground water recharge, open space, aesthetic values... AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS RESERVE PROGRAM § 623.1 Purpose and scope. (a) The regulations... wetland characteristics, such as hydrologic conditions of inundation or saturation of the soil and...

BIOLOGICAL INDICATOR DEVELOPMENT AND CLASSIFICATION FOR GREAT LAKES COASTAL WETLANDS

EPA Science Inventory

Great Lakes coastal wetlands are a valued aquatic resource that provide important ecological functions for the Great Lakes including serving as fish habitat, aquatic food web support, and nutrient and sediment retention from watersheds. Great Lakes resource managers need assessme...

7 CFR 1467.7 - Enrollment process.

Code of Federal Regulations, 2010 CFR

2010-01-01

... which provides for the restoration and protection of the functions and values of wetlands; (iii... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.7 Enrollment process. (a... easement acquisition activities after the property has been enrolled. (2) Restoration cost-share agreement...

7 CFR 1467.7 - Enrollment process.

Code of Federal Regulations, 2011 CFR

2011-01-01

... which provides for the restoration and protection of the functions and values of wetlands; (iii... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.7 Enrollment process. (a... easement acquisition activities after the property has been enrolled. (2) Restoration cost-share agreement...

Functional assessment of three wetlands constructed by the West Virginia Division of Highways

DOT National Transportation Integrated Search

2000-11-01

This study focused on soil nutrients, wildlife usage, diversity of vascular plants and major wildlife groups, and productivity as indicators. To provide a comparison to baseline values for these parameters, we selected three natural wetlands to serve...

Sediment accretion rates and sediment composition in Prairie Pothole wetlands under varying land use practices, Montana, United States

USGS Publications Warehouse

Preston, T.M.; Sojda, R.S.; Gleason, R.A.

2013-01-01

Increased sedimentation and nutrient cycle changes in Prairie Pothole Region wetlands associated with agriculture threaten the permanence and ecological functionality of these important resources. To determine the effects of land use on sedimentation and nutrient cycling, soil cores were analyzed for cesium-137 (137Cs), lead-210 (210Pb), and potassium-40 (40K) activities; textural composition; organic and inorganic carbon (C); and total nitrogen (N) from twelve wetlands surrounded by cropland, Conservation Reserve Program (CRP) lands, or native prairie uplands. Separate soil cores from nine of these wetlands were also analyzed for phosphorus (P), nitrate (NO3), and ammonium (NH4) concentrations. Wetlands surrounded by cropland had significantly greater linear sediment accretion rates than wetlands surrounded by CRP or native prairie. Linear sediment accretion rates from wetlands surrounded by cropland were 2.7 and 6 times greater than wetlands surrounded by native prairie when calculated from the initial and peak occurrence of 137Cs, respectively, and 0.15 cm y−1 (0.06 in yr−1) greater when calculated from 210Pb. Relative to wetlands surrounded by CRP, linear sediment accretion rates for wetlands surrounded by cropland were 4.4 times greater when calculated from the peak occurrence of 137Cs. No significant differences existed between the linear sediment accretion rates between wetlands surrounded by native prairie or CRP uplands. Wetlands surrounded by cropland had increased clay, P, NO3, and NH4, and decreased total C and N concentrations compared to wetlands surrounded by native prairie. Wetlands surrounded by CRP had the lowest P and NO3 concentrations and had clay, NH4, C, and N concentrations between those of cropland and native prairie wetlands. We documented increased linear sediment accretion rates and changes in the textural and chemical properties of sediments in wetlands with cultivated uplands relative to wetlands with native prairie uplands. These findings demonstrate the value of the CRP at protecting wetland catchments to reduce sedimentation.

Interaction of hydrological regime and vegetation in a seasonally flooded lake wetland (Poyang Lake) in China

NASA Astrophysics Data System (ADS)

Zhang, Qi

2017-04-01

Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetlands. To explore the influences of hydrological conditions on the spatial distribution of wetland vegetation, an experimental transect in Poyang Lake wetland, the largest freshwater lake in China, was selected as a study area. In-situ high time frequency observations of climate, soil moisture, groundwater level and surface water level were simultaneously conducted. Vegetation was sampled periodically to obtain species composition, diversity and biomass. Results show that significant hydrological gradient exists along the experimental transect. Both groundwater level and soil moisture demonstrate high correlation with the distribution of different communities of vegetation. Above- and belowground biomass present Gaussian models along the gradient of groundwater depth in growing seasons. It was found that the optimal average groundwater depths for above- and belowground biomass are 0.8 m and 0.5 m, respectively. Numerical simulations using HYDRUS-1D further indicated that the groundwater depths had significant influences on the water usage by vegetation, which suggested the high dependence of wetland vegetation on groundwater, even in a wet climate zone such as Poyang Lake. The study revealed new knowledge on the interaction of hydrological regime and wetland vegetation, and provided scientific support for an integrated management of balancing wetland ecology and water resources development in Poyang Lake, and other lake floodplain wetlands, with strong human interferences.

Mapping wetlands in Nova Scotia with multi-beam RADARSAT-2 Polarimetric SAR, optical satellite imagery, and Lidar data

NASA Astrophysics Data System (ADS)

Jahncke, Raymond; Leblon, Brigitte; Bush, Peter; LaRocque, Armand

2018-06-01

Wetland maps currently in use by the Province of Nova Scotia, namely the Department of Natural Resources (DNR) wetland inventory map and the swamp wetland classes of the DNR forest map, need to be updated. In this study, wetlands were mapped in an area southwest of Halifax, Nova Scotia by classifying a combination of multi-date and multi-beam RADARSAT-2 C-band polarimetric SAR (polSAR) images with spring Lidar, and fall QuickBird optical data using the Random Forests (RF) classifier. The resulting map has five wetland classes (open-water/marsh complex, open bog, open fen, shrub/treed fen/bog, swamp), plus lakes and various upland classes. Its accuracy was assessed using data from 156 GPS wetland sites collected in 2012 and compared to the one obtained with the current wetland map of Nova Scotia. The best overall classification was obtained using a combination of Lidar, RADARSAT-2 HH, HV, VH, VV intensity with polarimetric variables, and QuickBird multispectral (89.2%). The classified image was compared to GPS validation sites to assess the mapping accuracy of the wetlands. It was first done considering a group consisting of all wetland classes including lakes. This showed that only 69.9% of the wetland sites were correctly identified when only the QuickBird classified image was used in the classification. With the addition of variables derived from lidar, the number of correctly identified wetlands increased to 88.5%. The accuracy remained the same with the addition of RADARSAT-2 (88.5%). When we tested the accuracy for identifying wetland classes (e.g. marsh complex vs. open bog) instead of grouped wetlands, the resulting wetland map performed best with either QuickBird and Lidar, or QuickBird, Lidar, and RADARSAT-2 (66%). The Province of Nova Scotia's current wetland inventory and its associated wetland classes (aerial-photo interpreted) were also assessed against the GPS wetland sites. This provincial inventory correctly identified 62.2% of the grouped wetlands and only 18.6% of the wetland classes. The current inventory's poor performance demonstrates the value of incorporating a combination of new data sources into the provincial wetland mapping.

Where does boreal stream DOC come from? - Quantifying the contribution from different landscape compartments using stable C isotope ratios.

NASA Astrophysics Data System (ADS)

Brink Bylund, J.; Bastviken, D.; Morth, C.; Laudon, H.; Giesler, R.; Buffam, I.

2007-12-01

Stable carbon isotope (δ13C) ratios are frequently used as a source tracer of e.g. organic matter (OM) produced in terrestrial versus aquatic environments. To our knowledge there has been no previous attempt to quantify the relative contribution of dissolved organic carbon (DOC) from various landscape compartments in catchments of different sizes. Here, we test to what extent δ13C values can be used also to quantify the relative contribution of DOC from wetlands/riparian zones along streams, and off stream forest habitats, respectively. We present data on spatial and temporal variability of DOC concentrations and δ13C-DOC values, during the year of 2005 in Krycklan catchment, a boreal stream network in northern Sweden. Ten stream sites, ranging from order 1 to 4, were monitored in sub catchments with different wetland coverage. Spatial variation of DOC concentration showed a weak but statistically significant relationship with wetland area, with higher concentration with increasing percent of wetland in the drainage area. During base flow the difference in δ13C-DOC values was significantly different between forest (-27.5‰) and wetland (-28.1‰). This spatial pattern disappears during spring peak flow when higher discharge flushing upper soil layer and the riparian zone on DOC in the catchments. A simple mixing model using DOC and δ13C-DOC showed that stream water DOC could be describe as a mixture of DOC coming from forest (deep) groundwater and wetland/riparian zone water. The result indicates that during spring peak flow almost all stream DOC (84-100%) is derived from wetlands and riparian zones. The wetland/riparian water dominates the stream DOC flux at all hydrological events, except for two sites, one forest dominated and one mixed catchment, where the forest groundwater dominated the DOC transport during base flow. Although the total wetland area in Krycklan catchment only represent 8.3%, it contributed, together with riparian zones, to as much as 83% of the yearly DOC transport. This study shows that there is a great potential in using stable carbon isotopes to quantify the relative contribution of DOC from various landscape compartments in catchments. Quantitative patterns are crucial for several reasons. It is for example necessary in predicting the response to global warming which will result in a changed hydrology and shifts in the relative area of the landscape compartments in boreal environments. KEY WORDS carbon isotopes; dissolved organic carbon; streams; boreal; landscape compartments; wetland; groundwater

The influence of local- and landscape-level factors on wetland breeding birds in the Prairie Pothole Region of North and South Dakota

USGS Publications Warehouse

Igl, Lawrence D.; Shaffer, Jill A.; Johnson, Douglas H.; Buhl, Deborah A.

2017-08-17

We examined the relationship between local- (wetland) and landscape-level factors and breeding bird abundances on 1,190 depressional wetlands in the Prairie Pothole Region of North and South Dakota during the breeding seasons in 1995–97. The surveyed wetlands were selected from five wetland classes (alkali, permanent, semipermanent, seasonal, or temporary), two wetland types (natural or restored), and two landowner groups (private or Federal). We recorded 133 species of birds in the surveyed wetlands during the 3 years. We analyzed the nine most common (or focal) species (that is, species that were present in 25 percent or more of the 1,190 wetlands): the Red-winged Blackbird (Agelaius phoeniceus), Blue-winged Teal (Anas discors), Mallard (Anas platyrhynchos), American Coot (Fulica americana), Gadwall (Anas strepera), Common Yellowthroat (Geothlypis trichas), Yellow-headed Blackbird (Xanthocephalus xanthocephalus), Northern Shoveler (Anas clypeata), and Savannah Sparrow (Passerculus sandwichensis). Our results emphasize the ecological value of all wetland classes, natural and restored wetlands, and publicly and privately owned wetlands in this region, including wetlands that are generally smaller and shallower (that is, temporary and seasonal wetlands) and thus most vulnerable to drainage. Blue-winged Teal, Northern Shoveler, Gadwall, Common Yellowthroat, and Red-winged Blackbird had higher abundances on Federal than on private wetlands. Abundances differed among wetland classes for seven of the nine focal species: Blue-winged Teal, Northern Shoveler, Mallard, American Coot, Common Yellowthroat, Yellow-headed Blackbird, Red-winged Blackbird. American Coot had higher abundances on restored wetlands than on natural wetlands overall, and Gadwall and Common Yellowthroat had higher abundances on private restored wetlands than on private natural wetlands. The Common Yellowthroat was the only species that had higher abundances on restored private wetlands than on restored Federal wetlands. After adjusting for wetland size and the date and location of the surveys, our results demonstrated that incorporating wetland- and landscape-level factors in models can improve our ability to predict abundances of wetland birds in this region. The top model for eight of the nine focal species included wetland- and landscape-level factors, whereas the best model for Blue-winged Teal included only wetland-level attributes. Although local factors (for example, percent open water or emergent vegetation) in individual wetlands are important factors for some wetland breeding birds, it is important that natural resource managers consider landscape-level factors beyond the local factors in their conservation plans for wetland birds.

[Study on nutrient and salinity in soil covered with different vegetations in Shuangtaizi estuarine wetlands].

PubMed

Song, Xiao-Lin; Lü, Xian-Guo; Zhang, Zhong-Sheng; Chen, Zhi-Ke; Liu, Zheng-Mao

2011-09-01

Nutrient elements and salinity in soil covered by different vegetations including Phragmites australis (Clay.) Trin., Typha orientalis Presl., Puccinellia distans Parl, and Suaeda salsa in Shuangtaizi estuarine wetlands were investigated to study their distribution characteristics and to reveal the nutrient element variation during the vegetation succession processes. Results indicated that total potassium, total phosphorus and salinity were different significantly in soil between different plant communities while available phosphorus, total nitrogen, available nitrogen, available potassium, total sulfur, iron and soil organic carbon were different insignificantly. Correlation analysis suggested that soil organic carbon were related significantly to total nitrogen, available phosphorus, available potassium, which implied that decomposition of plant litter might be the mail source of soil nitrogen and available nutrient. Salinity was significantly related to total phosphorus and iron in soil. In Shuangtaizi estuarine wetland soil, ratios of carbon to nitrogen (R(C/N)) was in the range of 12.21-26.33 and the average value was 18.21, which was higher than 12.0. It indicated that soil organic carbon in Shuangtaizi estuarine mainly came from land but not ocean and plants contributed the most of soil organic matters. There was no significant difference in R(C/N) between soil from the four plant communities (F = 1.890, p = 0.151). R(C/N) was related significantly to sol salinity (r = 0.346 3, p = 0.035 8) and was increasing with soil salinity.

7 CFR 1467.12 - The WRPO development.

Code of Federal Regulations, 2011 CFR

2011-01-01

... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.12 The WRPO... WRPO will be developed to ensure that cost-effective restoration and maximization of wildlife benefits and wetland functions and values will result. Specifically, the WRPO will consider and address, to the...

7 CFR 1467.12 - The WRPO development.

Code of Federal Regulations, 2010 CFR

2010-01-01

... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.12 The WRPO... WRPO will be developed to ensure that cost-effective restoration and maximization of wildlife benefits and wetland functions and values will result. Specifically, the WRPO will consider and address, to the...

7 CFR 1467.15 - Violations and remedies.

Code of Federal Regulations, 2011 CFR

2011-01-01

... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.15 Violations... contract, or any restoration cost-share agreement involving the participant, the participant shall be given... important wetland functions and values or other rights of the United States under the easement. The...

7 CFR 1467.15 - Violations and remedies.

Code of Federal Regulations, 2010 CFR

2010-01-01

... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.15 Violations... contract, or any restoration cost-share agreement involving the participant, the participant shall be given... important wetland functions and values or other rights of the United States under the easement. The...

Occurrence and behavior of emerging contaminants in surface water and a restored wetland.

PubMed

Matamoros, Víctor; Arias, Carlos A; Nguyen, Loc Xuan; Salvadó, Victòria; Brix, Hans

2012-08-01

Pollution mitigation is an important target for restored wetlands, and although there is much information in relation to nutrient removal, little attention has been paid to emerging contaminants. This paper reports on the occurrence and attenuation capacity of 17 emerging contaminants in a restored wetland and two rivers in North-East Denmark. The compounds belong to the groups of pharmaceuticals, fragrances, antiseptics, fire retardants, pesticides, and plasticizers. Concentrations in surface waters ranged from 2 to 1476 ng L(-1). The compounds with the highest concentrations were diclofenac, 2-methyl-4-chlorophenoxyacetic acid (MCPA), caffeine, and tris(2-chloroethyl) phosphate (TCEP). The herbicide concentrations increased after a rain-fall event, demonstrating the agricultural run-off origin of these compounds, whereas the concentration of the other emerging contaminants was rather conservative. The mitigation capacity of the restored wetland for the compounds ranged from no attenuation to 84% attenuation (19% on average). Hence, restored wetlands may be considered as a feasible alternative for mitigating emerging contaminants from river waters. Copyright © 2012 Elsevier Ltd. All rights reserved.

Characterization of Terrestrial Water Dynamics in the Congo Basin Using GRACE and Satellite Radar Altimetry

NASA Technical Reports Server (NTRS)

Lee, Hyongki; Beighley, R. Edward; Alsdorf, Douglas; Jung, Hahn Chul; Shum, C. K.; Duan, Jianbin; Guo, Junyi; Yamazaki, Dai; Andreadis, Konstantinos

2011-01-01

The Congo Basin is the world's third largest in size (approx.3.7 million sq km), and second only to the Amazon River in discharge (approx.40,200 cu m/s annual average). However, the hydrological dynamics of seasonally flooded wetlands and floodplains remains poorly quantified. Here, we separate the Congo wetland into four 3deg 3deg regions, and use remote sensing measurements (i.e., GRACE, satellite radar altimeter, GPCP, JERS-1, SRTM, and MODIS) to estimate the amounts of water filling and draining from the Congo wetland, and to determine the source of the water. We find that the amount of water annually filling and draining the Congo wetlands is 111 cu km, which is about one-third the size of the water volumes found on the mainstem Amazon floodplain. Based on amplitude comparisons among the water volume changes and timing comparisons among their fluxes, we conclude that the local upland runoff is the main source of the Congo wetland water, not the fluvial process of river-floodplain water exchange as in the Amazon. Our hydraulic analysis using altimeter measurements also supports our conclusion by demonstrating that water surface elevations in the wetlands are consistently higher than the adjacent river water levels. Our research highlights differences in the hydrology and hydrodynamics between the Congo wetland and the mainstem Amazon floodplain.

Dynamic response of desert wetlands to abrupt climate change

PubMed Central

Springer, Kathleen B.; Manker, Craig R.; Pigati, Jeffrey S.

2015-01-01

Desert wetlands are keystone ecosystems in arid environments and are preserved in the geologic record as groundwater discharge (GWD) deposits. GWD deposits are inherently discontinuous and stratigraphically complex, which has limited our understanding of how desert wetlands responded to past episodes of rapid climate change. Previous studies have shown that wetlands responded to climate change on glacial to interglacial timescales, but their sensitivity to short-lived climate perturbations is largely unknown. Here, we show that GWD deposits in the Las Vegas Valley (southern Nevada, United States) provide a detailed and nearly complete record of dynamic hydrologic changes during the past 35 ka (thousands of calibrated 14C years before present), including cycles of wetland expansion and contraction that correlate tightly with climatic oscillations recorded in the Greenland ice cores. Cessation of discharge associated with rapid warming events resulted in the collapse of entire wetland systems in the Las Vegas Valley at multiple times during the late Quaternary. On average, drought-like conditions, as recorded by widespread erosion and the formation of desert soils, lasted for a few centuries. This record illustrates the vulnerability of desert wetland flora and fauna to abrupt climate change. It also shows that GWD deposits can be used to reconstruct paleohydrologic conditions at millennial to submillennial timescales and informs conservation efforts aimed at protecting these fragile ecosystems in the face of anthropogenic warming. PMID:26554007

Dynamic response of desert wetlands to abrupt climate change

USGS Publications Warehouse

Springer, Kathleen; Manker, Craig; Pigati, Jeffrey S.

2015-01-01

Desert wetlands are keystone ecosystems in arid environments and are preserved in the geologic record as groundwater discharge (GWD) deposits. GWD deposits are inherently discontinuous and stratigraphically complex, which has limited our understanding of how desert wetlands responded to past episodes of rapid climate change. Previous studies have shown that wetlands responded to climate change on glacial to interglacial timescales, but their sensitivity to short-lived climate perturbations is largely unknown. Here, we show that GWD deposits in the Las Vegas Valley (southern Nevada, United States) provide a detailed and nearly complete record of dynamic hydrologic changes during the past 35 ka (thousands of calibrated 14C years before present), including cycles of wetland expansion and contraction that correlate tightly with climatic oscillations recorded in the Greenland ice cores. Cessation of discharge associated with rapid warming events resulted in the collapse of entire wetland systems in the Las Vegas Valley at multiple times during the late Quaternary. On average, drought-like conditions, as recorded by widespread erosion and the formation of desert soils, lasted for a few centuries. This record illustrates the vulnerability of desert wetland flora and fauna to abrupt climate change. It also shows that GWD deposits can be used to reconstruct paleohydrologic conditions at millennial to submillennial timescales and informs conservation efforts aimed at protecting these fragile ecosystems in the face of anthropogenic warming.

Characterization of Terrestrial Water Dynamics in the Congo Basin Using GRACE and Satellite Radar Altimetry

NASA Technical Reports Server (NTRS)

Lee, Lyongki; Beighley, R. Edward; Alsdorf, Douglas; Jung, Hahn Chul; Shum, C. K.; Duan, Jianbin; Guo, Junyi; Yamazaki, Dai; Andreadis, Konstantinos

2011-01-01

The Congo Basin is the world's third largest in size (approximately 3.7 million km^2), and second only to the Amazon River in discharge (approximately 40,200 cms annual average). However, the hydrological dynamics of seasonally flooded wetlands and floodplains remains poorly quantified. Here, we separate the Congo wetland into four 3 degree x 3 degree regions, and use remote sensing measurements (i.e., GRACE, satellite radar altimeter, GPCP, JERS-1, SRTM, and MODIS) to estimate the amounts of water filling and draining from the Congo wetland, and to determine the source of the water. We find that the amount of water annually filling and draining the Congo wetlands is 111 km^3, which is about one-third the size of the water volumes found on the mainstem Amazon floodplain. Based on amplitude comparisons among the water volume changes and timing comparisons among their fluxes, we conclude that the local upland runoff is the main source of the Congo wetland water, not the fluvial process of river-floodplain water exchange as in the Amazon. Our hydraulic analysis using altimeter measurements also supports our conclusion by demonstrating that water surface elevations in the wetlands are consistently higher than the adjacent river water levels. Our research also highlights differences in the hydrology and hydrodynamics between the Congo wetland and the mainstem Amazon floodplain.

[Relationship between the nitrogen removal and oxygen demand in constructed wetlands].

PubMed

He, Lian-sheng; Liu, Hong-liang; Xi, Bei-dou; Zhu, Ying-bo; Wei, Zi-min; Huo, Shou-liang

2006-06-01

A simplified model of sequential N transformations and sink was applied to investigate the relationship between the nitrogen removal and oxygen demand to verify the validity of full nitrification-denitrification mechanism in a newly-built multi-stages constructed wetlands. Average net rates of N mineralization ranged from 0.01 to 0.28 g x (m2 x d)(-1), nitrification from 0.50 to 1.54 g x (m2 x d)(-1), denitrification from 0.41 to 1.13 g x (m2 x d)(-1)(3.4% approximately 35.4% of measured N removal in different stage) and plant assimilation from 0.07 to 0.26 g x (m2 x d)(-1) in the five tanks. Nitrification and denitrification occurred concurrently with BOD removal, even in the first stage receiving the higher-strength wastewater. Surprisingly, net areal nitrification rates, was correlated with BOD removal rates positively. Nitrification rates were also correlated linearly with average NH4+-N concentrations in the cascade tanks. The nitrogenous oxygen demand (NOD) required to support full nitrification of ammonia and mineralized Org-N in the wetland was in the upper range of that expected to be able to be supplied through surface and plant-mediated oxygen transfer. Some potential alternative nitrogen removal pathways with reduced overall oxygen requirements that have relevance to constructed wetlands were discussed.

Wetland Restoration Response Analysis using MODIS and Groundwater Data

PubMed Central

Melesse, Assefa M.; Nangia, Vijay; Wang, Xixi; McClain, Michael

2007-01-01

Vegetation cover and groundwater level changes over the period of restoration are the two most important indicators of the level of success in wetland ecohydrological restoration. As a result of the regular presence of water and dense vegetation, the highest evapotranspiration (latent heat) rates usually occur within wetlands. Vegetation cover and evapotranspiration of large areas of restoration like that of Kissimmee River basin, South Florida will be best estimated using remote sensing technique than point measurements. Kissimmee River basin has been the area of ecological restoration for some years. The current ecohydrological restoration activities were evaluated through fractional vegetation cover (FVC) changes and latent heat flux using Moderate Resolution Imaging Spectroradiometer (MODIS) data. Groundwater level data were also analyzed for selected eight groundwater monitoring wells in the basin. Results have shown that the average fractional vegetation cover and latent heat along 10 km buffer of Kissimmee River between Lake Kissimmee and Lake Okeechobee was higher in 2004 than in 2000. It is evident that over the 5-year period of time, vegetated and areas covered with wetlands have increased significantly especially along the restoration corridor. Analysis of groundwater level data (2000-2004) from eight monitoring wells showed that, the average monthly level of groundwater was increased by 20 cm and 34 cm between 2000 and 2004, and 2000 and 2003, respectively. This change was more evident for wells along the river. PMID:28903205

Land use pattern, socio-economic development, and assessment of their impacts on ecosystem service value: study on natural wetlands distribution area (NWDA) in Fuzhou city, southeastern China.

PubMed

Cai, Yuan-Bin; Zhang, Hao; Pan, Wen-Bin; Chen, Yan-Hong; Wang, Xiang-Rong

2013-06-01

This paper quantifies the allocation of ecosystem services value (ESV) associated with land use pattern and qualitatively examined impacts of land use changes and socio-economic factors on spatiotemporal variation of ESV in the Natural Wetland Distribution Area (NWDA), Fuzhou city, China. The results showed that total ESV of the study area decreased from 4,332.16 × 10(6) RMB Yuan in 1989 to 3,697.42 × 10(6) RMB Yuan in 2009, mainly due to the remarkable decreases in cropland (decreased by 55.3 %) and wetland (decreased by 74.2 %). Forest, water, and wetland played major roles in providing ecosystem services, accounting for over 90 % of the total ESV. Based on time series Landsat TM/ETM+ imagery, geographic information system, and historical data, analysis of the spatiotemporal variation of ESV from 1989 to 2009 was performed. It indicated that rapid expansion of urban areas along the Minjiang River resulted in significant changes in land use types, leading to a dramatic decline in ecosystem services. Meanwhile, because of land scarcity and unique ecosystem functions, the emergency of wetland and cropland protection in built-up area has become an urgent task of local authorities to the local government. Furthermore, there was still a significant negative correlation between ESV of cropland and wetland and the GDP. The results suggest that future planning of land use pattern should control encroachment of urban areas into cropland and wetland in addition to scientific and rational policies towards minimizing the adverse effects of urbanization.

Slowing the rate of loss of mineral wetlands on human dominated landscapes - Diversification of farmers markets to include carbon (Invited)

NASA Astrophysics Data System (ADS)

Creed, I. F.; Badiou, P.; Lobb, D.

2013-12-01

Canada is the fourth-largest exporter of agriculture and agri-food products in the world (exports valued at 28B), but instability of agriculture markets can make it difficult for farmers to cope with variability, and new mechanisms are needed for farmers to achieve economic stability. Capitalizing on carbon markets will help farmers achieve environmentally sustainable economic performance. In order to have a viable carbon market, governments and industries need to know what the carbon capital is and what potential there is for growth, and farmers need financial incentives that will not only allow them to conserve existing wetlands but that will also enable them to restore wetlands while making a living. In southern Ontario, farmers' needs to maximize the return on investment on marginal lands have resulted in loss of 70-90% of wetlands, making this region one of the most threatened region in terms of wetland degradation and loss in Canada. Our project establishes the role that mineral wetlands have in the net carbon balance by contributing insight into the potential benefits to carbon management provided by wetland restoration efforts in these highly degraded landscapes. The goal was to establish the magnitude of carbon offsets that could be achieved through wetland conservation (securing existing carbon stocks) and restoration (creating new carbon stocks). The experimental design was to focus on (1) small (0.2-2.0 ha) and (2) isolated (no inflow or outflow) mineral wetlands with the greatest restoration potential that included (3) a range of restoration ages (drained (0 yr), 3 yr, 6 yr, 12 yr, 20 yr, 35 yr, intact marshes) to capture potential changes in rates of carbon sequestration with restoration age of wetland. From each wetland, wetland soil carbon pools samples were collected at four positions: centre of wetland (open-water); emergent vegetation zone; wet meadow zone where flooding often occurs (i.e., high water mark); and upland where flooding rarely occurs (cores segmented into 5cm increments up to 45 cm, composited and analyzed for carbon pools using mass equivalent and carbon sequestration rates samples were taken at centre of wetland (open-water) (cores segmented into 1 cm increments up to 30 cm, composited and analyzed for Pb-210 and Cs-137 isotopes). The magnitude of wetland loss (≥10 ha) is estimated to be over 1.5 million ha in southern Ontario since the time of European settlement. About 75% of converted wetlands (1.1 million ha) are now classified as 'undifferentiated agricultural lands.' We use our measured carbon sequestration rate Mg CO2 equivalents ha/yr under different scenarios of landowner uptake (5-50%) and prices for carbon offsets (2-50/MgCO2 equivalents) to estimate carbon sequestration and the value of this sequestration in restored wetlands. The project provides empirical evidence that restoring wetlands for carbon sequence could improve the livelihood of farmers and that policies should be established to incentivize farmers to adopt wetland restoration practices on marginal areas in order to improve the economic performance and environmental sustainability of agriculture in Ontario.

Hurricane Matthew's Effects on Wetland Sources of Organic Matter to North Carolina Coastal Waters.

NASA Astrophysics Data System (ADS)

Rudolph, J. C.; Osburn, C. L.; Paerl, H. W.; Hounshell, A.

2017-12-01

Increased frequency and intensity of storm events such as tropical cyclones will have a major impact on estuarine and coastal biogeochemical cycling. Here, we determined the sources of dissolved and particulate organic matter (DOM and POM) as part of a larger study to quantify the short-term (several months) response of carbon and nitrogen cycling in the Neuse River Estuary-Pamlico Sound (NRE-PS) ecosystem to floodwaters associated with Hurricane Matthew. Sampling was conducted weekly in both the NRE-PS (October 2016 to January 2017), the Neuse River (NR) (October to December 2016) and in freshwater wetlands of the Neuse River above head of tide in March 2017. Specific ultraviolet (UV) absorbance at 254 nm (SUVA254) and stable carbon isotope ratios (δ13C-DOC) were used to determine the sources of DOM and POM transported to the NRE-PS in post-hurricane floodwaters. For DOM, SUVA254 values increased from 3.23 ±0.52 mg C L-1 m-1 in the NR to 4.14±0.52 mg C L-1 m-1 in the NRE and then declined to 3.63±0.32 mg C L-1 m-1 in PS. Combined with depleted δ13C-DOC values (-26 to -32‰) and elevated C:N values in the estuary and sound, these results confirm continued loading of fresh terrestrial organic matter into NRE-PS weeks after the storm. For POM, δ13C-POC and C:N ratio results likewise indicated a terrestrial source in floodwaters. SUVA254 values >3.5 mg C L-1 m-1 coupled with the depleted δ13C values and large C:N values were consistent with DOM primarily sourced from wetlands (e.g., wetland SUVA254 = 3.77±0.52 mg C L-1 m-1 in March 2017). We hypothesize that floodwaters connected riverine wetlands to the main channel of the NR, exporting DOM and POM into the NRE-PS. Our results indicate that upstream wetlands play a central and potentially significant role in organic matter enrichment and metabolism of estuarine and coastal waters, in light of increasing frequencies and intensities of tropical cyclones impacting coastal watersheds.

Character, quality and bioavailability of Dissolved Organic Carbon (DOC) in a boreal stream network (Invited)

NASA Astrophysics Data System (ADS)

Laudon, H.; Berggren, M.; Agren, A.; Jansson, M.

2010-12-01

The conceptual understanding of the role of terrestrially derived dissolved organic carbon (DOC) in freshwaters has been changing rapidly. While it was once considered mainly a pool of recalcitrant compounds, DOC is now better known for its interactivity and ability to affect both the biogeochemistry and ecology of streams, rivers and lakes. Here we summarize the recent work from the multi-investigatory project conducted in the Krycklan Catchment Study in Sweden with an emphasis on the spatial and temporal variability of the character and bioavailability of DOC. In total, 15 streams and their adjacent soils have been investigated. The streams cover a forest-wetland gradient, spanning from 0% to 69% wetland coverage (hence with a 100% to 31% forest cover). Lower values of the ratio between absorbance measured at 254 nm and 365 nm (A254/A365), in both soil plots and streams, indicated that wetland-derived DOC has a higher average molecular weight than forest DOC. Higher SUVA254 (DOC specific ultraviolet absorption at 254 nm) in wetland runoff indicated more aromatic DOC from wetlands than forests. In accordance, low molecular weight non-aromatic compounds such as free organic acids (OA), amino acids (AA) and carbohydrates (CH) had higher quantities in the forested streams. We have shown that a variety of the OA, AA and CH compounds can be significantly assimilated by bacteria, meeting 15-100% of the bacterial carbon demand and explaining most of the observed variance in bacterial growth efficiency. We can now also show that in small homogenous catchments, the hydrological functioning provides a first order control on the temporal variability of stream water DOC and its quality. As a consequence, streams with heterogeneous catchments undergo a temporal switch in the DOC source. In a typical boreal catchment of 10-20% wetlands, DOC originates predominantly from wetland sources during low flow conditions whereas the major source of DOC originates from forested areas of the catchment during high flow resulting in dramatic shifts in the character and bioavailability of DOC during different flow conditions. By connecting knowledge about the sources and quality of DOC with detailed hydrological process understanding, an improved representation of stream water DOC regulation can be provided. This work also illustrates that the sensitivity of stream water DOC in the boreal landscape ultimately depends on how individual landscape elements are affected, the proportion of these landscape elements and how these changes are propagated downstream.

A review of models and micrometeorological methods used to estimate wetland evapotranspiration

USGS Publications Warehouse

Drexler, J.Z.; Snyder, R.L.; Spano, D.; Paw, U.K.T.

2004-01-01

Within the past decade or so, the accuracy of evapotranspiration (ET) estimates has improved due to new and increasingly sophisticated methods. Yet despite a plethora of choices concerning methods, estimation of wetland ET remains insufficiently characterized due to the complexity of surface characteristics and the diversity of wetland types. In this review, we present models and micrometeorological methods that have been used to estimate wetland ET and discuss their suitability for particular wetland types. Hydrological, soil monitoring and lysimetric methods to determine ET are not discussed. Our review shows that, due to the variability and complexity of wetlands, there is no single approach that is the best for estimating wetland ET. Furthermore, there is no single foolproof method to obtain an accurate, independent measure of wetland ET. Because all of the methods reviewed, with the exception of eddy covariance and LIDAR, require measurements of net radiation (Rn) and soil heat flux (G), highly accurate measurements of these energy components are key to improving measurements of wetland ET. Many of the major methods used to determine ET can be applied successfully to wetlands of uniform vegetation and adequate fetch, however, certain caveats apply. For example, with accurate Rn and G data and small Bowen ratio (??) values, the Bowen ratio energy balance method can give accurate estimates of wetland ET. However, large errors in latent heat flux density can occur near sunrise and sunset when the Bowen ratio ?? ??? - 1??0. The eddy covariance method provides a direct measurement of latent heat flux density (??E) and sensible heat flux density (II), yet this method requires considerable expertise and expensive instrumentation to implement. A clear advantage of using the eddy covariance method is that ??E can be compared with Rn-G H, thereby allowing for an independent test of accuracy. The surface renewal method is inexpensive to replicate and, therefore, shows particular promise for characterizing variability in ET as a result of spatial heterogeneity. LIDAR is another method that has special utility in a heterogeneous wetland environment, because it provides an integrated value for ET from a surface. The main drawback of LIDAR is the high cost of equipment and the need for an independent ET measure to assess accuracy. If Rn and G are measured accurately, the Priestley-Taylor equation can be used successfully with site-specific calibration factors to estimate wetland ET. The 'crop' cover coefficient (Kc) method can provide accurate wetland ET estimates if calibrated for the environmental and climatic characteristics of a particular area. More complicated equations such as the Penman and Penman-Monteith equations also can be used to estimate wetland ET, but surface variability and lack of information on aerodynamic and surface resistances make use of such equations somewhat questionable. ?? 2004 John Wiley and Sons, Ltd.

Mallard brood movements, wetland use, and duckling survival during and following a prairie drought

USGS Publications Warehouse

Krapu, G.L.; Pietz, P.J.; Brandt, D.A.; Cox, R.R.

2006-01-01

We used radiotelemetry to study mallard (Anas platyrhynchos) brood movements, wetland use, and duckling survival during a major drought (1988-1992) and during the first 2 years of the subsequent wet period (1993-1994) at 4 51-km2 sites in prairie pothole landscapes in eastern North Dakota, USA. About two-thirds of 69 radiomarked mallard broods initiated moves from the nest to water before noon, and all left the nest during daylight. On average, broods used fewer wetlands, but moved greater distances during the dry period than the wet period. Broods of all ages were more likely to make inter-wetland moves during the wet period and probabilities of inter-wetland moves decreased as duckling age increased, especially during the dry period. Brood use of seasonal wetlands nearly doubled from 22% to 43% and use of semi-permanent wetlands declined from 73% to 50% from the dry to the wet period. Eighty-one of 150 radiomarked ducklings died during 1,604 exposure days. We evaluated survival models containing variables related to water conditions, weather, duckling age, and hatch date. Model-averaged risk ratios indicated that, on any given date, radiomarked ducklings were 1.5 (95% CI = 0.8-2.8) times more likely to die when the percentage of seasonal basins containing water (WETSEAS) was ???18% than when WETSEAS was >40%. An interaction between duckling age and occurrence of rain on the current or 2 previous days indicated that rain effects were pronounced when ducklings were 0-7 days old but negligible when they were 8-30 days old. The TMIN (mean daily minimum temperature on the current and 2 previous days) effects generally were consistent between duckling age classes, and the risk of duckling death increased 9.3% for each 1??C decrease in TMIN across both age classes. Overall, the 30-day survival rate of ducklings equipped with radiotransmitters was about 0.23 lower than the survival rate of those without radiotransmitiers. Unmarked ducklings were 7.6 (95% CI = 2.7-21.3) times more likely to die on any given day when WETSEAS was ???18% than when WETSEAS was >40%. Higher duckling survival and increased use of seasonal wetlands during the wet period suggest that mallard production will benefit from programs that conserve and restore seasonal wetland habitat. Given adverse effects of low temperatures on duckling survival, managers may want to include this stochastic variable in models used to predict annual production of mallards in the Prairie Pothole Region.

Emission of greenhouse gases and soil carbon sequestration in a riparian marsh wetland in central Ohio.

PubMed

Nag, Subir K; Liu, Ruiqiang; Lal, Rattan

2017-10-23

Wetlands are a C sink, but they also account for a large natural source of greenhouse gases (GHG), particularly methane (CH 4 ). Soils of wetlands play an important role in alleviating the global climate change regardless of the emission of CH 4 . However, there are uncertainties about the amount of C stored and emitted from wetlands because of the site specific factors. Therefore, the present study was conducted in a temperate riverine flow-through wetland, part of which was covered with emerging macrophyte Typhus latifolia in central Ohio, USA, with the objective to assess emissions of GHGs (CH 4, CO 2 , N 2 O) and measure C and nitrogen (N) stocks in wetland soil in comparison to a reference upland site. The data revealed that CH 4 emission from the open and vegetated wetland ranged from 1.03-0.51 Mg C/ha/y and that of CO 2 varied from 1.26-1.51 Mg C/ha/y. In comparison, CH 4 emission from reference upland site was negligible (0.01 Mg C/ha/y), but CO 2 emission was much higher (3.24 Mg C/ha/y). The stock of C in wetland soil was 85 to 125 Mg C/ha up to 0.3 m depth. The average rate of emission was 2.15 Mg C/ha/y, but the rate of sequestration was calculated as 5.55 Mg C/ha/y. Thus, the wetland was actually a C sink. Emission of N 2 O was slightly higher in vegetated wetland (0.153 mg N 2 O-N/m 2 /h) than the open wetland and the reference site (0.129 mg N 2 O-N/m 2 /h). Effect of temperature on emission of GHGs from the systems was also studied.

Specifically Designed Constructed Wetlands: A Novel Treatment Approach for Scrubber Wastewater

DOE Office of Scientific and Technical Information (OSTI.GOV)

John H. Rodgers Jr; James W. Castle; Chris Arrington: Derek Eggert

2005-09-01

A pilot-scale wetland treatment system was specifically designed and constructed at Clemson University to evaluate removal of mercury, selenium, and other constituents from flue gas desulfurization (FGD) wastewater. Specific objectives of this research were: (1) to measure performance of a pilot-scale constructed wetland treatment system in terms of decreases in targeted constituents (Hg, Se and As) in the FGD wastewater from inflow to outflow; (2) to determine how the observed performance is achieved (both reactions and rates); and (3) to measure performance in terms of decreased bioavailability of these elements (i.e. toxicity of sediments in constructed wetlands and toxicity ofmore » outflow waters from the treatment system). Performance of the pilot-scale constructed wetland treatment systems was assessed using two criteria: anticipated NPDES permit levels and toxicity evaluations using two sentinel toxicity-testing organisms (Ceriodaphnia dubia and Pimephales promelas). These systems performed efficiently with varied inflow simulations of FGD wastewaters removing As, Hg, and Se concentrations below NPDES permit levels and reducing the toxicity of simulated FGD wastewater after treatment with the constructed wetland treatment systems. Sequential extraction procedures indicated that these elements (As, Hg, and Se) were bound to residual phases within sediments of these systems, which should limit their bioavailability to aquatic biota. Sediments collected from constructed wetland treatment systems were tested to observe toxicity to Hyalella azteca or Chironomus tetans. Complete survival (100%) was observed for H. azteca in all cells of the constructed wetland treatment system and C. tentans had an average of 91% survival over the three treatment cells containing sediments. Survival and growth of H. azteca and C. tentans did not differ significantly between sediments from the constructed wetland treatment system and controls. Since the sediments of the constructed wetland treatment system are repositories for As, Hg, and Se and the bioavailability of these elements decreased after deposition, the pilot-scale constructed wetland treatment system contributed significantly to mitigation of risks to aquatic life from these elements.« less

Porewater chemistry in a treatment wetland: links to metal retention and release

NASA Astrophysics Data System (ADS)

Vadas, T. M.; Zhang, J.

2011-12-01

Constructed wetlands are gaining increased support for treatment of nonpoint source pollutants. A subsurface flow wetland treating runoff from an agricultural milkhouse floor and roof drainage has been monitored for metal removal. Influent dissolved concentrations from 5 to 30 ppb Cu and 60 to 800 ppb Zn were observed. Effluent concentrations of Zn were always lower from about 3 to 60 ppb Zn, however, Cu was typically around 10 ppb, and much larger at certain points in time, up to 95 ppb Cu. The results were similar in vegetated and non-vegetated wetlands, suggesting abiotic chemistry or microbial activity is controlling metal mobility. Porewater samples were taken using soil moisture lysimeters during both non-storm and storm events to examine metal and related chemistry with depth and distance in the wetland. Under non storm conditions, Cu and Zn average porewater concentrations were 64 and 250 ppb, respectively and did not vary much along the length of the wetland. During a storm event, Zn concentrations in the porewater initially increased near the inlet shortly after a storm, but typically decreased along the length and depth of the wetland to less than 60 ppb. Observed porewater Cu concentrations also increased near the inlet in some cases up to 700 ppb, but dropped rapidly with distance to less than 30 ppb near the middle of the wetland and increased again near the outlet. The dissolved Fe and Mn concentrations follow nearly opposite trends as Cu, increasing and then decreasing along the length of the wetland, suggesting possibly different roles in controlling Cu retention in each stage of the wetland, either co-precipitation with Cu initially, or reductive dissolution and release of Cu in later stages. An understanding of what controls metal retention and release is relevant to optimizing future design parameters of these wetlands.

Assessment of the risk of solar ultraviolet radiation to amphibians. III. Prediction of impacts in selected northern midwestern wetlands.

PubMed

Diamond, Stephen A; Peterson, Gregory S; Tietge, Joseph E; Ankley, Gerald T

2002-07-01

Solar ultraviolet radiation, especially UVB (280-320 nm), has been hypothesized to be at least partially responsible for adverse effects (e.g., declines and malformations) in amphibian species throughout the world. Evaluation of this hypothesis has been limited by the paucity of high-quality UV dose-response data and reliable estimates of typical UV doses that occur in amphibian habitats. In this preliminary risk assessment for effects of UV radiation on amphibians, dose-response relationships quantified in outdoor experiments were compared with UV exposure estimates for 26 wetlands in northern Minnesota and Wisconsin. A comparison of wetland doses, derived from model prediction, historical data, and dissolved organic carbon (DOC) characterization, with experimental effects levels for green (R. clamitans), northern leopard (R. pipiens), and mink (R. septentrionalis) frogs indicated that the risk of mortality and malformations due to UV exposure is low for the majority of wetlands evaluated. Wetland UV dose, averaged over the entire breeding season, exceeded effects doses for mortality for all three species in two of the 26 wetlands examined and for one species in an additional wetland. On the basis of evidence that shorter term doses caused mortality in amphibian larvae, 3-day doses were also evaluated. In three of the wetlands examined, 3-day doses in excess of 85% of full sunlight (the level that appeared to trigger effects in controlled experimentation) occurred at frequencies ranging 22-100% for all three species and at frequencies ranging from 15% to 58% for R. pipiens and R. septentrionalis in three additional wetlands. Risk of malformation in R. pipiens was apparent in five of the 26 wetlands evaluated. Overall, estimated UVB doses in 21 of the wetlands never exceeded experimental effects doses for mortality or malformations. These results suggest that most amphibians are not currently at significant risk for UVB effects in northern Minnesota and Wisconsin wetlands. However, continued reduction of ozone and other global climate change effects may increase UV doses in wetlands, suggesting that the risk of UV to amphibians should continue to be monitored and studied.

Monitoring wetland inundation dynamics in response to weather variability in the Chesapeake Bay watershed

USDA-ARS?s Scientific Manuscript database

Wetlands provide a broad range of ecosystem services, including flood control, water purification, groundwater replenishment, and biodiversity support. The provision of these services, which are especially valued in the Chesapeake Bay Watershed, is largely controlled by varying levels of wetness. ...

Global data bases on distribution, characteristics and methane emission of natural wetlands: Documentation of archived data tape

NASA Technical Reports Server (NTRS)

Matthews, Elaine

1989-01-01

Global digital data bases on the distribution and environmental characteristics of natural wetlands, compiled by Matthews and Fung (1987), were archived for public use. These data bases were developed to evaluate the role of wetlands in the annual emission of methane from terrestrial sources. Five global 1 deg latitude by 1 deg longitude arrays are included on the archived tape. The arrays are: (1) wetland data source, (2) wetland type, (3) fractional inundation, (4) vegetation type, and (5) soil type. The first three data bases on wetland locations were published by Matthews and Fung (1987). The last two arrays contain ancillary information about these wetland locations: vegetation type is from the data of Matthews (1983) and soil type from the data of Zobler (1986). Users should consult original publications for complete discussion of the data bases. This short paper is designed only to document the tape, and briefly explain the data sets and their initial application to estimating the annual emission of methane from natural wetlands. Included is information about array characteristics such as dimensions, read formats, record lengths, blocksizes and value ranges, and descriptions and translation tables for the individual data bases.

Comparison of meiofaunal abundance in two mangrove wetlands in Tong'an Bay, Xiamen, China

NASA Astrophysics Data System (ADS)

Zhou, Xiping; Cai, Lizhe; Fu, Sujing

2015-10-01

To compare meiofaunal community in the two mangrove wetlands in Tong'an Bay, Xiamen, China, and probe the response of meiofauna to high organic matter, sampling was carried out in Fenglin and Xiang'an mangrove wetlands in the bay. The results showed that the Ne/Co ratio (nematode to benthic copepod) and organic matter in Fenglin mangrove wetland were higher than those in Xiang'an mangrove wetland. The meiofaunal abundance in Fenglin mangrove was all lower than that in Xiang'an mangrove wetland in summer, autumn and spring, while the meiofaunal abundance in Fenglin mangrove was higher than that in Xiang'an mangrove wetland in winter. Two-way ANOVA results showed that the meiofaunal abundance and nematode abundance were significantly different between regions, seasons and region×season. With all the results in the present study, we confirmed that the positive response of meiofaunal and nematode abundance were only detected for medium organic matter contents according to the Xiang'an wetland's level, and that the distribution of meiofaunal abundance would be influenced by sand content. Higher copepod abundance and lower N/C value usually suggest better environmental quality.

Bacterial carbon utilization in vertical subsurface flow constructed wetlands.

PubMed

Tietz, Alexandra; Langergraber, Günter; Watzinger, Andrea; Haberl, Raimund; Kirschner, Alexander K T

2008-03-01

Subsurface vertical flow constructed wetlands with intermittent loading are considered as state of the art and can comply with stringent effluent requirements. It is usually assumed that microbial activity in the filter body of constructed wetlands, responsible for the removal of carbon and nitrogen, relies mainly on bacterially mediated transformations. However, little quantitative information is available on the distribution of bacterial biomass and production in the "black-box" constructed wetland. The spatial distribution of bacterial carbon utilization, based on bacterial (14)C-leucine incorporation measurements, was investigated for the filter body of planted and unplanted indoor pilot-scale constructed wetlands, as well as for a planted outdoor constructed wetland. A simple mass-balance approach was applied to explain the bacterially catalysed organic matter degradation in this system by comparing estimated bacterial carbon utilization rates with simultaneously measured carbon reduction values. The pilot-scale constructed wetlands proved to be a suitable model system for investigating microbial carbon utilization in constructed wetlands. Under an ideal operating mode, the bulk of bacterial productivity occurred within the first 10cm of the filter body. Plants seemed to have no significant influence on productivity and biomass of bacteria, as well as on wastewater total organic carbon removal.

A data-model integration approach toward improved understanding on wetland functions and hydrological benefits at the catchment scale

NASA Astrophysics Data System (ADS)

Yeo, I. Y.; Lang, M.; Lee, S.; Huang, C.; Jin, H.; McCarty, G.; Sadeghi, A.

2017-12-01

The wetland ecosystem plays crucial roles in improving hydrological function and ecological integrity for the downstream water and the surrounding landscape. However, changing behaviours and functioning of wetland ecosystems are poorly understood and extremely difficult to characterize. Improved understanding on hydrological behaviours of wetlands, considering their interaction with surrounding landscapes and impacts on downstream waters, is an essential first step toward closing the knowledge gap. We present an integrated wetland-catchment modelling study that capitalizes on recently developed inundation maps and other geospatial data. The aim of the data-model integration is to improve spatial prediction of wetland inundation and evaluate cumulative hydrological benefits at the catchment scale. In this paper, we highlight problems arising from data preparation, parameterization, and process representation in simulating wetlands within a distributed catchment model, and report the recent progress on mapping of wetland dynamics (i.e., inundation) using multiple remotely sensed data. We demonstrate the value of spatially explicit inundation information to develop site-specific wetland parameters and to evaluate model prediction at multi-spatial and temporal scales. This spatial data-model integrated framework is tested using Soil and Water Assessment Tool (SWAT) with improved wetland extension, and applied for an agricultural watershed in the Mid-Atlantic Coastal Plain, USA. This study illustrates necessity of spatially distributed information and a data integrated modelling approach to predict inundation of wetlands and hydrologic function at the local landscape scale, where monitoring and conservation decision making take place.

Decision Tree Repository and Rule Set Based Mingjiang River Estuarine Wetlands Classifaction

NASA Astrophysics Data System (ADS)

Zhang, W.; Li, X.; Xiao, W.

2018-05-01

The increasing urbanization and industrialization have led to wetland losses in estuarine area of Mingjiang River over past three decades. There has been increasing attention given to produce wetland inventories using remote sensing and GIS technology. Due to inconsistency training site and training sample, traditionally pixel-based image classification methods can't achieve a comparable result within different organizations. Meanwhile, object-oriented image classification technique shows grate potential to solve this problem and Landsat moderate resolution remote sensing images are widely used to fulfill this requirement. Firstly, the standardized atmospheric correct, spectrally high fidelity texture feature enhancement was conducted before implementing the object-oriented wetland classification method in eCognition. Secondly, we performed the multi-scale segmentation procedure, taking the scale, hue, shape, compactness and smoothness of the image into account to get the appropriate parameters, using the top and down region merge algorithm from single pixel level, the optimal texture segmentation scale for different types of features is confirmed. Then, the segmented object is used as the classification unit to calculate the spectral information such as Mean value, Maximum value, Minimum value, Brightness value and the Normalized value. The Area, length, Tightness and the Shape rule of the image object Spatial features and texture features such as Mean, Variance and Entropy of image objects are used as classification features of training samples. Based on the reference images and the sampling points of on-the-spot investigation, typical training samples are selected uniformly and randomly for each type of ground objects. The spectral, texture and spatial characteristics of each type of feature in each feature layer corresponding to the range of values are used to create the decision tree repository. Finally, with the help of high resolution reference images, the random sampling method is used to conduct the field investigation, achieve an overall accuracy of 90.31 %, and the Kappa coefficient is 0.88. The classification method based on decision tree threshold values and rule set developed by the repository, outperforms the results obtained from the traditional methodology. Our decision tree repository and rule set based object-oriented classification technique was an effective method for producing comparable and consistency wetlands data set.

Climate change and prairie pothole wetlands: mitigating water-level and hydroperiod effects through upland management

USGS Publications Warehouse

Renton, David A.; Mushet, David M.; DeKeyser, Edward S.

2015-01-01

Prairie pothole wetlands offer crucial habitat for North America’s waterfowl populations. The wetlands also support an abundance of other species and provide ecological services valued by society. The hydrology of prairie pothole wetlands is dependent on atmospheric interactions. Therefore, changes to the region’s climate can have profound effects on wetland hydrology. The relevant literature related to climate change and upland management effects on prairie pothole wetland water levels and hydroperiods was reviewed. Climate change is widely expected to affect water levels and hydroperiods of prairie pothole wetlands, as well as the biota and ecological services that the wetlands support. In general, hydrologic model projections that incorporate future climate change scenarios forecast lower water levels in prairie pothole wetlands and longer periods spent in a dry condition, despite potential increases in precipitation. However, the extreme natural variability in climate and hydrology of prairie pothole wetlands necessitates caution when interpreting model results. Recent changes in weather patterns throughout much of the Prairie Pothole Region have been in increased precipitation that results in increased water inputs to wetlands above losses associated with warmer temperatures. However, observed precipitation increases are within the range of natural climate variability and therefore, may not persist. Identifying management techniques with the potential to affect water inputs to prairie pothole wetlands would provide increased options for managers when dealing with the uncertainties associated with a changing climate. Several grassland management techniques (for example, grazing and burning) have the potential to affect water levels and hydroperiods of prairie pothole by affecting infiltration, evapotranspiration, and snow deposition.

Use of created cattail ( Typha) wetlands in mitigation strategies

NASA Astrophysics Data System (ADS)

Dobberteen, Ross A.; Nickerson, Norton H.

1991-11-01

In order to balance pressures for land-use development with protection of wetland resources, artificial wetlands have been constructed in an effort to replace lost ecosystems. Despite its regulatory appeal and prominent role in current mitigation strategies, it is unclear whether or not created systems actually compensate for lost wetland resources. Mitigation predictions that rely on artificial wetlands must be analyzed critically in terms of their efficacy. Destruction of wetlands due to burial by coal fly ash at a municipal landfill in Danvers, Massachusetts, USA, provided an opportunity to compare resulting growth of created cattail ( Typha) marshes with natural wetland areas. Once the appropriate cattail species was identified for growth under disturbed landfill conditions, two types of artificial wetlands were constructed. The two systems differed in their hydrologic attributes: while one had a surface water flow characteristic of most cattail wetlands, the second system mimicked soil and water conditions found in naturally occurring floating cattail marshes. Comparison of plant growth measurements for two years from the artificial systems with published values for natural cattail marshes revealed similar structure and growth patterns. Experiments are now in progress to investigate the ability of created cattail marshes to remove and accumulate heavy metals from polluted landfill leachate. Research of the type reported here must be pursued aggressively in order to document the performance of artificial wetlands in terms of plant structure and wetland functions. Such research should allow us to start to evaluate whether artificial systems actually compensate for lost wetlands by performing similar functions and providing the concomitant public benefits.

Polycyclic aromatic hydrocarbons (PAHs) in wetland soils under different land uses in a coastal estuary: toxic levels, sources and relationships with soil organic matter and water-stable aggregates.

PubMed

Xiao, Rong; Bai, Junhong; Wang, Junjing; Lu, Qiongqiong; Zhao, Qingqing; Cui, Baoshan; Liu, Xinhui

2014-09-01

The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the soils from industrial, wharf, cropland, milldam and natural wetland sites to characterize their distributions, toxic levels and possible sources in the Pearl River Estuary and identify their relationships with soil organic matter (SOM) and water-stable aggregates (WSAs). Our results indicate that the average concentration of total PAHs in this region reached a moderate pollution level, which was higher than that in other larger estuaries in Asia. The average level of total PAHs in industrial soils was 1.2, 1.5, 1.6 and 2.3 times higher than those in soils from wharf, cropland, milldam and natural wetland sites, respectively. Greater accumulation of PAHs occurred in the middle and/or bottom soil layers where 3-ring PAHs were dominant. Industrial soils also exhibited the highest toxic levels with the highest toxic equivalent concentrations of PAHs, followed by wharf and milldam soils, and the cropland and wetland soils had the lowest toxicity. The diagnostic ratios suggested that PAHs primarily originated from biomass and coal combustion at industrial and milldam sites, and petroleum combustion was determined to be the primary source of PAHs at the wharf, cropland and wetland sites. Both 3-ring and 4-ring PAHs in the milldam and wharf soils were significantly positively correlated with the SOM, whereas the 4,5,6-ring PAHs and total PAHs in industrial soils and the 2-ring PAHs in cropland soils were significantly negatively correlated with the SOM. In addition, large WSAs also exhibited a significant positive correlation with PAHs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Purifying capability, enzyme activity, and nitrification potentials in December in integrated vertical flow constructed wetland with earthworms and different substrates.

PubMed

Xu, Defu; Gu, Jiaru; Li, Yingxue; Zhang, Yu; Howard, Alan; Guan, Yidong; Li, Jiuhai; Xu, Hui

2016-01-01

The response of purifying capability, enzyme activity, nitrification potentials, and total number of bacteria in the rhizosphere in December to wetland plants, substrates, and earthworms was investigated in integrated vertical flow constructed wetlands (IVFCW). The removal efficiency of total nitrogen (TN), NH4-N, chemical oxygen demand (COD), and total phosphorus (TP) was increased when earthworms were added into IVFCW. A significantly average removal efficiency of N in IVFCW that employed river sand as substrate and in IVFCW that employed a mixture of river sand and Qing sand as substrate was not found. However, the average removal efficiency of P was higher in IVFCW with a mixture of river sand and Qing sand as substrate than in IVFCW with river sand as substrate. Invertase activity in December was higher in IVFCW that used a mixture of river sand and Qing sand as substrate than in IVFCW which used only river sand as substrate. However, urease activity, nitrification potential, and total number of bacteria in December was higher in IVFCW that employed river sand as substrate than in IVFCW with a mixture of river sand and Qing sand as substrate. The addition of earthworms into the integrated vertical flow constructed wetland increased the above-ground biomass, enzyme activity (catalase, urease, and invertase), nitrification potentials, and total number of bacteria in December. The above-ground biomass of wetland plants was significantly positively correlated with urease and nitrification potentials (p < 0.01). The addition of earthworms into IVFCW increased enzyme activity and nitrification potentials in December, which resulted in improving purifying capability.

Investigation of nitrogen transformations in a southern California constructed wastewater treatment wetland

USGS Publications Warehouse

Sartoris, J.J.; Thullen, J.S.; Barber, L.B.; Salas, D.E.

2000-01-01

A 9.9-ha combined habitat and wastewater treatment demonstration wetland was constructed and planted in the summer of 1994, at Eastern Municipal Water District’s (EMWD) Hemet/San Jacinto Regional Water Reclamation Facility (RWRF) in southern California. From January 1996 through September 1997, the marsh–pond–marsh wetland system was operated to polish an average of 3785 m3 d−1 (1×106 gal day−1) of secondary-treated effluent from the RWRF. Nitrogen removal was a major objective of this wetland treatment. Weekly inflow/outflow water quality monitoring of the wetland was supplemented with biannual, 45-station synoptic surveys within the system to determine internal distribution patterns of the nitrogen species (total ammonia, nitrite, nitrate, and organic nitrogen), total organic carbon (TOC), and ultraviolet absorbance at 254 nm (UV254). Synoptic surveys were carried out during May 22 and September 17, 1996, and May 6 and September 25, 1997 and the results were mapped using the ARC/INFO processing package and inverse distance weighted mathematical techniques. Distribution patterns of the various nitrogen species, TOC, and UV254 within the wetland indicate that the nitrogen dynamics of the system are influenced both by variations in treatment plant loading, and, increasingly, by the degree of coverage and maturity of the emergent vegetation.

Large emissions from floodplain trees close the Amazon methane budget.

PubMed

Pangala, Sunitha R; Enrich-Prast, Alex; Basso, Luana S; Peixoto, Roberta Bittencourt; Bastviken, David; Hornibrook, Edward R C; Gatti, Luciana V; Marotta, Humberto; Calazans, Luana Silva Braucks; Sakuragui, Cassia Mônica; Bastos, Wanderley Rodrigues; Malm, Olaf; Gloor, Emanuel; Miller, John Bharat; Gauci, Vincent

2017-12-14

Wetlands are the largest global source of atmospheric methane (CH 4 ), a potent greenhouse gas. However, methane emission inventories from the Amazon floodplain, the largest natural geographic source of CH 4 in the tropics, consistently underestimate the atmospheric burden of CH 4 determined via remote sensing and inversion modelling, pointing to a major gap in our understanding of the contribution of these ecosystems to CH 4 emissions. Here we report CH 4 fluxes from the stems of 2,357 individual Amazonian floodplain trees from 13 locations across the central Amazon basin. We find that escape of soil gas through wetland trees is the dominant source of regional CH 4 emissions. Methane fluxes from Amazon tree stems were up to 200 times larger than emissions reported for temperate wet forests and tropical peat swamp forests, representing the largest non-ebullitive wetland fluxes observed. Emissions from trees had an average stable carbon isotope value (δ 13 C) of -66.2 ± 6.4 per mil, consistent with a soil biogenic origin. We estimate that floodplain trees emit 15.1 ± 1.8 to 21.2 ± 2.5 teragrams of CH 4 a year, in addition to the 20.5 ± 5.3 teragrams a year emitted regionally from other sources. Furthermore, we provide a 'top-down' regional estimate of CH 4 emissions of 42.7 ± 5.6 teragrams of CH 4 a year for the Amazon basin, based on regular vertical lower-troposphere CH 4 profiles covering the period 2010-2013. We find close agreement between our 'top-down' and combined 'bottom-up' estimates, indicating that large CH 4 emissions from trees adapted to permanent or seasonal inundation can account for the emission source that is required to close the Amazon CH 4 budget. Our findings demonstrate the importance of tree stem surfaces in mediating approximately half of all wetland CH 4 emissions in the Amazon floodplain, a region that represents up to one-third of the global wetland CH 4 source when trees are combined with other emission sources.

Large emissions from floodplain trees close the Amazon methane budget

NASA Astrophysics Data System (ADS)

Pangala, Sunitha R.; Enrich-Prast, Alex; Basso, Luana S.; Peixoto, Roberta Bittencourt; Bastviken, David; Hornibrook, Edward R. C.; Gatti, Luciana V.; Marotta, Humberto; Calazans, Luana Silva Braucks; Sakuragui, Cassia Mônica; Bastos, Wanderley Rodrigues; Malm, Olaf; Gloor, Emanuel; Miller, John Bharat; Gauci, Vincent

2017-12-01

Wetlands are the largest global source of atmospheric methane (CH4), a potent greenhouse gas. However, methane emission inventories from the Amazon floodplain, the largest natural geographic source of CH4 in the tropics, consistently underestimate the atmospheric burden of CH4 determined via remote sensing and inversion modelling, pointing to a major gap in our understanding of the contribution of these ecosystems to CH4 emissions. Here we report CH4 fluxes from the stems of 2,357 individual Amazonian floodplain trees from 13 locations across the central Amazon basin. We find that escape of soil gas through wetland trees is the dominant source of regional CH4 emissions. Methane fluxes from Amazon tree stems were up to 200 times larger than emissions reported for temperate wet forests and tropical peat swamp forests, representing the largest non-ebullitive wetland fluxes observed. Emissions from trees had an average stable carbon isotope value (δ13C) of -66.2 ± 6.4 per mil, consistent with a soil biogenic origin. We estimate that floodplain trees emit 15.1 ± 1.8 to 21.2 ± 2.5 teragrams of CH4 a year, in addition to the 20.5 ± 5.3 teragrams a year emitted regionally from other sources. Furthermore, we provide a ‘top-down’ regional estimate of CH4 emissions of 42.7 ± 5.6 teragrams of CH4 a year for the Amazon basin, based on regular vertical lower-troposphere CH4 profiles covering the period 2010-2013. We find close agreement between our ‘top-down’ and combined ‘bottom-up’ estimates, indicating that large CH4 emissions from trees adapted to permanent or seasonal inundation can account for the emission source that is required to close the Amazon CH4 budget. Our findings demonstrate the importance of tree stem surfaces in mediating approximately half of all wetland CH4 emissions in the Amazon floodplain, a region that represents up to one-third of the global wetland CH4 source when trees are combined with other emission sources.

Habitat-specific nutrient removal and release in Oregon salt marshes

EPA Science Inventory

Wetlands can be sources, sinks and transformers of nutrients, although it is their role in nutrient removal that is valued as a water purification ecosystem service. In order to quantify that service for any wetland, it is important to understand the drivers of nutrient removal w...

Proceedings of the symposium: The Forested Wetlands of the Southern United States

Treesearch

Donald D. Hook; Russ Lea; [Editors

1989-01-01

Twenty-five papers are presented in five categories: Non point Sources of Pollution and the Functions and Values; Best Management Practices for Forested Wetlands; Streamside Management Strategies; Sensitive Areas Management; and Balancing Best Management Practices and Water Quality Standards for Feasibility, Economic, and Functional Effectiveness.

50 CFR 84.46 - What are the cost-sharing requirements?

Code of Federal Regulations, 2011 CFR

2011-10-01

... INTERIOR (CONTINUED) FINANCIAL ASSISTANCE-WILDLIFE SPORT FISH RESTORATION PROGRAM NATIONAL COASTAL WETLANDS... provide the value of land, including the land proposed for restoration, enhancement, or management as a..., if a State proposes to manage a contiguous wetland of 100 acres, and already owns 10 of the 100 acres...

24 CFR 55.20 - Decision making process.

Code of Federal Regulations, 2014 CFR

2014-04-01

... permit. In such a case, the wetland will be considered among the primary natural and beneficial functions.... Notices required under this part must be bilingual if the affected public is largely non-English speaking... related natural and beneficial functions and values of the floodplain or wetland that may be adversely...

Asiatic clam (Corbicula manilensis) and other foods used by waterfowl in the James River, Virginia

USGS Publications Warehouse

Perry, M.C.; Uhler, F.M.

1981-01-01

Corbicula manilensis was found in the gizzards of 24 ducks of 5 species taken from the James River, Virginia, between 1973 and 1976. Percent average volume in these species ranged from trace to 6%. This is the first known occurrence of this exotic clam in the food of duck in Chesapeake Bay. A total of 135 other food items was identified from the 116 gizzards of 9 species that were examined. Food that predominated included Cyperus spp., Leersia oryzoides, Polygonum spp., and Zea mays. The great diversity of food consumed in this fresh tidal section of the James River indicates the high value of these wetlands to waterfowl.

Leveraging field and remotely sensed data to reduce uncertainty in national inventories of coastal wetland carbon fluxes: Year 2 findings from the NASA "Blue" Carbon Monitoring System

NASA Astrophysics Data System (ADS)

Windham-Myers, L.; Holmquist, J. R.; Woo, I.; Bergamaschi, B. A.; Byrd, K. B.; Crooks, S.; Drexler, J. Z.; Feagin, R. A.; Ferner, M. C.; Gonneea, M. E.; Kroeger, K. D.; Megonigal, P.; Morris, J. T.; Schile, L. M.; Simard, M.; Sutton-Grier, A.; Takekawa, J.; Troxler, T.; Weller, D.; Callaway, J.; Herold, N.

2016-12-01

In Year 2, the NASA Blue Carbon Monitoring Systems group leveraged USDA, USFWS and NOAA datasets, extensive field datasets, and targeted remote-sensing products to address basic questions regarding the size of carbon (C) stocks, and the directions and magnitudes of C fluxes in the US coastal zone since 1996. We review the uncertainty associated with 5 major terms in our Land Use-Land Cover Change (LULCC)-based accounting, both nationally and within sentinel sites (Cape Cod, Chesapeake Bay, Everglades, Louisiana, San Francisco Bay, Puget Sound). 1) To make distinctions between tidal and non-tidal wetlands we have relied on a combination of wetland and LiDAR-derived elevation maps. Existing products appear sufficient for saline wetlands, however many freshwater wetlands (1M ha) may be tidal despite current hydrologic mapcodes. 2) We are currently estimating methane emissions using salinity regime as a proxy. Methane emissions are variable across intermediate salinities, though not captured by the current binary classification of wetlands as either fresh or saline. 3) We are currently using a combination of USDA's SSURGO and independent core data to map soil C stocks. Soil C density varies little and is consistent across depth, salinity regime, and dominant plant cover type. 4) To model soil C fluxes, with C accumulating as sea level rises and C released with erosion or oxidation, we have applied IPCC default emission factors for the 2% of tidal wetland acreage lost to water (the dominant conversion), but have modeled C gain in wetlands-remaining-wetlands (98% of CONUS tidal wetlands) based on correlations between sea-level rise and sediment accretion, with the equation - Δ soil organic C stock = Δ elevation x soil C density. 5) To quantify biomass change through time, we developed a robust (R2 > 0.6) hybrid mapping approach including object-based image analysis, multispectral data, and RADAR. Overall, soil and biomass C stocks appear readily estimated and improved from Tier 1 default values. To further reduce uncertainty in the US GHG inventory for coastal wetlands, we propose efforts to confirm the extent of tidal inundation, develop default values for methane emissions associated with intermediate salinities, and model soil C accretion, the dominant "blue carbon" sink, across continental and local gradients.

Linking hydrology, ecosystem function, and livelihood sustainability in African papyrus wetlands using a Bayesian Network Model

NASA Astrophysics Data System (ADS)

van Dam, A.; Gettel, G. M.; Kipkemboi, J.; Rahman, M. M.

2011-12-01

Papyrus wetlands in East Africa provide ecosystem services supporting the livelihoods of millions but are rapidly degrading due to economic development. For ecosystem conservation, an integrated understanding of the natural and social processes driving ecosystem change is needed. This research focuses on integrating the causal relationships between hydrology, ecosystem function, and livelihood sustainability in Nyando wetland, western Kenya. Livelihood sustainability is based on ecosystem services that include plant and animal harvest for building material and food, conversion of wetlands to crop and grazing land, water supply, and water quality regulation. Specific objectives were: to integrate studies of hydrology, ecology, and livelihood activities using a Bayesian Network (BN) model and include stakeholder involvement in model development. The BN model (Netica 4.16) had 35 nodes with seven decision nodes describing demography, economy, papyrus market, and rainfall, and two target nodes describing ecosystem function (defined by groundwater recharge, nutrient and sediment retention, and biodiversity) and livelihood sustainability (drinking water supply, crop production, livestock production, and papyrus yield). The conditional probability tables were populated using results of ecohydrological and socio-economic field work and consultations with stakeholders. The model was evaluated for an average year with decision node probabilities set according to data from research, expert opinion, and stakeholders' views. Then, scenarios for dry and wet seasons and for economic development (low population growth and unemployment) and policy development (more awareness of wetland value) were evaluated. In an average year, the probability for maintaining a "good" level of sediment and nutrient retention functions, groundwater recharge, and biodiversity was about 60%. ("Good" is defined by expert opinion based on ongoing field research.) In the dry season, the probability was reduced to about 40% and in the wet season increased to about 85%. Both ecosystem functions and livelihood sustainability were most sensitive to flooding and the human pressure, notably the area of crop conversion, grazing pressure, and papyrus harvest. Flooded conditions limit cropping, livestock herding and vegetation harvesting but have a strong positive effect on ecosystem function. Preliminary results suggest that the effects of economic and policy development on ecosystem function and livelihood sustainability were negligible, but more data on these aspects will be included in further model development. The advantage of this modeling approach, which integrates data from hydrological, ecological, and socio-economic studies, is that it highlights the relative effect of hydrologic conditions and socio-economic pressures on ecosystem function. This model is static, however, with long-term changes in climate and exploitation levels superimposed on seasonal hydrology dynamics. Further work should address this issue as well as further constrain probabilities at each node as field research continues.

A project summary: Water and energy budget assessment for a non-tidal wetland in the Sacramento-San Joaquin delta

USGS Publications Warehouse

Anderson, Frank E.; Snyder, R.L.; Paw, U.K.T.; Drexler, Judith Z.

2004-01-01

The methods used to obtain universal cover coefficient (Kc) values for a non-tidal restored wetland in the Sacramento-San Joaquin river delta, US, during the summer of the year 2002 and to investigate possible differences during changing wind patterns are described. A micrometeorological tower over the wetland was established to quantify actual evapotranspiration (ETa) rates and surface energy fluxes for water and energy budget analysis. The eddy-covariance (EC) system was used to measure the surface energy budget data in the period from May 23 to November 6, 2002. The results show that K c values should be lower during westerly than northerly wind events during the midseason period due to the reduced vapor pressure deficit.

Phytoplankton abundance and structural parameters of the critically endangered protected area Vaya Lake (Bulgaria).

PubMed

Dimitrova, Ralits; Nenova, Elena; Uzunov, Blagoy; Shishiniova, Maria; Stoyneva, Maya

2014-09-03

Vaya (Ramsar site, protected area and Natura 2000 site) is the biggest natural lake in Bulgaria and the shallowest Black Sea coastal lake, which during the last decades has undergone significant changes and was included as critically endangered in the Red List of Bulgarian Wetlands. Our studies were conducted during the summer and autumn months of three years - 2004-2006. The paper presents results on the phytoplankton abundance (numbers, biomass and carbon content) in combination with the indices of species diversity, evenness and dominance. Phytoplankton abundance was extremely high (average values of 1135 × 10 6 cells/L for the quantity and of 46 mg/L for the biomass) and increased in the end of the studied period (years 2005-2006), when decrease of species diversity and increase of the dominance index values were detected. The carbon content of the phytoplankton was at an average value of 9.7 mg/L and also increased from 2004 to 2006. Cyanoprokaryota dominated in the formation of the total carbon content of the phytoplankton, in its numbers (88%-97.8%), and in the biomass (62%-87.9%). All data on phytoplankton abundance and structural parameters in Vaya confirm the hypertrophic status of the lake and reflect the general negative trend in its development.

Agricultural wetlands as potential hotspots for mercury bioaccumulation: Experimental evidence using caged fish

USGS Publications Warehouse

Ackerman, Joshua T.; Eagles-Smith, Collin A.

2010-01-01

Wetlands provide numerous ecosystem services, but also can be sources of methylmercury (MeHg) production and export. Rice agricultural wetlands in particular may be important sites for MeHg bioaccumulation due to their worldwide ubiquity, periodic flooding schedules, and high use by wildlife. We assessed MeHg bioaccumulation within agricultural and perennial wetlands common to California's Central Valley during summer, when the majority of wetland habitats are shallowly flooded rice fields. We introduced caged western mosquitofish (Gambusia affinis) within white rice (Oryza sativa), wild rice (Zizania palustris), and permanent wetlands at water inlets, centers, and outlets. Total mercury (THg) concentrations and body burdens in caged mosquitofish increased rapidly, exceeding baseline values at introduction by 135% to 1197% and 29% to 1566% among sites, respectively, after only 60 days. Mercury bioaccumulation in caged mosquitofish was greater in rice fields than in permanent wetlands, with THg concentrations at wetland outlets increasing by 12.1, 5.8, and 2.9 times over initial concentrations in white rice, wild rice, and permanent wetlands, respectively. In fact, mosquitofish caged at white rice outlets accumulated 721 ng Hg/fish in just 60 days. Mercury in wild mosquito fish and Mississippi silversides (Menidia audens) concurrently sampled at wetland outlets also were greater in white rice and wild rice than permanent wetlands. Within wetlands, THg concentrations and body burdens of both caged and wild fish increased from water inlets to outlets in white rice fields, and tended to not vary among sites in permanent wetlands. Fish THg concentrations in agricultural wetlands were high, exceeding 0.2 ??g/g ww in 82% of caged fish and 59% of wild fish. Our results indicate that shallowly flooded rice fields are potential hotspots for MeHg bioaccumulation and, due to their global prevalence, suggest that agricultural wetlands may be important contributors to MeHg contamination.

Spatial and seasonal variations in stream water delta34S-dissolved organic matter in northern Sweden.

PubMed

Giesler, Reiner; Björkvald, Louise; Laudon, Hoalmar; Mörth, Carl-Magnus

2009-01-15

The discharge of terrestrial dissolved organic matter (DOM) by streams is an important cross-system linkage that strongly influences downstream aquatic ecosystems. Isotopic tracers are important tools that can help to unravel the source of DOM from different terrestrial compartments in the landscape. Here we demonstrate the spatial and seasonal variation of delta34S of DOM in 10 boreal streams to test if the tracer could provide new insights into the origin of DOM. We found large spatial and seasonal variations in stream water delta34S-DOM values ranging from -5.2 per thousand to +9.6 per thousand with an average of +4.0 +/- 0.6 (N = 62; average and 95% confidence interval). Large seasonal variations were found in stream water delta34S-DOM values: for example, a shift of more than 10 per thousand during the spring snowmelt in a wetland-dominated stream. Spatial differences were also observed during the winter base flow with higher delta34S-DOM values in the fourth-order Krycklan stream at the outlet of the 68 km2 catchment compared to the small (< 1 km2) headwater streams. Our data clearly show that the delta34S-DOM values have the potential to be used as a tracer to identify and generate new insights about terrestrial DOM sources in the boreal landscape.

Ecological risk-benefit analysis of a wetland development based on risk assessment using "expected loss of biodiversity".

PubMed

Oka, T; Matsuda, H; Kadono, Y

2001-12-01

Ecological risk from the development of a wetland is assessed quantitatively by means of a new risk measure, expected loss of biodiversity (ELB). ELB is defined as the weighted sum of the increments in the probabilities of extinction of the species living in the wetland due to its loss. The weighting for a particular species is calculated according to the length of the branch on the phylogenetic tree that will be lost if the species becomes extinct. The length of the branch on the phylogenetic tree is regarded as reflecting the extent of contribution of the species to the taxonomic diversity of the world of living things. The increments in the probabilities of extinction are calculated by a simulation used for making the Red List for vascular plants in Japan. The resulting ELB for the loss of Nakaikemi wetland is 9,200 years. This result is combined with the economic costs for conservation of the wetland to produce a value for the indicator of the "cost per unit of biodiversity saved." Depending on the scenario, the value is 13,000 yen per year-ELB or 110,000 to 420,000 yen per year-ELB (1 US dollar = 110 yen in 1999).

Use of quality indicators for long-term evaluation of heavy metals content in soils of an agro-ecological protected wetland: L'Albufera de Valencia Natural Park, Valencia, Spain

NASA Astrophysics Data System (ADS)

Pascual-Aguilar, Juan Antonio; Andreu, Vicente; Palop, Carla

2015-04-01

Due to the social, economical and environmental importance of agro-ecological wetlands, strategies for periodical evaluation of their environmental quality should be developed, particularly in those areas were a mixture of land uses are supporting the survival of wildlife and migrant species as is the case of most Mediterranean coastal wetlands. The aim of this work is to develop a strategy for a long-term assessment of the environmental quality of soils in a rice-wetland: L'Albufera Natural Park, Spain, in the surroundings of the metropolitan area of Valencia. The area was officially declared as Natural Park in 1986, integrating both the traditional irrigation system and the ecological importance derived from being a Mediterranean Wetland that is now transformed to a large extent in a rice-wetland allowing the presence of a large variety of migrant spices. The methodology consisted in the monitoring of 20 sites distributed in 5 sectors in and around the natural park of potentially contrasting anthropogenic pressure and land use. Soil samples collection were instrumented in two campaigns. The first one was in 1989 (three years after the official declaration as Natural Park of the wetland), and the second 19 years later in 2008. Seven heavy metals (Cd, Co, Cr, Cu, Ni, Pb and Zn) were analyzed to determine its total and extractable fractions by treatment with EDTA. Atomic Absorption Spectrometry, using graphite furnace when necessary, was used for the determination of metals. To evaluate the quality of soils at each sampling date four indicators were obtained, namely, Contamination Factor (CF), Geoaccumulation Index (Igeo), Pollution Load Index (PLI) and Potential Ecological Risk Index (PERI). Results obtained with quality indicators were further compared to obtain temporal and spatial trends using Geographical Information systems procedures. In general, there is a reduction of metal contents in the study area in both dates. The trend of metals according to average concentration (mg/kg) in 1989 and 2008 were Zn (60.38) > Pb (47.50) > Ni (29.10) > Cu (25.82) > Cr (16.04) > Co (11.40) > Cd (0.50) and Zn (68.82) > Cr (48.12) > Cu (34.93) > Pb (24.60) > Ni (22.49) > Co (6.58) > Cd (0.42), respectively. Average increments were found in Zn, Cr and Cu, which are related with high point (individual location and/or sector) values rather than a general trend in the area. With regard to soil quality, in general heavy metals loads are smaller in 2008 than in 1989, reflected by the low degree obtained with PERI. Nonetheless both Igeo and CF indicate that in 2008 Cd and Cr had still some degree of moderate contamination, and PLI highlight that the area where heavy metal presence were more relevant was the northern which is very close to the city of Valencia. Acknowledgements This work was supported by the Spanish Ministry of Science and Innovation through the project CONSOLIDER-INGENIO 2010 (CSD2009) and by the Ministry and the European Regional Development Fund (ERDF) (projects CGL2011-29703-C02-00, CGL2011-29703-C02-01, CGL2011-29703-C02-02).

The relevance of the Mediterranean Region to colonial waterbird conservation

USGS Publications Warehouse

Erwin, R.M.; Crivelli, Alain J.; Hafner, Heinz; Fasola, Mauro; Erwin, R. Michael; McCrimmon, Donald A.=

1996-01-01

The Mediterranean Sea is the largest partially enclosed sea in the world and provides habitat to more than 100 species of waterbirds from the Palearctic-North African-Middle Eastern regions. Even though the Mediterranean suffers from pollution, has little tidal influence, and is oligotrophic, more than half of the western Palearctic populations of numerous waterfowl species winter in the region. Thirty-three species of colonial waterbirds breed along the 46,000 km Mediterranean coastline with nine species considered threatened or endangered, mostly because of wetland loss and degradation. The long history of human activity and scientific investigations in the region has taught some valuable lessons. In the area of colonial waterbird biology and conservation, we have learned important lessons about the value of long-term monitoring and research on selected populations. From marking studies of Greater Flamingos (Phoenicopterus ruber roseus) and Little Egrets (Egretta garzetta) results have been used to derive useful information about metapopulation dynamics. Involvement of both African and European biologists allowed year-round Studies of these species that yielded valuable spin-offs for training in avian and wetland conservation. We have also learned the value of man-made wetlands as feeding and nesting sites for some colonial waterbirds. Careful evaluations of the habitat quality of different types of wetlands are required, as in contaminant levels such as lead shot and pesticides. Wetland conservationists have also learned from some instructive mistakes. Dam construction and agricultural incentive programs sponsored by the European Community, the World Bank, and others from the past have largely ignored impacts on wetlands and wildlife. In some areas, economic ventures such as aquaculture operations and salt mining have not involved waterbird habitat needs in their planning. Research and conservation needs include: (1) establishing regional monitoring programs and data banks for seabirds, wading birds, ducks, and geese; (2) implementing a wetland inventory for many Countries with little quantitative data on wetlands; (3) improving habitat quality assessments; (4) improving relationships with industry, the private citizenry, and government officials to further an appreciation for the value of wetlands and waterbirds; (5) enhancing training efforts, especially in underdeveloped Countries; (6) evaluating the effects of hunting and other disturbances to nesting and feeding waterbirds in different regions; (7) setting up 'sister-reserve' (twinned) sites in Europe and Africa to foster international linkages and training; and (8) fostering local-regional conservation programs to preserve reed beds, wet woodlots, and other key habitats.

The Fate and Stability of Eroding Wetland Soil Carbon in a Subsiding Deltaic Coastal Plain

NASA Astrophysics Data System (ADS)

White, J. R.; Steinmuller, H.; Chambers, L. G.; Fontenot, A.

2017-12-01

Coastal wetlands can respond to rapid rates of relative sea level rise via wetland submergence and/or erosion, which occur when wetlands are unable to vertically accrete to keep pace with sea level rise. As coastal wetlands erode, previously sequestered organic carbon is exposed to oxygen-rich estuarine water. This transition in redox from anaerobic to aerobic condition can trigger increased mineralization rates of decades to centuries'-old soil carbon. Barataria Bay, Louisiana has one of the highest coastal wetland land loss rates in the United States, primarily due to eustatic sea level rise coupled with coastal subsidence. Marsh-edge erosion rates measured over the past two years are on the order of 1.5 meters per year. Meter long soil cores were obtained from vegetated wetland sites and sectioned into 11 intervals to investigate aerobic and anaerobic mineralization rates with depth. In surface soils, organic carbon mineralization rates averaged 16 times greater than anaerobic mineralization rates. In deeper, older soils, the aerobic mineralization rate was still an order of magnitude greater than the anaerobic rate, suggesting a significant portion of this older, soil carbon is readily cycling back to the atmosphere after erosion followed by mineralization by microorganisms. These results have consequences for increased atmospheric CO2 concentrations in the future, as stable coastlines worldwide will be subjected to Barataria-bay levels of sea level rise in the next 50-75 years.

Subsurface Treatment of Domestic Wastewater Using Single Domicile Constructed Wetlands

NASA Astrophysics Data System (ADS)

Aseltyne, T.; Steer, D.; Fraser, L.

2001-05-01

Analysis of one year of input versus output water quality monitoring data from nine household wastewater treatment wetlands in western Ohio indicates that these systems substantially reduce effluent loads delivered to the local watershed. Overall performance as measured by output water quality improvement varies widely between the nine systems despite their close proximity and identical design. These three-cell systems (septic tank with 2 subsurface wetland cells) are found to reduce biological oxygen demand (BOD) 70-98%, fecal coliform 60-99.9%, NH3 29-97%, Phosphorus 21-99.9% and total suspended solids (TSS) up to 97%. NO3/NO2 readings were only taken at the second wetland cell, but show that NO3/NO2 levels are at 0.005-5.01 mg/l and well below the USEPA standards for discharge from a wetland. On average, the pH of the wastewater increases from 6.6 at the septic tank to 8.7 at the wetland output. Nearly all the monitoring data indicate clear decreases in nutrient loads and bacteria though individual systems are found to non-systematically fail to meet EPA discharge guidelines for one or more of the monitored loads. Preliminary analysis of the data indicates a decrease in overall efficiency of the wetlands in April that may be related to seasonal factors. These systems will be monitored for the next three years in order to relate changing performance trends to seasonal variability.

Hydrogeomorphic Classification of Wetlands on Mt. Desert Island, Maine, Including Hydrologic Susceptibility Factors for Wetlands in Acadia National Park

USGS Publications Warehouse

Nielsen, Martha G.

2006-01-01

The U.S. Geological Survey, in cooperation with the National Park Service, developed a hydrogeomorphic (HGM) classification system for wetlands greater than 0.4 hectares (ha) on Mt. Desert Island, Maine, and applied this classification using map-scale data to more than 1,200 mapped wetland units on the island. In addition, two hydrologic susceptibility factors were defined for a subset of these wetlands, using 11 variables derived from landscape-scale characteristics of the catchment areas of these wetlands. The hydrologic susceptibility factors, one related to the potential hydrologic pathways for contaminants and the other to the susceptibility of wetlands to disruptions in water supply from projected future changes in climate, were used to indicate which wetlands (greater than 1 ha) in Acadia National Park (ANP) may warrant further investigation or monitoring. The HGM classification system consists of 13 categories: Riverine-Upper Perennial, Riverine-Nonperennial, Riverine- Tidal, Depressional-Closed, Depressional-Semiclosed, Depressional-Open, Depressional-No Ground-Water Input, Mineral Soil Flat, Organic Soil Flat, Tidal Fringe, Lacustrine Fringe, Slope, and Hilltop/Upper Hillslope. A dichotomous key was developed to aid in the classification of wetlands. The National Wetland Inventory maps produced by the U.S. Fish and Wildlife Service provided the wetland mapping units used for this classification. On the basis of topographic map information and geographic information system (GIS) layers at a scale of 1:24,000 or larger, 1,202 wetland units were assigned a preliminary HGM classification. Two of the 13 HGM classes (Riverine-Tidal and Depressional-No Ground-Water Input) were not assigned to any wetlands because criteria for determining those classes are not available at that map scale, and must be determined by more site-specific information. Of the 1,202 wetland polygons classified, which cover 1,830 ha in ANP, 327 were classified as Slope, 258 were Depressional (Open, Semiclosed, and Closed), 231 were Riverine (Upper Perennial and Nonperennial), 210 were Soil Flat (Mineral and Organic), 68 were Lacustrine Fringe, 51 were Tidal Fringe, 22 were Hilltop/Upper Hillslope, and another 35 were small open water bodies. Most small, isolated wetlands classified on the island are Slope wetlands. The least common, Hilltop/Upper Hillslope wetlands, only occur on a few hilltops and shoulders of hills and mountains. Large wetland complexes generally consist of groups of Depressional wetlands and Mineral Soil Flat or Organic Soil Flat wetlands, often with fringing Slope wetlands at their edges and Riverine wetlands near streams flowing through them. The two analyses of wetland hydrologic susceptibility on Mt. Desert Island were applied to 186 wetlands located partially or entirely within ANP. These analyses were conducted using individually mapped catchments for each wetland. The 186 wetlands were aggregated from the original 1,202 mapped wetland polygons on the basis of their HGM classes. Landscape-level hydrologic, geomorphic, and soil variables were defined for the catchments of the wetlands, and transformed into scaled scores from 0 to 10 for each variable. The variables included area of the wetland, area of the catchment, area of the wetland divided by the area of the catchment, the average topographic slope of the catchment, the amount of the catchment where bedrock crops out with no soil cover or excessively thin soil cover, the amount of storage (in lakes and wetlands) in the catchment, the topographic relief of the catchment, the amount of clay-rich soil in the catchment, the amount of manmade impervious surface, whether the wetland had a stream inflow, and whether the wetland had a hydraulic connection to a lake or estuary. These data were determined using a GIS and data layers mapped at a scale of 1:24,000 or larger. These landscape variables were combined in different ways for the two hydrologic susceptibility fact

Biogeochemical Hotspots: Small Geographically Isolated Wetlands and their Impacts at the Landscape Scale

NASA Astrophysics Data System (ADS)

Basu, N. B.

2017-12-01

Wetlands provide a wide variety of ecosystem services, including retention of sediment and nutrients, and subsequent improvements in downstream water quality. In fact, a recent review suggests that 64% of reactive nitrogen (N) retention in US freshwater systems occurs in wetlands, while 28% occurs in lakes and reservoirs, and only 8% occurs in streams and rivers. Although the processes controlling nutrient retention in wetlands are well known, there is a lack of quantitative understanding of the relative nutrient filtering abilities of wetlands of various sizes, and in various landscape positions. Our inability to recognize the value of wetlands has led to their dramatic loss in the last few decades. Specifically, there has been an increased loss of geographically isolated wetlands, small upland wetlands that receive fewer legal protections due to their apparent isolation from jurisdictional waters. In this study, we use a meta-analyses approach to quantify the role of small wetlands in landscape scale nutrient processing. We synthesized data from 600 lentic systems around the world to gain insight into the relationship between hydrologic and biogeochemical controls on nutrient retention. Our results indicate that the first-order reaction rate constant k(T-1), is inversely proportional to the residence time, across 6 orders of magnitude in residence time for total N, total P, nitrate, and phosphate. We used a sediment-water model to show how nutrient removal processes are impacted by system size. Finally, the k-residence time relationships were upscaled to the landscape scale using a wetland size-frequency distribution. Results suggest that small wetlands play a disproportionately large role in landscape-scale nutrient processing—50% of nitrogen removal occurs in wetlands smaller than 10^2.5 m2 in our example. Thus, given the same loss in wetland area, the nutrient retention potential lost is greater when smaller wetlands are preferentially lost from the landscape. Such findings are significant to wetland protection and restoration efforts, which have historically focused on maximizing total wetland area rather than on preserving a distribution of different wetlands sizes within a landscape.

Caspian Rapid Assessment Method: a localized procedure for assessment of wetlands at southern fringe of the Caspian Sea.

PubMed

Khorami Pour, Sanaz; Monavari, Seyed Masoud; Riazi, Borhan; Khorasani, Nematollah

2015-07-01

Although Iran is of founders of the Ramsar Convention, there is no comprehensive information available in the country on the status of wetlands in the past or at present. There is also no specific guideline for assessing the status of wetlands in the basin of the Caspian Sea as an ecosystem with unique ecological features. The main aim of this study was to develop a new procedure called "Caspian Rapid Assessment Method" (CRAM) for assessment of wetlands at southern fringe of the Caspian Sea. To this end, 16 rapid assessment methods analyzed by US EPA in 2003 were reviewed to provide an inventory of rapid assessment indices. Excluding less important indices, the inventory was short-listed based on Delphi panelists' consensus. The CRAM was developed with 6 main criteria and 12 sub-criteria. The modified method was used to assess three important wetlands of Anzali, Boojagh and Miyankaleh at the southern border of the Caspian Sea. According to the obtained results, the highest score of 60 was assigned to the Anzali Wetland. Obtaining the scores of 56 and 47, Miyankaleh and Boojagh wetlands were ranked in the next priorities, respectively. At final stage, the accuracy of CRAM prioritization values was confirmed using the Friedman test. All of the wetlands were classified into category II, which indicates destroyed wetlands with rehabilitation potentials. In recent years, serious threats have deteriorated the wetlands from class III (normal condition) to the class II.

Wetlands as large-scale nature-based solutions: status and future challenges for research and management

NASA Astrophysics Data System (ADS)

Thorslund, Josefin; Jarsjö, Jerker; Destouni, Georgia

2017-04-01

Wetlands are often considered as nature-based solutions that can provide a multitude of services of great social, economic and environmental value to humankind. The services may include recreation, greenhouse gas sequestration, contaminant retention, coastal protection, groundwater level and soil moisture regulation, flood regulation and biodiversity support. Changes in land-use, water use and climate can all impact wetland functions and occur at scales extending well beyond the local scale of an individual wetland. However, in practical applications, management decisions usually regard and focus on individual wetland sites and local conditions. To understand the potential usefulness and services of wetlands as larger-scale nature-based solutions, e.g. for mitigating negative impacts from large-scale change pressures, one needs to understand the combined function multiple wetlands at the relevant large scales. We here systematically investigate if and to what extent research so far has addressed the large-scale dynamics of landscape systems with multiple wetlands, which are likely to be relevant for understanding impacts of regional to global change. Our investigation regards key changes and impacts of relevance for nature-based solutions, such as large-scale nutrient and pollution retention, flow regulation and coastal protection. Although such large-scale knowledge is still limited, evidence suggests that the aggregated functions and effects of multiple wetlands in the landscape can differ considerably from those observed at individual wetlands. Such scale differences may have important implications for wetland function-effect predictability and management under large-scale change pressures and impacts, such as those of climate change.

Reprint of Ecological health status of the Lagos wetland ecosystems: Implications for coastal risk reduction

NASA Astrophysics Data System (ADS)

Agboola, Julius I.; Ndimele, Prince E.; Odunuga, Shakirudeen; Akanni, Adeniran; Kosemani, Bosede; Ahove, Michael A.

2016-12-01

Lagos, a major urban agglomeration in the world is characterized by wetlands and basin for upstream rivers such as Ogun, Oshun and Yewa Rivers. Ongoing environmental pressures exerted by large-scale land reclamation for residential quarters, refuse and sewage dumping, and other uses, however, are suspected to have had a substantial impact on ecological health of the Lagos wetland ecosystems over the last few decades. To determine the impact of these pressures, we examined spatial changes in three wetlands areas- Badore/Langbasa (BL), Festac/Iba/Ijegun (FI) and Ologe/Otto-Awori (OO) through field sample collection and analyses of surface water, sediments, air-water interface gas fluxes and vegetations. Surface water conductivity, total suspended solids (TSS), alkalinity, chloride, biological oxygen demand (BOD), nitrate, phosphate and heavy metals (Zn, Cu, Fe, Na, Mn, Pb, Cd, K and Ni) exhibited relative spatial stability while other water quality parameters varied significantly (P < 0.05) across the wetland areas. Also, dissolved inorganic carbon (DIC) contributed to most of the total dissolved solids (TDS) since only DIC correlated significantly with TDS (r = 0.889; P = 0.05, n = 12) and TS (r = 0.891; P = 0.05, n = 12), suggesting a strong capacity for carbon sequestration and carbon sink across the wetland areas. None of the encountered vegetation species are in the vulnerable category of the International Union for Conservation of Nature (IUCN). There are indications of steady rise in greenhouse gas levels in Lagos since air CO2 value at BL have reached global threshold of 400 ppm with OO and FI closely approaching. We conclude that the Lagos wetland ecosystems, especially OO and FI still have some semblance of natural habitat. However, further destruction and unwise use of the resources could cause damage to physical, chemical, geological and biological processes in nature, which could result to grave socio-economic and cultural consequences to the local communities whose livelihood and lifestyle depend on these valued wetlands.

Ecological health status of the Lagos wetland ecosystems: Implications for coastal risk reduction

NASA Astrophysics Data System (ADS)

Agboola, Julius I.; Ndimele, Prince E.; Odunuga, Shakirudeen; Akanni, Adeniran; Kosemani, Bosede; Ahove, Michael A.

2016-12-01

Lagos, a major urban agglomeration in the world is characterized by wetlands and basin for upstream rivers such as Ogun, Oshun and Yewa Rivers. Ongoing environmental pressures exerted by large-scale land reclamation for residential quarters, refuse and sewage dumping, and other uses, however, are suspected to have had a substantial impact on ecological health of the Lagos wetland ecosystems over the last few decades. To determine the impact of these pressures, we examined spatial changes in three wetlands areas- Badore/Langbasa (BL), Festac/Iba/Ijegun (FI) and Ologe/Otto-Awori (OO) through field sample collection and analyses of surface water, sediments, air-water interface gas fluxes and vegetations. Surface water conductivity, total suspended solids (TSS), alkalinity, chloride, biological oxygen demand (BOD), nitrate, phosphate and heavy metals (Zn, Cu, Fe, Na, Mn, Pb, Cd, K and Ni) exhibited relative spatial stability while other water quality parameters varied significantly (P < 0.05) across the wetland areas. Also, dissolved inorganic carbon (DIC) contributed to most of the total dissolved solids (TDS) since only DIC correlated significantly with TDS (r = 0.889; P = 0.05, n = 12) and TS (r = 0.891; P = 0.05, n = 12), suggesting a strong capacity for carbon sequestration and carbon sink across the wetland areas. None of the encountered vegetation species are in the vulnerable category of the International Union for Conservation of Nature (IUCN). There are indications of steady rise in greenhouse gas levels in Lagos since air CO2 value at BL have reached global threshold of 400 ppm with OO and FI closely approaching. We conclude that the Lagos wetland ecosystems, especially OO and FI still have some semblance of natural habitat. However, further destruction and unwise use of the resources could cause damage to physical, chemical, geological and biological processes in nature, which could result to grave socio-economic and cultural consequences to the local communities whose livelihood and lifestyle depend on these valued wetlands.

Painted Bunting Breeding Bird Survey trends associated with landscape changes in Georgia and South Carolina

USGS Publications Warehouse

Meyers, J.M.

2000-01-01

Landscape changes during the first 3 decades of the Breeding Bird Survey (BBS) may account for the Painted Bunting's declining population trend. In the southeastern U.S., it is estimated that this bunting has declined 3.5 % per year since 1966. I collected landscape data centered on identical 5-stop areas (n = 33, 306 ha each) of the BBS during early (1960s - 1970s) and late decades (1980s - 1990s). Peak 30-yr counts for Painted Buntings were found at the center of the 5-stop areas. I used stepwise multiple regression analysis to model the mean number of Painted Buntings (in the area during 3 yr, dependent variable) associated with landscape metrics (independent variables). During the early decades the average amount of edge on developed land (p = 0.10), average patch size of agriculture land (p = 0.01), average size of shrub-scrub and young forest (p = 0.09), and average amount of edge for emergent wetlands (p = 0.03) explained 40% of the variation in Painted Buntings counts. In the late decades average amount of edge on developed land (p = 0.04) and average amount of edge on emergent wetlands (p = 0.005) explained 35% of the variation in Painted Bunting counts. Large losses of agricultural land (proportion = 0.177 to 0.094), which was developed or converted to intensively managed pin plantations, may have reduced potential bunting breeding habitat. Shrub-scrub and young forest habitat was constant (proportion = 0.136 to 0.134) but did not affect mean counts of buntings in the late decades. Protected emergent wetlands remained constnat also from the early to late decades (proportion = 0.056 to 0.06) and may provide habitat to maintain a smaller Painted Bunting population. At this time, it's unclear how develped land, which is increasing (proportion = 0.036 to 0.088), may be affecting the Painted Bunting population in GS and SC.

Investigating the sources and sinks of water of Congo's wetlands

NASA Astrophysics Data System (ADS)

Paiva, R. C. D.; O'Loughlin, F.; Alsdorf, D. E.; Durand, M. T.; Beighley, E., II; Calmant, S.; Lee, H.; Santos Da Silva, J.

2014-12-01

The Congo is the second largest river basin in the world and indeed there is still a lot to be investigated about the hydrology of this system. This region presents extensive wetlands that may play an important role on the hydrology, carbon and ecological dynamics of the Congo. However, previous studies indicate that these wetlands behave differently from the Amazon, other major rainforest basin, and how water enters and leaves the Cuvette Centrale wetland is still to be quantified. We investigate the sources and sinks of water to the Congo's wetlands. Our analyses range from simple examinations of precipitation and evaporation historical data to remote sensing datasets and 2 D hydrodynamic modelling of Congo wetlands. Early results show that water levels at wetlands are usually higher than adjacent Congo River water levels and amplitude of variation is considerably smaller. Also, floodplain channels are not observed in this region indicating that surface flows are diffusive. Mean annual precipitation range from 1600 to 2000 mm/year, evapotranspiration estimates are approximately 1100 mm/year while some estimates of groundwater recharge indicate values larger than 300 mm/year. These assessments suggest that volumes coming from local water balance could flood the wetlands to depths of only a few centimeters. Preliminary 2D hydrodynamic simulations show that water coming from main rivers produces at upstream areas can flood only a small part of wetland, mainly alongside these rivers.

Classifying and mapping wetlands and peat resources using digital cartography

USGS Publications Warehouse

Cameron, Cornelia C.; Emery, David A.

1992-01-01

Digital cartography allows the portrayal of spatial associations among diverse data types and is ideally suited for land use and resource analysis. We have developed methodology that uses digital cartography for the classification of wetlands and their associated peat resources and applied it to a 1:24 000 scale map area in New Hampshire. Classifying and mapping wetlands involves integrating the spatial distribution of wetlands types with depth variations in associated peat quality and character. A hierarchically structured classification that integrates the spatial distribution of variations in (1) vegetation, (2) soil type, (3) hydrology, (4) geologic aspects, and (5) peat characteristics has been developed and can be used to build digital cartographic files for resource and land use analysis. The first three parameters are the bases used by the National Wetlands Inventory to classify wetlands and deepwater habitats of the United States. The fourth parameter, geological aspects, includes slope, relief, depth of wetland (from surface to underlying rock or substrate), wetland stratigraphy, and the type and structure of solid and unconsolidated rock surrounding and underlying the wetland. The fifth parameter, peat characteristics, includes the subsurface variation in ash, acidity, moisture, heating value (Btu), sulfur content, and other chemical properties as shown in specimens obtained from core holes. These parameters can be shown as a series of map data overlays with tables that can be integrated for resource or land use analysis.

Effect of wetland management: are lentic wetlands refuges of plant-species diversity in the Andean–Orinoco Piedmont of Colombia?

PubMed Central

Murillo-Pacheco, Johanna I.; Rös, Matthias; Castro-Lima, Francisco; Verdú, José R.; López-Iborra, Germán M.

2016-01-01

Accelerated degradation of the wetlands and fragmentation of surrounding vegetation in the Andean–Orinoco Piedmont are the main threats to diversity and ecological integrity of these ecosystems; however, information on this topic is of limited availability. In this region, we evaluated the value of 37 lentic wetlands as reservoirs of woody and aquatic plants and analyzed diversity and changes in species composition within and among groups defined according to management given by: (1) type (swamps, heronries, rice fields, semi-natural lakes, constructed lakes and fish farms) and (2) origins (natural, mixed and artificial). A total of 506 plant species were recorded: 80% woody and 20% aquatic. Of these, 411 species (81%) were considered species typical of the area (Meta Piedmont distribution). Diversity patterns seem to be driven by high landscape heterogeneity and wetland management. The fish farms presented the highest diversity of woody plants, while swamps ranked highest for aquatic plant diversity. Regarding wetland origin, the artificial systems were the most diverse, but natural wetlands presented the highest diversity of typical species and can therefore be considered representative ecosystems at the regional scale. Our results suggest that lentic wetlands act as refuges for native vegetation of Meta Piedmont forest, hosting 55% of the woody of Piedmont species and 29% of the aquatic species of Orinoco basin. The wetlands showed a high species turnover and the results indicated that small wetlands (mean ± SD: size = 11 ± 18.7 ha), with a small area of surrounding forest (10 ± 8.6 ha) supported high local and regional plant diversity. To ensure long-term conservation of lentic wetlands, it is necessary to develop management and conservation strategies that take both natural and created wetlands into account. PMID:27602263

Distribution of Organic Carbon in the Sediments of Xinxue River and the Xinxue River Constructed Wetland, China.

PubMed

Cao, Qingqing; Wang, Renqing; Zhang, Haijie; Ge, Xiuli; Liu, Jian

2015-01-01

Wetland ecosystems are represented as a significant reservoir of organic carbon and play an important role in mitigating the greenhouse effect. In order to compare the compositions and distribution of organic carbon in constructed and natural river wetlands, sediments from the Xinxue River Constructed Wetland and the Xinxue River, China, were sampled at two depths (0-15 cm and 15-25 cm) in both upstream and downstream locations. Three types of organic carbon were determined: light fraction organic carbon, heavy fraction organic carbon, and dissolved organic carbon. The results show that variations in light fraction organic carbon are significantly larger between upstream and downstream locations than they are between the two wetland types; however, the opposite trend is observed for the dissolved organic carbon. There are no significant differences in the distribution of heavy fraction organic carbon between the discrete variables (e.g., between the two depths, the two locations, or the two wetland types). However, there are significant cross-variable differences; for example, the distribution patterns of heavy fraction organic carbon between wetland types and depths, and between wetland types and locations. Correlation analysis reveals that light fraction organic carbon is positively associated with light fraction nitrogen in both wetlands, while heavy fraction organic carbon is associated with both heavy fraction nitrogen and the moisture content in the constructed wetland. The results of this study demonstrate that the constructed wetland, which has a relatively low background value of heavy fraction organic carbon, is gradually accumulating organic carbon of different types, with the level of accumulation dependent on the balance between carbon accumulation and carbon decomposition. In contrast, the river wetland has relatively stable levels of organic carbon.

Distribution of Organic Carbon in the Sediments of Xinxue River and the Xinxue River Constructed Wetland, China

PubMed Central

Cao, Qingqing; Wang, Renqing; Zhang, Haijie; Ge, Xiuli; Liu, Jian

2015-01-01

Wetland ecosystems are represented as a significant reservoir of organic carbon and play an important role in mitigating the greenhouse effect. In order to compare the compositions and distribution of organic carbon in constructed and natural river wetlands, sediments from the Xinxue River Constructed Wetland and the Xinxue River, China, were sampled at two depths (0–15 cm and 15–25 cm) in both upstream and downstream locations. Three types of organic carbon were determined: light fraction organic carbon, heavy fraction organic carbon, and dissolved organic carbon. The results show that variations in light fraction organic carbon are significantly larger between upstream and downstream locations than they are between the two wetland types; however, the opposite trend is observed for the dissolved organic carbon. There are no significant differences in the distribution of heavy fraction organic carbon between the discrete variables (e.g., between the two depths, the two locations, or the two wetland types). However, there are significant cross-variable differences; for example, the distribution patterns of heavy fraction organic carbon between wetland types and depths, and between wetland types and locations. Correlation analysis reveals that light fraction organic carbon is positively associated with light fraction nitrogen in both wetlands, while heavy fraction organic carbon is associated with both heavy fraction nitrogen and the moisture content in the constructed wetland. The results of this study demonstrate that the constructed wetland, which has a relatively low background value of heavy fraction organic carbon, is gradually accumulating organic carbon of different types, with the level of accumulation dependent on the balance between carbon accumulation and carbon decomposition. In contrast, the river wetland has relatively stable levels of organic carbon. PMID:26230255

Effect of wetland management: are lentic wetlands refuges of plant-species diversity in the Andean-Orinoco Piedmont of Colombia?

PubMed

Murillo-Pacheco, Johanna I; Rös, Matthias; Escobar, Federico; Castro-Lima, Francisco; Verdú, José R; López-Iborra, Germán M

2016-01-01

Accelerated degradation of the wetlands and fragmentation of surrounding vegetation in the Andean-Orinoco Piedmont are the main threats to diversity and ecological integrity of these ecosystems; however, information on this topic is of limited availability. In this region, we evaluated the value of 37 lentic wetlands as reservoirs of woody and aquatic plants and analyzed diversity and changes in species composition within and among groups defined according to management given by: (1) type (swamps, heronries, rice fields, semi-natural lakes, constructed lakes and fish farms) and (2) origins (natural, mixed and artificial). A total of 506 plant species were recorded: 80% woody and 20% aquatic. Of these, 411 species (81%) were considered species typical of the area (Meta Piedmont distribution). Diversity patterns seem to be driven by high landscape heterogeneity and wetland management. The fish farms presented the highest diversity of woody plants, while swamps ranked highest for aquatic plant diversity. Regarding wetland origin, the artificial systems were the most diverse, but natural wetlands presented the highest diversity of typical species and can therefore be considered representative ecosystems at the regional scale. Our results suggest that lentic wetlands act as refuges for native vegetation of Meta Piedmont forest, hosting 55% of the woody of Piedmont species and 29% of the aquatic species of Orinoco basin. The wetlands showed a high species turnover and the results indicated that small wetlands (mean ± SD: size = 11 ± 18.7 ha), with a small area of surrounding forest (10 ± 8.6 ha) supported high local and regional plant diversity. To ensure long-term conservation of lentic wetlands, it is necessary to develop management and conservation strategies that take both natural and created wetlands into account.

Nitrogen transformations and balance in constructed wetlands for slightly polluted river water treatment using different macrophytes.

PubMed

Wu, Haiming; Zhang, Jian; Wei, Rong; Liang, Shuang; Li, Cong; Xie, Huijun

2013-01-01

Nitrogen removal processing in different constructed wetlands treating different kinds of wastewater often varies, and the contribution to nitrogen removal by various pathways remains unclear. In this study, the seasonal nitrogen removal and transformations as well as nitrogen balance in wetland microcosms treating slightly polluted river water was investigated. The results showed that the average total nitrogen removal rates varied in different seasons. According to the mass balance approach, plant uptake removed 8.4-34.3 % of the total nitrogen input, while sediment storage and N(2)O emission contributed 20.5-34.4 % and 0.6-1.9 % of nitrogen removal, respectively. However, the percentage of other nitrogen loss such as N(2) emission due to nitrification and denitrification was estimated to be 2.0-23.5 %. The results indicated that plant uptake and sediment storage were the key factors limiting nitrogen removal besides microbial processes in surface constructed wetland for treating slightly polluted river water.

Historic macrophyte development in Par Pond

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grace, J.B.

1985-08-01

Aerial photographs from 1975, 1980, and 1983 were examined to evaluate the changes that have occurred in the wetland vegetation of Par Pond, a reactor-cooling reservoir. Evaluation of the aerial photographs was based on comparisons with ground-level vegetation maps made during July 1984. Comparisons of photographs from August and December of 1983 revealed the main seasonal change in the aerial coverage of wetland vegetation to be the wintertime loss of non-persistent emergent species such as Nelumbo lutea and Nymphaea odorata. Comparisons between September 1980 and August 1983 revealed that the lakeward extent of non-persistent macrophytes has increased by an averagemore » of 8.2 m, though not all sites have changed equally. For persistent macrophytes (principally Typha), the average increase in lakeward extent between December 1975 and August 1983 was 3.48 m. The extensive development of wetland vegetation in Par Pond as well as the substantial spread of vegetation over only a few years time indicates the high suitability of this habitat for the growth of wetland plants.« less

Performance of a constructed wetland-pond system for treatment and reuse of wastewater from campus buildings.

PubMed

Ou, Wen-Sheng; Lin, Ying-Feng; Jing, Shuh-Ren; Lin, Hsien-Te

2006-11-01

A constructed wetland-pond system consisting of two free-water-surface-flow (FWS) wetland cells, a scenic pond, and a slag filter in series was used for reclamation of septic tank effluent from a campus building. The results show that FWS wetlands effectively removed major pollutants under a hydraulic loading rate between 2.1 and 4.2 cm/d, with average efficiencies ranging from 74 to 78% for total suspended solids, 73 to 88% for 5-day biochemical oxygen demand, 42 to 49% for total nitrogen, 34 to 70% for total phosphorous, 64 to 79% for total coliforms, and 90 to 99.9% for Escherichia coli. After passing through the scenic pond and slag filter, the reclaimed water was used for landscape irrigation. There were a variety of ornamental plants and aquatic animals established in the second FWS cell and scenic pond with good water quality, thus enhancing landscape and ecology amenity in campuses.

Spatial Distribution of Ground-Water Recharge Estimated with a Water-Budget Method for the Jordan Creek Watershed, Lehigh County, Pennsylvania

USGS Publications Warehouse

Risser, Dennis W.

2008-01-01

This report presents the results of a study by the U.S. Geological Survey, in cooperation with the Pennsylvania Geological Survey, to illustrate a water-budget method for mapping the spatial distribution of ground-water recharge for a 76-square-mile part of the Jordan Creek watershed, northwest of Allentown, in Lehigh County, Pennsylvania. Recharge was estimated by using the Hydrological Evaluation of Landfill Performance (HELP) water-budget model for 577 landscape units in Jordan Creek watershed, delineated on the basis of their soils, land use/land cover, and mean annual precipitation during 1951-2000. The water-budget model routes precipitation falling on each landscape unit to components of evapotranspiration, surface runoff, storage, and vertical percolation (recharge) for a five-layer soil column on a daily basis. The spatial distribution of mean annual recharge during 1951-2000 for each landscape unit was mapped by the use of a geographic information system. Recharge simulated by the water-budget model in Jordan Creek watershed during 1951-2000 averaged 12.3 inches per year and ranged by landscape unit from 0.11 to 17.05 inches per year. Mean annual recharge during 1951-2000 simulated by the water-budget model was most sensitive to changes to input values for precipitation and runoff-curve number. Mean annual recharge values for the crop, forest, pasture, and low-density urban land-use/land-cover classes were similar (11.2 to 12.2 inches per year) but were substantially less for high-density urban (6.8 inches per year), herbaceous wetlands (2.5 inches per year), and forested wetlands (1.3 inches per year). Recharge rates simulated for the crop, forest, pasture, and low-density urban land-cover classes were similar because those land-use/land-cover classes are represented in the model with parameter values that either did not significantly affect simulated recharge or tended to have offsetting effects on recharge. For example, for landscapes with forest land cover, values of runoff-curve number assigned to the model were smaller than for other land-use/land-cover classes (causing more recharge and less runoff), but the maximum depth of evapotranspiration was larger than for other land-use/ land-cover classes because of deeper root penetration in forests (causing more evapotranspiration and less recharge). The smaller simulated recharge for high-density urban and wetland land-use/land-cover classes was caused by the large values of runoff-curve number (greater than 90) assigned to those classes. The large runoff-curve number, however, certainly is not realistic for all wetlands; some wetlands act as areas of ground-water discharge and some as areas of recharge. Simulated mean annual recharge computed by the water-budget model for the 53-square-mile part of the watershed upstream from the streamflow-gaging station near Schnecksville was compared to estimates of recharge and base flow determined by analysis of streamflow records from 1967 to 2000. The mean annual recharge of 12.4 inches per year simulated by the water-budget method for 1967-2000 was less than estimates of mean annual recharge of 19.3 inches per year computed from the RORA computer program and base flow computed by the PART computer program (15.1 inches per year). In theory, the water-budget method provides a practical tool for estimating differences in recharge at local scales of interest, and the watershed- average recharge rate of 12.4 inches per year computed by the method is reasonable. However, the mean annual surface runoff of 4.5 inches per year simulated by the model is unrealistically small. The sum of surface runoff and recharge simulated by the water-budget model (16.9 inches per year) is 7 inches per year less than the streamflow measured at the gaging station near Schnecksville (23.9 inches per year) during 1967-2000, indicating that evapotranspiration is overestimated by the water-budget model by that amount. This discrepancy ca

Flightless and post-molt survival and movements of female mallards molting in Klamath Basin

USGS Publications Warehouse

Fleskes, Joseph P.; Mauser, David M.; Yee, Julie L.; Blehert, David S.; Yarris, Gregory S.

2010-01-01

Flightless and post-molt survival and movements were studied during August-May, 2001-2002, 2002- 2003 and 2006-2007 for 181 adult female Mallards (Anas platyrhynchos). Birds were radiotagged just before or early in their flightless period on four wetlands that differed in size on Klamath Basin (KB) National Wildlife Refuge complex. Flightless survival varied among years but was higher on two larger than two smaller wetlands; 30-day survival ranged from 11% (SE = 6.5%) on a small wetland in 2006 to 93% (SE = 6.5%) on a large wetland in 2001, and averaged 76.8% (SE = 6.1%). Most flightless mortality was from avian botulism (64%) and predation (26%). Of the 81 radiotagged Mallards that did not die in KB, 80% moved to the Central Valley of California (CVCA) before 31 January, 16% wintered in unknown areas, and 4% remained in KB through 31 January. Mallards departed KB 21 August-13 January (average: 11 Nov 2001, 25 Oct 2002, 19 Nov 2006). Post-molt survival during August-March in KB (20.7%, SE = 6.3%) was lower than in CVCA during this (62.9%, SE = 10.1%) and an earlier study. Survival in KB was consistently high only for females that molted in large permanent marshes, and although the impact of poor survival of molting females on Mallard population dynamics is unknown, KB water management plans should be developed that maintain these habitats.

Seasonal movement and home range of the Mariana Common Moorhen

USGS Publications Warehouse

Takano, L.L.; Haig, S.M.

2004-01-01

Adult Mariana Common Moorhens (Gallinula chloropus guami) were radio-marked on Guam (n = 25) and Saipan (n = 18) to determine home range, inter- and intraseasonal space use, and movement patterns among the Mariana Islands of Guam, Saipan, Tinian, and Rota. Birds were tracked throughout the dry and wet seasons in 2000 and 2001. During the dry season, no interisland movements were detected and most birds remained at a single wetland. However, some radio-marked adults on Guam (48%) and Saipan (11%) dispersed from their capture site to other wetland sites. Inter-and intraisland movements increased during the wet season. Interisland movement from Saipan to Tinian occurred at the onset of the wet season, although no birds were observed moving off Guam. Radio-marked adults on Guam (71%) and Saipan (70%) dispersed from their capture site to other wetlands. On Guam, moorhens moved farther in the wet season than the dry season. During the wet season frequency of movement among sites was inversely proportional to the average distance between wetlands. Guam moorhens used rivers more often during the wet season. Among nine dispersing adult moorhens captured during the wet season on Fena Reservoir, Guam, 67% returned to Fena Reservoir during the 2001 dry season. Home-range estimates on Guam averaged 3.1 ?? 4.8 ha (SD) and did not differ significantly between sexes or seasons. However, during the dry season, females exhibited significantly smaller mean core areas than males.

Seasonal movement and home range of the Mariana Common Moorhen

USGS Publications Warehouse

Takano, Leilani L.; Haig, Susan M.

2004-01-01

Adult Mariana Common Moorhens (Gallinula chloropus guami) were radio-marked on Guam (n = 25) and Saipan (n = 18) to determine home range, inter- and intraseasonal space use, and movement patterns among the Mariana Islands of Guam, Saipan, Tinian, and Rota. Birds were tracked throughout the dry and wet seasons in 2000 and 2001. During the dry season, no interisland movements were detected and most birds remained at a single wetland. However, some radio-marked adults on Guam (48%) and Saipan (11%) dispersed from their capture site to other wetland sites. Inter-and intraisland movements increased during the wet season. Interisland movement from Saipan to Tinian occurred at the onset of the wet season, although no birds were observed moving off Guam. Radio-marked adults on Guam (71%) and Saipan (70%) dispersed from their capture site to other wetlands. On Guam, moorhens moved farther in the wet season than the dry season. During the wet season frequency of movement among sites was inversely proportional to the average distance between wetlands. Guam moorhens used rivers more often during the wet season. Among nine dispersing adult moorhens captured during the wet season on Fena Reservoir, Guam, 67% returned to Fena Reservoir during the 2001 dry season. Home-range estimates on Guam averaged 3.1 ± 4.8 ha (SD) and did not differ significantly between sexes or seasons. However, during the dry season, females exhibited significantly smaller mean core areas than males.

Comparison of Habitat-Specific Nutrient Removal and Release in Pacific NW Salt Marshes at Multiple Spatial Scales

EPA Science Inventory

Wetlands can be sources, sinks and transformers of nutrients, although it is their role in nutrient removal that is valued as a water purification ecosystem service. In order to quantify that service for any wetland, it is important to understand the drivers of nutrient removal w...

Developing an index of wetland condition from ecological data: An example using HGM functional variables from the Nanticoke Watershed, USA

EPA Science Inventory

Demand for data on the ecological condition of wetlands is increasing as state and federal management programs recognize its value in reporting on the ambient condition of the resource, targeting restoration and protection efforts, evaluating the effects of mitigation and restora...

How much Carbon is Stored in Deserts? AN Approach for the Chilean Atacama Desert Using LANDSAT-8 Products

NASA Astrophysics Data System (ADS)

Hernández, H. J.; Acuña, T.; Reyes, P.; Torres, M.; Figueroa, E.

2016-06-01

The Atacama Desert in northern Chile is known as the driest place on Earth, with an average rainfall of about 15 mm per year. Despite these conditions, it contains a rich variety of flora with hundreds of species characterised by their extraordinary ability to adapt to this extreme environment. These biotic components have a direct link to important ecosystem services, especially those related to carbon storage and sequestration. No quantitative assessment is currently available for these services and the role of the desert in this matter remains unclear. We propose an approach to estimate above-ground biomass (AGB) using Landsat-8 data, which we tested in the Taparacá region, located in the northern section of the desert. To calibrate and validate the models, we used field data from 86 plots and several spectral indexes (NDVI, EVI and SAVI) obtained from the provisional Landsat-8 Surface-reflectance products. We applied randomised branch sampling and allometry principles (non-destructive methods) to collect biomass samples for all plant biological types: wetlands, steppes, shrubs and trees. All samples were dried in an oven until they reached constant weight and the final values were used to extrapolate dry matter content (AGB) to each plot in terms of kg m-2. We used all available scenes from September 2014 to August 2015 to calculate the maximum, minimum and average value for each index in each pixel within this period. For modeling, we used the method based on classification and regression trees called random forest (RF), available in the statistical software R-Project. The explained variance obtained by the RF algorithm was around 80-85%, and it improved when a wetland vector layer was used as the predictive factor in the model to reach the range 85-90%. The mean error was 1.45 kg m-2 of dry matter. The best model was obtained using the maximum and mean values of SAVI and EVI indexes. We were able to estimate total biomass storage of around 8 million tons (~ 4 million tons of C) for the whole region.

High Resolution Mapping of Wetland Ecosystems SPOT-5 Take 5 for Evaluation of Sentinel-2

NASA Astrophysics Data System (ADS)

Ade, Christiana; Hestir, Erin L.; Khanna, Shruti; Ustin, Susan L.

2016-08-01

Around the world wetlands are critical to human societies and ecosystems, providing services such as habitat, water, food and fiber, flood and nutrient control, and cultural, recreational and religious value. However, the dynamic nature of tidal wetlands makes measuring ecosystem responses to climate change, seasonal inundation regimes, and anthropogenic disturbance from current and previous Earth observing sensors challenging due to limited spatial and temporal resolutions. Sentinel- 2 will directly address this challenge by providing high spatial resolution data with frequent revisit time. This pilot study aims to develop methodology for future Sentinel-2 products and highlight the variability of tidal wetland ecosystems, thereby demonstrating the necessity of improved spatial particularly temporal resolution. Here the simulated Sentinel-2 dataset from the SPOT-5 Take 5 experiment reveals the capacity of the new sensor to simultaneously assess tidal wetland ecosystem phenology and water quality in inland waters.

Ecology of red maple swamps in the glaciated northeast: A community profile

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golet, F.C.; Calhoun, A.J.K.; DeRagon, W.R.

1993-06-01

In many areas of the glaciated northeastern United States, forested wetlands dominated by red maple (Acer rubrum) cover more of the landscape than all other nontidal wetland types combined. Yet surprisingly little of their ecology, functions, or social significance has been documented. Bogs, salt marshes, Atlantic white cedar swamps, and other less common types of wetlands have received considerable attention from scientists, but, except for botanical surveys, red maple swamps have been largely ignored. The report conveys what is known about these common wetlands and identifies topics most in need of investigation. Red maple swamps are so abundant and somore » widely distributed in the Northeast that their physical, chemical, and biological properties range widely as well, and their values to society are diverse. The central focus of the U.S. Fish and Wildlife Service community profile series is the plant and animal communities of wetlands and deepwater habitats.« less

Toxicity of stormwater treatment pond sediments to Hyallela azteca (Amphipoda)

USGS Publications Warehouse

Karouna-Renier, N.K.; Sparling, D.W.

1997-01-01

Stormwater wetlands are created to contain runoff from human developments and are designed to retain contaminants such as heavy metals, petroleum hydrocarbons, silt, pesticides, and nutrients before the runoff enter natural waterways. Because of this design, stormwater wetlands have a potential of becoming toxic sinks to organisms utilizing the wetlands for habitat. We conducted a 10-day sediment bioassay on Hyallela azteca as part of a larger study on the possible hazards of stormwater wetlands to aquatic invertebrates. Water and sediments from 10 wetlands separated into reference, residential, commercial, and highway land uses were used. No differences in survival were observed among land use categories, possibly because the ratio of acid volatile sulfides/simultaneously extractable metals (AVS/SEM) was > 1.0 for all of the ponds tested; values > 1 in this ratio are indications that toxic metals may not be bioavailable. Survival and growth rates correlated positively with AVS.

An assessment of the performance of municipal constructed wetlands in Ireland.

PubMed

Hickey, Anthony; Arnscheidt, Joerg; Joyce, Eadaoin; O'Toole, James; Galvin, Gerry; O' Callaghan, Mark; Conroy, Ken; Killian, Darran; Shryane, Tommy; Hughes, Francis; Walsh, Katherine; Kavanagh, Emily

2018-03-15

While performance assessments of constructed wetlands sites around the world have appraised their capacity for effective removal of organics, a large variance remains in these sites' reported ability to retain nutrients, which appears to depend on differences in design, operation and climate factors. Nutrient retention is a very important objective for constructed wetlands, to avoid eutrophication of aquatic environments receiving their effluents. This study assessed the performance of constructed wetlands in terms of nutrient retention and associated parameters under the humid conditions of Ireland's temperate maritime climate. A review of the performance of 52 constructed wetland sites from 17 local authorities aimed to identify the best performing types of constructed wetlands and the treatment factors determining successful compliance with environmental standards. Data analysis compared effluent results from constructed wetlands with secondary free surface flow or tertiary horizontal subsurface flow, hybrid systems and integrated constructed wetlands with those from small-scale mechanical wastewater treatment plants of the same size class. Nutrient concentrations in effluents of constructed wetlands were negatively correlated (p < .01) with specific area, i.e. the ratio of surface area and population equivalents. The latest generation of integrated constructed wetlands, which had applied design guidelines issued by the Department of the Environment, performed best. Storm management design features improved treatment performance of constructed wetlands significantly (p < .05) for total suspended solids concentrations and exceedance frequency of limit values for total nitrogen. Mechanical wastewater treatment plants, secondary free surface water and tertiary horizontal subsurface flow wetlands showed a very large variance in effluent concentrations for organic and nutrient parameters. E. coli numbers in effluents were lowest for integrated constructed wetlands with an arithmetic mean of 89 MPN/100 ml. Despite Ireland's humid climate, some constructed wetland sites achieved long or frequent periods of zero effluent discharge and thus did not transfer any waterborne pollution to their receptors during these periods. Copyright © 2018 Elsevier Ltd. All rights reserved.

Propagation of Human Enteropathogens in Constructed Horizontal Wetlands Used for Tertiary Wastewater Treatment ▿

PubMed Central

Graczyk, Thaddeus K.; Lucy, Frances E.; Tamang, Leena; Mashinski, Yessika; Broaders, Michael A.; Connolly, Michelle; Cheng, Hui-Wen A.

2009-01-01

Constructed subsurface flow (SSF) and free-surface flow (FSF) wetlands are being increasingly implemented worldwide into wastewater treatments in response to the growing need for microbiologically safe reclaimed waters, which is driven by an exponential increase in the human population and limited water resources. Wastewater samples from four SSF and FSF wetlands in northwestern Ireland were tested qualitatively and quantitatively for Cryptosporidium spp., Giardia duodenalis, and human-pathogenic microsporidia, with assessment of their viability. Overall, seven species of human enteropathogens were detected in wetland influents, vegetated areas, and effluents: Cryptosporidium parvum, C. hominis, C. meleagridis, C. muris, G. duodenalis, Encephalitozoon hellem, and Enterocytozoon bieneusi. SSF wetland had the highest pathogen removal rate (i.e., Cryptosporidium, 97.4%; G. duodenalis, 95.4%); however, most of these values for FSF were in the negative area (mean, −84.0%), meaning that more pathogens were discharged by FSF wetlands than were delivered to wetlands with incoming wastewater. We demonstrate here that (i) the composition of human enteropathogens in wastewater entering and leaving SSF and FSF wetlands is highly complex and dynamic, (ii) the removal and inactivation of human-pathogenic microorganisms were significantly higher at the SSF wetland, (iii) FSF wetlands may not always provide sufficient remediation for human enteropathogens, (iv) wildlife can contribute a substantial load of human zoonotic pathogens to wetlands, (v) most of the pathogens discharged by wetlands were viable, (vi) large volumes of wetland effluents can contribute to contamination of surface waters used for recreation and drinking water abstraction and therefore represent a serious public health threat, and (vii) even with the best pathogen removal rates achieved by SSF wetland, the reduction of pathogens was not enough for a safety reuse of the reclaimed water. To our knowledge, this is the first report of C. meleagridis from Ireland. PMID:19411413

Influence of chlorothalonil on the removal of organic matter in horizontal subsurface flow constructed wetlands.

PubMed

Casas-Zapata, Juan C; Ríos, Karina; Florville-Alejandre, Tomás R; Morató, Jordi; Peñuela, Gustavo

2013-01-01

This study investigates the effects of chlorothalonil (CLT) on chemical oxygen demand (COD) and dissolved organic carbon (DOC) in pilot-scale horizontal subsurface flow constructed wetlands (HSSFCW) planted with Phragmites australis. Physicochemical parameters of influent and effluent water samples, microbial population counting methods and statistical analysis were used to evaluate the influence of CLT on organic matter removal efficiency. The experiments were conducted on four planted replicate wetlands (HSSFCW-Pa) and one unplanted control wetland (HSSFCW-NPa). The wetlands exhibited high average organic matter removal efficiencies (HSSFCW-Pa: 80.6% DOC, 98.0% COD; HSSFCW-NPa: 93.2% DOC, 98.4% COD). The addition of CLT did not influence organic removal parameters. In all cases CLT concentrations in the effluent occurred in concentrations lower than the detection limit of the analytical method. Microbial population counts from HSSFCW-Pa showed significant correlations among different microbial groups and with different physicochemical variables. The apparent independence of organic matter removal and CLT inputs, along with the CLT depletion observed in effluent samples demonstrated that HSSFCW are a viable technology for the treatment of agricultural effluents contaminated with organo-chloride pesticides like CLT.

[Selection and purification potential evaluation of woody plant in vertical flow constructed wetlands in the subtropical area].

PubMed

Chen, Yong-Hua; Wu, Xiao-Fu; Hao, Jun; Chen, Ming-Li; Zhu, Guang-Yu

2014-02-01

In order to solve the problem that wetland herbaceous plants tend to die during winter in subtropics areas, selection and purification potential evaluation experiments were carried out by introducing into the constructed wetlands 16 species of woody wetland plants. Cluster analysis was performed by including the morphological characteristics, physiological characteristics, as well as nitrogen and phosphorus accumulation of the woody wetland plants. The results indicated that there were significant differences among the tested woody plants in their survival rate, height increase, root length increase and vigor, Chlorophyll content, Superoxide dismutase, Malonaldehyde, Proline, Peroxidase, biomass, average concentration and accumulation of nitrogen and phosphorus. Based on the established evaluation system, the tested plants were clustered into 3 groups. The plants in the 1st group possessing high purification potentials are Nerium oleander and Hibiscus syriacus. Those in the 2nd group possessing moderate purification potentials are Trachycarpus fortune, Llex latifolia Thunb., Gardenia jasminoides, Serissa foetida and Ilex crenatacv Convexa. And those in the 3rd group with low purification potentials are Jasminum udiflorum, Hedera helix, Ligustrum vicaryi, Ligustrum lucidum, Buxus sempervives, Murraya paniculata, Osmanthus fragrans, Mahoniafortune and Photinia serrulata.

Chemical Interactions of Uranium in Water, Sediments, and Plants Along a Watershed Adjacent to the Abandoned Jackpile Mine

NASA Astrophysics Data System (ADS)

Blake, J.; De Vore, C. L.; Avasarala, S.; Ali, A.; Roldan, C.; Bowers, F.; Spilde, M.; Artyushkova, K.; Cerrato, J.

2015-12-01

The chemical interactions, mobility, and plant uptake of uranium (U) near abandoned mine wastes was investigated along the Rio Paguate, adjacent to the Jackpile Mine, located in Laguna Pueblo, New Mexico. Elevated U concentrations in surface water adjacent to mine waste range from 30 to 710 μg/L seasonally and decrease to 5.77 to 10.0 μg/L at a wetland 4.5 kilometers downstream of the mine. Although U concentrations in stream water are elevated, aqua regia acid digestions performed on co-located stream bed and stream bank sediments reveal that there is limited U accumulation on sediments along the reach between the mine and wetland, with most sediment concentrations being near the 3 mg/kg crustal average. However, U concentrations in sediments in the wetland are 4 times the background concentrations in the area. Individual results from salt cedar roots, stems, and leaves collected along the river transect show higher U concentrations in the roots adjacent to the mine waste (20 and 55 mg/kg) and lower in the stems and leaves. Translocation values calculated below 1 are evident in many of the plant samples, suggesting that U root to shoot translocation is minimal and U is accumulating in the roots. Concentrations of U in salt cedar roots from downstream of the mine waste decrease to 15 mg/kg. X-ray photoelectron spectroscopy analysis on sediment samples adjacent to the mine waste show a 75:25% ratio of Fe(III) to Fe(II), which can have an effect on adsorption properties. Electron microprobe results suggest that the ore in this area is present as a uranium-phosphate phase. Our results suggest that dilution, uptake by plants, and U sorption to wetland sediments are the dominant factors that help to decrease the U concentrations downstream of the mine.

Soil respiration in typical plant communities in the wetland surrounding the high-salinity Ebinur Lake

NASA Astrophysics Data System (ADS)

Li, Yanhong; Zhao, Mingliang; Li, Fadong

2018-03-01

Soil respiration in wetlands surrounding lakes is a vital component of the soil carbon cycle in arid regions. However, information remains limited on the soil respiration around highly saline lakes during the plant growing season. Here, we aimed to evaluate diurnal and seasonal variation in soil respiration to elucidate the controlling factors in the wetland of Ebinur Lake, Xinjiang Uygur Autonomous Region, western China. We used a soil carbon flux automatic analyzer (LI-840A) to measure soil respiration rates during the growing season (April to November) in two fields covered by reeds and tamarisk and one field with no vegetation (bare soil) from 2015 to 2016. The results showed a single peak in the diurnal pattern of soil respiration from 11:00 to 17:00 for plots covered in reeds, tamarisk, and bare soil, with minimum values being detected from 03:00 to 07:00. During the growing season, the soil respiration of reeds and tamarisk peaked during the thriving period (4.16 and 3.75 mmol•m-2•s-1, respectively), while that of bare soil peaked during the intermediate growth period (0.74 mmol•m-2•s-1). The soil respiration in all three plots was lowest during the wintering period (0.08, 0.09, and-0.87 mmol•m-2•s-1, respectively). Air temperature and relative humidity significantly influenced soil respiration. A significant linear relationship was detected between soil respiration and soil temperature for reeds, tamarisk, and bare soil. The average Q10 of reeds and tamarisk were larger than that of bare soil. However, soil moisture content was not the main factor controlling soil respiration. Soil respiration was negatively correlated with soil pH and soil salinity in all three plot types. In contrast, soil respiration was positively correlated with organic carbon. Overall, CO2 emissions and greenhouse gases had a relatively weak effect on the wetlands surrounding the highly saline Ebinur Lake.

Leachate treatment system using constructed wetlands, Town of Fenton sanitary landfill, Broome County, New York. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-11-01

Municipal sanitary landfills generate leachate that New York State regulations require to be collected and treated to avoid contaminating surface water and groundwater. One option for treating leachate is to haul it to municipal wastewater treatment facility. This option may be expensive, may require excessive energy for transportation, and may require pretreatment to protect the receiving facility`s processes. An alternative is on-site treatment and discharge. Personnel from the Town of Fenton, New York; Hawk Engineering, P.C.; Cornell University; and Ithaca College designed, built, and operated a pilot constructed wetland for treating leachate at the Town of Fenton`s municipal landfill. Themore » system, consisting of two overland flow beds and two subsurface flow beds has been effective for 18 months in reducing levels of ammonia (averaging 85% removal by volatilization and denitrification) and total iron (averaging 95% removal by precipitation and sedimentation), two key constituents of the Fenton landfill`s leachate. The system effects these reductions with zero chemical and energy inputs and minimal maintenance. A third key constituent of the leachate, manganese, apparently passes through the beds with minimal removal. Details and wetland considerations are described.« less

Effects of Consumptive Water Use on Biodiversity in Wetlands of International Importance

PubMed Central

2013-01-01

Wetlands are complex ecosystems that harbor a large diversity of species. Wetlands are among the most threatened ecosystems on our planet, due to human influences such as conversion and drainage. We assessed impacts from water consumption on the species richness of waterbirds, nonresidential birds, water-dependent mammals, reptiles and amphibians in wetlands, considering a larger number of taxa than previous life cycle impact assessment methods. Effect factors (EF) were derived for 1184 wetlands of international importance. EFs quantify the number of global species-equivalents lost per m2 of wetland area loss. Vulnerability and range size of species were included to reflect conservation values. Further, we derived spatially explicit characterization factors (CFs) that distinguish between surface water and groundwater consumption. All relevant watershed areas that are contributing to feeding the respective wetlands were determined for CF applications. In an example of rose production, we compared damages of water consumption in Kenya and The Netherlands. In both cases, the impact was largest for waterbirds. The total impact from water consumption in Kenya was 67 times larger than in The Netherlands, due to larger species richness and species’ vulnerability in Kenya, as well as more arid conditions and larger amounts of water consumed. PMID:24087849

Effects of consumptive water use on biodiversity in wetlands of international importance.

PubMed

Verones, Francesca; Saner, Dominik; Pfister, Stephan; Baisero, Daniele; Rondinini, Carlo; Hellweg, Stefanie

2013-01-01

Wetlands are complex ecosystems that harbor a large diversity of species. Wetlands are among the most threatened ecosystems on our planet, due to human influences such as conversion and drainage. We assessed impacts from water consumption on the species richness of waterbirds, nonresidential birds, water-dependent mammals, reptiles and amphibians in wetlands, considering a larger number of taxa than previous life cycle impact assessment methods. Effect factors (EF) were derived for 1184 wetlands of international importance. EFs quantify the number of global species-equivalents lost per m(2) of wetland area loss. Vulnerability and range size of species were included to reflect conservation values. Further, we derived spatially explicit characterization factors (CFs) that distinguish between surface water and groundwater consumption. All relevant watershed areas that are contributing to feeding the respective wetlands were determined for CF applications. In an example of rose production, we compared damages of water consumption in Kenya and The Netherlands. In both cases, the impact was largest for waterbirds. The total impact from water consumption in Kenya was 67 times larger than in The Netherlands, due to larger species richness and species' vulnerability in Kenya, as well as more arid conditions and larger amounts of water consumed.

Competitive sorption and desorption behavior for three fluoroquinolone antibiotics in a wastewater treatment wetland soil.

PubMed

Conkle, Jeremy L; Lattao, Charisma; White, John R; Cook, Robert L

2010-09-01

Significant amounts of pharmaceuticals are discharged into the environment through wastewater effluent. Sorption has been shown to be a significant aqueous removal pathway for many of these compounds. Competition between ciprofloxacin (CIP), ofloxacin (OFL) and norfloxacin (NOR) and their sorption to, and desorption from, a surrogate Louisiana wastewater treatment wetland soil were investigated to gain insight into the fate and transport of the pollutants within wastewater treatment wetlands. This study was undertaken in the context of a treatment wetland that continuously receives pharmaceuticals. Therefore it is important to understand the total capacity of this soil to sorb these compounds. Sorption to this treatment wetland soil was found to provide a major and potentially long-term removal pathway for these antibiotics from wastewater. LogK(F) values for all three compounds were between 4.09 and 3.90 for sorption and 4.24 and 4.05 microg(1-1/)(n)(cm(3))(1/)(n)g(-1) for desorption. The compounds were sorbed in amounts ranging from 60% to 90% for high and low loading, respectively. The majority of the compounds were sorbed to the soil within the first 20h, indicating that treatment wetland may not need long retention times (weeks to months) in order to remove these compounds. Sorption K(D) values for competition (20 ppm of each compound for 60 ppm of total fluoroquinolones) ranged from 2300 to 3800 cm(3)g(-1) which is between both the 20 (4300-5800 cm(3)g(-1)) and 60 (1300-3000 cm(3)g(-1)) ppm single compound K(D) values, indicating that there is competition between these three compound for sorption sites. Sorption and desorption data (single component and mixture) collectively provide the following evidence: (1) NOR and, to a lesser extent, CIP outcompete OFL for sorption sites, (2) OFL sorbes to its share of "quality" sorption sites, and (3) competition only occurs for lesser "quality" binding sites. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Investigation of the heavy metal contamination of the sediments from the yellow river wetland nature reserve of zhengzhou, china.

PubMed

Cheng, Q; Wang, W; Wang, H; Wang; Zhao, Z

2012-01-01

Heavy metal pollution in the sediment of the Yellow River draws wide attention in the recent years. The Yellow River Wetland Nature Reserve of Zhengzhou is one of the major wetlands of the river and located at the beginning of the lower reach. In this article, we aimed to investigate the degree and the sources of the metal pollution in the reserve. Metals as Cu, Pb, Cr, Cd and Mn in the sediment were monitored using flame atomic absorption spectrometry. The index of geo-accumulation (I(geo)) and the modified degree of contamination (mC(d)) were developed to evaluate individual metal pollution and overall enrichment impact of the elements. Compared with sediment quality guidelines, the effect of Cr and Pb are more serious than others. I(geo) values show Pb pollution are moderate at the Xinzhai, Langchenggang and Nansutan sites, and mC(d) analysis indicate the whole contamination at the Wantan, Langchenggang and Nansutan sites was low. Principal component analysis indicated that the first factor was Cu, Mn and Cd, mainly from soil erosion and the irrational use of phosphate fertilizers; the second Pb from fossil fuel burning; and the third Cr from weathering process. We conclude that Pb contamination is serious in the reserve, and the main sources of the metal are crude oil consumption and coal combustion of the brick kilns around. We also draw a conclusion that it is vital to evaluate contamination degree with both individual elements and overall average.

Investigation of the Heavy Metal Contamination of the Sediments from the Yellow River Wetland Nature Reserve of Zhengzhou, China

PubMed Central

Cheng, Q; Wang, W; Wang, H; Wang; Zhao, Z

2012-01-01

Background Heavy metal pollution in the sediment of the Yellow River draws wide attention in the recent years. The Yellow River Wetland Nature Reserve of Zhengzhou is one of the major wetlands of the river and located at the beginning of the lower reach. In this article, we aimed to investigate the degree and the sources of the metal pollution in the reserve. Methods: Metals as Cu, Pb, Cr, Cd and Mn in the sediment were monitored using flame atomic absorption spectrometry. The index of geo-accumulation (Igeo) and the modified degree of contamination (mCd) were developed to evaluate individual metal pollution and overall enrichment impact of the elements. Results: Compared with sediment quality guidelines, the effect of Cr and Pb are more serious than others. Igeo values show Pb pollution are moderate at the Xinzhai, Langchenggang and Nansutan sites, and mCd analysis indicate the whole contamination at the Wantan, Langchenggang and Nansutan sites was low. Principal component analysis indicated that the first factor was Cu, Mn and Cd, mainly from soil erosion and the irrational use of phosphate fertilizers; the second Pb from fossil fuel burning; and the third Cr from weathering process. Conclusion: We conclude that Pb contamination is serious in the reserve, and the main sources of the metal are crude oil consumption and coal combustion of the brick kilns around. We also draw a conclusion that it is vital to evaluate contamination degree with both individual elements and overall average. PMID:23113147

Vertical Subsurface Flow (VSSF) constructed wetland for domestic wastewater treatment

NASA Astrophysics Data System (ADS)

Perdana, M. C.; Sutanto, H. B.; Prihatmo, G.

2018-04-01

Vertical Subsurface Flow Constructed Wetland (VSSF) is appraised to become an alternative solution for treating domestic wastewater effectively and efficiently. The system which imitates the natural wetland concept is able to reduce organic material and nutrients in wastewater; therefore, it will be more feasible to be discharged to the environment. This study aimed to compare which species is more recommended to be applied for reducing organic material and nutrients in domestic wastewater. This experimental study applied four treatments, i.e 1) control (unplanted), 2) single species Iris pseudacorus, 3) single species Echinodorus palaefolius, and 4) combination (Iris pseudacorus and Echinodorus palaefolius) with three days of retention time. The application of those plants aims for holding the role in increasing wastewater quality and adding aesthetic impression at once. The plants were planted on VSSF media, in relatively same of weight and size to compare their effectiveness in decreasing organic and inorganic load. The parameters measured pervade TDS, pH, BOD5, COD, Nitrate, and Phosphate. The plants’ condition was also observed during and after the system worked. The result showed that the best average value of effectiveness for each of parameters: COD by combination treatment (50.76%), BOD5 by single I. pseudacorus (30.15%), Nitrate by single E. palaefolius (58.06%), Phosphate by single E. palaefolius (99.5%), and TDS by E.palaefolius (3.25%). The result showed that there was a significant difference of Nitrate and Phosphate reduction between control and three other treatments, while pH parameter showed non-significant change among them. In term of performance, I.pseudacorus seemed showed a preferable achievement.

Application of a constructed wetland system for polluted stream remediation

NASA Astrophysics Data System (ADS)

Tu, Y. T.; Chiang, P. C.; Yang, J.; Chen, S. H.; Kao, C. M.

2014-03-01

In 2010, the multi-function Kaoping River Rail Bridge Constructed Wetland (KRRBW) was constructed to improve the stream water quality and rehabilitate the ecosystem of the surrounding environment of Dashu Region, Kaohsiung, Taiwan. The KRRBW consists of five wetland basins with a total water surface area of 15 ha, a total hydraulic retention time (HRT) of 10.1 days at a averaged flow rate of 14 740 m3/day, and an averaged water depth of 1.1 m. The influent of KRRBW coming from the local drainage systems containing untreated domestic, agricultural, and industrial wastewaters. Based on the quarterly investigation results of water samples taken in 2011-2012, the overall removal efficiencies were 91% for biochemical oxygen demand (BOD), 75% for total nitrogen (TN), 96% for total phosphorus (TP), and 99% for total coliforms (TC). The calculated first-order decay rates for BOD, TN, TP, NH3-N, and TC ranged from 0.14 (TN) to 0.42 (TC) 1/day. This indicates that the KRRBW was able to remove organics, TC, and nutrients effectively. The high ammonia/nitrate removal efficiency indicates that nitrification and denitrification processes occurred simultaneously in the wetland system, and the detected nitrite concentration confirmed the occurrence of denitrification/nitrification. Results from sediment analyses reveal that the sediment contained high concentrations of organics (sediment oxygen demand = 1.9-5.2 g O2/m2 day), nutrients (up to 15.8 g total nitrogen/kg of sediment and 1.48 g total phosphorus/kg of sediment), and metals (up to 547 mg/kg of Zn and 97 mg/kg of Cu). Appropriate wetland management strategies need to be developed to prevent the release of contaminants into the wetland system. The wetland system caused the variations in the microbial diversities and dominant microbial bacteria. Results show the dominant nitrogen utilization bacteria including Denitratisoma oestradiolicum, Nitrosospira sp., Nitrosovibrio sp., D. oestradiolicum, Alcaligenes sp., Steroidobacter denitrificans, Hydrocarboniphaga effuse were responsible for nitrogen removal, and the dominant carbon degrading bacteria (Stenotrophomonas maltophilia, H. effuse, Alcaligenes sp., Pseudomonas sp., Fusibacter sp., Chlofoflexi, Guggenheimella bovis, Bacillus pumilus) were responsible for carbon reduction. The denaturing gradient gel electrophoresis (DGGE) and nucleotide sequence techniques provide a guide for microbial ecology evaluation, which can be used as an indication of contaminants removal. Results from this study show that constructed wetlands have the potential to be developed into an environmentally acceptable river water quality improvement and wastewater polishment alternative for practical application.

Assessing the impacts of climate change and dams on floodplain inundation and wetland connectivity in the wet-dry tropics of northern Australia

NASA Astrophysics Data System (ADS)

Karim, Fazlul; Dutta, Dushmanta; Marvanek, Steve; Petheram, Cuan; Ticehurst, Catherine; Lerat, Julien; Kim, Shaun; Yang, Ang

2015-03-01

Floodplain wetlands and their hydrological connectivity with main river channels in the Australian wet-dry tropics are under increasing pressure from global climate change and water resource development, and there is a need for modelling tools to estimate the time dynamics of connectivity. This paper describes an integrated modelling framework combining conceptual rainfall-runoff modelling, river system modelling and hydrodynamic (HD) modelling to estimate hydrological connectivity between wetlands and rivers in the Flinders and Gilbert river catchments in northern Australia. Three historical flood events ranging from a mean annual flood to a 35-year return period flood were investigated using a two dimensional HD model (MIKE 21). Inflows from upstream catchments were estimated using a river network model. Local runoff within the HD modelling domain was simulated using the Sacramento rainfall-runoff model. The Shuttle Radar Topography Mission (SRTM) derived 30 m DEM was used to reproduce floodplain topography, stream networks and wetlands in the HD model. The HD model was calibrated using stream gauge data and inundation maps derived from satellite (MODIS: MODerate resolution Imaging Spectroradiometer) imagery. An algorithm was developed to combine the simulated water heights with the DEM to quantify inundation and flow connection between wetlands and rivers. The connectivity of 18 ecologically important wetlands on the Flinders floodplain and 7 on the Gilbert floodplain were quantified. The impacts of climate change and water resource development on connectivity to individual wetlands were assessed under a projected dry climate (2nd driest of 15 GCMs), wet climate (2nd wettest of 15 GCMs) and dam conditions. The results indicate that changes in rainfall under a wetter and drier future climate could have large impacts on area, duration and frequency of inundation and connectivity. Topographic relief, river bank elevation and flood magnitude were found to be the key factors contributing to the level of connectivity. Under a wetter future climate the average duration of connection of wetlands to the main river channel increased by 7% and under a drier climate it decreased by 18%. Construction of a 248 GL dam in the Flinders catchment and two (498 and 271 GL capacity) in the Gilbert catchment could reduce the average duration of connectivity by 1% and 2% in the Flinders and Gilbert catchments respectively. This information is potentially useful to future studies on the flood-dependent ecology in this region.

Are wetland regulations cost effective for species protection? A case study of amphibian metapopulations.

PubMed

Bauer, Dana Marie; Paton, Peter W C; Swallow, Stephen K

2010-04-01

Recent declines in amphibian populations have raised concern among conservation biologists, with habitat loss and degradation due to human activities among the leading causes. The most common policies used to protect the habitat of pond-breeding amphibians are wetland regulations that safeguard the wetland itself. However, many amphibians spend much of their adult lives foraging and over-wintering in upland habitats and exist as metapopulations with dispersal among ponds. With no consideration of lands in the dispersal matrix, wetland policies may be ineffective at protecting amphibians or other wetland species that disperse across the landscape. This paper examined the adequacy and cost effectiveness of alternative conservation policies and their corresponding land use patterns on the long-term persistence of pond-breeding amphibians in exurban landscapes. We used computer simulations to compare outcomes of wetland buffer policies and broader landscape-wide conservation policies across a variety of landscape scenarios, and we conducted sensitivity analyses on the model's species parameters in order to generalize our results to other wetland species. Results showed that, in the majority of human-dominated landscapes, some amount of dispersal matrix protection is necessary for long-term species persistence. However, in landscapes with extremely low-intensity land use (e.g., low-density residential housing) and high pond density, wetland buffer policies may be all that is required. It is not always more cost effective to protect core habitat over the dispersal matrix, a common conservation practice. Conservation costs that result from forgone residential, commercial, or agricultural activities can vary substantially but increase in a nonlinear manner regardless of land use zoning. There appears to be a threshold around an average habitat patch occupancy level of 80%, after which opportunity costs rise dramatically.

Emerging role of wetland methane emissions in driving 21st century climate change.

PubMed

Zhang, Zhen; Zimmermann, Niklaus E; Stenke, Andrea; Li, Xin; Hodson, Elke L; Zhu, Gaofeng; Huang, Chunlin; Poulter, Benjamin

2017-09-05

Wetland methane (CH 4 ) emissions are the largest natural source in the global CH 4 budget, contributing to roughly one third of total natural and anthropogenic emissions. As the second most important anthropogenic greenhouse gas in the atmosphere after CO 2 , CH 4 is strongly associated with climate feedbacks. However, due to the paucity of data, wetland CH 4 feedbacks were not fully assessed in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The degree to which future expansion of wetlands and CH 4 emissions will evolve and consequently drive climate feedbacks is thus a question of major concern. Here we present an ensemble estimate of wetland CH 4 emissions driven by 38 general circulation models for the 21st century. We find that climate change-induced increases in boreal wetland extent and temperature-driven increases in tropical CH 4 emissions will dominate anthropogenic CH 4 emissions by 38 to 56% toward the end of the 21st century under the Representative Concentration Pathway (RCP2.6). Depending on scenarios, wetland CH 4 feedbacks translate to an increase in additional global mean radiative forcing of 0.04 W·m -2 to 0.19 W·m -2 by the end of the 21st century. Under the "worst-case" RCP8.5 scenario, with no climate mitigation, boreal CH 4 emissions are enhanced by 18.05 Tg to 41.69 Tg, due to thawing of inundated areas during the cold season (December to May) and rising temperature, while tropical CH 4 emissions accelerate with a total increment of 48.36 Tg to 87.37 Tg by 2099. Our results suggest that climate mitigation policies must consider mitigation of wetland CH 4 feedbacks to maintain average global warming below 2 °C.

Emerging role of wetland methane emissions in driving 21st century climate change

PubMed Central

Zimmermann, Niklaus E.; Stenke, Andrea; Li, Xin; Hodson, Elke L.; Zhu, Gaofeng; Huang, Chunlin; Poulter, Benjamin

2017-01-01

Wetland methane (CH4) emissions are the largest natural source in the global CH4 budget, contributing to roughly one third of total natural and anthropogenic emissions. As the second most important anthropogenic greenhouse gas in the atmosphere after CO2, CH4 is strongly associated with climate feedbacks. However, due to the paucity of data, wetland CH4 feedbacks were not fully assessed in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The degree to which future expansion of wetlands and CH4 emissions will evolve and consequently drive climate feedbacks is thus a question of major concern. Here we present an ensemble estimate of wetland CH4 emissions driven by 38 general circulation models for the 21st century. We find that climate change-induced increases in boreal wetland extent and temperature-driven increases in tropical CH4 emissions will dominate anthropogenic CH4 emissions by 38 to 56% toward the end of the 21st century under the Representative Concentration Pathway (RCP2.6). Depending on scenarios, wetland CH4 feedbacks translate to an increase in additional global mean radiative forcing of 0.04 W·m−2 to 0.19 W·m−2 by the end of the 21st century. Under the “worst-case” RCP8.5 scenario, with no climate mitigation, boreal CH4 emissions are enhanced by 18.05 Tg to 41.69 Tg, due to thawing of inundated areas during the cold season (December to May) and rising temperature, while tropical CH4 emissions accelerate with a total increment of 48.36 Tg to 87.37 Tg by 2099. Our results suggest that climate mitigation policies must consider mitigation of wetland CH4 feedbacks to maintain average global warming below 2 °C. PMID:28827347

Ecological relationships of breeding blue-winged teal to prairie potholes

USGS Publications Warehouse

Drewien, R.C.; Springer, P.F.

1969-01-01

Ecology of breeding blue-winged teal (Anas discors) was studied on the Waubay Study Area in Day County, South Dakota, in 1965 and 1966. Breeding pair use of the wetland habitat and importance of Type 1 ponds in the wetland complex were evaluated. Changes in breeding pair densities and wetland habitat conditions on the study area were compared for the 16-year period, 1950-66.Blue-winged teal pair densities of 30.7 and 33.0 per square mile in 1965 and 1966, respectively, were above the 16-year average from 1950 to 1966 and near the maximum for this period. Blue-winged teal comprised 46.7 per cent of the waterfowl breeding population in 1965 and 51.7 per cent in 1966. Number of water areas per square mile through mid-spring 1965 was comparable to the average for the 16-year period, whereas during late spring 1965 and throughout the 1966 spring breeding seasons the number of water areas increased to near optimum conditions.Annual breeding-pair densities from 1950 to 1966 appeared to be largely influenced by water conditions, and pair-density fluctuations resulted from changes in number of wet ponds from late April through mid-May. Variations in water conditions after this period did not appear to have as great an effect on numbers of breeding teal.Use of wetland habitat by pairs changed throughout the spring breeding seasons. During the post-arrival period, teal congregated on larger wetlands. With onset of egg-laying, pairs dispersed into ponds throughout the wetland complex to establish breeding home ranges. Other factors that influenced changes in habitat use included: 1) pond type and size, 2) breeding cycle phenology, 3) availability of wet ponds, and 4) land use. Number of blue-winged teal pairs per unit area of water was highest in 1965 and 1966 on Type 1B ponds, followed in decreasing order by Types 3, 1A, and 4 and 5. Greater use of Type 1B ponds was probably related to larger ratio of edge or shore line to unit area of water. Interspersion of many small wetlands throughout the breeding habitat provided for maximum pair dispersal during egg-laying and early incubation stages of the reproductive cycle.

Quantifying spatial variability of depth of peat burn in wetlands in relation to antecedent characteristics using field data, multi-temporal and multi-spectral LiDAR

NASA Astrophysics Data System (ADS)

Chasmer, L.; Flade, L.; Virk, R.; Montgomery, J. S.; Hopkinson, C.; Thompson, D. K.; Petrone, R. M.; Devito, K.

2017-12-01

Landscape changes in the hydrological characteristics of wetlands in some parts of the Boreal region of Canada are occurring as a result of climate-induced feedbacks and anthropogenic disturbance. Wetlands are largely resilient to wildfire, however, natural, climatic and anthropogenic disturbances can change surface water regimes and predispose wetlands to greater depth of peat burn. Over broad areas, peat loss contributes to significant pollution emissions, which can affect community health. In this study, we a) quantify depth of peat burn and relationships to antecedent conditions (species type, topography, surficial geology) within three classified wetlands found in the Boreal Plains ecoregion of western Canada; and b) examine the impacts of wildfire on post-fire ground surface energy balance to determine how peat loss might affect local hydro-climatology and surface water feedbacks. High-resolution optical imagery, pre- and post-burn multi-spectral Light Detection And Ranging (LiDAR), airborne thermal infrared imagery, and field validation data products are integrated to identify multiple complex interactions within the study wetlands. LiDAR-derived depth of peat burn is within 1 cm (average) compared with measured (RMSE = 9 cm over the control surface), demonstrating the utility of LiDAR with high point return density. Depth of burn also correlates strongly with variations in Normalised Burn Ratio (NBR) determined for ground surfaces only. Antecedent conditions including topographic position, soil moisture, soil type and wetland species also have complex interactions with depth of peat loss within wetlands observed in other studies. However, while field measurements are important for validation and understanding eco-hydrological processes, results from remote sensing are spatially continuous. Temporal LiDAR data illustrate the full range of variability in depth of burn and wetland characteristics following fire. Finally, measurements of instantaneous surface temperature indicate that the temperatures of burned wetlands are significantly warmer by up to 10oC compared to non-burned wetlands, altering locally variable sensible vs. latent energy exchanges and implications for further post-fire evaporative losses.

The land value impacts of wetland restoration.

PubMed

Kaza, Nikhil; BenDor, Todd K

2013-09-30

U.S. regulations require offsets for aquatic ecosystems damaged during land development, often through restoration of alternative resources. What effect does large-scale wetland and stream restoration have on surrounding land values? Restoration effects on real estate values have substantial implications for protecting resources, increasing tax base, and improving environmental policies. Our analysis focuses on the three-county Raleigh-Durham-Chapel Hill, North Carolina region, which has experienced rapid development and extensive aquatic ecological restoration (through the state's Ecosystem Enhancement Program [EEP]). Since restoration sites are not randomly distributed across space, we used a genetic algorithm to match parcels near restoration sites with comparable control parcels. Similar to propensity score analysis, this technique facilitates statistical comparison and isolates the effects of restoration sites on surrounding real estate values. Compared to parcels not proximate to any aquatic resources, we find that, 1) natural aquatic systems steadily and significantly increase parcel values up to 0.75 mi away, and 2) parcels <0.5 mi from EEP restoration sites have significantly lower sale prices, while 3) parcels >0.5 mi from EEP sites gain substantial amenity value. When we control for intervening water bodies (e.g. un-restored streams and wetlands), we find a similar inflection point whereby parcels <0.5 mi from EEP sites exhibit lower values, and sites 0.5-0.75 mi away exhibit increased values. Our work points to the need for higher public visibility of aquatic ecosystem restoration programs and increased public information about their value. Copyright © 2013 Elsevier Ltd. All rights reserved.

Root-Associated Methane Oxidation and Methanogenesis: Key Determinants of Wetland Methane Emissions

NASA Technical Reports Server (NTRS)

King, G. M.

1997-01-01

During the award period, we have assessed the extent and controls of methane oxidation in north temperate wetlands. It is evident that wetlands have been a major global source of atmospheric methane in the past, and are so at present. It is also evident that microbial methane oxidation consumes a variable fraction of total wetland methane production, perhaps 10%-90%. Methane oxidation is thus a potentially important control of wetland methane emission. Our efforts have been designed to determine the extent of the process, its controls, and possible relationships to changes that might be expected in wetlands as a consequence of anthropogenic or climate-related disturbances. Current work, has emphasized controls of methane oxidation associated with rooted aquatic plants. As for the sediment-water interface, we have observed that oxygen availability is a primary limiting factor. Our conclusion is based on several different lines of evidence obtained from in vitro and in situ analyses. First, we have measured the kinetics of methane oxidation by intact plant roots harboring methane-oxidizing bacteria, as well as the kinetics of the methanotrophs themselves. Values for the half-saturation constant (apparent K(sub m)) are approximately 5 microns. These values are roughly equivalent to, or much less than porewater methane concentrations, indicating that uptake is likely saturated with respect to methane, and that some other parameter must limit activity. Methane concentrations in the lacunar spaces at the base of plant stems are also comparable to the half-saturation constants (when expressed as equivalent dissolved concentrations), providing further support for limitation of uptake by parameters other than methane.

Climate change and intertidal wetlands.

PubMed

Ross, Pauline M; Adam, Paul

2013-03-19

Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause-the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the "squeeze" experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change.

Climate Change and Intertidal Wetlands

PubMed Central

Ross, Pauline M.; Adam, Paul

2013-01-01

Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause—the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the “squeeze” experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change. PMID:24832670

Are isolated wetlands groundwater recharge hotspots?

NASA Astrophysics Data System (ADS)

Webb, A.; Wicks, C. M.; Brantley, S. T.; Golladay, S. W.

2017-12-01

Geographically isolated wetlands (GIWs) are a common landscape feature in the mantled karst terrain of the Dougherty Plain physiographic district in Southwestern Georgia. These wetlands support a high diversity of obligate/facultative wetland flora and fauna, including several endangered species. While the ecological value of these wetlands is well documented, the hydrologic effects of GIWs on larger watershed processes, such as water storage and aquifer recharge, are less clear. Our project seeks to understand the spatial and temporal variation in recharge across GIWs on this mantled karst landscape. In particular, our first step is to understand the role of isolated wetlands (presumed sinkholes) in delivering water into the underlying aquifer. Our hypothesis is that many GIWs are actually water-filled sinkholes and are locations of focused recharge feeding either the underlying upper Floridan aquifer or the nearby creeks. If we are correct, then these sinkholes should exhibit "drains", i.e., conduits into the limestone bedrock. Thus, the purposes of our initial study are to image the soil-limestone contact (the buried epikarstic surface) and determine if possible subsurface drains exist. Our field work was conducted at the Joseph W Jones Ecological Research Center. During the dry season, we conducted ground penetrating radar (GPR) surveys as grids and lines across a large wetland and across a field with no surface expression of a wetland or sinkhole. We used GPR (200 MHz antenna) with 1-m spacing between antenna and a ping rate of 1 ping per 40 centimeters. Our results show that the epikarstic surface exhibits a drain underneath the wetland (sinkhole) and that no similar feature was seen under the field, even though the survey grid and spacing were similar. As our project progresses, we will survey additional wetlands occurring across varying soil types to determine the spatial distribution between surface wetlands and subsurface drains.

How much swamp are we talking here?: Propagating uncertainty about the area of coastal wetlands into the U.S. greenhouse gas inventory

NASA Astrophysics Data System (ADS)

Holmquist, J. R.; Crooks, S.; Windham-Myers, L.; Megonigal, P.; Weller, D.; Lu, M.; Bernal, B.; Byrd, K. B.; Morris, J. T.; Troxler, T.; McCombs, J.; Herold, N.

2017-12-01

Stable coastal wetlands can store substantial amounts of carbon (C) that can be released when they are degraded or eroded. The EPA recently incorporated coastal wetland net-storage and emissions within the Agricultural Forested and Other Land Uses category of the U.S. National Greenhouse Gas Inventory (NGGI). This was a seminal analysis, but its quantification of uncertainty needs improvement. We provide a value-added analysis by estimating that uncertainty, focusing initially on the most basic assumption, the area of coastal wetlands. We considered three sources: uncertainty in the areas of vegetation and salinity subclasses, uncertainty in the areas of changing or stable wetlands, and uncertainty in the inland extent of coastal wetlands. The areas of vegetation and salinity subtypes, as well as stable or changing, were estimated from 2006 and 2010 maps derived from Landsat imagery by the Coastal Change Analysis Program (C-CAP). We generated unbiased area estimates and confidence intervals for C-CAP, taking into account mapped area, proportional areas of commission and omission errors, as well as the number of observations. We defined the inland extent of wetlands as all land below the current elevation of twice monthly highest tides. We generated probabilistic inundation maps integrating wetland-specific bias and random error in light-detection and ranging elevation maps, with the spatially explicit random error in tidal surfaces generated from tide gauges. This initial uncertainty analysis will be extended to calculate total propagated uncertainty in the NGGI by including the uncertainties in the amount of C lost from eroded and degraded wetlands, stored annually in stable wetlands, and emitted in the form of methane by tidal freshwater wetlands.

Demonstration Results of Phytoremediation of Explosives-Contaminated Groundwater Using Constructed Wetlands at the Milan Army Ammunition Plant, Milan, Tennessee Volume I (Phase II Demonstration Results).

DTIC Science & Technology

1998-12-01

influence community respiration, photosynthesis, solubility of dissolved oxygen, redox potential, biochemical reaction rates, and ensuing treatment...Conductivity 15-8 15.1.3.5 Dissolved Oxygen Concentration 15-12 15.1.3.6 Redox Potential 15-14 15.1.3.7 pH 15-16 15.1.3.8 Nutrients and Water Quality 15-19...Average Redox Potential of Wetland Waters From June 17, 6-27 1996, to September 16, 1997 Phytoremediation Demonstration Milan AAP FIGURE NUMBER

SENTINEL-1 and SENTINEL-2 Data Fusion for Wetlands Mapping: Balikdami, Turkey

NASA Astrophysics Data System (ADS)

Kaplan, G.; Avdan, U.

2018-04-01

Wetlands provide a number of environmental and socio-economic benefits such as their ability to store floodwaters and improve water quality, providing habitats for wildlife and supporting biodiversity, as well as aesthetic values. Remote sensing technology has proven to be a useful and frequent application in monitoring and mapping wetlands. Combining optical and microwave satellite data can help with mapping and monitoring the biophysical characteristics of wetlands and wetlands` vegetation. Also, fusing radar and optical remote sensing data can increase the wetland classification accuracy. In this paper, data from the fine spatial resolution optical satellite, Sentinel-2 and the Synthetic Aperture Radar Satellite, Sentinel-1, were fused for mapping wetlands. Both Sentinel-1 and Sentinel-2 images were pre-processed. After the pre-processing, vegetation indices were calculated using the Sentinel-2 bands and the results were included in the fusion data set. For the classification of the fused data, three different classification approaches were used and compared. The results showed significant improvement in the wetland classification using both multispectral and microwave data. Also, the presence of the red edge bands and the vegetation indices used in the data set showed significant improvement in the discrimination between wetlands and other vegetated areas. The statistical results of the fusion of the optical and radar data showed high wetland mapping accuracy, showing an overall classification accuracy of approximately 90 % in the object-based classification method. For future research, we recommend multi-temporal image use, terrain data collection, as well as a comparison of the used method with the traditional image fusion techniques.

A blue carbon soil database: Tidal wetland stocks for the US National Greenhouse Gas Inventory

NASA Astrophysics Data System (ADS)

Feagin, R. A.; Eriksson, M.; Hinson, A.; Najjar, R. G.; Kroeger, K. D.; Herrmann, M.; Holmquist, J. R.; Windham-Myers, L.; MacDonald, G. M.; Brown, L. N.; Bianchi, T. S.

2015-12-01

Coastal wetlands contain large reservoirs of carbon, and in 2015 the US National Greenhouse Gas Inventory began the work of placing blue carbon within the national regulatory context. The potential value of a wetland carbon stock, in relation to its location, soon could be influential in determining governmental policy and management activities, or in stimulating market-based CO2 sequestration projects. To meet the national need for high-resolution maps, a blue carbon stock database was developed linking National Wetlands Inventory datasets with the USDA Soil Survey Geographic Database. Users of the database can identify the economic potential for carbon conservation or restoration projects within specific estuarine basins, states, wetland types, physical parameters, and land management activities. The database is geared towards both national-level assessments and local-level inquiries. Spatial analysis of the stocks show high variance within individual estuarine basins, largely dependent on geomorphic position on the landscape, though there are continental scale trends to the carbon distribution as well. Future plans including linking this database with a sedimentary accretion database to predict carbon flux in US tidal wetlands.

Microtopography enhances nitrogen cycling and removal in created mitigation wetlands

USGS Publications Warehouse

Wolf, K.L.; Ahn, C.; Noe, G.B.

2011-01-01

Natural wetlands often have a heterogeneous soil surface topography, or microtopography (MT), that creates microsites of variable hydrology, vegetation, and soil biogeochemistry. Created mitigation wetlands are designed to mimic natural wetlands in structure and function, and recent mitigation projects have incorporated MT as one way to attain this goal. Microtopography may influence nitrogen (N) cycling in wetlands by providing adjacent areas of aerobic and anaerobic conditions and by increasing carbon storage, which together facilitate N cycling and removal. This study investigated three created wetlands in the Virginia Piedmont that incorporated disking-induced MT during construction. One site had paired disked and undisked plots, allowing an evaluation of the effects of this design feature on N flux rates. Microtopography was measured using conventional survey equipment along a 1-m circular transect and was described using two indices: tortuosity (T), describing soil surface roughness and relief, and limiting elevation difference (LD), describing soil surface relief. Ammonification, nitrification, and net N mineralization were determined with in situ incubation of modified ion-exchange resin cores and denitrification potential was determined using denitrification enzyme assay (DEA). Results demonstrated that disked plots had significantly greater LD than undisked plots one year after construction. Autogenic sources of MT (e.g. tussock-forming vegetation) in concert with variable hydrology and sedimentation maintained and in some cases enhanced MT in study wetlands. Tortuosity and LD values remained the same in one wetland when compared over a two-year period, suggesting a dynamic equilibrium of MT-forming and -eroding processes at play. Microtopography values also increased when comparing the original induced MT of a one-year old wetland with MT of older created wetlands (five and eight years old) with disking-induced MT, indicating that MT can increase by natural processes over time. When examined along a hydrologic gradient, LD increased with proximity to an overflow point as a result of differential sediment deposition and erosion during flood events. Nitrification increased with T and denitrification potential increased with LD, indicating that microtopographic heterogeneity enhances coupled N fluxes. The resulting N flux patterns may be explained by the increase in oxygen availability elicited by greater T (enhancing nitrification) and by the adjacent zones of aerobic and anaerobic conditions elicited by greater LD (enhancing coupled nitrification and denitrification potential). Findings of this study support the incorporation of MT into the design and regulatory evaluation of created wetlands in order to enhance N cycling and removal. ?? 2011.

Comparison of Habitat-Specific Nutrient Removal and Release in Pacific NW Salt Marshes at Multiple Spatial Scales - CERF

EPA Science Inventory

Wetlands can be sources, sinks and transformers of nutrients, although it is their role in nutrient removal that is valued as a water purification ecosystem service. In order to quantify that service for any wetland, it is important to understand the drivers of nutrient removal w...

7 CFR 1467.9 - Wetlands Reserve Enhancement Program.

Code of Federal Regulations, 2010 CFR

2010-01-01

... purpose of WREP is to target and leverage resources to address high priority wetlands protection...) Section 1467.8(a)(3)(i) is adjusted to reduce the fair market value of the land by an amount equal to the... Practices appraisal or a market survey; and (ii) Section 1467.8(a)(3)(ii) is adjusted to reduce the...

A Field Guide to Kentucky Lakes and Wetlands.

ERIC Educational Resources Information Center

Kentucky State Div. of Water, Frankfort. Kentucky Natural Resources and Environmental Protection Cabinet.

Lakes and wetlands make up that part of Kentucky's water bodies commonly referred to as standing waters. These waters serve many purposes for the people of the state and are necessary and valued elements of its natural resources. This field guide was designed to provide useful background information and reference material for the study of these…

Estimating wetland connectivity to streams in the Prairie Pothole Region: An isotopic and remote sensing approach

USGS Publications Warehouse

Brooks, J. R.; Mushet, David M.; Vanderhoof, Melanie; Leibowitz, Scott G.; Neff, Brian; Christensen, J. R.; Rosenberry, Donald O.; Rugh, W. D.; Alexander, L.C.

2018-01-01

Understanding hydrologic connectivity between wetlands and perennial streams is critical to understanding the reliance of stream flow on inputs from wetlands. We used the isotopic evaporation signal in water and remote sensing to examine wetland‐stream hydrologic connectivity within the Pipestem Creek watershed, North Dakota, a watershed dominated by prairie‐pothole wetlands. Pipestem Creek exhibited an evaporated‐water signal that had approximately half the isotopic‐enrichment signal found in most evaporatively enriched prairie‐pothole wetlands. Groundwater adjacent to Pipestem Creek had isotopic values that indicated recharge from winter precipitation and had no significant evaporative enrichment, indicating that enriched surface water did not contribute significantly to groundwater discharging into Pipestem Creek. The estimated surface water area necessary to generate the evaporation signal within Pipestem Creek was highly dynamic, varied primarily with the amount of discharge, and was typically greater than the immediate Pipestem Creek surface water area, indicating that surficial flow from wetlands contributed to stream flow throughout the summer. We propose a dynamic range of spilling thresholds for prairie‐pothole wetlands across the watershed allowing for wetland inputs even during low‐flow periods. Combining Landsat estimates with the isotopic approach allowed determination of potential (Landsat) and actual (isotope) contributing areas in wetland‐dominated systems. This combined approach can give insights into the changes in location and magnitude of surface water and groundwater pathways over time. This approach can be used in other areas where evaporation from wetlands results in a sufficient evaporative isotopic signal.

Contributions of humic substances to the dissolved organic carbon pool in wetlands from different climates.

PubMed

Watanabe, Akira; Moroi, Kunio; Sato, Hiromu; Tsutsuki, Kiyoshi; Maie, Nagamitsu; Melling, Lulie; Jaffé, Rudolf

2012-08-01

Wetlands are an important source of DOM. However, the quantity and quality of wetlands' DOM from various climatic regions have not been studied comprehensively. The relationship between the concentrations of DOM (DOC), humic substances (HS) and non-humic substances (NHS) in wetland associated sloughs, streams and rivers, in cool temperate (Hokkaido, Japan), sub-tropical (Florida, USA), and tropical (Sarawak, Malaysia) regions was investigated. The DOC ranged from 1.0 to 15.6 mg CL(-1) in Hokkaido, 6.0-24.4 mg CL(-1) in Florida, and 18.9-75.3 mg CL(-1) in Sarawak, respectively. The relationship between DOC and HS concentrations for the whole sample set was regressed to a primary function with y-intercept of zero (P<0.005) and a slope value of 0.841. A similar correlation was observed between DOC and NHS concentrations, with a smaller slope value of 0.159. However, the correlation coefficient of the latter was much larger when the data was regressed to a logarithmic curve. These observations suggest the presence of a general tendency that the increased DOC in the river waters was mainly due to the increased supply of HS from wetland soils, whereas the rate of the increase in the NHS supply has an upper limit which may be controlled by primary productivity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Causes of hot-spot wetland loss in the Mississippi delta plain

USGS Publications Warehouse

Morton, R.A.; Tiling, G.; Ferina, N.F.

2003-01-01

Field surveys and sediment cores were used to estimate marsh erosion and land subsidence at Madison Bay, a well-known wetland loss hot spot in coastal Louisiana. Former marshes of Madison Bay are under about 1 m of water. Nearly two-thirds of the permanent flooding was caused by rapid subsidence in the late 1960s, whereas the other third was caused by subsequent erosion. Subsidence rates near Madison Bay since the 1960s (???20 mm/yr) are an order of magnitude greater than deltaic subsidence rates averaged for the past 400-4000 yr (???2 mm/yr). The rapid acceleration and unexpected decline in wetland losses in the Mississippi delta plain are difficult to explain on the basis of most physical and biogeochemical processes. There are, however, close temporal and spatial correlations among regional wetland loss, high subsidence rates, and large-volume fluid production from nearby hydrocarbon fields. The decreased rates of wetland loss since the 1970s may be related to decreased rates of subsidence caused by significantly decreased rates of subsurface fluid withdrawal. Annual fluid production from the Lapeyrouse, Lirette, and Bay Baptiste fields that encompass Madison Bay accelerated in the 1960s, peaked about 1970, and then declined abruptly. Large decreases in pore pressure in the Lapeyrouse field have likely altered subsurface stresses and reactivated a major fault that coincides with the wetland loss hot spot. Therefore, wetland losses at Madison Bay can be closely linked to rapid subsidence and possible fault reactivation induced by long-term, large-volume hydrocarbon production. ?? 2003. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

Sediment retention in a bottomland hardwood wetland in Eastern Arkansas

USGS Publications Warehouse

Kleiss, B.A.

1996-01-01

One of the often-stated functions of wetlands is their ability to remove sediments and other particulates from water, thus improving water quality in the adjacent aquatic system. However, actual rates of suspended sediment removal have rarely been measured in freshwater wetland systems. To address this issue, suspended sediment dynamics were measured in a 85-km2 bottomland hardwood (BLH) wetland adjacent to the highly turbid Cache River in eastern Arkansas during the 1988-1990 water years. A suspended sediment mass balance was calculated using depth-integrated, flow-weighted daily measurements at wetland inflow and outflow points. Over the three-year period, suspended sediment load decreased an average of 14% between upstream and downstream sampling points. To test the idea that the suspended sediments were retained by the adjacent wetland and to determine what portion of the BLH forest was most responsible for retaining the suspended sediments, concurrent measurements of sediment accretion were made at 30 sites in the wetland using feldspar clay marker horizons, sedimentation disks, the 137cesium method, and dendrogeomorphic techniques. Sedimentation rates exceeding 1 cm/yr were measured in frequently flooded areas dominated by Nyssa aquatica and Taxodium distichum. Maximum sedimentation rates did not occur on the natural levee, as would be predicted by classical fluvial geomorphology, but in the "first bottom," where retention time of the water reached a maximum. Multiple regression was used to relate sedimentation rates with several physical and biological factors. A combination of distance from the river, flood duration, and tree basal area accounted for nearly 90% of the variation in sedimentation rates.

Integrated Water Resources Simulation Model for Rural Community

NASA Astrophysics Data System (ADS)

Li, Y.-H.; Liao, W.-T.; Tung, C.-P.

2012-04-01

The purpose of this study is to develop several water resources simulation models for residence houses, constructed wetlands and farms and then integrate these models for a rural community. Domestic and irrigation water uses are the major water demand in rural community. To build up a model estimating domestic water demand for residence houses, the average water use per person per day should be accounted first, including water uses of kitchen, bathroom, toilet and laundry. On the other hand, rice is the major crop in the study region, and its productive efficiency sometimes depends on the quantity of irrigation water. The water demand can be estimated by crop water use, field leakage and water distribution loss. Irrigation water comes from rainfall, water supply system and reclaimed water which treated by constructed wetland. In recent years, constructed wetlands play an important role in water resources recycle. They can purify domestic wastewater for water recycling and reuse. After treating from constructed wetlands, the reclaimed water can be reused in washing toilets, watering gardens and irrigating farms. Constructed wetland is one of highly economic benefits for treating wastewater through imitating the processing mechanism of natural wetlands. In general, the treatment efficiency of constructed wetlands is determined by evapotranspiration, inflow, and water temperature. This study uses system dynamics modeling to develop models for different water resource components in a rural community. Furthermore, these models are integrated into a whole system. The model not only is utilized to simulate how water moves through different components, including residence houses, constructed wetlands and farms, but also evaluates the efficiency of water use. By analyzing the flow of water, the water resource simulation model can optimizes water resource distribution under different scenarios, and the result can provide suggestions for designing water resource system of a rural community. Keywords: Water Resources, Simulation Model, Domestic Water, Irrigation, Constructed Wetland, Rural Community

Modelling nitrogen transformation and removal in mara river basin wetlands upstream of lake Victoria

NASA Astrophysics Data System (ADS)

Mayo, Aloyce W.; Muraza, Marwa; Norbert, Joel

2018-06-01

Lake Victoria, the largest lake in Africa, is a resource of social-economic potential in East Africa. This lake receives water from numerous tributaries including Mara River, which contributes about 4.8% of the total Lake water inflow. Unfortunately, Mara River basin faces environmental problems because of intensive settlement, agriculture, overgrazing in the basin and mining activities, which has lead to water pollution in the river, soil erosion and degradation, decreased soil fertility, loss of vegetation cover, decreased water infiltration capacity and increased sedimentation. One of the pollutants carried by the river includes nitrogen, which has contributed to ecological degradation of the Lake Victoria. Therefore this research work was intended to determine the effectiveness of Mara River wetland for removal of nitrogen and to establish nitrogen removal mechanisms in the wetland. To predict nitrogen removal in the wetland, the dynamics of nitrogen transformation was studied using a conceptual numerical model that takes into account of various processes in the system using STELLA II version 9.0®2006 software. Samples of model input from water, plants and sediments were taken for 45 days and were analyzed for pH, temperature, and DO in situ and chemical parameters such as NH3-N, Org-N, NO2-N, and NO3-N were analyzed in the laboratory in accordance with Standard methods. For plants, the density, dominance, biomass productivity and TN were determined and for sediments TN was analyzed. Inflow into the wetland was determined using stage-discharge relationship and was found to be 734,400 m3/day and the average wetland volume was 1,113,500 m3. Data collected by this study were used for model calibration of nitrogen transformation in this wetland while data from another wetland were used for model validation. It was found that about 37.8% of total nitrogen was removed by the wetland system largely through sedimentation (26.6%), plant uptake (6.6%) and denitrification (4.6%).

A Study on Spectral Signature Analysis of Wetland Vegetation Based on Ground Imaging Spectrum Data

NASA Astrophysics Data System (ADS)

Ling, Chengxing; Liu, Hua; Ju, Hongbo; Zhang, Huaiqing; You, Jia; Li, Weina

2017-10-01

The objective of this study was to verify the application of imaging spectrometer in wetland vegetation remote sensing monitoring, based on analysis of wetland vegetation spectral features. Spectral information of Carex vegetation spectral data under different water environment was collected bySOC710VP and ASD FieldSpec 3; Meanwhile, the chlorophyll contents of wheat leaves were tested in the lab. A total 9 typical vegetation indices were calculated by using two instruments’ data which were spectral values from 400nm to 1000 nm. Then features between the same vegetation indices and soil water contents for two applications were analyzed and compared. The results showed that there were same spectrum curve trends of Carex vegetation (soil moisture content of 51%, 32%, 14% and three regional comparative analysis)reflectance between SOC710VP and ASD FieldSpec 3, including the two reflectance peak of 550nm and 730 nm, two reflectance valley of 690 nm and 970nm, and continuous near infrared reflectance platform. However, The two also have a very clear distinction: (1) The reflection spectra of SOC710VP leaves of Carex Carex leaf spectra in the three soil moisture environment values are greater than ASD FieldSpec 3 collected value; (2) The SOC710VP reflectivity curve does not have the smooth curve of the original spectrum measured by the ASD FieldSpec 3, the amplitude of fluctuation is bigger, and it is more obvious in the near infrared band. It is concluded that SOC710VP spectral data are reliable, with the image features, spectral curve features reliable. It has great potential in the research of hyperspectral remote sensing technology in the development of wetland near earth, remote sensing monitoring of wetland resources.

Assessing the potential for using wetlands as intermediary storages to conjunctively maintain ecological values and support agricultural demands.

PubMed

Ning, Nathan S P; Watkins, Susanne C; Gawne, Ben; Nielsen, Daryl L

2012-09-30

Water sharing to meet both agricultural and environmental demands is a critical issue affecting the health of many floodplain river systems around the world. This study explored the potential for using wetlands as temporary off-river storages to conjunctively maintain ecological values and support agricultural demands by assessing the effects of artificial drawdown on wetland aquatic plant communities. An initial experiment was undertaken in outdoor mesocosms in which four different treatments were compared over a 131 day duration: (1) natural drawdown where the water was left to drawdown naturally via evaporation; (2) partial drawdown where approximately half of the volume of water was pumped out after 42 days; (3) stepped drawdown where approximately half of the volume of water pumped out after 42 days, and then the remaining volume of water was pumped out after 117 days; and (4) total drawdown where all of the of water was pumped out after 117 days. A complementary field study was subsequently undertaken where two wetlands were left to drawdown naturally and two were partially drawn down artificially (i.e. had approximately half of their volume removed by pumping). Results from both of these studies indicated that neither aquatic plant abundance nor taxon richness were adversely affected by partial drawdown. Rather, both studies showed that aquatic plant communities subjected to a partial drawdown treatment became more species rich and diverse than communities subjected to a natural drawdown treatment. This suggests that it may be possible to use wetlands as intermediary storages for the dual purposes of maintaining ecological values and supporting agricultural demands. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Factors affecting wetland connectivity for wintering semipalmated sandpipers (Calidris pusilla) in the Caribbean

USGS Publications Warehouse

Parks, Morgan A.; Collazo, Jaime A.; Ramos Alvarez, Katsi R.

2016-01-01

Wetland connectivity provides migratory shorebirds varying options to meet energy requirements to survive and complete their annual cycle. Multiple factors mediate movement and residency of spatially segregated wetlands. Information on these factors is lacking in the tropics, yet such information is invaluable for conservation design. The influence of seven biotic and abiotic factors on local movement and residency rates of Semipalmated Sandpipers (Calidris pusilla) among three major wetlands in southwestern Puerto Rico in 2013–2014 was assessed using multi-state models. The model with highest support (AICc wi= 0.78) indicated that weekly residency rates increased seasonally, and were positively influenced by bird abundance and the interaction of prey density and rainfall. Movement rates were negatively influenced by inter-wetland distance, which varied annually, ranging from 0.01 ± 0.004 to 0.33 ± 0.08. Age class (adult, juvenile), extent of shoreline habitat (km), and body condition (estimated percent fat) did not influence residency rates (95% CIs overlapped Betas). Our findings indicated that coastal wetlands in southwestern Puerto Rico were connected, pointing at the joint value of salt flats and mangroves for overwintering Semipalmated Sandpipers. Connectivity between different types of wetlands likely widens resource diversity, which is essential for coping with unpredictable environments. Additional work is needed to generalize our understanding of inter-wetland dynamics and their potential benefits to inform shorebird conservation strategies in the Caribbean.

Importance of hydrogeochemical processes in the coastal wetlands: A case study from Edremit-Dalyan coastal wetland, Balıkesir-Turkey

NASA Astrophysics Data System (ADS)

Somay, Melis A.

2016-11-01

Investigating the hydrogeochemical properties of wetlands allow us to protect them in a sustainable fashion in global scale. Edremit-Dalyan coastal wetland (EDCW) is located in southern part of Biga Peninsula (Mount Ida) which is the most important eco-tourism center in Turkey. Water sampling was done from the hydrologic basin of coastal wetland that consists of a geothermal site, ore deposits area, treatment facility area and olive tree breeding area. EC values of wetland vary between 440 and 2190 μS/cm and water type shows a shift from CaHCO3 to NaClSO4. Al, As, Cd, Cu, Fe, Pb and Zn concentrations exceed the tolerance limits in wetland area probably due to ore deposits around the Edremit Plain. Concentrations of As are high in wetland area exceeding both aquatic life and drinking water As standards of 10 μg/L by as much as 3 times are observed. The dominant As species is As (III). For the living organisms, this situation can be dangerous. Oxygen-18 and deuterium composition of the samples between -7.18 and -6.13‰, and between -42.6 and -34.4‰, respectively in the study area and all the waters are of meteoric origin. Oxygen-18 enrichment can be observed around Derman and coastal zone due to the geothermal activity and evaporation, respectively.

Influence of changes in wetland inundation extent on net fluxes of carbon dioxide and methane in northern high latitudes from 1993 to 2004

USGS Publications Warehouse

Zhuang, Qianlai; Zhu, Xudong; He, Yujie; Prigent, Catherine; Melillo, Jerry M.; McGuire, A. David; Prinn, Ronald G.; Kicklighter, David W.

2015-01-01

Estimates of the seasonal and interannual exchanges of carbon dioxide (CO2) and methane (CH4) between land ecosystems north of 45°N and the atmosphere are poorly constrained, in part, because of uncertainty in the temporal variability of water-inundated land area. Here we apply a process-based biogeochemistry model to evaluate how interannual changes in wetland inundation extent might have influenced the overall carbon dynamics of the region during the time period 1993–2004. We find that consideration by our model of these interannual variations between 1993 and 2004, on average, results in regional estimates of net methane sources of 67.8 ± 6.2 Tg CH4 yr−1, which is intermediate to model estimates that use two static inundation extent datasets (51.3 ± 2.6 and 73.0 ± 3.6 Tg CH4 yr−1). In contrast, consideration of interannual changes of wetland inundation extent result in regional estimates of the net CO2 sink of −1.28 ± 0.03 Pg C yr−1 with a persistent wetland carbon sink from −0.38 to −0.41 Pg C yr−1 and a upland sink from −0.82 to −0.98 Pg C yr−1. Taken together, despite the large methane emissions from wetlands, the region is a consistent greenhouse gas sink per global warming potential (GWP) calculations irrespective of the type of wetland datasets being used. However, the use of satellite-detected wetland inundation extent estimates a smaller regional GWP sink than that estimated using static wetland datasets. Our sensitivity analysis indicates that if wetland inundation extent increases or decreases by 10% in each wetland grid cell, the regional source of methane increases 13% or decreases 12%, respectively. In contrast, the regional CO2 sink responds with only 7–9% changes to the changes in wetland inundation extent. Seasonally, the inundated area changes result in higher summer CH4 emissions, but lower summer CO2 sinks, leading to lower summer negative greenhouse gas forcing. Our analysis further indicates that wetlands play a disproportionally important role in affecting regional greenhouse gas budgets given that they only occupy approximately 10% of the total land area in the region.

Trends in Accretion Rates of Riverine Sediments in a Distal Bay and Wetlands Using 7-Beryllium as a Tracer: Fourleague Bay, Louisiana.

NASA Astrophysics Data System (ADS)

Restreppo, G. A.; Bentley, S. J.; Wang, J.; Xu, K.

2017-12-01

To combat land loss along the Mississippi River Delta, Louisiana has launched a historic campaign to sustain and regrow coastal lands using, in part, sediment diversions. Previous research has focused primarily on sand sized sediment load, which is usually deposited proximal to a river's delta or a diversion's outlet. Fine sediments constitute the majority of sediment load in the Mississippi, but are under-studied with respect to dispersal processes, particularly in terms of sediment supply to distal deltaic bays and wetlands. The Atchafalaya River and associated wetlands serve as prime study areas for this purpose. Bimonthly time-series push cores were collected from May 2015 to May 2016 along ten sites within Fourleague Bay, Louisiana. Fourleague Bay has remained stable against the deteriorative effects of relative sea level rise, standing out along Louisiana's declining coastline. Of the ten field sites, five are located across a longitudinal transect in the middle bay, while the other five are located in adjacent marshes. All sites fall within 10 to 30 km of the Atchafalaya Delta, extending south towards the Gulf of Mexico. Cores were extruded in 2 cm intervals, dried, ground, and analyzed via gamma spectrometry for the presence of 7Be. Inventories of 7Be were then calculated and used to determine daily mass accretion rate (MAR) over twelve months. Average MAR values for the bay and the marshes are compared with Atchafalaya River discharge, wind data, and atmospheric pressure through the year of sampling. Peak marsh MAR, 0.88 ± 0.20 kg m-2 d-1, occurs just after historically high river discharge. Peak bay MAR, 1.2 ± 0.67 kg m-2 d-1, occurs during seasonal low river discharge and calm winds. Average bay and marsh MARs have a moderate to strong, negative correlation when compared. Results indicate sediment bypass of the bay floor during periods of moderate to high river discharge, entering the marshes directly when inundation occurs and enhanced by the passage of strong atmospheric fronts. Only during periods of low river discharge and relatively calm winds do riverine sediments aggregate directly onto the bay floor.

[Seasonal variations of soil enzyme activities in typical plant communities in the Ebinur Lake wetland, China].

PubMed

Zhu, Hai Qiang; Li, Yan Hong; Li, Fa Dong

2017-04-18

In this study, the soil catalase, phosphatase and urease activities of typical plant communities of reed (Phragmites australis) and tamarisk (Tamarix ramosissima) and their influencing factors were investigated in Ebinur Lake wetland. The results showed that three soil enzyme activities of reed and tamarisk had seasonal dynamic characteristics during different growth periods. For the reed community, the peak concentrations of soil catalase, phosphatase and urease appeared at vigorous stage with 3.26, 0.60 and 0.33 mg·g -1 , respectively, and the minimum value occurred at budding stage and leaf-expansion stage. For the tamarisk community, the peak values of three soil enzyme activities appeared at withered stage with values of 6.33, 0.58 and 0.21 mg·g -1 , respectively, and the valley values were observed at flowering and vigorous stages. Urease was stable during different growth periods, and it could be used as an indicator to identify the differences of soil enzyme activities in the wetlands. The enzyme activities of reed and tamarisk had significant positive correlation with soil organic matter and total P in all growth periods, while there was no significant relationship between enzyme activities and soil water content. The enzyme activities of reed had significant positive correlation with ammonium nitrogen in the rapid growth period. There were no significant relationships between enzyme activities and soil salinity in both communities. The soil enzyme activities of reed and tamarisk were controlled by many factors. Soil organic matter, soil water and soil temperature were the main factors influencing the enzyme activities in the Ebinur Lake wetland.

Porewater inputs drive Fe redox cycling in the water column of a temperate mangrove wetland

NASA Astrophysics Data System (ADS)

Holloway, Ceylena J.; Santos, Isaac R.; Rose, Andrew L.

2018-07-01

Iron is a vital micronutrient within coastal marine ecosystems, playing an integral role in the scale and dynamics of primary production and carbon cycling in the world's oceans. We investigated the relative importance of in situ Fe(II) production from photochemical, microbial and thermal Fe reduction in the surface water column as well as advective porewater inputs in a temperate saline wetland in Australia containing mangrove and saltmarsh vegetation. The diel average concentration of Fe(II) (0.63 ± 0.21 μM, accounting for >70% of the total dissolved Fe present in surface water) was much higher than commonly reported in oxygenated marine waters despite high dissolved oxygen concentrations (81-112% saturation), pH (7.7-7.8) and salinity (33-36) that favor Fe oxidation. In situ production of Fe(II) in the surface water column was primarily driven by microbial processes rather than photochemical and thermal reduction, with a maximum production rate of 4.9 × 10-3 nM s-1. Advective porewater Fe(II) inputs to the wetland averaged over a diel cycle (3.0 × 10-1 nM s-1) were an order of magnitude greater than the combined Fe(II) production rate from autochthonous water column processes (1.0 × 10-2 nM s-1). A bottom up model based on the estimated individual fluxes was used to explain the high Fe(II) concentrations measured during a 24 h time series experiment. Combined, different lines of evidence suggest that advective porewater exchange provides significant quantities of Fe(II) to the estuarine wetland.

Managing wetlands for waterbirds: How managers can make a difference in improving habitat to support a North American Bird Conservation Plan

USGS Publications Warehouse

Erwin, R.M.; Laubhan, M.K.; Cornely, J.E.; Bradshaw, D.M.; Bonney, Rick; Pashley, David N.; Cooper, Robert; Niles, Larry

2000-01-01

Wetlands are the most productive ecosystems in the world, yet they have suffered more loss and degradation than any other ecosystem. Not surprisingly, 50% (29 of 58) of all the bird species in the U. S. (excluding Hawaii and territories) that are listed either as federally threatened or endangered, or are on the U. S. Fish & Wildlife Service 1995 List of Migratory Nongame Birds of Management Concern, occupy wetland or aquatic habitats even though many remaining wetlands across the North American landscape already are managed primarily for waterbirds. Some of these wetlands are administered by federal and state entities (e.g., national wildlife refuges, national and state parks, state wetland management areas) or are maintained on private lands through federally supported restoration and enhancement programs (e.g., Conservation Reserve Program, Wetland Reserve Program, Waterfowl Production Areas, and Partners for Wildlife). Private organizations, such as the National Audubon Society, The Nature Conservancy, and private hunting clubs, also own wetland areas that are managed specifically to benefit wildlife. If management philosophies are altered to consider the entire complex of wetlands, many wetlands can provide benefits to a broad array of waterbirds, as opposed to just one or a few species. However, challenges for natural resource managers are in forming partnerships with owners-managers of wetlands where the objectives are not primarily wildlife oriented. These owners or managers need to be included in wetland training workshops in an attempt to educate them about wetland values and secondary wildlife benefits that may be derived in flooded agricultural lands, aquaculture ponds, altered coastal marshes (mosquito control), and salt evaporation ponds. In some cases, compensation for crop damages by wildlife may be a necessary part of any cooperative agreements. In the development of a North American Bird Conservation Plan we propose a four-step approach and recommend that emphasis be placed on working with Joint Ventures of the North American Waterfowl Management Plan to ensure that a diverse array of waterbird species will benefit. Efforts also should be devoted to developing similar partnerships in areas where important wetland resources exist but no Joint Ventures are planned.

Methylmercury production in sediment from agricultural and non-agricultural wetlands in the Yolo Bypass, California, USA

USGS Publications Warehouse

Marvin-DiPasquale, Mark; Windham-Myers, Lisamarie; Agee, Jennifer L.; Kakouros, Evangelos; Kieu, Le H.; Fleck, Jacob A.; Alpers, Charles N.; Stricker, Craig A.

2014-01-01

As part of a larger study of mercury (Hg) biogeochemistry and bioaccumulation in agricultural (rice growing) and non-agricultural wetlands in California's Central Valley, USA, seasonal and spatial controls on methylmercury (MeHg) production were examined in surface sediment. Three types of shallowly-flooded agricultural wetlands (white rice, wild rice, and fallow fields) and two types of managed (non-agricultural) wetlands (permanently and seasonally flooded) were sampled monthly-to-seasonally. Dynamic seasonal changes in readily reducible ‘reactive’ mercury (Hg(II)R), Hg(II)-methylation rate constants (kmeth), and concentrations of electron acceptors (sulfate and ferric iron) and donors (acetate), were all observed in response to field management hydrology, whereas seasonal changes in these parameters were more muted in non-agricultural managed wetlands. Agricultural wetlands exhibited higher sediment MeHg concentrations than did non-agricultural wetlands, particularly during the fall through late-winter (post-harvest) period. Both sulfate- and iron-reducing bacteria have been implicated in MeHg production, and both were demonstrably active in all wetlands studied. Stoichiometric calculations suggest that iron-reducing bacteria dominated carbon flow in agricultural wetlands during the growing season. Sulfate-reducing bacteria were not stimulated by the addition of sulfate-based fertilizer to agricultural wetlands during the growing season, suggesting that labile organic matter, rather than sulfate, limited their activity in these wetlands. Along the continuum of sediment geochemical conditions observed, values of kmeth increased approximately 10,000-fold, whereas Hg(II)R decreased 100-fold. This suggests that, with respect to the often opposing trends of Hg(II)-methylating microbial activity and Hg(II) availability for methylation, microbial activity dominated the Hg(II)-methylation process, and that along this biogeochemical continuum, conditions that favored microbial sulfate reduction resulted in the highest calculated MeHg production potential rates. Rice straw management options aimed at limiting labile carbon supplies to surface sediment during the post-harvest fall–winter period may be effective in limiting MeHg production within agricultural wetlands.

Surrounding land cover types as predictors of palustrine wetland vegetation quality in conterminous USA

USGS Publications Warehouse

Stapanian, Martin A.; Gara, Brian; Schumacher, William

2018-01-01

The loss of wetland habitats and their often-unique biological communities is a major environmental concern. We examined vegetation data obtained from 380 wetlands sampled in a statistical survey of wetlands in the USA. Our goal was to identify which surrounding land cover types best predict two indices of vegetation quality in wetlands at the regional scale. We considered palustrine wetlands in four regions (Coastal Plains, North Central East, Interior Plains, and West) in which the dominant vegetation was emergent, forested, or scrub-shrub. For each wetland, we calculated weighted proportions of eight land cover types surrounding the area in which vegetation was assessed, in four zones radiating from the edge of the assessment area to 2 km. Using Akaike's Information Criterion, we determined the best 1-, 2- and 3-predictor models of the two indices, using the weighted proportions of the land cover types as potential predictors. Mean values of the two indices were generally higher in the North Central East and Coastal Plains than the other regions for forested and emergent wetlands. In nearly all cases, the best predictors of the indices were not the dominant surrounding land cover types. Overall, proportions of forest (positive effect) and agriculture (negative effect) surrounding the assessment area were the best predictors of the two indices. One or both of these variables were included as predictors in 65 of the 72 models supported by the data. Wetlands surrounding the assessment area had a positive effect on the indices, and ranked third (33%) among the predictors included in supported models. Development had a negative effect on the indices and was included in only 28% of supported models. These results can be used to develop regional management plans for wetlands, such as creating forest buffers around wetlands, or to conserve zones between wetlands to increase habitat connectivity.

Impact of Climate Variability on the Hydrogeochemistry of Ecologically Important Prairie Wetlands and Lakes

NASA Astrophysics Data System (ADS)

Goldhaber, M. B.; Mills, C. T.; Mushet, D. M.; Stricker, C. A.; Rover, J.

2015-12-01

The Prairie Pothole region encompasses 715,000 km2 of the north central US and south central Canada and contains millions of small wetlands and lakes. It sustains large populations of shore birds and migratory waterfowl. PPR ecology is influenced by wetland geochemistry, which can range dramatically over short distances (≤ 200m) from dilute Ca2+-HCO3- to saline Na+-Mg2+-SO42- compositions. These compositional differences result, in part, from long-term critical zone processes in upland areas coupled to groundwater inflow, but they are also influenced by climate. Climate impacts on the geochemistry of 167 wetlands/lakes from a 9700 km2 area of North Dakota (USA) were studied. The chemical composition of these wetlands was determined in the early 1970's during slightly dry climatic conditions and again in 2012-2013, a period of exceptional precipitation. Dilution dominated wetland geochemical trends. Concentrations of Cl-, Na+, K+, and Mg2+ generally decreased in 2012-2013 compared to earlier data. In contrast Ca2+ increased, and SO42- change was variable. The processes driving these modifications were evaluated using inverse (mass balance based) geochemical modeling. The decrease in the largely inert ion, Na+ by rainwater addition was used to approximate the net dilution factor of the wetlands which ranged to >9. This volume increase was associated with large expansions of wetland area determined from time-series Landsat data. Introducing dissolution of authigenic CaCO3, a known constituent of wetland sediments, matched the observed Ca2+ increase. Addition of SO42--enriched groundwater (composition determined from well analyses) was required to model wetlands with increased SO42-. Those wetlands with increased SO42- had more negative δ34SSO4 values, a result consistent with a previously established isotopically light marine pyrite source for groundwater SO42-. Understanding the evolution of wetland chemistry may aid in assessing future climatic impacts to the PPR.

Methylmercury production in sediment from agricultural and non-agricultural wetlands in the Yolo Bypass, California, USA.

PubMed

Marvin-DiPasquale, Mark; Windham-Myers, Lisamarie; Agee, Jennifer L; Kakouros, Evangelos; Kieu, Le H; Fleck, Jacob A; Alpers, Charles N; Stricker, Craig A

2014-06-15

As part of a larger study of mercury (Hg) biogeochemistry and bioaccumulation in agricultural (rice growing) and non-agricultural wetlands in California's Central Valley, USA, seasonal and spatial controls on methylmercury (MeHg) production were examined in surface sediment. Three types of shallowly-flooded agricultural wetlands (white rice, wild rice, and fallow fields) and two types of managed (non-agricultural) wetlands (permanently and seasonally flooded) were sampled monthly-to-seasonally. Dynamic seasonal changes in readily reducible 'reactive' mercury (Hg(II)R), Hg(II)-methylation rate constants (kmeth), and concentrations of electron acceptors (sulfate and ferric iron) and donors (acetate), were all observed in response to field management hydrology, whereas seasonal changes in these parameters were more muted in non-agricultural managed wetlands. Agricultural wetlands exhibited higher sediment MeHg concentrations than did non-agricultural wetlands, particularly during the fall through late-winter (post-harvest) period. Both sulfate- and iron-reducing bacteria have been implicated in MeHg production, and both were demonstrably active in all wetlands studied. Stoichiometric calculations suggest that iron-reducing bacteria dominated carbon flow in agricultural wetlands during the growing season. Sulfate-reducing bacteria were not stimulated by the addition of sulfate-based fertilizer to agricultural wetlands during the growing season, suggesting that labile organic matter, rather than sulfate, limited their activity in these wetlands. Along the continuum of sediment geochemical conditions observed, values of kmeth increased approximately 10,000-fold, whereas Hg(II)R decreased 100-fold. This suggests that, with respect to the often opposing trends of Hg(II)-methylating microbial activity and Hg(II) availability for methylation, microbial activity dominated the Hg(II)-methylation process, and that along this biogeochemical continuum, conditions that favored microbial sulfate reduction resulted in the highest calculated MeHg production potential rates. Rice straw management options aimed at limiting labile carbon supplies to surface sediment during the post-harvest fall-winter period may be effective in limiting MeHg production within agricultural wetlands. © 2013.

Influence of earthworm Eisenia fetida on Iris pseudacorus's photosynthetic characteristics, evapotranspiration losses and purifying capacity in constructed wetland systems.

PubMed

Xu, Defu; Li, Yingxue; Fan, Xiaolong; Guan, Yidong; Fang, Hua; Zhao, Xiaoli

2013-01-01

Four constructed wetland systems were studied to investigate the effects of adding Eisenia fetida on the purifying capacity of constructed wetlands. Addition of E. fetida increased the photosynthetic rate (Pn), transpiration rate (Tr) and chlorophyll meter value of leaves of Iris pseudacorus L. in the constructed wetlands by 16, 35 and 7%, respectively. Compared with the substrate only system, evapotranspiration losses were increased by 8, 48 and 56% for the wetland systems with substrate and E. fetida, with substrate and I. pseudacorus, and with substrate, I. pseudacorus and E. fetida, respectively. Addition of E. fetida to the substrate only and substrate and plant wetland systems decreased the substrate bulk density by 3 and 6%, respectively. The addition of E. fetida to the system with substrate and plants increased the removal efficiency of chemical oxygen demand (CODMn), total nitrogen (TN) and total phosphorus by 5, 7 and 22%, respectively. Evapotranspiration losses were significantly positively correlated with the removal efficiency of CODMn (P < 0.01). The significantly negative correlation between the removal efficiency TN and bulk density was found (P < 0.05). Therefore, E. fetida could stimulate I. pseudacorus growth and improve the substrate bulk density in the constructed wetland, resulting in enhanced purifying capacity.

Integrating ecosystem services in terrestrial conservation planning.

PubMed

Yuan, Mei-Hua; Lo, Shang-Lien; Yang, Chih-Kai

2017-05-01

The purpose of this study is to estimate the benefits of ecosystem services for prioritization of land use conservation and to highlight the importance of ecosystem services by comparison between ecosystem service value and green GDP accounting. Based on land use pattern and benefit transfer method, this research estimated value of ecosystem services in Taiwan. Scientific information of land use and land cover change is accessed through multi-year satellite imagery moderate resolution imaging spectroradiometer (MODIS), and geographic information system (GIS) technology. Combined with benefit transfer method, this research estimated the ecosystem service valuation of forest, grassland, cropland, wetland, water, and urban for the period of 2000 to 2015 in Taiwan. It is found that forest made the greatest contribution and the significant increasing area of wetland has huge potential benefit for environmental conservation in Taiwan. We recommend placing maintaining wetland ecosystem in Taiwan with higher priority. This research also compared ecosystem service value with natural capital consumption which would essentially facilitate policy makers to understand the relationship between benefits gained from natural capital and the loss from human-made capital.

Valuing improved wetland quality using choice modeling

NASA Astrophysics Data System (ADS)

Morrison, Mark; Bennett, Jeff; Blamey, Russell

1999-09-01

The main stated preference technique used for estimating environmental values is the contingent valuation method. In this paper the results of an application of an alternative technique, choice modeling, are reported. Choice modeling has been developed in the marketing and transport applications but has only been used in a handful of environmental applications, most of which have focused on use values. The case study presented here involves the estimation of the nonuse environmental values provided by the Macquarie Marshes, a major wetland in New South Wales, Australia. Estimates of the nonuse value the community places on preventing job losses are also presented. The reported models are robust, having high explanatory power and variables that are statistically significant and consistent with expectations. These results provide support for the hypothesis that choice modeling can be used to estimate nonuse values for both environmental and social consequences of resource use changes.

Assessment of submarine groundwater discharge and associated dissolved inorganic carbon into a coastal wetland, western Taiwan via time-series observations of 222Rn

NASA Astrophysics Data System (ADS)

Hsu, Feng-Hsin; Su, Chih-Chieh; Wang, Pei-Ling

2017-04-01

We investigated submarine groundwater discharge (SGD) and associated dissolved inorganic carbon flux into the Gaomei wetland, which is located south of the Tachia river's mouth, western Taiwan. This area is characterized by a great tidal range (over 3 m at spring tide) and a shallow unconfined aquifer (˜2 m below the seafloor) with high groundwater recharging rates (over 500 mm yr-1) in the hinterland. In this study we argue that in the Gaomei wetland, tidal pumping causes an exchanging between groundwater and seawater, resulting in an overall dissolved inorganic carbon (DIC) flux into the wetland. Time-series observations of 222Rn were conducted over 2 tidal cycles in both dry (May of 2014) and wet seasons (August of 2014) seasons at a station 500 m offshore. Our result shows a good response to tidal fluctuation with higher 222Rn activities at low tide and lower 222Rn activities at high tide. Based on a 222Rn mass balance model taking all sources and sinks into account, we estimated a SGD flux ranging from -3.86 to 69 cm d-1 with slightly higher fluxes during the wet season (average SGD flux 22 cm d-1) compared to the dry season (average SGD flux 16 cm d-1). Our negative SGD flux estimates observed during high tides suggest that seawater infiltrates into the sediments during flood tide and discharges during ebb tide, proving the concept of seawater exchange across the water-sediment interface. The overall SGD-borne DIC fluxes range between 1.82×106 and 2.48×106 mol d-1 in dry and wet seasons, respectively, that are 26 % and 36 % of the river-induced DIC fluxes. Such an export of DIC flux from the groundwater (or recycled seawater) might have an impact on coastal biogeochemistry in the Gaomei wetland.

Comparison of 13 equations for determining evapotranspiration from a prairie wetland, Cottonwood Lake Area, North Dakota, USA

USGS Publications Warehouse

Rosenberry, Donald O.; Stannard, David L.; Winter, Thomas C.; Martinez, Margo L.

2004-01-01

Evapotranspiration determined using the energy-budget method at a semi-permanent prairie-pothole wetland in east-central North Dakota, USA was compared with 12 other commonly used methods. The Priestley-Taylor and deBruin-Keijman methods compared best with the energy-budget values; mean differences were less than 0.1 mm d−1, and standard deviations were less than 0.3 mm d−1. Both methods require measurement of air temperature, net radiation, and heat storage in the wetland water. The Penman, Jensen-Haise, and Brutsaert-Stricker methods provided the next-best values for evapotranspiration relative to the energy-budget method. The mass-transfer, deBruin, and Stephens-Stewart methods provided the worst comparisons; the mass-transfer and deBruin comparisons with energy-budget values indicated a large standard deviation, and the deBruin and Stephens-Stewart comparisons indicated a large bias. The Jensen-Haise method proved to be cost effective, providing relatively accurate comparisons with the energy-budget method (mean difference=0.44 mm d−1, standard deviation=0.42 mm d−1) and requiring only measurements of air temperature and solar radiation. The Mather (Thornthwaite) method is the simplest, requiring only measurement of air temperature, and it provided values that compared relatively well with energy-budget values (mean difference=0.47 mm d−1, standard deviation=0.56 mm d−1). Modifications were made to several of the methods to make them more suitable for use in prairie wetlands. The modified Makkink, Jensen-Haise, and Stephens-Stewart methods all provided results that were nearly as close to energy-budget values as were the Priestley-Taylor and deBruin-Keijman methods, and all three of these modified methods only require measurements of air temperature and solar radiation. The modified Hamon method provided values that were within 20 percent of energy-budget values during 95 percent of the comparison periods, and it only requires measurement of air temperature. The mass-transfer coefficient, associated with the commonly used mass-transfer method, varied seasonally, with the largest values occurring during summer.

Investigating spatial variability in gas-flux dynamics within Big Cypress National Preserve, Florida using hydrogeophysical methods

NASA Astrophysics Data System (ADS)

Sirianni, M.; Comas, X.; Shoemaker, B.; Job, M. J.; Cooper, H.

2016-12-01

Globally, wetland soils play an important role in regulating climate change by functioning as a source or sink for atmospheric carbon, particularly in terms of methane and carbon dioxide. While many historic studies defined the function of wetland soils in the global carbon budget, the gas-flux dynamics of subtropical wetlands is largely unknown. Big Cypress National Preserve is a collection of subtropical wetlands in southwestern Florida, including extensive forested (cypress, pine, hardwood) and sawgrass ecosystems that dry and flood annually in response to rainfall. The U.S. Geological Survey employs eddy covariance methods at several locations within the Preserve to quantify carbon and methane exchanges at ecosystem scales. While eddy covariance towers are a convenient tool for measuring gas fluxes, their footprint is spatially extensive (hundreds of meters); and thus spatial variability at smaller scales is masked by averaging or even overlooked. We intend to estimate small-scale contributions of organic and calcitic soils to gas exchanges measured by the eddy covariance towers using a combination of geophysical, hydrologic and ecologic techniques. Preliminary results suggest that gas releases from flooded calcitic soils are much greater than organic soils. These results - and others - will help build a better understanding of the role of subtropical wetlands in the global carbon budget.

Risk of inundation to coastal wetlands and soil organic carbon and organic nitrogen accounting in Louisiana, USA.

PubMed

Zhong, Biao; Xu, Y Jun

2011-10-01

Exceeding 1.2 million acres (4856 km(2)) since the 1930s, coastal wetland loss has been the most threatening environmental problem in Louisiana, United States. This study utilized high-resolution LiDAR (Light Detection and Ranging) and DEM (Digital Elevation Model) data sets to assess the risk of potential wetland loss due to future sea level rises, their spatial distribution, and the associated loss of soil organic carbon (SOC) and organic nitrogen (SON) estimated from the State Soil Geographic (STATSGO) Database and National Wetlands Inventory (NWI) digital data. Potential inundation areas were divided into five elevation scales: < 0 cm, 0-50 cm, 50-100 cm, 100-150 cm, and 150-200 cm above mean sea level. The study found that southeastern Louisiana on the Mississippi River Delta, specifically the Pontchartrain and Barataria Basins, are most vulnerable to sea-level rise induced inundation. Accordingly, approximately 42,264,600 t of SOC and 2,817,640 t of SON would be inundated by 2050 using an average wetland SOC density (203 t per hectare) for the inundation areas between 0 and 50 cm. The estimated annual SOC and SON loss from Louisiana's coast is 17% of annual organic carbon and 6-8% of annual organic nitrogen inputs from the Mississippi River.

Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots

NASA Astrophysics Data System (ADS)

Powell, C. L.; Goltz, M. N.; Agrawal, A.

2014-12-01

Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~ 1.9 mg L- 1, and initial aqueous [CAH] ~ 150 μg L- 1; cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12 ± 0.01 and 0.59 ± 0.07 d- 1, respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds.

Degradation kinetics of chlorinated aliphatic hydrocarbons by methane oxidizers naturally-associated with wetland plant roots.

PubMed

Powell, C L; Goltz, M N; Agrawal, A

2014-12-01

Chlorinated aliphatic hydrocarbons (CAHs) are common groundwater contaminants that can be removed from the environment by natural attenuation processes. CAH biodegradation can occur in wetland environments by reductive dechlorination as well as oxidation pathways. In particular, CAH oxidation may occur in vegetated wetlands, by microorganisms that are naturally associated with the roots of wetland plants. The main objective of this study was to evaluate the cometabolic degradation kinetics of the CAHs, cis-1,2-dichloroethene (cisDCE), trichloroethene (TCE), and 1,1,1-trichloroethane (1,1,1TCA), by methane-oxidizing bacteria associated with the roots of a typical wetland plant in soil-free system. Laboratory microcosms with washed live roots investigated aerobic, cometabolic degradation of CAHs by the root-associated methane-oxidizing bacteria at initial aqueous [CH4] ~1.9mgL(-1), and initial aqueous [CAH] ~150μgL(-1); cisDCE and TCE (in the presence of 1,1,1TCA) degraded significantly, with a removal efficiency of approximately 90% and 46%, respectively. 1,1,1TCA degradation was not observed in the presence of active methane oxidizers. The pseudo first-order degradation rate-constants of TCE and cisDCE were 0.12±0.01 and 0.59±0.07d(-1), respectively, which are comparable to published values. However, their biomass-normalized degradation rate constants obtained in this study were significantly smaller than pure-culture studies, yet they were comparable to values reported for biofilm systems. The study suggests that CAH removal in wetland plant roots may be comparable to processes within biofilms. This has led us to speculate that the active biomass may be on the root surface as a biofilm. The cisDCE and TCE mass losses due to methane oxidizers in this study offer insight into the role of shallow, vegetated wetlands as an environmental sink for such xenobiotic compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Two faces of agricultural intensification hanging over aquatic biodiversity: The case of chironomid diversity from farm ponds vs. natural wetlands in a coastal region

NASA Astrophysics Data System (ADS)

Fenoy, Encarnación; Casas, J. Jesús

2015-05-01

Increasing agricultural land use and intensification have given rise to the loss and eutrophication of coastal wetlands worldwide. In Mediterranean coastal regions, irrigated agriculture, in turn, has prompted the proliferation of farm ponds which might compensate for wetland loss and degradation if their management regimen results are compatible with biodiversity conservation. Here, we studied regional (γ-), local (α-) and interlocal (β-) diversities of chironomids in coastal wetlands and irrigation ponds from a Mediterranean region, to determine the contribution of each habitat type to regional diversity, and to disentangle which environmental factors, anthropogenic or natural, contributed most to explain diversity patterns. Regional diversity was slightly, but still significantly, higher in natural wetlands than in farm ponds, which can be attributed to the significantly higher β-diversity in natural wetlands, since, despite the much larger surface area of wetlands, both habitat types did not differ in local diversity (α-diversity). In both habitats, however, the contribution of β-diversity to regional diversity was higher compared to that of α-diversity, and the component 'spatial species turnover' exceeded that of the component 'nestedness' of β-diversity. This, together with an outstanding assemblage complementarity (approx. 50%) between habitat types, emphasizes the vital contribution of farm ponds, together with natural wetlands, to regional diversity. Despite the higher salinity and eutrophication of natural wetlands that tended to reduce diversity in chironomid assemblages, their more heterogeneous shore line likely compensated somewhat for such negative effects. Unlike wetlands, the homogeneous and unvegetated shore of farm ponds, in conjunction with their intensive management, probably induced adverse effects on local and interlocal diversity. Specific recommendations are given in this regards to mitigate impacts and improve the value of both habitats for biodiversity conservation.

Shorebird use of South Carolina managed and natural coastal wetlands

USGS Publications Warehouse

Weber, Louise M.; Haig, Susan M.

1996-01-01

While many migrating and wintering shorebird (Charadriiformes) species face declines in quality and quantity of natural stopover sites, diked wetlands managed for shorebirds may provide supplemental habitat. We describe an integrative shorebird-waterfowl management strategy used at Tom Yawkey Wildlife Center on South Island, South Carolina, during 3 winter-spring seasons (1991-93). We compared shorebird use and invertebrate density between diked, managed wetlands and adjacent natural coastal mudflat areas. About 3,000 shorebirds overwintered each year at the site. Migration numbers peaked at 15,000-19,000 during late May. In 1991, shorebird density and absolute numbers were higher (P < 0.05) in managed wetlands at high tide than natural mudflats at low tide. In 1993, we counted shorebird density at low tide both in managed wetlands and Mother Norton Shoals, the largest natural area. During February, shorebird frequency was higher in Mother Norton Shoals and lower in managed wetlands than expected values based on area (P < 0.005). In contrast, from March to May, shorebird frequency was higher in managed wetlands and lower in natural mudflats than expected (P < 0.005 for each month). Invertebrate density from March to May was generally greater in managed wetlands than at Mother Norton Shoals, which may explain shorebird preference during that time. Greater invertebrate density did not explain the pattern in February. Mean water depth in managed wetlands for each shorebird species was <5 cm except for American avocet (Recurvirostra americana) which used deeper water (xI? = 8.4 cm, SD = 4.5). Results indicate that an integrative shorebird-waterfowl management strategy provides supplemental shorebird habitat at high tide, and managed wetlands can be preferred to local natural mudflat areas at low tide.

How the novel integration of electrolysis in tidal flow constructed wetlands intensifies nutrient removal and odor control.

PubMed

Ju, Xinxin; Wu, Shubiao; Huang, Xu; Zhang, Yansheng; Dong, Renjie

2014-10-01

Intensified nutrient removal and odor control in a novel electrolysis-integrated tidal flow constructed wetland were evaluated. The average removal efficiencies of COD and NH4(+)-N were above 85% and 80% in the two experimental wetlands at influent COD concentration of 300 mg/L and ammonium nitrogen concentration of 60 mg/L regardless of electrolysis integration. Effluent nitrate concentration decreased from 2.5mg/L to 0.5mg/L with the reduction in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2). This result reveals the important role of current intensity in nitrogen transformation. Owing to the ferrous and ferric iron coagulant formed through the electro-dissolution of the iron anode, electrolysis integration not only exerted a positive effect on phosphorus removal but also effectively inhibited sulfide accumulation for odor control. Although electrolysis operation enhanced nutrient removal and promoted the emission of CH4, no significant difference was observed in the microbial communities and abundance of the two experimental wetlands. Copyright © 2014 Elsevier Ltd. All rights reserved.

Landscape-Scale Analysis of Wetland Sediment Deposition from Four Tropical Cyclone Events

PubMed Central

Tweel, Andrew W.; Turner, R. Eugene

2012-01-01

Hurricanes Katrina, Rita, Gustav, and Ike deposited large quantities of sediment on coastal wetlands after making landfall in the northern Gulf of Mexico. We sampled sediments deposited on the wetland surface throughout the entire Louisiana and Texas depositional surfaces of Hurricanes Katrina, Rita, Gustav, and the Louisiana portion of Hurricane Ike. We used spatial interpolation to model the total amount and spatial distribution of inorganic sediment deposition from each storm. The sediment deposition on coastal wetlands was an estimated 68, 48, and 21 million metric tons from Hurricanes Katrina, Rita, and Gustav, respectively. The spatial distribution decreased in a similar manner with distance from the coast for all hurricanes, but the relationship with distance from the storm track was more variable between events. The southeast-facing Breton Sound estuary had significant storm-derived sediment deposition west of the storm track, whereas sediment deposition along the south-facing coastline occurred primarily east of the storm track. Sediment organic content, bulk density, and grain size also decreased significantly with distance from the coast, but were also more variable with respect to distance from the track. On average, eighty percent of the mineral deposition occurred within 20 km from the coast, and 58% was within 50 km of the track. These results highlight an important link between tropical cyclone events and coastal wetland sedimentation, and are useful in identifying a more complete sediment budget for coastal wetland soils. PMID:23185635

A Cost-Effectiveness Analysis of Seminatural Wetlands and Activated Sludge Wastewater-Treatment Systems

NASA Astrophysics Data System (ADS)

Mannino, Ilda; Franco, Daniel; Piccioni, Enrico; Favero, Laura; Mattiuzzo, Erika; Zanetto, Gabriele

2008-01-01

A cost-effectiveness analysis was performed to evaluate the competitiveness of seminatural Free Water Surface (FWS) wetlands compared to traditional wastewater-treatment plants. Six scenarios of the service costs of three FWS wetlands and three different wastewater-treatment plants based on active sludge processes were compared. The six scenarios were all equally effective in their wastewater-treatment capacity. The service costs were estimated using real accounting data from an experimental wetland and by means of a market survey. Some assumptions had to be made to perform the analysis. A reference wastewater situation was established to solve the problem of the different levels of dilution that characterize the inflow water of the different systems; the land purchase cost was excluded from the analysis, considering the use of public land as shared social services, and an equal life span for both seminatural and traditional wastewater-treatment plants was set. The results suggest that seminatural systems are competitive with traditional biotechnological systems, with an average service cost improvement of 2.1-fold to 8-fold, according to the specific solution and discount rate. The main improvement factor was the lower maintenance cost of the seminatural systems, due to the self-regulating, low artificial energy inputs and the absence of waste to be disposed. In this work, only the waste-treatment capacity of wetlands was considered as a parameter for the economic competitiveness analysis. Other goods/services and environmental benefits provided by FWS wetlands were not considered.

Tree swallows (Tachycineta bicolor) nesting on wetlands impacted by oil sands mining are highly parasitized by the bird blow fly Protocalliphora spp.

PubMed

Gentes, Marie-Line; Whitworth, Terry L; Waldner, Cheryl; Fenton, Heather; Smits, Judit E

2007-04-01

Oil sands mining is steadily expanding in Alberta, Canada. Major companies are planning reclamation strategies for mine tailings, in which wetlands will be used for the bioremediation of water and sediments contaminated with polycyclic aromatic hydrocarbons and naphthenic acids during the extraction process. A series of experimental wetlands were built on companies' leases to assess the feasibility of this approach, and tree swallows (Tachycineta bicolor) were designated as upper trophic biological sentinels. From May to July 2004, prevalence and intensity of infestation with bird blow flies Protocalliphora spp. (Diptera: Calliphoridae) were measured in nests on oil sands reclaimed wetlands and compared with those on a reference site. Nestling growth and survival also were monitored. Prevalence of infestation was surprisingly high for a small cavity nester; 100% of the 38 nests examined were infested. Nests on wetlands containing oil sands waste materials harbored on average from 60% to 72% more blow fly larvae than those on the reference site. Nestlings on reclaimed sites suffered mean parasitic burdens about twice that of those on the reference site; and for comparable parasitic load, they exhibited greater pathologic effects (e.g., decreased body mass) than control nestlings. The heavy blow fly infestation on oil sands-impacted wetlands suggests that oil sands mining disturbs several components of the local ecosystem, including habitat characteristics, blow fly predators, and host resistance to parasites.

Hydrologic response of desert wetlands to Holocene climate change: preliminary results from the Soda Springs area, Mojave National Preserve, California

USGS Publications Warehouse

Pigati, Jeffrey S.; Reheis, Marith C.; McGeehin, John P.; Honke, Jeffrey S.; Bright, J.

2016-01-01

Desert wetlands are common features in arid environments and include a variety of hydrologic facies, including seeps, springs, marshes, wet meadows, ponds, and spring pools. Wet ground conditions and dense stands of vegetation in these settings combine to trap eolian, alluvial, and fluvial sediments that accumulate over time. The resulting deposits are collectively called ground-water discharge (GWD) deposits, and contain information on how small desert watersheds responded to climate change in the past. Most GWD studies in the southwestern U.S. have focused on the late Pleistocene because the Holocene was too dry to support the extensive wetland systems that were so pervasive just a few millennia earlier. Here we describe the results of a pilot project that involves coring extant wetlands and analyzing the sedimentology and microfauna of the recovered sediment to infer Holocene hydrologic conditions. In 2011, a series of cores were taken near wetlands situated along the western margin of the Soda Lake basin in the Mojave National Preserve of southern California. The core sediments appear to show that the wetlands responded to the relatively minor climate fluctuations that characterized the Holocene. However, our analysis was limited by relatively low sediment recovery (which only averaged 70-80%) and a general paucity of datable materials in the cores. Additional studies aimed at improving recovery and developing new techniques for concentrating plant microfossils (plant remains that are <150 m in diameter) for radiocarbon dating are ongoing.

Evaluation of wetland implementation strategies on phosphorus reduction at a watershed scale

NASA Astrophysics Data System (ADS)

Abouali, Mohammad; Nejadhashemi, A. Pouyan; Daneshvar, Fariborz; Adhikari, Umesh; Herman, Matthew R.; Calappi, Timothy J.; Rohn, Bridget G.

2017-09-01

Excessive nutrient use in agricultural practices is a major cause of water quality degradation around the world, which results in eutrophication of the freshwater systems. Among the nutrients, phosphorus enrichment has recently drawn considerable attention due to major environmental issues such as Lake Erie and Chesapeake Bay eutrophication. One approach for mitigating the impacts of excessive nutrients on water resources is the implementation of wetlands. However, proper site selection for wetland implementation is the key for effective water quality management at the watershed scale, which is the goal of this study. In this regard, three conventional and two pseudo-random targeting methods were considered. A watershed model called the Soil and Water Assessment Tool (SWAT) was coupled with another model called System for Urban Stormwater Treatment and Analysis IntegratioN (SUSTAIN) to simulate the impacts of wetland implementation scenarios in the Saginaw River watershed, located in Michigan. The inter-group similarities of the targeting strategies were investigated and it was shown that the level of similarity increases as the target area increases (0.54-0.86). In general, the conventional targeting method based on phosphorus load generated per unit area at the subwatershed scale had the highest average reduction among all the scenarios (44.46 t/year). However, when considering the total area of implemented wetlands, the conventional method based on long-term impacts of wetland implementation showed the highest amount of phosphorus reduction (36.44 t/year).

Field evidence for linking Altosid applications with increased amphibian deformities in southern leopard frogs [abstract

USGS Publications Warehouse

Sparling, D.W.

1998-01-01

During the summer of 1997 we repeatedly sprayed Altosid, a formulation of 4% methoprene used for mosquito control, on six constructed macrocosms. Six additional macrocosms were sprayed with Abate4E, containing the organophosphate pesticide temephos, and six were sprayed with water (controls). The wetlands were created on an impermeable foundation for research purposes and averaged 215 m2 in area and 0.5 m deep. Application rates and frequency of Abate4E and Altosid followed label directions and mimicked procedures for mosquito control in National Wildlife Refuges. In early September juvenile frogs and metamorphing tadpoles were collected with dip nets from each pond and examined for deformities. In all, 91 juveniles and metamorph southern leopard frogs (Rana utricularia) were collected from Altosid sprayed wetlands with 14 (15%) demonstrating deformities. Seventyseven juveniles and metamorphs were collected from control wetlands with three (4%) showing deformities. Only six juveniles and metamorphs were collected from Abate4E wetlands and none showed deformities. Deformities included missing or deformed hind limbs (9 of 10 involving only the right hind limb), missing eyes, and abnormal color. The differences in rate of deformities was dependent on treatment (X2=6.44, p< 0.02). The number of leopard frogs caught per unit effort (tadpoles and juveniles) differed among treatments (p=0.032) with Abate4E wetlands producing fewer individuals per capture effort than either Altosid or control wetlands.

A cost-effectiveness analysis of seminatural wetlands and activated sludge wastewater-treatment systems.

PubMed

Mannino, Ilda; Franco, Daniel; Piccioni, Enrico; Favero, Laura; Mattiuzzo, Erika; Zanetto, Gabriele

2008-01-01

A cost-effectiveness analysis was performed to evaluate the competitiveness of seminatural Free Water Surface (FWS) wetlands compared to traditional wastewater-treatment plants. Six scenarios of the service costs of three FWS wetlands and three different wastewater-treatment plants based on active sludge processes were compared. The six scenarios were all equally effective in their wastewater-treatment capacity. The service costs were estimated using real accounting data from an experimental wetland and by means of a market survey. Some assumptions had to be made to perform the analysis. A reference wastewater situation was established to solve the problem of the different levels of dilution that characterize the inflow water of the different systems; the land purchase cost was excluded from the analysis, considering the use of public land as shared social services, and an equal life span for both seminatural and traditional wastewater-treatment plants was set. The results suggest that seminatural systems are competitive with traditional biotechnological systems, with an average service cost improvement of 2.1-fold to 8-fold, according to the specific solution and discount rate. The main improvement factor was the lower maintenance cost of the seminatural systems, due to the self-regulating, low artificial energy inputs and the absence of waste to be disposed. In this work, only the waste-treatment capacity of wetlands was considered as a parameter for the economic competitiveness analysis. Other goods/services and environmental benefits provided by FWS wetlands were not considered.

Dynamic characteristics of soil respiration in Yellow River Delta wetlands, China

NASA Astrophysics Data System (ADS)

Wang, Xiao; Luo, Xianxiang; Jia, Hongli; Zheng, Hao

2018-02-01

The stable soil carbon (C) pool in coastal wetlands, referred to as "blue C", which has been extensively damaged by climate change and soil degradation, is of importance to maintain global C cycle. Therefore, to investigate the dynamic characteristics of soil respiration rate and evaluate C budgets in coastal wetlands are urgently. In this study, the diurnal and seasonal variation of soil respiration rate in the reed wetland land (RL) and the bare wetland land (BL) was measured in situ with the dynamic gas-infrared CO2 method in four seasons, and the factors impacted on the dynamic characteristics of soil respiration were investigated. The results showed that the diurnal variation of soil respiration rate consistently presented a "U" curve pattern in April, July, and September, with the maximum values at 12:00 a.m. and the minimum values at 6:00 a.m. In the same season, the diurnal soil respiration rate in RL was significantly greater than those in BL (P < 0.05). In April, July, and September, the mean diurnal soil respiration rate was 0.14, 0.42, and 0.39 μmol m-2 s-1 in RL, 0.05, 0.22, 0.13, and 0.01 μmol m-2 s-1 in BL, respectively. Soil surface temperature was the primary factor that influenced soil respiration, which was confirmed by the exponential positive correlation between the soil respiration rate and soil surface temperature in BL and RL (P < 0.05). In addition, the high salinity of soils suppressed soil respiration, confirming by the significantly negative correlation between soil respiration rate and the content of soluble salt. These results will be useful for understanding the mechanisms underlying soil respiration and elevating C sequestration potential in the coastal wetlands.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hornibrook, E.R.C.; Longstaffe, F.J.; Fyfe, W.S.

Two types of distribution for {alpha}{sub c} values are observed in anaerobic environments when {delta}{sup 13}C-{Sigma}CO{sub 2} and {delta}{sub 13}C-CH{sub 4} values are measured across gradients of depth or age of organic debris. The type-I distribution involves a systematic increase in {alpha}{sub c} values with depth as a result of decreasing {delta}{sup 13}C-CH{sub 4} and increasing {delta}{sup 13}C-{Sigma}CO{sub 2} values. This behavior corresponds to a progressive increase in the prevalence of methanogenesis by the CO{sub 2} reduction pathway relative to acetate fermentation. Utilization of autotrophically formed acetate by methanogens would also cause an increase in {alpha}{sub c} values. The type-IImore » distribution occurs when both {delta}{sup 13}C-CH{sub 4} and {delta}{sup 13}C-{Sigma}CO{sub 2} values decrease with depth, resulting in approximately constant {alpha}{sub c} values. This condition corresponds with a strong dependence of methanogens on porewater {Sigma}CO{sub 2} as a carbon source by way of either the CO{sub 2} reduction pathway or utilization of autotrophically formed acetate. Freshwater wetlands possess both types of {alpha}{sub c} value distribution. Defining the type of {alpha}{sub c} distributions in different wetlands could reduce uncertainty in estimating the {delta}{sup 13}C value of CH{sub 4} emissions. Hence, the prevalence of type-I vs. type-II {alpha}{sub c} distributions in wetlands may have practical importance for the refinement of global CH{sub 4} budgets that rely on {sup 13}C/{sup 12}C ratios for mass balance.« less

Gaseous fluxes from subsurface flow constructed wetlands for wastewater treatment.

PubMed

Mander, Ulo; Lõhmus, Krista; Teiter, Sille; Nurk, Kaspar; Mauring, Tõnu; Augustin, Jürgen

2005-01-01

We measured nitrous oxide (N2O), dinitrogen (N2), and methane (CH4) fluxes in two constructed wetlands (CW) in Estonia using the closed chamber method and the He-O method in the period from October 2000 to March 2003. Emission rates of N2O-N, N2-N and CH4-C from both CWs varied significantly on a both spatial and temporal scale, ranging from 1 to 2,600, 170 to 130,000, and -1.7 to 87,200 microg m(-2) h(-1) respectively. The average flux of N2O from the microsites in the Kodijärve horizontal subsurface flow (HSSF) CW and Kõo hybrid CW ranged from 27 to 370 and from 72 to 500 microg N2O-N m(-2) h(-1), respectively, whereas the average dinitrogen flux from the microsites in the HSSF CW in Kodijärve was 2-3 magnitudes higher than the N2O flux, ranging from 19,500 to 33,300 microg N2-N m(-2) h(-1). The average methane emissions from the microsites in the Kodijärve HSSF CW and the Kõo hybrid CW ranged from 31 to 12,100 and from 950 to 5,750 microg CH4-C m(-2) h(-1), respectively. The highest emission values for all three gases were observed in the warm period. There was a significant relationship between emission rates and water table depth: CH4 and N2 emission increased and N2O emission decreased when the water table did rise. Although the emission of N2O and CH4 from CWs was found to be relatively high, their global warming potential (GWP) in the time horizon of 100 years is not significant, ranging from 4.5 to 16.3 tonnes of CO2 equivalents per ha per year in Kodijärve and from 12.1 to 17.3 t CO2 equivalents ha(-1) yr(-1) in Kõo.

Spectral discrimination of macrophyte species during different seasons in a tropical wetland using in-situ hyperspectral remote sensing

NASA Astrophysics Data System (ADS)

Saluja, Ridhi; Garg, J. K.

2017-10-01

Wetlands, one of the most productive ecosystems on Earth, perform myriad ecological functions and provide a host of ecological services. Despite their ecological and economic values, wetlands have experienced significant degradation during the last century and the trend continues. Hyperspectral sensors provide opportunities to map and monitor macrophyte species within wetlands for their management and conservation. In this study, an attempt has been made to evaluate the potential of narrowband spectroradiometer data in discriminating wetland macrophytes during different seasons. main objectives of the research were (1) to determine whether macrophyte species could be discriminated based on in-situ hyperspectral reflectance collected over different seasons and at each measured waveband (400-950nm), (2) to compare the effectiveness of spectral reflectance and spectral indices in discriminating macrophyte species, and (3) to identify spectral wavelengths that are most sensitive in discriminating macrophyte species. Spectral characteristics of dominant wetland macrophyte species were collected seasonally using SVC GER 1500 portable spectroradiometer over the 400 to 1050nm spectral range at 1.5nm interval, at the Bhindawas wetland in the state of Haryana, India. Hyperspectral observations were pre-processed and subjected to statistical analysis, which involved a two-step approach including feature selection (ANOVA and KW test) and feature extraction (LDA and PCA). Statistical analysis revealed that the most influential wavelengths for discrimination were distributed along the spectral profile from visible to the near-infrared regions. The results suggest that hyperspectral data can be used discriminate wetland macrophyte species working as an effective tool for advanced mapping and monitoring of wetlands.

Exposure and Figure Out of Climate Induced Alterations in the Wetlands of Banglades

NASA Astrophysics Data System (ADS)

Siddiquee, S. A.; Rahman, M. Z.

2015-12-01

Unique geographic location and geo-morphological conditions of Bangladesh have made the wetlands of this country one of the most vulnerable to climate change. Wetland plays a crucial role in maintaining the ecological balance of ecosystems and cultural figures and which occupy around 50% of the area. Drought, excessive temperature, mountain snowfields and glaciers melting, riverbank erosion, salinity intrusion, flashflood, storm surges, higher water temperatures, precipitation anomalies, coastal cyclones, seasonal anomalies and extremes are main threats to the wetland ecosystem. Enhanced UV-B radiation and increased summer precipitation will significantly increase dissolved organic carbon concentrations altering major biogeochemical cycles and also will result into the expansion of range for many invasive aquatic weeds. Generally, rising temperature will lower water quality through a fall in oxygen concentrations, release of phosphorus from sediments, increased thermal stability, and altered mixing patterns. As a result biodiversity is getting degraded, many species of flora and fauna are getting threatened, and wetland-based ecosystem is getting degenerated. At the same time, the living conditions of local people are deteriorating as livelihoods, socioeconomic institutions, and extensive cultural values as well. For conserving and managing wetlands technology, legislation, educational knowledge, action plan strategy and restoration practices are required. In order to address the human needs in the changing climate community-based adaptation approaches and wetland restoration, practices had been taken in almost every type of wetlands in Bangladesh. Therefore, Bangladesh now needs a comprehensive strategy and integrated system combining political, economic, social, technological approaches and institutional supports to address sustainable wetland restoration, conservation and the newly added crisis, climate change.

Climatic Alterations of Wetlands: Conservation and Adaptation Practices in Bangladesh

NASA Astrophysics Data System (ADS)

Siddiquee, S. A.

2016-02-01

Unique geographic location and geo-morphological conditions of Bangladesh have made the wetlands of this country one of the most vulnerable to climate change. Wetland plays a crucial role in maintaining the ecological balance of ecosystems and cultural figures and which occupy around 50% of the area. Drought, excessive temperature, mountain snowfields and glaciers melting, riverbank erosion, salinity intrusion, flashflood, storm surges, higher water temperatures, precipitation anomalies, coastal cyclones, seasonal anomalies and extremes are main threats to the wetland ecosystem. Enhanced UV-B radiation and increased summer precipitation will significantly increase dissolved organic carbon concentrations altering major biogeochemical cycles and also will result into the expansion of range for many invasive aquatic weeds. Generally, rising temperature will lower water quality through a fall in oxygen concentrations, release of phosphorus from sediments, increased thermal stability, and altered mixing patterns. As a result biodiversity is getting degraded, many species of flora and fauna are getting threatened, and wetland-based ecosystem is getting degenerated. At the same time, the living conditions of local people are deteriorating as livelihoods, socioeconomic institutions, and extensive cultural values as well. For conserving and managing wetlands technology, legislation, educational knowledge, action plan strategy and restoration practices are required. In order to address the human needs in the changing climate community-based adaptation approaches and wetland restoration, practices had been taken in almost every type of wetlands in Bangladesh. Therefore, Bangladesh now needs a comprehensive strategy and integrated system combining political, economic, social, technological approaches and institutional supports to address sustainable wetland restoration, conservation and the newly added crisis, climate change.

The influence of urbanisation on macroinvertebrate biodiversity in constructed stormwater wetlands.

PubMed

Mackintosh, Teresa J; Davis, Jenny A; Thompson, Ross M

2015-12-01

The construction of wetlands in urban environments is primarily carried out to assist in the removal of contaminants from wastewaters; however, these wetlands have the added benefit of providing habitat for aquatic invertebrates, fish and waterbirds. Stormwater quantity and quality is directly related to impervious area (roads, sealed areas, roofs) in the catchment. As a consequence, it would be expected that impervious area would be related to contaminant load and biodiversity in receiving waters such as urban wetlands. This study aimed to establish whether the degree of urbanisation and its associated changes to stormwater runoff affected macroinvertebrate richness and abundance within constructed wetlands. Urban wetlands in Melbourne's west and south east were sampled along a gradient of urbanisation. There was a significant negative relationship between total imperviousness (TI) and the abundance of aquatic invertebrates detected for sites in the west, but not in the south east. However macroinvertebrate communities were relatively homogenous both within and between all study wetlands. Chironomidae (non-biting midges) was the most abundant family recorded at the majority of sites. Chironomids are able to tolerate a wide array of environmental conditions, including eutrophic and anoxic conditions. Their prevalence suggests that water quality is impaired in these systems, regardless of degree of urbanisation, although the causal mechanism is unclear. These results show some dependency between receiving wetland condition and the degree of urbanisation of the catchment, but suggest that other factors may be as important in determining the value of urban wetlands as habitat for wildlife. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation of the seasonal performance of a water reclamation pond-constructed wetland system for removing emerging contaminants.

PubMed

Matamoros, Víctor; Salvadó, Victòria

2012-01-01

The capacity of a full-scale reclamation pond-constructed wetland (CW) system to eliminate 27 emerging contaminants (i.e. pharmaceuticals, sunscreen compounds, fragrances, antiseptics, fire retardants, pesticides, and plasticizers) and the seasonal occurrence of these contaminants is studied. The compounds with the highest concentrations in the secondary effluent are diclofenac, caffeine, ketoprofen, and carbamazepine. The results show that the constructed wetland (61%) removes emerging contaminants significantly more efficiently than the pond (51%), presumably due to the presence of plants (Phragmites and Thypa) as well as the higher hydraulic residence time (HRT) in the CW. A greater seasonal trend to the efficient removal of these compounds is observed in the pond than in the CW. The overall mass removal efficiency of each individual compound ranged from 27% to 93% (71% on average), which is comparable to reported data in advanced treatments (photo-fenton and membrane filtration). The seasonal average content of emerging contaminants in the river water (2488 ng L(-1)) next to the water reclamation plant is found to be higher than the content in the final reclaimed water (1490 ng L(-1)), suggesting that the chemical quality of the reclaimed water is better than available surface waters. Copyright © 2011 Elsevier Ltd. All rights reserved.

Spatially simulating changes of soil water content and their effects on carbon sequestration in Canada's forests and wetlands

NASA Astrophysics Data System (ADS)

Ju, Weimin; Chen, Jing M.; Black, T. Andrew; Barr, Alan G.; McCaughey, Harry

2010-07-01

The variations of soil water content (SWC) and its influences on the carbon (C) cycle in Canada's forests and wetlands were studied through model simulations using the Integrated Terrestrial Ecosystem Carbon (InTEC) model. It shows that Canada's forests and wetlands experienced spatially and temporally heterogeneous changes in SWC from 1901 to 2000. SWC changes caused average NPP to decrease 40.8 Tg C yr-1 from 1901 to 2000, whereas the integrated effect of non-disturbance factors (climate change, CO2 fertilization and N deposition) enhanced NPP by 9.9%. During 1981-2000, the reduction of NPP caused by changes in SWC was 58.1 Tg C yr-1 whereas non-disturbance factors together caused NPP to increase by 16.6%. SWC changes resulted in an average increase of 4.1 Tg C yr-1 in the net C uptake during 1901-2000, relatively small compared with the enhancement in C uptake of 50.2 Tg C yr-1 by the integrated effect of non-disturbance factors. During 1981-2000, changes in SWC caused a reduction of 3.8 Tg C yr-1 in net C sequestration whereas the integrated factors increased net C sequestration by 54.1 Tg C yr-1. Increase in SWC enhanced C sequestration in all ecozones.

Habitat use by prairie raccoons during the waterfowl breeding season

USGS Publications Warehouse

Fritzell, E.K.

1978-01-01

Mobility and habitat use of raccoons (Procyon lotor) in an intensively farmed area of the prairie pothole region were studied during the waterfowl breeding seasons (April-July) of 1973-75. Over 5700 locations of 30 raccoons were analyzed. Movement patterns varied with sex, age, and reproductive status. Adult males moved regularly throughout slightly overlapping ranges that averaged 2560 ha. Yearling males dispersed during May-June but their movements before and after dispersal were similar. Parous or pregnant females (mostly adults) had ranges averaging 806 ha but their movements were confined to smaller areas near the litter site after parturition. Nulliparous yearling females did not disperse and their ranges averaged 656 ha. Building sites, wooded areas, and wetlands were the only habitats preferentially used both at night and during the day. Eighty-one percent of all nocturnal locations and 94 percent of all diurnal locations were in these 3 habitats which comprised only 10 percent of the study area. Use of building sites decreased concomitantly with increased use of wetlands. Upland habitats were seldom used.

Microbial diversity in hummock and hollow soils of three wetlands on the Qinghai-Tibetan Plateau revealed by 16S rRNA pyrosequencing.

PubMed

Deng, Yongcui; Cui, Xiaoyong; Hernández, Marcela; Dumont, Marc G

2014-01-01

The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo) on the Qinghai-Tibetan Plateau, the world's highest plateau. A total of 36 bacterial phyla were detected. Proteobacteria (34.5% average relative abundance), Actinobacteria (17.3%) and Bacteroidetes (11%) had the highest relative abundances across all sites. Chloroflexi, Acidobacteria, Verrucomicrobia, Firmicutes, and Planctomycetes were also relatively abundant (1-10%). In addition, archaeal sequences belonging to Euryarchaea, Crenarchaea and Thaumarchaea were detected. Alphaproteobacteria sequences, especially of the order Rhodospirillales, were significantly more abundant in Maduo than Hongyuan and Dangxiong wetlands. Compared with Hongyuan soils, Dangxiong and Maduo had significantly higher relative abundances of Gammaproteobacteria sequences (mainly order Xanthomonadales). Hongyuan wetland had a relatively high abundance of methanogens (mainly genera Methanobacterium, Methanosarcina and Methanosaeta) and methanotrophs (mainly Methylocystis) compared with the other two wetlands. Principal coordinate analysis (PCoA) indicated that the microbial community structure differed between locations and microtopographies and canonical correspondence analysis indicated an association between microbial community structure and soil properties or geography. These insights into the microbial community structure and the main controlling factors in wetlands of the Qinghai-Tibetan Plateau provide a valuable background for further studies on biogeochemical processes in this distinct ecosystem.

Pollution-tolerant invertebrates enhance greenhouse gas flux in urban wetlands.

PubMed

Mehring, Andrew S; Cook, Perran L M; Evrard, Victor; Grant, Stanley B; Levin, Lisa A

2017-09-01

One of the goals of urban ecology is to link community structure to ecosystem function in urban habitats. Pollution-tolerant wetland invertebrates have been shown to enhance greenhouse gas (GHG) flux in controlled laboratory experiments, suggesting that they may influence urban wetland roles as sources or sinks of GHG. However, it is unclear if their effects can be detected in highly variable conditions in a field setting. Here we use an extensive data set on carbon dioxide (CO 2 ), methane (CH 4 ), and nitrous oxide (N 2 O) flux in sediment cores (n = 103) collected from 10 urban wetlands in Melbourne, Australia during summer and winter in order to test for invertebrate enhancement of GHG flux. We detected significant multiplicative enhancement effects of temperature, sediment carbon content, and invertebrate density on CH 4 and CO 2 flux. Each doubling in density of oligochaete worms or large benthic invertebrates (oligochaete worms and midge larvae) corresponded to ~42% and ~15% increases in average CH 4 and CO 2 flux, respectively. However, despite exceptionally high densities, invertebrates did not appear to enhance N 2 O flux. This was likely due to fairly high organic carbon content in sediments (range 2.1-12.6%), and relatively low nitrate availability (median 1.96 μmol/L NO 3 - -N), which highlights the context-dependent nature of community structural effects on ecosystem function. The invertebrates enhancing GHG flux in this study are ubiquitous, and frequently dominate faunal communities in impaired aquatic ecosystems. Therefore, invertebrate effects on CO 2 and CH 4 flux may be common in wetlands impacted by urbanization, and urban wetlands may make greater contributions to the total GHG budgets of cities if the negative impacts of urbanization on wetlands are left unchecked. © 2017 by the Ecological Society of America.

Estimated ultraviolet radiation doses in wetlands in six national parks

USGS Publications Warehouse

Diamond, S.A.; Trenham, P.C.; Adams, Michael J.; Hossack, B.R.; Knapp, R.A.; Stark, L.; Bradford, D.; Corn, P.S.; Czarnowski, K.; Brooks, P.D.; Fagre, D.B.; Breen, B.; Dentenbeck, N.E.; Tonnessen, K.

2005-01-01

Ultraviolet-B radiation (UV-B, 280–320-nm wavelengths) doses were estimated for 1024 wetlands in six national parks: Acadia (Acadia), Glacier (Glacier), Great Smoky Mountains (Smoky), Olympic (Olympic), Rocky Mountain (Rocky), and Sequoia/Kings Canyon (Sequoia). Estimates were made using ground-based UV-B data (Brewer spectrophotometers), solar radiation models, GIS tools, field characterization of vegetative features, and quantification of DOC concentration and spectral absorbance. UV-B dose estimates were made for the summer solstice, at a depth of 1 cm in each wetland. The mean dose across all wetlands and parks was 19.3 W-h m−2 (range of 3.4–32.1 W-h m−2). The mean dose was lowest in Acadia (13.7 W-h m−2) and highest in Rocky (24.4 W-h m−2). Doses were significantly different among all parks. These wetland doses correspond to UV-B flux of 125.0 μW cm−2 (range 21.4–194.7 μW cm−2) based on a day length, averaged among all parks, of 15.5 h. Dissolved organic carbon (DOC), a key determinant of water-column UV-B flux, ranged from 0.6 (analytical detection limit) to 36.7 mg C L−1 over all wetlands and parks, and reduced potential maximal UV-B doses at 1-cm depth by 1%–87 %. DOC concentration, as well as its effect on dose, was lowest in Sequoia and highest in Acadia (DOC was equivalent in Acadia, Glacier, and Rocky). Landscape reduction of potential maximal UV-B doses ranged from zero to 77% and was lowest in Sequoia. These regional differences in UV-B wetland dose illustrate the importance of considering all aspects of exposure in evaluating the potential impact of UV-B on aquatic organisms.

The effect of river pulsing on sedimentation and nutrients in created riparian wetlands.

PubMed

Nahlik, Amanda M; Mitsch, William J

2008-01-01

Sedimentation under pulsed and steady-flow conditions was investigated in two created flow-through riparian wetlands in central Ohio over 2 yr. Hydrologic pulses of river water lasting for 6 to 8 d were imposed on each wetland from January through June during 2004. Mean inflow rates during pulses averaged 52 and 7 cm d(-1) between pulses. In 2005, the wetlands received a steady-flow regime of 11 cm d(-1) with no major hydrologic fluctuations. Thirty-two sediment traps were deployed and sampled once per month in April, May, June, and July for two consecutive years in each wetland. January through March were not sampled in either year due to frozen water surfaces in the wetlands. Gross sedimentation (sedimentation without normalizing for differences between years) was significantly greater in the pulsing study period (90 kg m(-2)) than in the steady-flow study period (64 kg m(-2)). When normalized for different hydrologic and total suspended solid inputs between years, sedimentation for April through July was not significantly different between pulsing and steady-flow study periods. Sedimentation for the 3 mo that received hydrologic pulses (April, May, and June) was significantly lower during pulsing months than in the corresponding steady-flow months. Large fractions of inorganic matter in collected sediments indicated that allochthonous inputs were the main contributor to sedimentation in these wetlands. Organic matter fractions of collected sediments were consistently greater in the steady-flow study period (1.8 g kg(-1)) than in the pulsed study period (1.5 g kg(-1)), consistent with greater primary productivity in the water column during steady-flow conditions.

Microbial Diversity in Hummock and Hollow Soils of Three Wetlands on the Qinghai-Tibetan Plateau Revealed by 16S rRNA Pyrosequencing

PubMed Central

Deng, Yongcui; Cui, Xiaoyong; Hernández, Marcela; Dumont, Marc G.

2014-01-01

The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo) on the Qinghai-Tibetan Plateau, the world’s highest plateau. A total of 36 bacterial phyla were detected. Proteobacteria (34.5% average relative abundance), Actinobacteria (17.3%) and Bacteroidetes (11%) had the highest relative abundances across all sites. Chloroflexi, Acidobacteria, Verrucomicrobia, Firmicutes, and Planctomycetes were also relatively abundant (1–10%). In addition, archaeal sequences belonging to Euryarchaea, Crenarchaea and Thaumarchaea were detected. Alphaproteobacteria sequences, especially of the order Rhodospirillales, were significantly more abundant in Maduo than Hongyuan and Dangxiong wetlands. Compared with Hongyuan soils, Dangxiong and Maduo had significantly higher relative abundances of Gammaproteobacteria sequences (mainly order Xanthomonadales). Hongyuan wetland had a relatively high abundance of methanogens (mainly genera Methanobacterium, Methanosarcina and Methanosaeta) and methanotrophs (mainly Methylocystis) compared with the other two wetlands. Principal coordinate analysis (PCoA) indicated that the microbial community structure differed between locations and microtopographies and canonical correspondence analysis indicated an association between microbial community structure and soil properties or geography. These insights into the microbial community structure and the main controlling factors in wetlands of the Qinghai-Tibetan Plateau provide a valuable background for further studies on biogeochemical processes in this distinct ecosystem. PMID:25078273

Counteracting wetland overgrowth increases breeding and staging bird abundances

NASA Astrophysics Data System (ADS)

Lehikoinen, Petteri; Lehikoinen, Aleksi; Mikkola-Roos, Markku; Jaatinen, Kim

2017-01-01

Human actions have led to loss and degradation of wetlands, impairing their suitability as habitat especially for waterbirds. Such negative effects may be mitigated through habitat management. To date scientific evidence regarding the impacts of these actions remains scarce. We studied guild specific abundances of breeding and staging birds in response to habitat management on 15 Finnish wetlands. In this study management actions comprised several means of vegetation removal to thwart overgrowth. Management cost efficiency was assessed by examining the association between site-specific costs and bird abundances. Several bird guilds exhibited positive connections with both habitat management as well as with invested funds. Most importantly, however, red-listed species and species with special conservation concern as outlined by the EU showed positive correlations with management actions, underlining the conservation value of wetland management. The results suggest that grazing was especially efficient in restoring overgrown wetlands. As a whole this study makes it clear that wetland habitat management constitutes a feasible conservation tool. The marked association between invested funds and bird abundance may prove to be a valuable tool for decision makers when balancing costs and impact of conservation measures against one another.

Suspended particulate matter flocculation in a natural tidal wetland located in the San Francisco Estuary

NASA Astrophysics Data System (ADS)

Saraceno, J.; Bergamaschi, B. A.; Wright, S. A.; Boss, E.; Downing, B. D.; Fleck, J.; Ganju, N. K.

2011-12-01

Suspended mineral and algal particles together comprise suspended particulate matter (SPM). The SPM size distribution influences the quantity and color of light penetration and the adsorption and transport of contaminants such as pesticides and metals. It is widely known that interaction with wetlands alters the size distribution and quality of particles through local primary production, differential settling and particle aggregation, however, our understanding of how tidal wetland processes affect SPM quantity and size spectra has been hampered by the difficulty of directly observing these parameters at tidal time scales. To evaluate how SPM concentration and size varied over tidal time scales and to better understand the relationship between organic matter and sediment characteristics, simultaneous measurements of dissolved organic matter, SPM concentration and organic content as well as in situ surrogates of particle concentration (turbidity, particulate attenuation, volume concentration) and particle size (laser diffraction) were carried out with measurements of current velocity (acoustic Doppler velocity meter) in the main channel of Brown's Island located in the western San Joaquin/Sacramento River Delta, CA. The study period coincided with high estuary sediment levels following a significant precipitation runoff event. In the Brown Island wetland, particle concentration and size dynamics were tied to variations in water level and velocity. Turbidity and attenuation covaried with the volume concentration of particles smaller than 33 um, which on average represented greater than 50% of particle population by volume. On average, these SPM concentration surrogates were three times higher in flood water than in ebb water; consistent with a loss of fine particles on the island. Following the highest flood tide, the decrease in fine particles was coincident with an increase in the concentration of particles larger than 130 um; a finding consistent with particle flocculation. Additionally, the timing of flocculation was coincident with periods of elevated dissolved organic matter, suggesting organic matter played a role in the formation of large aggregates. Measurements of SPM organic content in ebb water revealed that SPM was enriched in organic matter by up to 50% following interaction with the wetland. Newly formed aggregates were carried out to the estuary with the ebb tide. These results indicate that the Browns Island wetland (and presumably other similar wetlands throughout the San Francisco Bay-Delta) plays an important role in estuarine biogeochemistry and particle cycling because flocculated particles have higher settling velocities and optical properties than their component particles and will behave differently. The implications of these findings are relevant to several tidal wetland management concerns such as the maintenance of marsh elevation, the cycling and transport of contaminants, and water clarity.

Evolution of stable carbon-isotope compositions for methane and carbon dioxide in freshwater wetlands and other anaerobic environments

NASA Astrophysics Data System (ADS)

Hornibrook, Edward R. C.; Longstaffe, Frederick J.; Fyfe, William S.

2000-03-01

Two types of distribution for α C values are observed in anaerobic environments when δ 13C-ΣCO 2 and δ 13C-CH 4 values are measured across gradients of depth or age of organic debris. The type-I distribution involves a systematic increase in α C values with depth as a result of decreasing δ 13C-CH 4 and increasing δ 13C-ΣCO 2 values. This behavior corresponds to a progressive increase in the prevalence of methanogenesis by the CO 2 reduction pathway relative to acetate fermentation. Utilization of autotrophically formed acetate by methanogens would also cause an increase in α C values. The type-II distribution occurs when both δ 13C-CH 4 and δ 13C-ΣCO 2 values decrease with depth, resulting in approximately constant α C values. This condition corresponds with a strong dependence of methanogens on porewater ΣCO 2 as a carbon source by way of either the CO 2 reduction pathway or utilization of autotrophically formed acetate. Freshwater wetlands possess both types of α C value distribution. Wetlands with type-I distributions exhibit curves with slopes that vary probably as a function of deposition and preservation of labile organic carbon. An abundance of labile substrates in anaerobic soils yields steeper curves because aceticlastic methanogenesis predominates and δ 13C-CH 4 and δ 13C-CO 2 values are high. Diminished transfer of labile carbon to the methanogenic zone results in an increased prevalence of the CO 2 reduction pathway, yielding low δ 13C-CH 4 values and shallowly sloping curves. Aerobic oxidation of organic matter or decay involving sulfate reduction produces CO 2 with low δ 13C values, which also will contribute to shallowly sloping curves. The size of the dissolved CO 2 pool can influence the sensitivity of δ 13C-CO 2 values to change during methanogenesis. Regression curves of δ 13C-CH 4 and δ 13C-ΣCO 2 values from four wetlands with type-I distributions intersect at δ 13C-CH 4 = -40.7 ± 6.1‰ (1σ) and δ 13C-ΣCO 2 = -23.9 ± 4.8‰ (1σ). These values are similar to δ 13C values for methyl and carboxyl moieties within acetate produced by anaerobic degradation of fresh C 3 plant matter. A low abundance of acetate during aceticlastic methanogenesis will result in minimal expression of metabolic kinetic isotope effects (KIEs) and production of CH 4 and CO 2 with δ 13C values similar to the intramolecular distribution of sedimentary acetate. The type-II distribution is prevalent in marine environments, probably because of substrate depletion in the sulfate reduction zone. The type-I distribution does occur in marine settings where deposition rates of organic matter are high. Landfills possess only the type-I distribution of α C values and exhibit unusually steep curves, possibly because methanogenesis occurs predominantly from acetate produced by fermentation at mesophilic temperatures. The high abundance of acetate in landfill leachate may permit varying degrees of expression of the KIE associated with aceticlastic methanogenesis. Outgassing of 12CO 2 may contribute further to the steepening of α C curves in landfills and other anaerobic environments possessing a type-I distribution. Defining the type of α C distributions in different wetlands could reduce uncertainty in estimating the δ 13C value of CH 4 emissions. Hence, the prevalence of type-I vs. type-II α C distributions in wetlands may have practical importance for the refinement of global CH 4 budgets that rely on 13C/ 12C ratios for mass balance.

Throughfall and stemflow dynamics in a riparian cedar swamp: possible ecohydrological feedbacks

NASA Astrophysics Data System (ADS)

Duval, T. P.

2012-12-01

Partitioning of rainfall through forest canopies as throughfall and stemflow have deservedly been the subject of much research in the past; however, very little is known about the fluxes of water and solutes through forested wetland communities. Temperate swamps are characterized by intermittent canopy coverage, with areas that are denser than upland forests of similar species, but also contain canopy gaps of meadow and marsh communities,. Understanding the role of vegetation on the distribution of precipitation in these ecosystems is necessary to effectively constrain water balance estimates and predict possible community responses to shifting climate regimes. This study examines throughfall, stemflow, and interception dynamics in a riparian cedar swamp in Alliston, Ontario, Canada over the 2012 growing season. Throughfall averaged 76 % of above-canopy rainfall; however, there were spatial-magnitude interaction variations within the swamp. For events less than 20 mm, between 17 and 75 % of the measured swamp floor received greater depth of rain than above the canopy, whereas for events greater than 20 mm only between 2 and 23 % of the sampled swamp floor received more water than the actual event. The observed spatial variability in throughfall was not related to leaf area index, suggesting remote sensing modelling efforts may not be an accurate method for quantification of wetland precipitation dynamics. Stemflow along the predominantly cedar trees averaged 5 %; therefore, net precipitation on a seasonal basis in this cedar swamp was 81 % of above canopy rainfall. Throughfall DOC and total nitrogen concentrations averaged 31 and 2.2 mg/L, respectively, with stemflow DOC and TN concentrations averaging 109 and 6.5 mg/L, respectively. These values are much higher than reported for upland forest species. In general, throughfall magnitudes increased and solute concentrations decreased with increasing distance from the existing forest boles. The delivery of high reactive-solute concentrations through stemflow and comparatively reduced throughfall water fluxes closer to the trees may represent an ecohydrological feedback to cedar maintenance in swamp ecosystems by enriching the root zone soil with nutrients and shedding water away from the roots in a system where the presence of water is viewed as a stress to optimal growth.

Uncertainty In Greenhouse Gas Emissions On Carbon Sequestration In Coastal and Freshwater Wetlands of the Mississippi River Delta: A Subsiding Coastline as a Proxy for Future Global Sea Level

NASA Astrophysics Data System (ADS)

White, J. R.; DeLaune, R. D.; Roy, E. D.; Corstanje, R.

2014-12-01

The highly visible phenomenon of wetland loss in coastal Louisiana (LA) is examined through the prism of carbon accumulation, wetland loss and greenhouse gas (GHG) emissions. The Mississippi River Deltaic region experiences higher relative sea level rise due to coupled subsidence and eustatic sea level rise allowing this region to serve as a proxy for future projected golbal sea level rise. Carbon storage or sequestration in rapidly subsiding LA coastal marsh soils is based on vertical marsh accretion and areal change data. While coastal marshes sequester significant amount of carbon through vertical accretion, large amounts of carbon, previously sequested in the soil profile is lost through annual deterioration of these coastal marshes as well as through GHG emissions. Efforts are underway in Louisiana to access the carbon credit market in order to provide significant funding for coastal restoration projects. However, there is very large uncertainty on GHG emission rates related to both marsh type and temporal (daily and seasonal) effects. Very little data currently exists which addresses this uncertainty which can significantly affect the carbon credit value of a particular wetland system. We provide an analysis of GHG emission rates for coastal freshwater, brackish and and salt marshes compared to the net soil carbon sequestration rate. Results demonstrate that there is very high uncertainty on GHG emissions which can substantially alter the carbon credit value of a particular wetland system.

Assessing coastal plain wetland composition using advanced spaceborne thermal emission and reflection radiometer imagery

NASA Astrophysics Data System (ADS)

Pantaleoni, Eva

Establishing wetland gains and losses, delineating wetland boundaries, and determining their vegetative composition are major challenges that can be improved through remote sensing studies. We used the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) to separate wetlands from uplands in a study of 870 locations on the Virginia Coastal Plain. We used the first five bands from each of two ASTER scenes (6 March 2005 and 16 October 2005), covering the visible to the short-wave infrared region (0.52-2.185mum). We included GIS data layers for soil survey, topography, and presence or absence of water in a logistic regression model that predicted the location of over 78% of the wetlands. While this was slightly less accurate (78% vs. 86%) than current National Wetland Inventory (NWI) aerial photo interpretation procedures of locating wetlands, satellite imagery analysis holds great promise for speeding wetland mapping, lowering costs, and improving update frequency. To estimate wetland vegetation composition classes, we generated a classification and regression tree (CART) model and a multinomial logistic regression (logit) model, and compared their accuracy in separating woody wetlands, emergent wetlands and open water. The overall accuracy of the CART model was 73.3%, while for the logit model was 76.7%. The CART producer's accuracy of the emergent wetlands was higher than the accuracy from the multinomial logit (57.1% vs. 40.7%). However, we obtained the opposite result for the woody wetland category (68.7% vs. 52.6%). A McNemar test between the two models and NWI maps showed that their accuracies were not statistically different. We conducted a subpixel analysis of the ASTER images to estimate canopy cover of forested wetlands. We used top-of-atmosphere reflectance from the visible and near infrared bands, Delta Normalized Difference Vegetation Index, and a tasseled cap brightness, greenness, and wetness in linear regression model with canopy cover as the dependent variable. The model achieved an adjusted-R 2 of 0.69 (RMSE = 2.7%) for canopy cover less than 16%, and an adjusted-R 2 of 0.04 (RMSE = 19.8%) for higher canopy cover values. Taken together, these findings suggest that satellite remote sensing, in concert with other spatial data, has strong potential for mapping both wetland presence and type.

Water, sanitation and hygiene in wetlands. A case study from the Ewaso Narok Swamp, Kenya.

PubMed

Anthonj, Carmen; Rechenburg, Andrea; Kistemann, Thomas

2016-10-01

Wetlands can be both a blessing and a curse. They are beneficial sources of safe water and nutrition and places from which humans derive their livelihoods. At the same time, wetlands are known to be sources of disease-causing microorganisms and invertebrates that can threaten human health. Safe water, sanitation and personal hygiene (WASH) are crucial preconditions for the prevention of disease transmission. And of special importance for people living in wetlands, depending on and being exposed to them. WASH should be prioritized especially in those wetlands that are subject to intensive use, that have a poor sanitation infrastructure, and which at the same time only provide limited water resources. However, despite this critical importance, WASH in wetlands is not well characterized in literature. This study therefore aimed at providing insights into the water, sanitation and hygiene conditions and behavioural determinants of households in wetlands by presenting the case of a rural wetland in East Africa. The mixed method approach included a broad set of empirical data collected during a household survey (n=400), an observational WASH assessment (n=397) and in-depth interviews (n=20) conducted from January to March 2015 in Ewaso Narok Swamp in Kenya. Different user groups of the wetland were targeted. The study in Ewaso Narok Swamp showed that wetland users' water supply and storage, sanitation and personal hygiene conditions were inadequate for large parts of the community and significantly differed between groups. Whereas the WASH conditions of people working in the service sector were rather positive, for pastoralists, they were correspondingly negative. The WASH behaviour was also perceived to be inadequate influenced by a variety of determining factors. The observational index as applied in this study indicated to be a valuable, rapid and efficient tool for assessing domestic WASH and for detecting differences between different groups in wetlands. Combined with the quantitative and qualitative data, the approach served as a very helpful model to develop a multi-layered understanding of WASH conditions and related behaviour. The people in the researched wetland use by far less improved water sources and sanitation facilities than the nationwide average for rural populations. Since Ewaso Narok Swamp serves as a model case for the domestic WASH conditions in a rural wetland in semiarid East Africa, this fact make the study relevant not only at a national, but also at an international level. The results underline the previously formulated need of an integrative approach that first and foremost complements wetland management by public health interventions. In order to improve WASH conditions and to change behaviour in the long term, interventions should include the provision of clean water and sanitation infrastructure, as well as widespread health education. The approach proved to be useful for wetland environments and will be integrated into the development of a health impact assessment tool for wetlands. Moreover, it can be adopted in other contexts. Copyright © 2016 Elsevier GmbH. All rights reserved.

Natural infection of gastrointestinal nematodes in long-nosed armadillos Dasypus novemcinctus Linnaeus, 1758 from Pantanal wetlands, Aquidauana sub-region, Mato Grosso do Sul State, with the description of Hadrostrongylus speciosum n. gen. et n. sp. (Molineidae: Anoplostrongylinae).

PubMed

Lux Hoppe, Estevam G; do Nascimento, Adjair Antonio

2007-03-15

This study evaluated the gastrointestinal helminth fauna of long-nosed armadillos, Dasypus novemcinctus, from the Pantanal wetlands, Aquidauana sub-region, Aquidauana County, Mato Grosso do Sul State, Brazil. Thirteen species of nematodes, comprising seven genera and four families, were recovered from their gastrointestinal tracts. The following descriptors of infection were determined: prevalence, variation of intensity, average intensity and abundance. Hadrostrongylus speciosum n. gen. et n. sp. is first described here.

Relationships between landscape pattern, wetland characteristics, and water quality in agricultural catchments.

PubMed

Moreno-Mateos, David; Mander, Ulo; Comín, Francisco A; Pedrocchi, César; Uuemaa, Evelyn

2008-01-01

Water quality in streams is dependent on landscape metrics at catchment and wetland scales. A study was undertaken to evaluate the correlation between landscape metrics, namely patch density and area, shape, heterogeneity, aggregation, connectivity, land-use ratio, and water quality variables (salinity, nutrients, sediments, alkalinity, other potential pollutants and pH) in the agricultural areas of a semiarid Mediterranean region dominated by irrigated farmlands (NE Spain). The study also aims to develop wetland construction criteria in agricultural catchments. The percentage of arable land and landscape homogeneity (low value of Simpson index) are significantly correlated with salinity (r(2) = 0.72) and NO(3)-N variables (r(2) = 0.49) at catchment scale. The number of stock farms was correlated (Spearman's corr. = 0.60; p < 0.01) with TP concentration in stream water. The relative abundance of wetlands and the aggregation of its patches influence salinity variables at wetland scale (r(2) = 0.59 for Na(+) and K(+) concentrations). The number and aggregation of wetland patches are closely correlated to the landscape complexity of catchments, measured as patch density (r(2) = 0.69), patch size (r(2) = 0.53), and landscape heterogeneity (r(2) = 0.62). These results suggest that more effective results in water quality improvement would be achieved if we acted at both catchment and wetland scales, especially reducing landscape homogeneity and creating numerous wetlands scattered throughout the catchment. A set of guidelines for planners and decision makers is provided for future agricultural developments or to improve existing ones.

A Process-based, Climate-Sensitive Model to Derive Methane Emissions from Natural Wetlands: Application to 5 Wetland Sites, Sensitivity to Model Parameters and Climate

NASA Technical Reports Server (NTRS)

Walter, Bernadette P.; Heimann, Martin

1999-01-01

Methane emissions from natural wetlands constitutes the largest methane source at present and depends highly on the climate. In order to investigate the response of methane emissions from natural wetlands to climate variations, a 1-dimensional process-based climate-sensitive model to derive methane emissions from natural wetlands is developed. In the model the processes leading to methane emission are simulated within a 1-dimensional soil column and the three different transport mechanisms diffusion, plant-mediated transport and ebullition are modeled explicitly. The model forcing consists of daily values of soil temperature, water table and Net Primary Productivity, and at permafrost sites the thaw depth is included. The methane model is tested using observational data obtained at 5 wetland sites located in North America, Europe and Central America, representing a large variety of environmental conditions. It can be shown that in most cases seasonal variations in methane emissions can be explained by the combined effect of changes in soil temperature and the position of the water table. Our results also show that a process-based approach is needed, because there is no simple relationship between these controlling factors and methane emissions that applies to a variety of wetland sites. The sensitivity of the model to the choice of key model parameters is tested and further sensitivity tests are performed to demonstrate how methane emissions from wetlands respond to climate variations.

Environmental Quality and Aquatic Invertebrate Metrics Relationships at Patagonian Wetlands Subjected to Livestock Grazing Pressures.

PubMed

Epele, Luis Beltrán; Miserendino, María Laura

2015-01-01

Livestock grazing can compromise the biotic integrity and health of wetlands, especially in remotes areas like Patagonia, which provide habitat for several endemic terrestrial and aquatic species. Understanding the effects of these land use practices on invertebrate communities can help prevent the deterioration of wetlands and provide insights for restoration. In this contribution, we assessed the responses of 36 metrics based on the structural and functional attributes of invertebrates (130 taxa) at 30 Patagonian wetlands that were subject to different levels of livestock grazing intensity. These levels were categorized as low, medium and high based on eight features (livestock stock densities plus seven wetland measurements). Significant changes in environmental features were detected across the gradient of wetlands, mainly related to pH, conductivity, and nutrient values. Regardless of rainfall gradient, symptoms of eutrophication were remarkable at some highly disturbed sites. Seven invertebrate metrics consistently and accurately responded to livestock grazing on wetlands. All of them were negatively related to increased levels of grazing disturbance, with the number of insect families appearing as the most robust measure. A multivariate approach (RDA) revealed that invertebrate metrics were significantly affected by environmental variables related to water quality: in particular, pH, conductivity, dissolved oxygen, nutrient concentrations, and the richness and coverage of aquatic plants. Our results suggest that the seven aforementioned metrics could be used to assess ecological quality in the arid and semi-arid wetlands of Patagonia, helping to ensure the creation of protected areas and their associated ecological services.

Ground water recharge and discharge in the central Everglades

USGS Publications Warehouse

Harvey, Judson W.; Krupa, Steven L.; Krest, James M.

2004-01-01

Rates of ground water recharge and discharge are not well known in the central Everglades. Here we report estimates of ground water recharge and discharge at 15 sites in the Everglades Nutrient Removal Project and in Water Conservation Area 2A (WCA-2A), along with measurements of hydraulic properties of peat at 11 sites. A simple hydrogeologic simulation was used to assess how specific factors have influenced recharge and discharge. Simulations and measurements agreed that the highest values of recharge and discharge occur within 600 m of levees, the result of ground water flow beneath levees. There was disagreement in the interior wetlands of WCA-2A (located > 1000 m from levees) where measurements of recharge and discharge were substantially higher than simulated fluxes. A five-year time series (1997 to 2002) of measured fluxes indicated that recharge and discharge underwent reversals in direction on weekly, monthly, and annual timescales at interior sites in WCA-2A. Ground water discharge tended to occur during average to moderately dry conditions when local surface water levels were decreasing. Recharge tended to occur during moderately wet periods or during very dry periods just as water levels began to increase following precipitation or in response to a pulse of surface water released from water-control structures by water managers. Discharge also tended to occur at sites in the wetland interior for ∼1 week preceding the arrival of the surface water pulse. We conclude that ground water recharge and discharge vary cyclically in the interior wetlands of the central Everglades, driven by the differential responses of surface water and ground water to annual, seasonal, and weekly trends in precipitation and operation of water-control structures.

Habitat use and home range of the endangered gold-spotted pond frog (Rana chosenica).

PubMed

Ra, Nam-Yong; Sung, Ha-Cheol; Cheong, Seokwan; Lee, Jung-Hyun; Eom, Junho; Park, Daesik

2008-09-01

Because of their complex life styles, amphibians and reptiles living in wetlands require both aquatic and terrestrial buffer zones in their protected conservation areas. Due to steep declines in wild populations, the gold-spotted pond frog (Rana chosenica) is listed as vulnerable by the IUCN. However, lack of data about its movements and use of habitat prevents effective conservation planning. To determine the habitat use and home range of this species, we radio-tracked 44 adult frogs for 37 days between 10 July and 4 Nov. 2007 to observe three different populations in the breeding season, non-breeding season, and late fall. The gold-spotted pond frog was very sedentary; its daily average movement was 9.8 m. Frogs stayed close to breeding ponds (within 6.6 m), and did not leave damp areas surrounding these ponds, except for dormancy migration to terrestrial sites such as dried crop fields. The average distance of dormancy migration of seven frogs from the edge of their breeding ponds was 32.0 m. The average size of an individual's home range was 713.8 m(2) (0.07 ha). The year-round population home range, which accounts for the home ranges of a population of frogs, was determined for two populations to be 8,765.0 m(2) (0.88 ha) and 3,700.9 m(2) (0.37 ha). Our results showed that to conserve this endangered species, appropriately sized wetlands and extended terrestrial buffer areas surrounding the wetlands (at least 1.33 ha, diameter 130 m) should be protected.

The Brazilian freshwater wetscape: Changes in tree community diversity and composition on climatic and geographic gradients

PubMed Central

Wittmann, Florian; Marques, Márcia C. M.; Damasceno Júnior, Geraldo; Budke, Jean Carlos; Piedade, Maria T. F.; de Oliveira Wittmann, Astrid; Montero, Juan Carlos; de Assis, Rafael L.; Targhetta, Natália; Parolin, Pia; Junk, Wolfgang J.

2017-01-01

Wetlands harbor an important compliment of regional plant diversity, but in many regions data on wetland diversity and composition is still lacking, thus hindering our understanding of the processes that control it. While patterns of broad-scale terrestrial diversity and composition typically correlate with contemporary climate it is not clear to what extent patterns in wetlands are complimentary, or conflicting. To elucidate this, we consolidate data from wetland forest inventories in Brazil and examine patterns of diversity and composition along temperature and rainfall gradients spanning five biomes. We collated 196 floristic inventories covering an area >220 ha and including >260,000 woody individuals. We detected a total of 2,453 tree species, with the Amazon alone accounting for nearly half. Compositional patterns indicated differences in freshwater wetland floras among Brazilian biomes, although biomes with drier, more seasonal climates tended to have a larger proportion of more widely distributed species. Maximal alpha diversity increased with annual temperature, rainfall, and decreasing seasonality, patterns broadly consistent with upland vegetation communities. However, alpha diversity-climate relationships were only revealed at higher diversity values associated with the uppermost quantiles, and in most sites diversity varied irrespective of climate. Likewise, mean biome-level differences in alpha-diversity were unexpectedly modest, even in comparisons of savanna-area wetlands to those of nearby forested regions. We describe attenuated wetland climate-diversity relationships as a shifting balance of local and regional effects on species recruitment. Locally, excessive waterlogging strongly filters species able to colonize from regional pools. On the other hand, increased water availability can accommodate a rich community of drought-sensitive immigrant species that are able to track buffered wetland microclimates. We argue that environmental conditions in many wetlands are not homogeneous with respect to regional climate, and that responses of wetland tree communities to future climate change may lag behind that of non-wetland, terrestrial habitat. PMID:28394937

Diversity, distribution and hydrocarbon biodegradation capabilities of microbial communities in oil-contaminated cyanobacterial mats from a constructed wetland.

PubMed

Abed, Raeid M M; Al-Kharusi, Samiha; Prigent, Stephane; Headley, Tom

2014-01-01

Various types of cyanobacterial mats were predominant in a wetland, constructed for the remediation of oil-polluted residual waters from an oil field in the desert of the south-eastern Arabian Peninsula, although such mats were rarely found in other wetland systems. There is scarce information on the bacterial diversity, spatial distribution and oil-biodegradation capabilities of freshwater wetland oil-polluted mats. Microbial community analysis by Automated Ribosomal Spacer Analysis (ARISA) showed that the different mats hosted distinct microbial communities. Average numbers of operational taxonomic units (OTUsARISA) were relatively lower in the mats with higher oil levels and the number of shared OTUsARISA between the mats was <60% in most cases. Multivariate analyses of fingerprinting profiles indicated that the bacterial communities in the wetland mats were influenced by oil and ammonia levels, but to a lesser extent by plant density. In addition to oil and ammonia, redundancy analysis (RDA) showed also a significant contribution of temperature, dissolved oxygen and sulfate concentration to the variations of the mats' microbial communities. Pyrosequencing yielded 282,706 reads with >90% of the sequences affiliated to Proteobacteria (41% of total sequences), Cyanobacteria (31%), Bacteriodetes (11.5%), Planctomycetes (7%) and Chloroflexi (3%). Known autotrophic (e.g. Rivularia) and heterotrophic (e.g. Azospira) nitrogen-fixing bacteria as well as purple sulfur and non-sulfur bacteria were frequently encountered in all mats. On the other hand, sequences of known sulfate-reducing bacteria (SRBs) were rarely found, indicating that SRBs in the wetland mats probably belong to yet-undescribed novel species. The wetland mats were able to degrade 53-100% of C12-C30 alkanes after 6 weeks of incubation under aerobic conditions. We conclude that oil and ammonia concentrations are the major key players in determining the spatial distribution of the wetland mats' microbial communities and that these mats contribute directly to the removal of hydrocarbons from oil field wastewaters.

Integration of Palmer Drought Severity Index and remote sensing data to simulate wetland water surface from 1910 to 2009 in Cottonwood Lake area, North Dakota

USGS Publications Warehouse

Huang, Shengli; Dahal, Devendra; Young, Claudia; Chander, Gyanesh; Liu, Shuguang

2011-01-01

Spatiotemporal variations of wetland water in the Prairie Pothole Region are controlled by many factors; two of them are temperature and precipitation that form the basis of the Palmer Drought Severity Index (PDSI). Taking the 196 km2 Cottonwood Lake area in North Dakota as our pilot study site, we integrated PDSI, Landsat images, and aerial photography records to simulate monthly water surface. First, we developed a new Wetland Water Area Index (WWAI) from PDSI to predict water surface area. Second, we developed a water allocation model to simulate the spatial distribution of water bodies at a resolution of 30 m. Third, we used an additional procedure to model the small wetlands (less than 0.8 ha) that could not be detected by Landsat. Our results showed that i) WWAI was highly correlated with water area with an R2 of 0.90, resulting in a simple regression prediction of monthly water area to capture the intra- and inter-annual water change from 1910 to 2009; ii) the spatial distribution of water bodies modeled from our approach agreed well with the water locations visually identified from the aerial photography records; and iii) the R2 between our modeled water bodies (including both large and small wetlands) and those from aerial photography records could be up to 0.83 with a mean average error of 0.64 km2 within the study area where the modeled wetland water areas ranged from about 2 to 14 km2. These results indicate that our approach holds great potential to simulate major changes in wetland water surface for ecosystem service; however, our products could capture neither the short-term water change caused by intensive rainstorm events nor the wetland change caused by human activities.

Inferring tidal wetland stability from channel sediment fluxes: observations and a conceptual model

USGS Publications Warehouse

Ganju, Neil K.; Nidzieko, Nicholas J.; Kirwan, Matthew L.

2013-01-01

Anthropogenic and climatic forces have modified the geomorphology of tidal wetlands over a range of timescales. Changes in land use, sediment supply, river flow, storminess, and sea level alter the layout of tidal channels, intertidal flats, and marsh plains; these elements define wetland complexes. Diagnostically, measurements of net sediment fluxes through tidal channels are high-temporal resolution, spatially integrated quantities that indicate (1) whether a complex is stable over seasonal timescales and (2) what mechanisms are leading to that state. We estimated sediment fluxes through tidal channels draining wetland complexes on the Blackwater and Transquaking Rivers, Maryland, USA. While the Blackwater complex has experienced decades of degradation and been largely converted to open water, the Transquaking complex has persisted as an expansive, vegetated marsh. The measured net export at the Blackwater complex (1.0 kg/s or 0.56 kg/m2/yr over the landward marsh area) was caused by northwesterly winds, which exported water and sediment on the subtidal timescale; tidally forced net fluxes were weak and precluded landward transport of suspended sediment from potential seaward sources. Though wind forcing also exported sediment at the Transquaking complex, strong tidal forcing and proximity to a turbidity maximum led to an import of sediment (0.031 kg/s or 0.70 kg/m2/yr). This resulted in a spatially averaged accretion of 3.9 mm/yr, equaling the regional relative sea level rise. Our results suggest that in areas where seaward sediment supply is dominant, seaward wetlands may be more capable of withstanding sea level rise over the short term than landward wetlands. We propose a conceptual model to determine a complex's tendency toward stability or instability based on sediment source, wetland channel location, and transport mechanisms. Wetlands with a reliable portfolio of sources and transport mechanisms appear better suited to offset natural and anthropogenic loss.

Environmental control of methane fluxes over a Danish peatland

NASA Astrophysics Data System (ADS)

Herbst, M.; Ringgaard, R.; Friborg, T.; Soegaard, H.

2009-12-01

Reducing the greenhouse gas (GHG) emissions from natural and anthropogenic environments has become a key issue over the last decades. In Denmark the management of the wetlands is playing a key role in these attempts. The wetland area of Skjern Meadows in the western part of Denmark is one of the best known examples of peatland restauration in northern Europe. The valley of the Skjern river was restored in 2002, after it had been drained for about 35 years. A micrometeorological instrument mast was erected in the centre of the 2200 ha large area in the summer of 2008, in order to facilitate continuous eddy covariance measurements of the exchange of carbon dioxide and methane between the peatland and the atmosphere. A sonic anemometer (R3, Gill) was used together with a closed-path CO2 analyzer (LI-7000, Li-Cor) and a closed-path CH4 analyzer (DLT-100, Los Gatos). A measurement height of 7 m above the surface ensures that the observed eddy fluxes represent an average signal from the entire peatland. The first year of data collection confirmed the expectation that the area functions as a moderate CO2 sink, whilst it releases methane into the atmosphere. During a 12-months period starting in September 2008, the wetland removed 119 g CO2-C per m2 from the atmosphere and emitted 6 g CH4-C per m2. If the amount of the emitted CH4 is converted into CO2 equivalents, it remained lower than the annual CO2 uptake (188 versus 437 g CO2). This means that the restored peatland functions as a weak greenhouse gas sink, despite its methane production. Whilst the annual CO2 uptake at Skjern Meadows was similar to that reported by Friborg et al. (2003) for a Siberian wetland, the CH4 emission was much lower. The average CO2 and CH4 flux rates were both lower than those estimated for a Dutch wetland by Hendriks et al. (2007). The CH4 emission showed no particular diurnal pattern, but daily rates varied considerably throughout the year. This variability can be correlated to variations in the soil temperature, the water level and the carbon fixation rates of the vegetation. The highest CH4 emission rates with peak values around 160 mg m-2d-1 were observed in the late summer and early autumn of 2008, after the site had experienced a prolonged period of high rainfall while the temperature was still high. In contrast, CH4 emission rates never exceeded 20 mg m-2d-1 during the winter and the unusually dry spring of 2009. An exponential relationship was found between the soil temperature in 0.2 m depth and the methane flux into the atmosphere. A comparison of this relation with complementary observations from other studies indicates that a general temperature response function for the CH4 emission from northern peatlands can be developed. If such a response function can be validated for other sites as well, it would be a big step towards an improved predictability of the full greenhouse gas budget of northern peatlands in a changing climate. References: Friborg T, Søgaard H, Christensen TR, Lloyd CR, Panikov NS (2003) Siberian wetlands: Where a sink is a source. Geophys. Res. Letters, Vol. 30, No. 21, 2129. Hendriks DMD, van Huissteden J, Dolman AJ, van der Molen MK (2007) The full greenhouse gas balance of an abandoned peat meadow. Biogeosciences 4, 411-424.

Evapotranspiration from pilot-scale constructed wetlands planted with Phragmites australis in a Mediterranean environment.

PubMed

Milani, Mirco; Toscano, Attilio

2013-01-01

This article reports the results of evapotranspiration (ET) experiments carried out in Southern Italy (Sicily) in a pilot-scale constructed wetland (CW) made of a combination of vegetated (Phragmites australis) and unvegetated sub-surface flow beds. Domestic wastewater from a conventional wastewater treatment plant was used to fill the beds. Microclimate data was gathered from an automatic weather station close to the experimental plant. From June to November 2009 and from April to November 2010, ET values were measured as the amount of water needed to restore the initial volume in the beds after a certain period. Cumulative reference evapotranspiration (ET(0)) was similar to the cumulative ET measured in the beds without vegetation (ET(con)), while the Phragmites ET (ET (phr) ) was significantly higher underlining the effect of the vegetation. The plant coefficient of P. australis (K(p)) was very high (up to 8.5 in August 2009) compared to the typical K(c) for agricultural crops suggesting that the wetland environment was subjected to strong "clothesline" and "oasis" effects. According to the FAO 56 approach, K(p) shows different patterns and values in relation to growth stages correlating significantly to stem density, plant height and total leaves. The mean Water Use Efficiency (WUE) value of P. australis was quite low, about 2.27 g L(-1), probably due to the unlimited water availability and the lack of the plant's physiological adaptations to water conservation. The results provide useful and valid information for estimating ET rates in small-scale constructed wetlands since ET is a relevant issue in arid and semiarid regions. In these areas CW feasibility for wastewater treatment and reuse should also be carefully evaluated for macrophytes in relation to their WUE values.

Bathymetry and vegetation in isolated marsh and cypress wetlands in the northern Tampa Bay Area, 2000-2004

USGS Publications Warehouse

Haag, Kim H.; Lee, Terrie M.; Herndon, Donald C.

2005-01-01

Wetland bathymetry and vegetation mapping are two commonly used lines of evidence for assessing the hydrologic and ecologic status of expansive coastal and riverine wetlands. For small isolated freshwater wetlands, however, bathymetric data coupled with vegetation assessments are generally scarce, despite the prevalence of isolated wetlands in many regions of the United States and the recognized importance of topography as a control on inundation patterns and vegetation distribution. In the northern Tampa Bay area of west-central Florida, bathymetry was mapped and vegetation was assessed in five marsh and five cypress wetlands. These 10 isolated wetlands were grouped into three categories based on the effects of ground-water withdrawals from regional municipal well fields: natural (no effect), impaired (drier than natural), and augmented (wetlands with artificially augmented water levels). Delineation of the wetland perimeter was a critical component for estimating wetland-surface area and stored water volume. The wetland perimeter was delineated by the presence of Serenoa repens (the 'palmetto fringe') at 9 of the 10 sites. At the 10th site, where the palmetto fringe was absent, hydric-soils indicators were used to delineate the perimeter. Bathymetric data were collected using one or more techniques, depending on the physical characteristics of each wetland. Wetland stage was measured hourly using continuous stage recorders. Wetland vegetation was assessed semiannually for 2 1/2 years in fixed plots located at three distinct elevations. Vegetation assessments were used to determine the community composition and the relative abundance of obligate, facultative wet, and facultative species at each elevation. Bathymetry maps were generated, and stage-area and stage-volume relations were developed for all 10 wetlands. Bathymetric data sets containing a high density of data points collected at frequent and regular spatial intervals provided the most useful stage-area and stage-volume relations. Bathymetric maps of several wetlands also were generated using a low density of data points collected along transect lines or contour lines. In a comparative analysis of the three mapping approaches, stage-area and stage-volume relations based on transect data alone underestimated (by 50-100 percent over certain ranges of stage) the wetland area and volume compared to results using a high density of data points. Adding data points collected along one elevation contour below the wetland perimeter to the transect data set greatly improved the agreement of the resulting stage-area and stage-volume relations to the high-density mapping approach. Stage-area relations and routinely monitored stage data were used to compare and contrast the average flooded area in a natural marsh and an impaired marsh over a 2-year period. Vegetation assessments used together with flooded-area information provided the potential for extrapolating vegetation results from points or transects to wetlands as a whole. A comparison of the frequency of flooding of different areas of the wetland and the species composition in vegetation plots at different elevations indicated the dependence of vegetation on inundation frequency. Because of the broad tolerances of many wetlands plants to a range of inundation conditions, however, vegetation assessments alone provided less definitive evidence of the hydrologic differences between the two sites, and hydrologic changes occurring during the 2 years, than the flooded-area frequencies. Combining flooded-area frequencies with vegetation assessments could provide a more versatile and insightful approach for determining the ecological status of wetlands than using vegetation and stage data alone. Flooded-area frequencies may further provide a useful approach for assessing the ecological status of wetlands where historical vegetation surveys and stage data are lacking. Comparing the contemporary flooded-area frequencies a

Temporal variability of methane fluxes in West Siberian taiga bogs and its implications for estimating regional methane emission

NASA Astrophysics Data System (ADS)

Sabrekov, Alexander; Ilyasov, Danil; Terentieva, Irina; Glagolev, Mikhail; Maksyutov, Shamil

2017-04-01

The West Siberia Lowland (WSL) is the biggest peatland area in Eurasia and is situated in the high latitudes experiencing enhanced rate of climate change. During 2015-16 summer periods, seasonal measurements of methane emission were made at the field station «Mukhrino» in the WSL middle taiga zone. The study was made at 3 wetland ecosystem types covering 80% of the taiga wetland area: i) waterlogged hollows or depressed areas with water level above the moss surface, ii) oligotrophic hollows or depressed parts of bogs with water level beneath the moss surface, iii) forested bogs with dwarf shrubs-sphagnum vegetation. Seven series of measurements were made by a static chamber method in 2016 and four series - in 2015. In 2015, we observed non-typical weather conditions including early dry spring and short cold rainy summer. Oppositely, weather conditions in 2016 were closer to average long-term with warmer drier summer. Significant difference between these years allowed analyzing the temporal variability and its sources. Average methane flux rates from forested bogs were 0.57 mgCH4/m2/h in 2016 and 0.33 mgCH4/m2/h in 2015. Seasonal dynamic during both years had similar concave downward shape. The highest fluxes were observed in June and were corresponded to the highest WTL, the main limiting factor of emission from forested bogs. The lowest fluxes in July were related to the low WTL combining with the highest temperature of upper methanotrophy layer. Average methane flux rates from oligotrophic hollows were 7.18 mgCH4/m2/h in 2016 and 4.28 mgCH4/m2/h in 2015. Seasonal dynamic of methane emission was indistinct in 2015. On the contrary, in 2016 it had regular seasonal pattern with peak emissions in July, which were four times higher than in 2015. WTL was not the limiting factor for CH4 emission from oligotrophic hollows, because even in the driest ones it was only 10 cm below the surface. Thus, the difference between peak emissions in 2015 and 2016 was mainly related to the temperature, which was considerably higher in 2016. Average methane flux rates from waterlogged hollows were 2.19 mgCH4/m2/h in 2016 and 4.07 mgCH4/m2/h in 2015. Seasonal dynamic had prominent shape in both years, however, peak emissions were observed in different months. Overall, patterns of emission in these ecosystems had more complicate nature and needs future investigations. Regional methane emission was estimated using new wetland map by Terentieva et al. (2016). Seasonal dynamic data for 2015-16 years gave the regional flux of 161 and 1257 ktCH4/yr for forested bogs and oligotrophic hollows, respectively. Similar values were obtained using not seasonal dynamic but only flux medians for 2015-16 years. However, the usage of old dataset gave only 32 and 841 ktCH4/yr for forested bogs and oligotrophic hollows, respectively. Thus, seasonal dynamics data had lower impact on regional methane emission estimate comparing to interannual variability data. Terentieva, I.E., Glagolev, M.V., Lapshina, E.D., Sabrekov, A.F., Maksyutov, S. Mapping of West Siberian taiga wetland complexes using Landsat imagery: implications for methane emissions // Biogeosciences. 2016. V. 13. № 16. P. 4615-4626.

Temporal Data Fusion Approaches to Remote Sensing-Based Wetland Classification

NASA Astrophysics Data System (ADS)

Montgomery, Joshua S. M.

This thesis investigates the ecology of wetlands and associated classification in prairie and boreal environments of Alberta, Canada, using remote sensing technology to enhance classification of wetlands in the province. Objectives of the thesis are divided into two case studies, 1) examining how satellite borne Synthetic Aperture Radar (SAR), optical (RapidEye & SPOT) can be used to evaluate surface water trends in a prairie pothole environment (Shepard Slough); and 2) investigating a data fusion methodology combining SAR, optical and Lidar data to characterize wetland vegetation and surface water attributes in a boreal environment (Utikuma Regional Study Area (URSA)). Surface water extent and hydroperiod products were derived from SAR data, and validated using optical imagery with high accuracies (76-97% overall) for both case studies. High resolution Lidar Digital Elevation Models (DEM), Digital Surface Models (DSM), and Canopy Height Model (CHM) products provided the means for data fusion to extract riparian vegetation communities and surface water; producing model accuracies of (R2 0.90) for URSA, and RMSE of 0.2m to 0.7m at Shepard Slough when compared to field and optical validation data. Integration of Alberta and Canadian wetland classifications systems used to classify and determine economic value of wetlands into the methodology produced thematic maps relevant for policy and decision makers for potential wetland monitoring and policy development.

Simulation of Constructed Wetland in treating Wastewater using Fuzzy Logic Technique

NASA Astrophysics Data System (ADS)

Sudarsan, J. S.; Subramani, Sheekha; Rajan, Rajitha J.; Shah, Isha; Nithiyanantham, S.

2018-04-01

Constructed wetlands act as a natural alternative to conventional methods of wastewater treatment. CW are found effective in wastewater containing inorganic matter, organic matter, toxic compounds, metals, nitrogen, phosphorous, heavy metals, organic chemicals, and pathogens. The treatment efficiency by the adaptation of CWs in treatment process is achieved by a complex interaction between plants, microorganisms, soil matrix and substances in the wastewater. Constructed wetland treatment systems are engineered systems designed in such a manner that it could take advantages of those processes occurring in natural wetlands in treating the wastewater concerned, but in a more controlled environment. Petrochemical wastewater was the type of wastewater taken for the study. Characteristics of petrochemical wastewater mainly oil, Biological Oxygen Demand (BOD) and Chemical oxygen demand (COD) were selected for treatment in constructed wetland as they are predominant in petrochemical wastewater. The conventional methods followed in the treatment are chemical and biological treatment. In this study, a fuzzy model for water quality assessment has been developed and water quality index value was obtained. The experiment conducted and further analysis using fuzzy logic indicated that interpretation of certain imprecise data can be improved within fuzzy inference system (FIS). Based on the analysis, we could observe that Typha sp contained wetland cell showed greater efficiency in removal of parameters such as COD and BOD than Phragmites sp. wetland cell.

Megafauna and frozen soil: the drivers of atmospheric CH4 dynamics

NASA Astrophysics Data System (ADS)

Zimov, N.; Zimov, S. A.

2010-12-01

During the last deglaciation (LD) a strong increase in atmospheric methane (CH4) concentrations occurred simultaneously with a rise in Greenland temperatures indicating that in the north, during this time period, strong CH4 sources “awakened”, as additionally documented by the appearance of a strong gradient between northern (Greenland) and southern (Antarctica) hemisphere atmospheric CH4 concentrations. This rise could not be caused by wetland expansion. A reconstruction of peatland formation dynamics has indicated that wetlands on Earth were few in LD and only actively expanded 10,000 yr BP, after atmospheric CH4 concentrations began to decline. Destabilization of methane clathrates also could not be the source for atmospheric CH4 increase. Geological CH4 (including methane clathrates) has the highest deuterium content (δD) among all of the known sources of CH4 while atmospheric CH4 δD values determined for the LD were record low. To explain recorded atmospheric CH4 and its isotopic dynamics required a strong northern source, which was active only during the LD and that provided very low δD CH4 values. Such a source is permafrost thawing under anaerobic conditions (or better stated soils of mammoth steppe-tundra ecosystems). Permafrost thawing is the strongest, among known, wetland sources (usually over 100g CH4/m2yr) and has a unique isotopic signature (δD = -400 per mil (-338 to -479 per mil), δ13C = -73 per mil (-58 to -99 per mil)). The main sources of atmospheric CH4 have different isotopic signatures (δ13C, δD). The isotopic content of atmospheric CH4 is a simple function of the weight average for all of the sources. Inclusion of permafrost source into a budget model of the atmospheric methane and its isotopes allowed us to reconstruct the dynamics of methane’s main sources. Model indicated geological source to be negligible as in LGM so and in LD and Holocene. During the glaciation, the largest methane source was megafauna, whose 1.4-1.7 billion ton biomass was larger than the modern biomass of human and domestic animals combined. During the LD, the largest methane source was the thawing of steppe-tundra soils. During the Holocene the largest CH4 source was wetlands. All these estimates correspond with the scales of permafrost degradation in the LD, megafaunal extinction and increase in fire intensity derived from charcoal within stratigraphic columns.

Repeated fault rupture recorded by paleoenvironmental changes in a wetland sedimentary sequence ponded against the Alpine Fault, New Zealand

NASA Astrophysics Data System (ADS)

Clark, K.; Berryman, K. R.; Cochran, U. A.; Bartholomew, T.; Turner, G. M.

2010-12-01

At Hokuri Creek, in south Westland, New Zealand, an 18 m thickness of Holocene sediments has accumulated against the upthrown side of the Alpine Fault. Recent fluvial incision has created numerous exposures of this sedimentary sequence. At a decimetre to metre scale there are two dominant types of sedimentary units: clastic-dominated, grey silt packages, and organic-dominated, light brown peaty-silt units. These units represent repeated alternations of the paleoenvironment due to fault rupture over the past 7000 years. We have located the event horizons within the sedimentary sequence, and identified evidence to support earthquake-driven paleoenvironmental change (rather than climatic variability), and developed a model of paleoenvironmental changes over a typical seismic cycle. To quantitatively characterise the sediments we use high resolution photography, x-ray imaging, magnetic-susceptibility and total carbon analysis. To understand the depositional environment we used diatom and pollen studies. The organic-rich units have very low magnetic susceptibility and density values, with high greyscale and high total carbon values. Diatoms indicate these units represent stable wetland environments with standing water and predominantly in-situ organic material deposition. The clastic-rich units are characterised by higher magnetic susceptibility and density values, with low greyscale and total carbon. The clastic-rich units represent environments of flowing water and deep pond settings that received predominantly catchment-derived silt and sand. The event horizon is located at the upper contact of the organic-rich horizons. The event horizon contact marks a drastic change in hydrologic regime as fault rupture changed the stream base level and there was a synchronous influx of clastic sediment as the catchment responded to earthquake shaking. During the interseismic period the flowing-water environment gradually stabilised and returned to an organic-rich wetland. Such cycles were repeated 18 times at Hokuri Creek. Evidence that fault rupture was responsible for the cyclical paleoenvironmental changes at Hokuri Creek include: the average time period for each organic- and clastic-rich couplet to be deposited approximately equals the long-term average Alpine Fault recurrence interval, and the most recent events recorded at Hokuri correlate to an earthquake dated in paleoseismic trenches 100 km along strike; fault rupture is the only mechanism that can create accommodation space for 18 m of sediment to accumulate, and the sedimentary units can be traced from the outcrop to the fault trace and show tectonic deformation. The record of 18 fault rupture events at Hokuri Creek is one of the longest records of surface ruptures on a major plate boundary fault. High-resolution dating and statistical treatment of the radiocarbon data (Biasi et al., this meeting) has resulted in major advances in understanding the long-term behaviour of the Alpine Fault (Berryman et al., this meeting).

Synergizing green and gray infrastructures to increase water supply resilience in the Brazos River basin in Texas

NASA Astrophysics Data System (ADS)

Gao, H.; Yamazaki, D.; Finley, T.; Bohn, T. J.; Low, G.; Sabo, J. L.

2017-12-01

Water infrastructure lies at the heart of the challenges and opportunities of Integrated Water Resource Management (IWRM). Green infrastructure (e.g., wetlands restoration) presents an alternative to its hard-path counterpart - gray infrastructure, which often has external, economic and unmeasured ecological costs. But the science framework to prioritize green infrastructure buildout is nascent. In this study, we addressed this gap in Brazos River basin in Texas, in the context of corporate decisions to secure water supplies for various water stewardship objectives. We developed a physically-based tool to quantify the potential for wetland restoration to restore desired flows (hydrology), and a financial framework for comparing its cost-benefit with heightening an existing dam (conservation finance). Our framework has three components. First, we harnessed a topographic index (HAND) to identify the potential wetlands sites. Second, we coupled a land surface model (VIC) with a hydrodynamic model (CaMa-Flood) to investigate the effects of wetland size, location, and vegetation on hydrology. Finally, we estimated the net present value, indirect rate of return and payback period for green (wetlands) vs. gray (reservoir expansion) infrastructure. We found wetlands have more substantial impact on peak flow than baseflow. Interestingly, wetlands can improve baseflow reliability but not directly except with the largest (>400 km2) projects. Peak flow reduction volumes of wetlands if used as credits towards reservoir flood-control storage provide adequate conservation storage to deliver guaranteed reliability of baseflow. Hence, the synergy of existing dams with newly created wetlands offers a promising natural solution to increase water supply resilience, while green projects also generate revenue compared to their gray counterparts. This study demonstrates the possibility of using innovative engineering design to synergize green and gray infrastructures to convert water conflict to opportunities.

Estimation of Net Groundwater Recharge Using Natural Drawdown Events in Subtropical Isolated Wetland Ecosystems

NASA Astrophysics Data System (ADS)

Perkins, D. B.; Min, J.; Jawitz, J. W.

2008-12-01

Restoration of ditched and drained wetlands in the Lake Okeechobee basin, Florida, USA is currently under study for possible amelioration of anthropogenic phosphorus enrichment of the lake. To date most research in this area has focused on the biogeochemical role of these wetlands. Here we focus on the dynamic hydrology of these systems and the resulting control on biogeochemical cycling. Four depressional wetlands in the basin were monitored for approximately three years to understand the interaction between wetland surface water and adjacent upland groundwater system. A coupled hydrologic-biogeochemical model was created to evaluate restoration scenarios. Determining wetland-scale hydraulic conductivity was an important aspect of the hydrologic model. Based on natural drawdown events observed at wetland-upland well pairs, hydraulic conductivities of top sandy soil layers surrounding the isolated wetlands were calculated using the Dupuit equation under a constrained water budget framework. The drawdown-based hydraulic conductivity estimates of 1.1 to 18.7 m/d (geometric mean of 4.8 m/d) were about three times greater than slug test- based values (1.5 ± 1.1 m/d), which is consistent with scale-dependent expectations. Model-based net groundwater recharge rate at each depressional wetland was predicted based on the estimated hydraulic conductivities, which corresponded to 50 to 72% of rainfall in the same period. These variances appeared to be due to the relative difference of ditch bottom elevation controlling the surface runoff as well as the spatial heterogeneity of the sandy aquifer. Results from this study have implications for nutrient loads to Lake Okeechobee via groundwater as well as water quality monitoring and management strategies aimed to reduce solute export (especially P) from the upstream catchment area to Lake Okeechobee.

Time scales of change in chemical and biological parameters after engineered levee breaches adjacent to Upper Klamath and Agency Lakes, Oregon

USGS Publications Warehouse

Kuwabara, James S.; Topping, Brent R.; Carter, James L.; Wood, Tamara M.; Parcheso, Francis; Cameron, Jason M.; Asbill, Jessica R.; Carlson, Rick A.; Fend, Steven V.

2012-01-01

Eight sampling trips were coordinated after engineered levee breaches hydrologically reconnected both Upper Klamath Lake and Agency Lake, Oregon, to adjacent wetlands. The reconnection, by a series of explosive blasts, was coordinated by The Nature Conservancy to reclaim wetlands that had for approximately seven decades been leveed for crop production. Sets of nonmetallic porewater profilers (U.S. Patent 8,051,727 B1; November 8, 2011; http://www.uspto.gov/web/patents/patog/ week45/OG/html/1372-2/US08051727-20111108.html.) were deployed during these trips in November 2007, June 2008, May 2009, July 2009, May 2010, August 2010, June 2011, and July 2011 (table 1). Deployments temporally spanned the annual cyanophyte bloom of Aphanizomenon flos-aquae and spatially involved three lake and four wetland sites. Spatial and temporal variation in solute benthic flux was determined by the field team, using the profilers, over an approximately 4-year period beginning 3 days after the levee breaches. The highest flux to the water column of dissolved organic carbon (DOC) was detected in the newly flooded wetland, contrasting negative or insignificant DOC fluxes at adjacent lake sites. Over the multiyear study, DOC benthic fluxes dissipated in the reconnected wetlands, converging to values similar to those for established wetlands and to the adjacent lake (table 2). In contrast to DOC, benthic sources of soluble reactive phosphorus, ammonium, dissolved iron and manganese from within the reconnected wetlands were consistently elevated (that is, significant in magnitude relative to riverine and established-wetland sources) indicating a multi-year time scale for certain chemical changes after the levee breaches (table 2). Colonization of the reconnected wetlands by aquatic benthic invertebrates during the study trended toward the assemblages in established wetlands, providing further evidence of a multiyear transition of this area to permanent aquatic habitat (table 3). Both the lake and wetland benthic environments substantively contribute to macro- and micronutrients in the water column. Wetland areas undergoing restoration, and those being used for water storage, function very differently relatively to the established wetland within the Upper Klamath Lake National Wildlife Refuge, adjacent Upper Klamath Lake. Developing long-term management strategies for water quality in the Upper Klamath Basin requires recognition of the multi-year time scales associated with restoring wetlands that provide natural, seasonal ecosystem function and services.

Sediment Carbon Accumulation in Southern Latitude Saltmarsh Communities of Tasmania, Australia.

PubMed

Ellison, Joanna C; Beasy, Kim M

2018-05-02

Carbon sequestration values of wetlands are greatest in their sediments. Northern hemisphere research dominates the earlier saltmarsh carbon sequestration literature, recently augmented by analyses across mainland Australia where species assemblages, catchment histories and environmental settings differ. No previous assessment has been made for Tasmania. Carbon stores and accumulation rates in saltmarsh sediments of the Rubicon estuary, Tasmania, were investigated. Carbon was determined from sediment cores by Elemental Analyser, combined with analysis of organic content and bulk density. Carbon accumulation was determined using short-term and long-term sediment accretion indicators. Results showed carbon densities to be lower than global averages, with variation found between carbon stores of native and introduced species zones. Cores from introduced Spartina anglica indicated a trend of higher sediment carbon percentages relative to cores from native saltmarsh Juncus kraussii and Sarcocornia quinqueflora , and in finer grain sizes. Sediment carbon stock of 30 cm depths was 49.5 Mg C ha −1 for native saltmarsh and 55.5 Mg C ha −1 for Spartina . Carbon percentages were low owing to high catchment inorganic sediment yields, however carbon accumulation rates were similar to global averages, particularly under Spartina . Covering 85% of saltmarsh area in the estuary, Spartina contributes the majority to carbon stores, potentially indicating a previously unrecognized value for this invasive species in Australia.

Wastewater polishing by a channelized macrophyte-dominated wetland and anaerobic digestion of the harvested phytomass.

PubMed

Cohen, Michael F; Hare, Caden; Kozlowski, John; McCormick, Rachel S; Chen, Lily; Schneider, Linden; Parish, Meghan; Knight, Zane; Nelson, Timothy A; Grewell, Brenda J

2013-01-01

Constructed wetlands (CW) offer a mechanism to meet increasingly stringent regulatory standards for wastewater treatment while minimizing energy inputs. Additionally, harvested wetland phytomass subjected to anaerobic digestion can serve as a source of biogas methane. To investigate CW wastewater polishing activities and potential energy yield we constructed a pair of secondary wastewater-fed channelized CW modules designed to retain easily harvestable floating aquatic vegetation and maximize exposure of water to roots and sediment. Modules that were regularly harvested averaged a nitrate removal rate of 1.1 g N m(-2) d(-1); harvesting, sedimentation and gasification were responsible for 30.5%, 8.0% and 61.5% of the N losses, respectively. Selective harvesting of a module to maintain dominance of filamentous algae had no effect on nitrate removal rate but lowered productivity by one-half. The average monthly productivity for unselectively harvested modules was 9.3 ± 1.7 g dry wt. m(-2) d(-1) (±SE). Cessation of harvesting in one module resulted in a significant increase in nitrate removal rate and decrease in phosphate removal rate. Compared to the influent, the effluent of the harvested module had significantly lower levels of estrogenic activity, as determined by a quantitative PCR-based juvenile trout bioassay, and significantly lower densities of E. coli. In mixed vertical-flow reactors anaerobic co-digestion of equal dry weight proportions of harvested aquatic vegetation, wine yeast lees and dairy manure was greatly improved when the manure was replaced with the crude glycerol by-product of biodiesel production. Remaining solids were vermicomposted for use as a soil amendment. Our results indicate that incorporation of constructed wetlands into an integrated treatment system can simultaneously enhance the economic and energetic feasibility of wastewater and organic waste treatment processes.

Sulfur transformations in pilot-scale constructed wetland treating high sulfate-containing contaminated groundwater: a stable isotope assessment.

PubMed

Wu, Shubiao; Jeschke, Christina; Dong, Renjie; Paschke, Heidrun; Kuschk, Peter; Knöller, Kay

2011-12-15

Current understanding of the dynamics of sulfur compounds inside constructed wetlands is still insufficient to allow a full description of processes involved in sulfur cycling. Experiments in a pilot-scale horizontal subsurface flow constructed wetland treating high sulfate-containing contaminated groundwater were carried out. Application of stable isotope approach combined with hydro-chemical investigations was performed to evaluate the sulfur transformations. In general, under inflow concentration of about 283 mg/L sulfate sulfur, sulfate removal was found to be about 21% with a specific removal rate of 1.75 g/m(2)·d. The presence of sulfide and elemental sulfur in pore water about 17.3 mg/L and 8.5 mg/L, respectively, indicated simultaneously bacterial sulfate reduction and re-oxidation. 70% of the removed sulfate was calculated to be immobilized inside the wetland bed. The significant enrichment of (34)S and (18)O in dissolved sulfate (δ(34)S up to 16‰, compared to average of 5.9‰ in the inflow, and δ(18)O up to 13‰, compared to average of 6.9‰ in the inflow) was observed clearly correlated to the decrease of sulfate loads along the flow path through experimental wetland bed. This enrichment also demonstrated the occurrence of bacterial sulfate reduction as well as demonstrated by the presence of sulfide in the pore water. Moreover, the integral approach shows that bacterial sulfate reduction is not the sole process controlling the isotopic composition of dissolved sulfate in the pore water. The calculated apparent enrichment factor (ɛ = -22‰) for sulfur isotopes from the δ(34)S vs. sulfate mass loss was significantly smaller than required to produce the observed difference in δ(34)S between sulfate and sulfide. It indicated some potential processes superimposing bacterial sulfate reduction, such as direct re-oxidation of sulfide to sulfate by oxygen released from plant roots and/or bacterial disproportionation of elemental sulfur. Furthermore, 41% of residual sulfate was calculated to be from sulfide re-oxidation, which demonstrated that the application of stable isotope approach combined with the common hydro-chemical investigations is not only necessary for a general qualitative evaluation of sulfur transformations in constructed wetlands, but also leads to a quantitative description of intermediate processes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Case Study: Sensitivity Analysis of the Barataria Basin Barrier Shoreline Wetland Value Assessment Model

DTIC Science & Technology

2014-07-01

wetlands in providing resting, foraging , breeding, and nursery habitat to a diverse assemblage of fish and wildlife species in coastal Louisiana (EWG...services, including fish and wildlife production, storm damage reduction, and recreation. Federal, state, and local partners have jointly pursued large...habitat units” (HU) provided by a given alternative. Whereas traditional HEP models focused on specific taxa, WVA assesses the fish and wildlife community

Modeling sediment accumulation in North American playa wetlands in response to climate change, 1940-2100

USGS Publications Warehouse

Burris, Lucy; Skagen, Susan K.

2013-01-01

Playa wetlands on the west-central Great Plains of North America are vulnerable to sediment infilling from upland agriculture, putting at risk several important ecosystem services as well as essential habitats and food resources of diverse wetland-dependent biota. Climate predictions for this semi-arid area indicate reduced precipitation which may alter rates of erosion, runoff, and sedimentation of playas. We forecasted erosion rates, sediment depths, and resultant playa wetland depths across the west-central Great Plains and examined the relative roles of land use context and projected changes in precipitation in the sedimentation process. We estimated erosion with the Revised Universal Soil Loss Equation (RUSLE) using historic values and downscaled precipitation predictions from three general circulation models and three emissions scenarios. We calibrated RUSLE results using field sediment measurements. RUSLE is appealing for regional scale modeling because it uses climate forecasts with monthly resolution and other widely available values including soil texture, slope and land use. Sediment accumulation rates will continue near historic levels through 2070 and will be sufficient to cause most playas (if not already filled) to fill with sediment within the next 100 years in the absence of mitigation. Land use surrounding the playa, whether grassland or tilled cropland, is more influential in sediment accumulation than climate-driven precipitation change.

Photoinduced degradation of carbaryl in a wetland surface water.

PubMed

Miller, Penney L; Chin, Yu-Ping

2002-11-06

The photoinduced degradation of carbaryl (1-naphthyl-N-methyl carbamate) was studied in a wetland's surface water to examine the photochemical processes influencing its transformation. For this particular wetland water, at high pH, it was difficult to delineate the photolytic contribution to the overall degradation of carbaryl. At lower pH values, the extent of the degradation attributable to indirect pathways, that is, in the presence of naturally occurring photosensitizers, increased significantly. Moreover, the photoenhanced degradation at the lower pH values was found to be seasonally and spatially dependent. Analysis of water samples revealed two primary constituents responsible for the observed indirect photolytic processes: nitrate and dissolved natural organic matter (NOM). Nitrate in the wetland appears at high concentrations (> or =1 mM) seasonally after the application of fertilizers in the watershed and promotes contaminant destruction through the photochemical production of the hydroxyl radical (HO*). The extent of the observed indirect photolysis pathway appears to be dependent upon the concentration of nitrates and the presence of HO* scavengers such as dissolved NOM and carbonate alkalinity. Paradoxically, during low-nitrate events (<50 microM), NOM becomes the principal photosensitizer through either the production of HO*, direct energy transfer from the excited triplet state, and/or production of an unidentified transient species.

Pool spacing, channel morphology, and the restoration of tidal forested wetlands of the Columbia River, U.S.A.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Diefenderfer, Heida L.; Montgomery, David R.

2008-10-09

Tidal forested wetlands have sustained substantial areal losses, and restoration practitioners lack a description of many ecosystem structures associated with these late-successional systems in which surface water is a significant controlling factor on the flora and fauna. The roles of large woody debris in terrestrial and riverine ecosystems have been well described compared to functions in tidal areas. This study documents the role of large wood in forcing channel morphology in Picea-sitchensis (Sitka spruce) dominated freshwater tidal wetlands in the floodplain of the Columbia River, U.S.A. near the Pacific coast. The average pool spacing documented in channel surveys of threemore » freshwater tidal forested wetlands near Grays Bay were 2.2 ± 1.3, 2.3 ± 1.2, and 2.5 ± 1.5. There were significantly greater numbers of pools on tidal forested wetland channels than on a nearby restoration site. On the basis of pool spacing and the observed sequences of log jams and pools, the tidal forested wetland channels were classified consistent with a forced step-pool class. Tidal systems, with bidirectional flow, have not previously been classified in this way. The classification provides a useful basis for restoration project design and planning in historically forested tidal freshwater areas, particularly in regard to the use of large wood in restoration actions and the development of pool habitats for aquatic species. Significant modifications by beaver on these sites warrant further investigation to explore the interactions between these animals and restoration actions affecting hydraulics and channel structure in tidal areas.« less

Are the traditional large-scale drought indices suitable for shallow water wetlands? An example in the Everglades.

PubMed

Zhao, Dehua; Wang, Penghe; Zuo, Jie; Zhang, Hui; An, Shuqing; Ramesh, Reddy K

2017-08-01

Numerous drought indices have been developed over the past several decades. However, few studies have focused on the suitability of indices for studies of ephemeral wetlands. The objective is to answer the following question: can the traditional large-scale drought indices characterize drought severity in shallow water wetlands such as the Everglades? The question was approached from two perspectives: the available water quantity and the response of wetland ecosystems to drought. The results showed the unsuitability of traditional large-scale drought indices for characterizing the actual available water quantity based on two findings. (1) Large spatial variations in precipitation (P), potential evapotranspiration (PE), water table depth (WTD) and the monthly water storage change (SC) were observed in the Everglades; notably, the spatial variation in SC, which reflects the monthly water balance, was 1.86 and 1.62 times larger than the temporal variation between seasons and between years, respectively. (2) The large-scale water balance measured based on the water storage variation had an average indicating efficiency (IE) of only 60.01% due to the redistribution of interior water. The spatial distribution of variations in the Normalized Different Vegetation Index (NDVI) in the 2011 dry season showed significantly positive, significantly negative and weak correlations with the minimum WTD in wet prairies, graminoid prairies and sawgrass wetlands, respectively. The significant and opposite correlations imply the unsuitability of the traditional large-scale drought indices in evaluating the effect of drought on shallow water wetlands. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhanced P, N and C removal from domestic wastewater using constructed wetland employing construction solid waste (CSW) as main substrate.

PubMed

Yang, Y; Wang, Z M; Liu, C; Guo, X C

2012-01-01

Construction solid waste (CSW), an inescapable by-product of the construction and demolition process, was used as main substrate in a four-stage vertical subsurface flow constructed wetland system to improve phosphorus P removal from domestic wastewater. A 'tidal flow' operation was also employed in the treatment system. Under a hydraulic loading rate (HLR) of 0.76 m3/m2 d for 1st and 3rd stage and HLR of 0.04 m3/m2 d for 2nd and 4th stage of the constructed wetland system respectively and tidal flow operation strategy, average removal efficiencies of 99.4% for P, 95.4% for ammoniacal-nitrogen, 56.5% for total nitrogen and 84.5% for total chemical oxygen demand were achieved during the operation period. The CSW-based constructed wetland system presents excellent P removal performance. The adoption of tidal flow strategy creates the aerobic/anoxic condition intermittently in the treatment system. This can achieve better oxygen transfer and hence lead to more complete nitrification and organic matter removal and enhanced denitrification. Overall, the CSW-based tidal flow constructed wetland system holds great promise for enabling high rate removal of P, ammoniacal-nitrogen and organic matter from domestic wastewater, and transforms CSW from a waste into a useful material.

Effects of vegetation management in constructed wetland treatment cells on water quality and mosquito production

USGS Publications Warehouse

Thullen, J.S.; Sartoris, J.J.; Nelson, S.M.

2002-01-01

The impact of three vegetation management strategies on wetland treatment function and mosquito production was assessed in eight free water surface wetland test cells in southern California during 1998–1999. The effectiveness of the strategies to limit bulrush Schoenoplectus californicus culm density within the cells was also investigated. Removing accumulated emergent biomass and physically limiting the area in which vegetation could reestablish, significantly improved the ammonia–nitrogen removal efficiency of the wetland cells, which received an ammonia-dominated municipal wastewater effluent (average loading rate=9.88 kg/ha per day NH4-N). We determined that interspersing open water with emergent vegetation is critical for maintaining the wetland's treatment capability, particularly for systems high in NH4-N. Burning aboveground plant parts and thinning rhizomes only temporarily curtailed vegetation proliferation in shallow zones, whereas creating hummocks surrounded by deeper water successfully restricted the emergent vegetation to the shallower hummock areas. Since the hummock configuration kept open water areas interspersed throughout the stands of emergent vegetation, the strategy was also effective in reducing mosquito production. Decreasing vegetation biomass reduced mosquito refuge areas while increasing mosquito predator habitat. Therefore, the combined goals of water quality improvement and mosquito management were achieved by managing the spatial pattern of emergent vegetation to mimic an early successional growth stage, i.e. actively growing plants interspersed with open water.

Effects of vegetation management in constructed wetland treatment cells on water quality and mosquito production

USGS Publications Warehouse

Thullen, J.S.; Sartoris, J.J.; Walton, W.E.

2002-01-01

The impact of three vegetation management strategies on wetland treatment function and mosquito production was assessed in eight free water surface wetland test cells in southern California during 1998-1999. The effectiveness of the strategies to limit bulrush Schoenoplectus californicus culm density within the cells was also investigated. Removing accumulated emergent biomass and physically limiting the area in which vegetation could reestablish, significantly improved the ammonia - nitrogen removal efficiency of the wetland cells, which received an ammonia-dominated municipal wastewater effluent (average loading rate = 9.88 kg/ha per day NH4-N). We determined that interspersing open water with emergent vegetation is critical for maintaining the wetland's treatment capability, particularly for systems high in NH4-N. Burning aboveground plant parts and thinning rhizomes only temporarily curtailed vegetation proliferation in shallow zones, whereas creating hummocks surrounded by deeper water successfully restricted the emergent vegetation to the shallower hummock areas. Since the hummock configuration kept open water areas interspersed throughout the stands of emergent vegetation, the strategy was also effective in reducing mosquito production. Decreasing vegetation biomass reduced mosquito refuge areas while increasing mosquito predator habitat. Therefore, the combined goals of water quality improvement and mosquito management were achieved by managing the spatial pattern of emergent vegetation to mimic an early successional growth stage, i.e. actively growing plants interspersed with open water. ?? 2002 Elsevier Science B.V. All rights reserved.

Hematologic and plasma biochemical reference intervals for Morelet's crocodiles (Crocodylus moreletii) in the northern wetlands of Campeche, Mexico.

PubMed

Padilla, Sergio E; Weber, Manuel; Jacobson, Elliott R

2011-07-01

Health surveys and hematologic and plasma biochemical analyses were conducted in 52 free-ranging and 51 captive Morelet's crocodiles (Crocodylus moreletii) in Campeche, Mexico, March-September 2007. Blood samples from 92 crocodiles (45 free-ranging and 47 captive) were collected for hematologic and plasma biochemical analyses. Average values of erythrocytes of free-ranging crocodiles were 1,046,166 cells/μl, and total white cells were 1.03 × 10(4) cells/μl. Captive crocodiles had erythrocyte and leukocyte values of 1,100,416 cells/μl and 8.51 × 10(3) cells/μl, respectively. There were no significant differences in values of erythrocytes or in hematocrit between free-ranging and captive crocodiles, or between sexes, or among size classes. Counts of leukocytes in free-ranging crocodiles were significantly higher than in captive individuals. The mean values of plasma analytes were 69.55 mg/l (glucose), 250.14 mg/l (cholesterol), 3.04 mg/l (uric acid), 2.70 mg/l (creatinine), and 20.20 IU/l (alanine aminotransferase). There were significant differences in cholesterol between free-ranging and captive crocodiles and between sexes.