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1

Vegetation establishment and evolution in four ponds that received sewage and wastewater in a portion of the Olezoa wetland complex, Yaounde, Cameroon, central Africa  

SciTech Connect

A study of the spatial and temporal changes in the pattern and distribution of tropical wetland vegetation in four ponds that received sewage and wastewater discharge, was undertaken for a small wetland ecosystem in the Olezoa drainage basin in Yaounde, Cameroon. More than 25 years of nutrient loading has led to the eutrophication and subsequent establishment of wetland vegetation in these ponds. Estimated free water surface areas of the ponds in 1964, 1976, and 1986 and 1992 determined from digitized aerial photographs and field measurements suggests a decline of 70 to 100% in the pond surface areas due to invasion and colonization by plants. The rate of pond surface decline and vegetation development is correlated with the construction of sewage plants and the discharge of untreated sewage and wastewater into the ponds. The main wetland plants that are established in the ponds consist of aquatic species Nymphae lotus, Enhydra fluctuants, Pistia stratiotes, Commelina sp., Ipomea aquatica and terrestrial species Echinochloa sp., Thalia welwitschii, Polygonum senegalense, Leersia haxandra and Cyperus papyrus. The pattern of wetland plant succession that resulted within each pond is correlated to the timing, duration and magnitude of sewage and wastewater discharge into the wetland complex.

Atekwana, E.A. (Western Michigan Univ., Kalamazoo, MI (United States). Dept. of Geology); Agendia, P.L. (Univ. of Yaounde (Cameroon). Dept. of Plant Biology)

1994-04-01

2

Disturbance metrics predict a wetland Vegetation Index of Biotic Integrity  

USGS Publications Warehouse

Indices of biological integrity of wetlands based on vascular plants (VIBIs) have been developed in many areas in the USA. Knowledge of the best predictors of VIBIs would enable management agencies to make better decisions regarding mitigation site selection and performance monitoring criteria. We use a novel statistical technique to develop predictive models for an established index of wetland vegetation integrity (Ohio VIBI), using as independent variables 20 indices and metrics of habitat quality, wetland disturbance, and buffer area land use from 149 wetlands in Ohio, USA. For emergent and forest wetlands, predictive models explained 61% and 54% of the variability, respectively, in Ohio VIBI scores. In both cases the most important predictor of Ohio VIBI score was a metric that assessed habitat alteration and development in the wetland. Of secondary importance as a predictor was a metric that assessed microtopography, interspersion, and quality of vegetation communities in the wetland. Metrics and indices assessing disturbance and land use of the buffer area were generally poor predictors of Ohio VIBI scores. Our results suggest that vegetation integrity of emergent and forest wetlands could be most directly enhanced by minimizing substrate and habitat disturbance within the wetland. Such efforts could include reducing or eliminating any practices that disturb the soil profile, such as nutrient enrichment from adjacent farm land, mowing, grazing, or cutting or removing woody plants.

Stapanian, Martin A.; Mack, John; Adams, Jean V.; Gara, Brian; Micacchion, Mick

2013-01-01

3

FLUVIAL DISTURBANCE AND WETLAND VEGETATION DEVELOPMENT, UPPER MAIN STEM, WILLAMETTE RIVER, OREGON, USA  

EPA Science Inventory

Hydrogeomorphic processes drive vegetation establishment, and promote development of diverse wetland and riparian types associated with lotic ecosystems. The main objective of this study was to estimate the rate and pattern of vegetation development on bars tracked since 1936, a...

4

Evaluating Vegetation in the National Wetland Condition Assessment  

EPA Science Inventory

Vegetation is a key biotic indicator of wetland ecological condition and forms a critical element of the USEPA 2011 National Wetland Condition Assessment. Data describing plant species composition and abundance, vegetation structure, and ground surface characteristics were colle...

5

Vegetation Mapping in Lake Champlain Wetlands.  

National Technical Information Service (NTIS)

Detailed canopy vegetation maps at a scale of 1:20,000 have been produced for two major wetlands in the Missisquoi and Lamoille River Deltas of the Lake Champlain Basin, based on the interpretation of medium-high altitude color aerial photography. Photo i...

A. O. Lind W. G. Howland

1975-01-01

6

Vegetation Communities of 20-year-old Created Depressional Wetlands  

Microsoft Academic Search

Many studies have chronicled the early development of vegetation in wetlands created as mitigation for wetland impacts; however, very few studies have followed the floristics of wetlands that are more than 10 years post-creation. This article reports the results of vegetation composition and structural analysis within eleven 20-yr-old created non-tidal, emergent wetlands. Vegetation and inundation were sampled in 173 plots within

Robert B. Atkinson; James E. Perry; John Cairns Jr

2005-01-01

7

Vegetative Nutrient Pools in a Constructed Wetland in Southeastern Idaho  

Microsoft Academic Search

We examined the vegetative pools of carbon (C), nitrogen (N), and phosphorus (P) in constructed wetlands receiving irrigation return flows in southeastern Idaho. Seven native wetland plant species were introduced into the wetlands in 1999. Carex nebrascensis, Eleocharis palustris, Juncus balticus, and Scheonoplectus maritimus were planted in replicate wetland meadows (primary filters), and Scheonoplectus acutus, Scheonoplectus pungens, and Typha latifolia

Andrew M. Ray; Richard S. Inouye

2006-01-01

8

Vegetation establishment success in restored carolina bay depressions on the Savannah River Site, South Carolina - phase one  

Microsoft Academic Search

Successful wetlands restoration must re-establish or enhance three parameters: wetland hydrology, hydric soils, and hydrophytic vegetation (Mitsch and Gosselink 2000). On the Savannah River Site, South Carolina, restoration of small Carolina bay depression-wetlands was initiated in FY 2001 to provide wetland acreage for mitigation banking (US DOE 1997). Sixteen small depressions that had historically been drained for agricultural purposes were

Sharitz; A. Rebecca; John Mulhouse

2004-01-01

9

Vegetation survey of PEN Branch wetlands  

SciTech Connect

A survey was conducted of vegetation along Pen Branch Creek at Savannah River Site (SRS) in support of K-Reactor restart. Plants were identified to species by overstory, understory, shrub, and groundcover strata. Abundance was also characterized and richness and diversity calculated. Based on woody species basal area, the Pen Branch delta was the most impacted, followed by the sections between the reactor and the delta. Species richness for shrub and groundcover strata were also lowest in the delta. No endangered plant species were found. Three upland pine areas were also sampled. In support of K Reactor restart, this report summarizes a study of the wetland vegetation along Pen Branch. Reactor effluent enters Indian Grove Branch and then flows into Pen Branch and the Pen Branch Delta.

Not Available

1991-01-01

10

Vegetation and environmental conditions in recently restored wetlands in the prairie pothole region of the USA  

Microsoft Academic Search

How closely the vegetation of restored wetlands resembles that of comparable natural wetlands is a function of the probability of propagules of wetland species reaching reflooded wetlands and how similar environmental conditions in the restored wetland are those in the natural wetlands. Three years after reflooding, we examined the vegetation composition, water level fluctuations, soil organic carbon content, and soil

Susan M. Galatowitsch; Arnold G. van der Valk

1996-01-01

11

Metric Similarity in Vegetation-Based Wetland Assessment Methods  

EPA Science Inventory

Wetland vegetation is a recognized indicator group for wetland assessments, but until recently few published protocols used plant-based indicators. To examine the proliferation of such protocols since 1999, this report reviewed 20 published index of biotic integrity (IBI) type p...

12

Classification of Wetlands Vegetation Using Small Scale Color Infrared Imagery.  

National Technical Information Service (NTIS)

A classification system for Chesapeake Bay wetlands was derived from the correlation of film density classes and actual vegetation classes. The data processing programs used were developed by the Laboratory for the Applications of Remote Sensing. These pr...

F. S. L. Williamson

1975-01-01

13

Changes in the Vegetation Cover in a Constructed Wetland at Argonne National Laboratory, Illinois  

SciTech Connect

Wetlands are valuable resources that are disappearing at an alarming rate. Land development has resulted in the destruction of wetlands for approximately 200 years. To combat this destruction, the federal government passed legislation that requires no net loss of wetlands. The United States Army Corps of Engineers (USACE) is responsible for regulating wetland disturbances. In 1991, the USACE determined that the construction of the Advanced Photon Source at Argonne National Laboratory would damage three wetlands that had a total area of one acre. Argonne was required to create a wetland of equal acreage to replace the damaged wetlands. For the first five years after this wetland was created (1992-1996), the frequency of plant species, relative cover, and water depth was closely monitored. The wetland was not monitored again until 2002. In 2003, the vegetation cover data were again collected with a similar methodology to previous years. The plant species were sampled using quadrats at randomly selected locations along transects throughout the wetland. The fifty sampling locations were monitored once in June and percent cover of each of the plant species was determined for each plot. Furthermore, the extent of standing water in the wetland was measured. In 2003, 21 species of plants were found and identified. Eleven species dominated the wetland, among which were reed canary grass (Phalaris arundinacea), crown vetch (Coronilla varia), and Canada thistle (Cirsium arvense). These species are all non-native, invasive species. In the previous year, 30 species were found in the same wetland. The common species varied from the 2002 study but still had these non-native species in common. Reed canary grass and Canada thistle both increased by more than 100% from 2002. Unfortunately, the non-native species may be contributing to the loss of biodiversity in the wetland. In the future, control measures should be taken to ensure the establishment of more desired native species.

Bergman, C.L.; LaGory, K.

2004-01-01

14

Comparison of the prevalence index and average wetland values for identification of wetland vegetation  

SciTech Connect

Prevalence index values (FICWD, 1989) and average wetland values for all species present were compared for three wetland gas pipeline rights-of-way (ROWS) and adjacent natural areas. The similarities in results using these two indicator values suggest that an average wetland value may offer a simpler, less time-consuming method of evaluating the vegetation of a study site as an indication of wetness. Both PIVs and AWVs, are presented for the ROWs and the adjacent natural area at each site.

Zimmerman, R.E.; Shem, L.M.; Gowdy, M.J. [Argonne National Lab., IL (United States); Van Dyke, G.D. [Trinity Christian Coll., Palos Heights, IL (United States); Hackney, C.T. [North Carolina Univ., Wilmington, NC (United States)

1992-07-01

15

Comparison of the prevalence index and average wetland values for identification of wetland vegetation  

SciTech Connect

Prevalence index values (FICWD, 1989) and average wetland values for all species present were compared for three wetland gas pipeline rights-of-way (ROWS) and adjacent natural areas. The similarities in results using these two indicator values suggest that an average wetland value may offer a simpler, less time-consuming method of evaluating the vegetation of a study site as an indication of wetness. Both PIVs and AWVs, are presented for the ROWs and the adjacent natural area at each site.

Zimmerman, R.E.; Shem, L.M.; Gowdy, M.J. (Argonne National Lab., IL (United States)); Van Dyke, G.D. (Trinity Christian Coll., Palos Heights, IL (United States)); Hackney, C.T. (North Carolina Univ., Wilmington, NC (United States))

1992-01-01

16

[Estimating total nitrogen content in wetland vegetation based on measured reflectance spectra].  

PubMed

More and more urban wetlands have been supplied with reclaimed water. And monitoring the growth condition of large-area wetland vegetation is playing a very important role in wetland restoration and reconstruction. Recently, remote sensing technology has become an important tool for vegetation growth monitoring. The South Wetland in the Olympic Park, a typical wetland using reused water, was selected as the research area. The leaf reflectance spectra and were acquired for the main wetland plants reed (Phragmites australis) and cattail (Typha angustifolia) with an ASD FieldSpec 3 spectrometer (350 2 500 nm). The total nitrogen (TN) content of leaf samples was determined by Kjeldahl method subsequently. The research established univariate models involving simple ratio spectral index (SR) model and normalized difference spectral index (ND) model, as well as multivariate models including stepwise multiple linear regression (SMLR) model and partial least squares regression (PLSR) model. Moreover, the accuracy of all the models was tested through cross-validated coefficient of determination (R2(CV)) and cross-validated root mean square error (RMSE(CV)). The results showed that (1) comparing different types of wetland plants, the accuracy of all established prediction models using Phragmites australis reflectance spectra was higher than that using Typha angustifolia reflectance spectra. (2) compared with univariate techniques, multivariate regressions improved the estimation of TN concentration in leaves. (3) among the various investigated models, the accuracy of PLSR model was the highest (R2(CV) = 0.80, RMSE(CV) = 0.24). PLSR provided the most useful explorative tool for unraveling the relationship between spectral reflectance and TN consistence of leaves. The result would not only provide a scientific basis for remote sensing retrieval of biochemical variables of wetland vegetation, but also provide a strong scientific basis for the monitoring and management of urban wetlands using recycled water. PMID:22512191

Liu, Ke; Zhao, Wen-ji; Guo, Xiao-yu; Wang, Yi-hong; Sun, Yong-hua; Miao, Qian

2012-02-01

17

Coevolution of hydraulic, soil and vegetation processes in estuarine wetlands  

NASA Astrophysics Data System (ADS)

Estuarine wetlands of south eastern Australia, typically display a vegetation zonation with a sequence mudflats - mangrove forest - saltmarsh plains from the seaward margin and up the topographic gradient. Estuarine wetlands are among the most productive ecosystems in the world, providing unique habitats for fish and many terrestrial species. They also have a carbon sequestration capacity that surpasess terrestrial forest. Estuarine wetlands respond to sea-level rise by vertical accretion and horizontal landward migration, in order to maintain their position in the tidal frame. In situations in which buffer areas for landward migration are not available, saltmarsh can be lost due to mangrove encroachment. As a result of mangrove invasion associated in part with raising estuary water levels and urbanisation, coastal saltmarsh in parts of south-eastern Australia has been declared an endangered ecological community. Predicting estuarine wetlands response to sea-level rise requires modelling the coevolving dynamics of water flow, soil and vegetation. This paper presents preliminary results of our recently developed numerical model for wetland dynamics in wetlands of the Hunter estuary of NSW. The model simulates continuous tidal inflow into the wetland, and accounts for the effect of varying vegetation types on flow resistance. Coevolution effects appear as vegetation types are updated based on their preference to prevailing hydrodynamic conditions. The model also considers that accretion values vary with vegetation type. Simulations are driven using local information collected over several years, which includes estuary water levels, accretion rates, soil carbon content, flow resistance and vegetation preference to hydraulic conditions. Model results predict further saltmarsh loss under current conditions of moderate increase of estuary water levels.

Trivisonno, Franco; Rodriguez, Jose F.; Riccardi, Gerardo; Saco, Patricia; Stenta, Hernan

2014-05-01

18

Setting reclamation targets and evaluating progress: Submersed aquatic vegetation in natural and post-oil sands mining wetlands in Alberta, Canada  

Microsoft Academic Search

Oil sands mining disturbs thousands of hectares of boreal landscape, about 65% of which is wetland. Its reclamation will constitute the largest wetland reclamation project in Canadian history. We developed a unified analytical framework that we used to set reclamation targets and evaluate reclamation progress using submersed aquatic vegetation (SAV). We sampled SAV in 38 minimally disturbed wetlands to establish

Rebecca C. Rooney; Suzanne E. Bayley

2011-01-01

19

The hydraulic efficiency of fringing versus banded vegetation in constructed wetlands  

Microsoft Academic Search

This paper describes a numerical model study that has been undertaken to investigate the effects of emergent fringing and banded vegetation on the hydraulic characteristics of constructed wetlands. The model study demonstrates that poorly designed wetlands with inappropriate layout of wetland vegetation can result in a significant reduction in the hydraulic efficiency of the wetland system. An empirical relationship is

Graham A. Jenkins; Margaret Greenway

2005-01-01

20

The present and future role of coastal wetland vegetation in protecting shorelines: Answering recent challenges to the paradigm  

USGS Publications Warehouse

For more than a century, coastal wetlands have been recognized for their ability to stabilize shorelines and protect coastal communities. However, this paradigm has recently been called into question by small-scale experimental evidence. Here, we conduct a literature review and a small meta-analysis of wave attenuation data, and we find overwhelming evidence in support of established theory. Our review suggests that mangrove and salt marsh vegetation afford context-dependent protection from erosion, storm surge, and potentially small tsunami waves. In biophysical models, field tests, and natural experiments, the presence of wetlands reduces wave heights, property damage, and human deaths. Meta-analysis of wave attenuation by vegetated and unvegetated wetland sites highlights the critical role of vegetation in attenuating waves. Although we find coastal wetland vegetation to be an effective shoreline buffer, wetlands cannot protect shorelines in all locations or scenarios; indeed large-scale regional erosion, river meandering, and large tsunami waves and storm surges can overwhelm the attenuation effect of vegetation. However, due to a nonlinear relationship between wave attenuation and wetland size, even small wetlands afford substantial protection from waves. Combining man-made structures with wetlands in ways that mimic nature is likely to increase coastal protection. Oyster domes, for example, can be used in combination with natural wetlands to protect shorelines and restore critical fishery habitat. Finally, coastal wetland vegetation modifies shorelines in ways (e.g. peat accretion) that increase shoreline integrity over long timescales and thus provides a lasting coastal adaptation measure that can protect shorelines against accelerated sea level rise and more frequent storm inundation. We conclude that the shoreline protection paradigm still stands, but that gaps remain in our knowledge about the mechanistic and context-dependent aspects of shoreline protection.

Gedan, Keryn B.; Kirwan, Matthew L.; Wolanski, Eric; Barbier, Edward B.; Silliman, Brian R.

2011-01-01

21

Vegetation establishment in convectively accelerated streams  

NASA Astrophysics Data System (ADS)

We study the conditions for vegetation establishment within river reaches with converging boundaries. Common to many such rivers worldwide is the existence of a limiting front (e.g., Figure 1a) beyond which all the riverbed vegetation is uprooted by flooding events. There are however exceptions, which leads to an interesting ecomorphodynamic problem (existence and position of the front). We use a theoretical 1-D framework based on morphodynamic equations modified in order to account for the presence of vegetation (Perona et al., submitted), and obtain the link between the position of the vegetated front and river eco-hydraulic variables under steady and unsteady conditions. We apply our framework to a number of flume experiments (unsteady flow) where Avena sativa L. (common oat) seedlings grow subject to periodic flow disturbances within a convergent flume channel (Figure 1b). We find that depending on the outcome of the competition between hydrological and biological processes there is either a limiting spatial front within the convergent section beyond which vegetation cannot survive, or vegetation colonizes the entire riverbed. The existence and the position of the front depend on the ability for vegetation to take root efficiently and withstand uprooting by the flow of the convectively accelerated stream (Crouzy et al., in press). The active role of vegetation and of unit streampower in this particular ecomorphodynamic process are then discussed in relation to the conceptual model of Gurnell and Petts (2006), and under the light of our theoretical and experimental results. REFERENCES - Crouzy, B., K. Edmaier, N. Pasquale and P. Perona (in press). Impact of floods on the statistical distribution of riverbed vegetation. Geomorphology doi:10.1016/j.geomorph.2012.09.013. - Gurnell A., Petts G. (2006). Trees as riparian engineers: The Tagliamento River, Italy. Earth Surface Processes and Landforms, 31: 1558--1574. - Perona, P., B. Crouzy, S. Mc Lelland, P. Molnar and C. Camporeale. Ecomorphodynamics of rivers with converging boundaries. Earth Surface Processes and Landforms, submitted.

Crouzy, B.; McLelland, S. J.; Molnar, P.; Camporeale, C.; Perona, P.

2013-12-01

22

Early vegetational changes on a forested wetland constructed for mitigation  

USGS Publications Warehouse

Changes in vegetation were studied on 15 acres of a 35 acre forested wetland created as a mitigation site in Anne Arundel County, Maryland during 1994-96. Meter-square sampling on four different hydrologic elevations determined that grasses initially dominated the area, but decreased from 59 percent in 1994 to 51 percent in 1995 and 30 percent in 1996. Herbaceous non-grass plants (forbs) increased from 19 percent to 56 percent in the three-year period. Area with no plant cover decreased from 21 percent in 1994 to 11 percent in 1995, and 10 percent in 1996. Woody plants comprised 2 percent of the cover in 1994, increased to 4 percent in 1995, and remained at 4 percent in 1996. The increase of woody plants was mainly from natural regeneration (pioneer) plants. Monitoring of the transplanted trees and shrubs indicated 35 percent mortality and little growth of surviving plants. The pioneer woody plant forming most of the cover was black willow (Salix nigra). Differences in the vegetation were observed among the four elevations, although no differences were observed for the major vegetation classes between plots that were planted and those that were not planted with woody plants. Dominant grass species was redtop (Agrostis stolonifera), which comprised 51 percent of the cover in 1994 and 42 percent cover in 1995 and 23 percent in 1996. Other species that were common were bush clover (Lespedeza cuneata), Japanese clover (Lespedeza striata) and flat pea (Lathyrus sylvestris). All four of these dominant species were part of the original seed mixtures that were seeded on the site. A total of 134 species of plants was recorded on the site indicating a fairly diverse community for a newly established habitat.

Perry, M.C.; Osenton, P.C.; Sibrel, C.B.

1997-01-01

23

Gas transfer through wetland surface water due to waving vegetation  

NASA Astrophysics Data System (ADS)

We investigate the effect of honami motions in a wetland system, where ';honami' refers to the wind-driven movement of vegetation. We hypothesize that this movement stirs the water column and thus contributes to the transfer of dissolved gases across the air-water interface. To understand the magnitude of this effect, a wetland honami was simulated in the laboratory using an array of plastic tubes to represent vegetation. Starting from deoxygenated water, we measured dissolved oxygen at mid-depth in the water column using a YSI ProODO as the water equilibrated with the atmosphere. From this DO time series, we calculated the gas transfer velocity, k, using the thin film gas transport model. We compare the results to other drivers of gas transfer in wetland surface water, including thermal convection and wind shear at the air-water interface. The results can help predict the role that surface-water stirring plays in connecting wetland soils with the atmosphere. This, in turn, can help predict biogeochemical processes and wetlands' impacts on greenhouse gases.

Foster, M. R.; Variano, E. A.

2013-12-01

24

Classification of wetlands vegetation using small scale color infrared imagery  

NASA Technical Reports Server (NTRS)

A classification system for Chesapeake Bay wetlands was derived from the correlation of film density classes and actual vegetation classes. The data processing programs used were developed by the Laboratory for the Applications of Remote Sensing. These programs were tested for their value in classifying natural vegetation, using digitized data from small scale aerial photography. Existing imagery and the vegetation map of Farm Creek Marsh were used to determine the optimal number of classes, and to aid in determining if the computer maps were a believable product.

Williamson, F. S. L.

1975-01-01

25

Plant community, primary productivity, and environmental conditions following wetland re-establishment in the Sacramento-San Joaquin Delta, California  

USGS Publications Warehouse

Wetland restoration can mitigate aerobic decomposition of subsided organic soils, as well as re-establish conditions favorable for carbon storage. Rates of carbon storage result from the balance of inputs and losses, both of which are affected by wetland hydrology. We followed the effect of water depth (25 and 55 cm) on the plant community, primary production, and changes in two re-established wetlands in the Sacramento San-Joaquin River Delta, California for 9 years after flooding to determine how relatively small differences in water depth affect carbon storage rates over time. To estimate annual carbon inputs, plant species cover, standing above- and below-ground plant biomass, and annual biomass turnover rates were measured, and allometric biomass models for Schoenoplectus (Scirpus) acutus and Typha spp., the emergent marsh dominants, were developed. As the wetlands developed, environmental factors, including water temperature, depth, and pH were measured. Emergent marsh vegetation colonized the shallow wetland more rapidly than the deeper wetland. This is important to potential carbon storage because emergent marsh vegetation is more productive, and less labile, than submerged and floating vegetation. Primary production of emergent marsh vegetation ranged from 1.3 to 3.2 kg of carbon per square meter annually; and, mid-season standing live biomass represented about half of the annual primary production. Changes in species composition occurred in both submerged and emergent plant communities as the wetlands matured. Water depth, temperature, and pH were lower in areas with emergent marsh vegetation compared to submerged vegetation, all of which, in turn, can affect carbon cycling and storage rates. ?? Springer Science+Business Media B.V. 2009.

Miller, R. L.; Fujii, R.

2010-01-01

26

AIS-2 spectra of California wetland vegetation  

NASA Technical Reports Server (NTRS)

Spectral data gathered by Airborne Imaging Spectrometers-2 from wetlands were analyzed. Spectra representing stands of green Salicornia virginica, green Sesuvium verrucosum, senescing Distichlis spicata, a mixture of senescing Scirpus acutus and Scirpus californicus, senescing Scirpus paludosus, senescent S. paludosus, mowed senescent S. paludosus, and soil were isolated. No difference among narrowband spectral reflectance of the cover types was apparent between 0.8 to 1.6 micron. There were, however, broadband differences in brightness. These differences were sufficient to permit a fairly accurate decomposition of the image into its major cover type components using a procedure that assumes an additive linear mixture of surface spectra.

Gross, Michael F.; Ustin, Susan L.; Klemas, Vytautas

1987-01-01

27

Diurnal Cycles of Trace Gas Transfer through Wetland Vegetation  

NASA Astrophysics Data System (ADS)

Natural and constructed wetlands are major sources of biogeochemical trace gases, and have recently gained attention as tools for passive remediation of discharging groundwater contaminated with volatile organic compounds (VOCs). Wetland plants act as conduits for the volatilization of dissolved compounds from the interstitial pore waters of aquatic sediments to the atmosphere, so clarifying the mechanisms of this vegetation-mediated gas transport is essential to understanding the emissions of compounds including methane and VOCs. The conservative gas tracer sulfur hexafluoride (SF6) was used to examine mechanisms of gas transport through the wetland macrophytes Scirpus acutus and Typha latifolia in greenhouse mesocosm experiments. The results provide novel experimental evidence for the enhancement by light of plant-mediated gas fluxes through S. acutus, a species with no previously documented light-activated gas transport mechanism. A nonlinear saturation model was fit to the tracer flux data using least-squares regression. The mechanism for this light-enhanced flux was investigated in additional experiments in which atmospheric humidity was deliberately manipulated. These results will be discussed with respect to the role of transpiration in enhancing plant-mediated gas transport. The SF6 flux data also quantify inter-species and seasonal variability in gas transfer rates, and capture the dynamics of pressurized gas flows in T. latifolia. A numerical model of gas transport mechanisms in the root and rhizosphere system was calibrated with experimental data and used to further examine mechanisms of gas exchange between saturated wetland sediments, vegetation, and the atmosphere.

Reid, M. C.; Ho, D. T.; Jaffe, P. R.

2010-12-01

28

Carbon gas fluxes in re-established wetlands on organic soils differ relative to plant community and hydrology  

USGS Publications Warehouse

We measured CO2 and CH4 fluxes for 6 years following permanent flooding of an agriculturally managed organic soil at two water depths (~25 and ~55 cm standing water) in the Sacramento–San Joaquin Delta, California, as part of research studying C dynamics in re-established wetlands. Flooding rapidly reduced gaseous C losses, and radiocarbon data showed that this, in part, was due to reduced oxidation of "old" C preserved in the organic soils. Both CO2 and CH4 emissions from the water surface increased during the first few growing seasons, concomitant with emergent marsh establishment, and thereafter appeared to stabilize according to plant communities. Areas of emergent marsh vegetation in the shallower wetland had greater net CO2 influx (-485 mg Cm-1 h-1), and lower CH4 emissions (11.5 mg Cm-2 h-1), than in the deeper wetland (-381 and 14.1 mg Cm-2 h-1, respectively). Areas with submerged and floating vegetation in the deeper wetland had CH4 emissions similar to emergent vegetation (11.9 and 12.6 mg Cm-2 h-1, respectively), despite lower net CO2 influx (-102 gC m-2 h-1). Measurements of plant moderated net CO2 influx and CH4 efflux indicated greatest potential reduction of greenhouse gases in the more shallowly flooded wetland.

Miller, Robin L.

2011-01-01

29

Texture classification of vegetation cover in high altitude wetlands zone  

NASA Astrophysics Data System (ADS)

The aim of this study was to investigate the utility of datasets composed of texture measures and other features for the classification of vegetation cover, specifically wetlands. QUEST decision tree classifier was applied to a SPOT-5 image sub-scene covering the typical wetlands area in Three River Sources region in Qinghai province, China. The dataset used for the classification comprised of: (1) spectral data and the components of principal component analysis; (2) texture measures derived from pixel basis; (3) DEM and other ancillary data covering the research area. Image textures is an important characteristic of remote sensing images; it can represent spatial variations with spectral brightness in digital numbers. When the spectral information is not enough to separate the different land covers, the texture information can be used to increase the classification accuracy. The texture measures used in this study were calculated from GLCM (Gray level Co-occurrence Matrix); eight frequently used measures were chosen to conduct the classification procedure. The results showed that variance, mean and entropy calculated by GLCM with a 9*9 size window were effective in distinguishing different vegetation types in wetlands zone. The overall accuracy of this method was 84.19% and the Kappa coefficient was 0.8261. The result indicated that the introduction of texture measures can improve the overall accuracy by 12.05% and the overall kappa coefficient by 0.1407 compared with the result using spectral and ancillary data.

Wentao, Zou; Bingfang, Wu; Hongbo, Ju; Hua, Liu

2014-03-01

30

Characterization of microtopography and its influence on vegetation patterns in created wetlands  

USGS Publications Warehouse

Created wetlands are increasingly used to mitigate wetland loss. Thus, identifying wetland creation methods that enhance ecosystem development might increase the likelihood of mitigation success. Noting that the microtopographic variation found in natural wetland settings may not commonly be found in created wetlands, this study explores relationships between induced microtopography, hydrology, and plant species richness/ diversity in non-tidal freshwater wetlands, comparing results from two created wetland complexes with those from a mature reference wetland complex in northern Virginia. Elevation, steel rod oxidation depth, and species cover were measured along replicate multiscale (0.5 m-, 1 m-, 2 m-, and 4 m-diameter) tangentially conjoined circular transects in each wetland. Microtopography was surveyed using a total station and results used to derive three roughness indices: tortuosity, limiting slope, and limiting elevation difference. Steel rod oxidation depth was used to estimate water table depth, with data collected four times during the growing season for each study site. Plant species cover was estimated visually in 0.2 m2 plots surveyed at peak growth and used to assess species richness, diversity, and wetland prevalence index. Differences in each attribute were examined among disked and non-disked created wetlands and compared to a natural wetland as a reference. Disked and non-disked created wetlands differed in microtopography, both in terms of limiting elevation difference and tortuosity. However, both were within the range of microtopography encompassed by natural wetlands. Disked wetlands supported higher plant diversity and species richness than either natural or non-disked wetlands, as well as greater within-site species assemblage variability than non-disked wetlands. Irrespective of creation method, plant diversity in created wetlands was correlated with tortuosity and limiting elevation difference, similar to correlations observed for natural wetlands. Vegetation was more hydrophytic at disked sites than at non-disked sites, and of equivalent wetland indicator status to natural sites, even though all sites appeared comparable in terms of hydrology. Results suggest that disking may enhance vegetation community development, thus better supporting the goals of wetland mitigation. ?? 2007, The Society of Wetland Scientists.

Moser, K.; Ahn, C.; Noe, G.

2007-01-01

31

Promoting species establishment in a phragmites-dominated great lakes coastal wetland  

USGS Publications Warehouse

This study examined efforts to promote species establishment and maintain diversity in a Phragmites-dominated wetland where primary control measures were underway. A treatment experiment was performed at Crane Creek, a drowned-river-mouth wetland in Ottawa National Wildlife Refuge along the shore of western Lake Erie. Following initial aerial spraying of Phragmites with glyphosate, this study tested combinations of cutting, raking, and additional hand spraying of Phragmites with glyphosate as methods to promote growth of other wetland species and increase plant diversity. Percent-cover vegetation data were collected in permanent plots before and after treatments, and follow-up sampling was performed the following year. Increased species richness, species emergence, and relative dominance of non-Phragmites taxa were used as measures of treatment success. We also examined treatment effects on Phragmites cover. Dimensionality of seedbank and soil properties was reduced using principal component analysis. With the exception of nitrogen, soil nutrients affected species establishment, non-Phragmites taxa dominance, and Phragmites cover. A more viable seedbank led to greater species emergence. Treatments had differential effects on diversity depending on elevation and resulting degree of hydrologic inundation. Whereas raking to remove dead Phragmites biomass was central to promoting species establishment in dry areas, spraying had a greater impact in continually inundated areas. For treatment success across elevations into the year following treatments, spraying in combination with cutting and raking had the greatest effect. The results of this study suggest that secondary treatments can produce a short-term benefit to the plant community in areas treated for Phragmites.

Carlson, M. L.; Kowalski, K. P.; Wilcox, D. A.

2009-01-01

32

Dual-season mapping of wetland inundation and vegetation for the central Amazon basin  

Microsoft Academic Search

Wetland extent was mapped for the central Amazon region, using mosaicked L-band synthetic aperture radar (SAR) imagery acquired by the Japanese Earth Resources Satellite-1. For the wetland portion of the 18×8° study area, dual-season radar mosaics were used to map inundation extent and vegetation under both low-water and high-water conditions at 100-m resolution, producing the first high-resolution wetlands map for

Laura L. Hess; John M. Melack; Evlyn M. l. m. Novo; Claudio C. f. Barbosa; Mary Gastil

2003-01-01

33

Influence of hummocks and emergent vegetation on hydraulic performance in a surface flow wastewater treatment wetland  

Microsoft Academic Search

A series of tracer experiments were conducted biannually at the start and end of the vegetation growing season in a surface flow wastewater treatment wetland located near Phoenix, AZ. Tracer experiments were conducted prior to and following reconfiguration and replanting of a 1.2 ha treatment wetland from its original design of alternating shallow and deep zones to incorporate hummocks (shallow

Steffanie H. Keefe; Robert L. Runkel; Roland D. Wass; Eric A. Stiles; Larry B. Barber

2010-01-01

34

Using MODIS Normalized Difference Vegetation Index to monitor seasonal and inter-annual dynamics of wetland vegetation in the Great Artesian Basin: a baseline for assessment of future changes in a unique ecosystem  

NASA Astrophysics Data System (ADS)

The Great Artesian Basin mound springs (Australia) are unique wetland ecosystems of great significance. However, these unique ecosystems are endangered by anthropogenic water extraction. Relationships have been established between the vegetated wetland area and the discharge associated with individual springs, providing a potential means of monitoring groundwater flow using measurements of wetland area. Previous studies using this relationship to monitor Great Artesian Basin springs have used aerial photography or high resolution satellite images, giving sporadic temporal information. These "snapshot " studies need to be placed within a longer and more regular context to better assess changes in response to aquifer draw-downs. In this study, the potential of medium resolution MODIS Normalized Difference Vegetation Index data for studying the long-term and high frequency temporal dynamics of wetland vegetation at the Dalhousie Spring Complex of the GAB is tested. Photosynthetic activity within Dalhousie wetlands could be differentiated from surrounding land responses. The study showed good correlation between wetland vegetated area and groundwater flow, but also the important influence of natural species phenologies, rainfall, and human activity on the observed seasonal and inter-annual vegetation dynamic. Declining trends in the extent of wetland areas were observed over the 2000- 2009 period followed by a return of wetland vegetation since 2010. This study underlined the need to continue long-term medium resolution satellite studies of the Great Artesian Basin as these data provide a good understanding of variability within the wetlands, give temporal context for less frequent studies and a strong baseline for assessment of future changes.

Petus, C.; Lewis, M.; White, D.

2012-07-01

35

Establishment of a constructed wetland in extreme dryland  

Microsoft Academic Search

Background, aim, and scope  The project was set to construct an extensive wetland in the southernmost region of Israel at Kibbutz Neot Smadar (30°02?45?\\u000a N and 35°01?19? E). The results of the first period of monitoring, summary, and perspectives are presented. The constructed\\u000a wetland (CW) was built and the subsequent monitoring performed in the framework of the Southern Arava Sustainable Waste

Yoram Tencer; Gil Idan; Marjorie Strom; Uri Nusinow; Dorit Banet; Eli Cohen; Peter Schröder; Oren Shelef; Shimon Rachmilevitch; Ines Soares; Amit Gross; Avi Golan-Goldhirsh

2009-01-01

36

The flood pulse as the underlying driver of vegetation in the largest wetland and fishery of the Mekong Basin.  

PubMed

The Tonle Sap is the largest wetland in Southeast Asia and one of the world's most productive inland fisheries. The Mekong River inundates the Tonle Sap every year, shaping a mosaic of natural and agricultural habitats. Ongoing hydropower development, however, will dampen the flood pulse that maintains the Tonle Sap. This study established the current underlying relationship among hydrology, vegetation, and human use. We found that vegetation is strongly influenced by flood duration; however, this relationship was heavily distorted by fire, grazing, and rice cultivation. The expected flood pulse alteration will result in higher water levels during the dry season, permanently inundating existing forests. The reduction of the maximum flood extent will facilitate agricultural expansion into natural habitats. This study is the most comprehensive field survey of the Tonle Sap to date, and it provides fundamental knowledge needed to understand the underlying processes that maintain this important wetland. PMID:23877417

Arias, Mauricio E; Cochrane, Thomas A; Norton, David; Killeen, Timothy J; Khon, Puthea

2013-11-01

37

Influence of hummocks and emergent vegetation on hydraulic performance in a surface flow wastewater treatment wetland  

NASA Astrophysics Data System (ADS)

A series of tracer experiments were conducted biannually at the start and end of the vegetation growing season in a surface flow wastewater treatment wetland located near Phoenix, AZ. Tracer experiments were conducted prior to and following reconfiguration and replanting of a 1.2 ha treatment wetland from its original design of alternating shallow and deep zones to incorporate hummocks (shallow planting beds situated perpendicular to flow). Tracer test data were analyzed using analysis of moments and the one-dimensional transport with inflow and storage numerical model to evaluate the effects of the seasonal vegetation growth cycle and hummocks on solute transport. Following reconfiguration, vegetation coverage was relatively small, and minor changes in spatial distribution influenced wetland hydraulics. During start-up conditions, the wetland underwent an acclimation period characterized by small vegetation coverage and large transport cross-sectional areas. At the start of the growing season, new growth of emergent vegetation enhanced hydraulic performance. At the end of the growing season, senescing vegetation created short-circuiting. Wetland hydrodynamics were associated with high volumetric efficiencies and velocity heterogeneities. The hummock design resulted in breakthrough curves characterized by multiple secondary tracer peaks indicative of varied flow paths created by bottom topography.

Keefe, Steffanie H.; Daniels, Joan S. (Thullen); Runkel, Robert L.; Wass, Roland D.; Stiles, Eric A.; Barber, Larry B.

2010-11-01

38

Performance Variations of COD and Nitrogen Removal by Vegetated Submerged Bed Wetlands  

Microsoft Academic Search

Vegetated submerged bed wetlands can supplement treatment of onsite wastewater systems. This study evaluated vegetation, media, and seasonal impacts on system performance in six meso scale rock plant filters with and without narrow leaf cattails (Typha augustifolia). Daily chemical oxygen demand (COD) reductions in planted cells averaged 85 percent and weekly total nitrogen (TN) reductions averaged 50 percent. Planted cells

Qiang He; Kyle R. Mankin

2002-01-01

39

ASSESSING THE IMPACTS OF AN INCREASE IN WATER LEVEL ON WETLAND VEGETATION  

EPA Science Inventory

Three different approaches for assessing the impact of a permanent increase in water level on wetland vegetation were studied using a long-term, controlled, and replicated experiment. hese approaches were (1) digitized vegetation maps derived from aerial photographs; (2) vegetati...

40

Variability of soil microbial respiration under different vegetation succession stages in Jiuduansha wetland  

Microsoft Academic Search

The soil microbial respiration (SMR) and physicochemical characteristics of Jiuduansha wetland at the Yangtze Estuary were analyzed in order to clarify the variability of SMR under different vegetation succession stages and its influencing factors. The results indicated that SMR of different vegetation succession stages are significantly various (P < 0.05). The SMR of the Spartina alterniflora (S. alterniflora) zone (0.43

Yushu Tang; Lei Wang; Jianwei Jia; Yanli Li; Wenquan Zhang; Hongli Wang; Xiaohua Fu; Yiquan Le

2011-01-01

41

Influence of hydrologic regime and vegetation on phosphorus retention in Everglades stormwater treatment area wetlands  

Microsoft Academic Search

The Florida (USA) Everglades ecosystem has been impacted due to increased loading of nutrients, in particular phos- phorus (P), primarily from adjacent agricultural areas. Consequently, restoration measures involve the establishment of stormwater treatment areas (STAs) comprising a series of constructed wetlands. A series of mesocosms were established at the inflow of the Everglades Nutrient Removal Project wetland, the first such

John R. White; K. Ramesh Reddy; M. Z. Moustafa

2004-01-01

42

Influence of hydrologic regime and vegetation on phosphorus retention in Everglades stormwater treatment area wetlands  

Microsoft Academic Search

The Florida (USA) Everglades ecosystem has been impacted due to increased loading of nutrients, in particular phosphorus (P), primarily from adjacent agricultural areas. Consequently, restoration measures involve the establishment of stormwater treatment areas (STAs) comprising a series of constructed wetlands. A series of mesocosms were established at the inflow of the Everglades Nutrient Removal Project wetland, the first such STA

John R. White; K. Ramesh Reddy; M. Z. Moustafa

2004-01-01

43

Aircraft MSS data registration and vegetation classification of wetland change detection  

USGS Publications Warehouse

Portions of the Savannah River floodplain swamp were evaluated for vegetation change using high resolution (5a??6 m) aircraft multispectral scanner (MSS) data. Image distortion from aircraft movement prevented precise image-to-image registration in some areas. However, when small scenes were used (200-250 ha), a first-order linear transformation provided registration accuracies of less than or equal to one pixel. A larger area was registered using a piecewise linear method. Five major wetland classes were identified and evaluated for change. Phenological differences and the variable distribution of vegetation limited wetland type discrimination. Using unsupervised methods and ground-collected vegetation data, overall classification accuracies ranged from 84 per cent to 87 per cent for each scene. Results suggest that high-resolution aircraft MSS data can be precisely registered, if small areas are used, and that wetland vegetation change can be accurately detected and monitored.

Christensen, E.J.; Jensen, J.R.; Ramsey, E.W., III; Mackey, H.E., Jr.

1988-01-01

44

Multi-temporal classification of TerraSAR-X data for wetland vegetation mapping  

NASA Astrophysics Data System (ADS)

This paper is concerned with vegetation wetland mapping using multi-temporal SAR imagery. Whilst wetlands play a key role in controlling flooding and nonpoint source pollution, sequestering carbon and providing an abundance of ecological services, knowledge of the flora and fauna of these environments is patchy, and understanding of their ecological functioning is still insufficient for a reliable functional assessment on areas larger than a few ha. The aim of this paper is to evaluate multitemporal TerraSAR-X imagery to map precisely the distribution of vegetation formations within wetlands, in determining seasonally flooded areas of wetlands. A series of six dual-polarization TerraSAR-X images (HH/VV) were acquired in 2012 during dry and wet seasons. Polarimetric and intensity parameters, which present a temporal variation that depends on wetland flooding status and vegetation roughness, were firstly extracted. The parameters were then classified based on Support Vector Machines (SVM) techniques using a specific kernel adapted to the comparison of time-series data. The results show that the Shannon entropy parameter allows discriminating vegetation formations within wetland with more accuracy than intensity parameters.

Betbeder, Julie; Rapinel, Sébastien; Corpetti, Thomas; Pottier, Eric; Corgne, Samuel; Hubert Moy, Laurence

2013-10-01

45

Transfer of tracers and pesticides in lab scale wetland systems: the role of vegetation  

NASA Astrophysics Data System (ADS)

Surface wetlands can collect contaminated runoff from urban or agricultural catchments and have intrinsic physical, chemical and biological retention and removal processes useful for mitigating contaminants, including pesticides, and thus limiting the contamination of aquatic ecosystems. Yet little is known about the transfer of pesticides between wetlands collecting pesticides runoff and groundwater, and the subsequent threat of groundwater contamination. In particular, the influence of wetland vegetation and related processes during pesticide transfer is largely unknown. Here we evaluate the transfer of the widely used herbicide Isoproturon (IPU) and the fungicide Metalaxyl (MTX) with that of Uranine (UR) and Sulphorhodamine (SRB) in a vegetated and a non-vegetated lab-scale wetland. UR and SRB had successfully served as a reference for pesticides in surface wetlands. We filled two 65 cm long and 15 cm diameter borosilicate columns with sediment cores from a wetland, one without and one with vegetation (Phragmites australis, Cav.). When a constant flow-through rate of 0.33 ml min-1 was reached, tracers and pesticides were injected simultaneously and continuously. The hydrological mass balance and tracer concentrations were measured daily at the outlet of the lab-scale wetland. Samples for pesticides and hydrochemical analyses were collected biweekly. The lab-scale wetlands were covered to limit evaporation and light decay of injected compounds. The reactive transfer of compounds in the vegetated and non-vegetated lab-scale wetland was compared based on breakthrough curves (BTC's) and model parameters of the lumped parameter model CXTFIT. The hydrologic balance revealed that the intensity of transpiration and hence plant activity in the lab-scale wetlands progressively decreased and then apparently ceased after about eight days following continuous pesticide injection. In this first phase, no significant difference in the hydrologic balances could be observed between the vegetated and the non-vegetated column. In a second phase, vegetation transpiration progressively increased, as inferred from lower volumes of effluent water in the vegetated system. Overall, the behavior of pesticides and tracers, as inferred from the BTC's, were similar. This suggests that fluorescent tracers may be used as a reference for pesticides when studying the surface-groundwater interface. Both pesticides and tracers showed larger recovery rates (UR: 81.7 to 78.6%; SRB: 65.6 to 55.9%; IPU: 76.6 to 79.7%; MTX: 39.5 to 37.5%) and lower retention in the vegetated system. We attribute this finding to preferential flow paths along plant roots. Overall, our study suggests that wetland vegetation and rhizosheric processes may have a dual role in wetland pollutant transfer: while wetland vegetation may enhance retention and bio-degradation of contaminants in surface water, it may also generate preferential flow paths and hence facilitate pollutant transfer to groundwater. Acknowledgment: This study has been funded by the European Union (INTERREG) in the framework of the PhytoRet Project.

Durst, R.; Imfeld, G.; Lange, J.

2012-04-01

46

Temperature sensitivity of greenhouse gas production in wetland soils of different vegetation  

Microsoft Academic Search

Organic matter decomposition regulates rates of carbon loss (CO2 and CH4) in wetlands and has implications for carbon sequestration in the context of changing global temperature. Here we determined\\u000a the influence of temperature and vegetation type on both aerobic and anaerobic decomposition of organic matter in subtropical\\u000a wetland soils. As in many other studies, increased temperature resulted in higher rates

K. S. Inglett; P. W. Inglett; K. R. Reddy; T. Z. Osborne

47

Cold Season Nitrogen Removal in a High Loaded Free Water Surface Wetland with Emergent Vegetation  

Microsoft Academic Search

The aim of this study was to quantify nitrogen removal in high loaded free water surface wetlands dominated by emergent vegetation.\\u000a It was undertaken in two subsystems of the full-scale wetland Alhagen in Nynäshamn, Sweden. Time proportional samples were\\u000a taken at the inlets and outlets for 2 weeks in September and November 2005, respectively, and the water flow was monitored.

Christer Svedin; Sofia Kallner Bastviken; Karin S. Tonderski

48

Vegetation Response to Re-flooding in the Mesopotamian Wetlands, Southern Iraq  

Microsoft Academic Search

Wetlands in the Mesopotamian Plain in southern Iraq were extensively drained in the 1990s. Re-flooding of drained areas commenced\\u000a in 2003, and included parts of the Central marsh between the Euphrates and Tigris Rivers. New vegetation in the re-flooded\\u000a areas of the Central marsh was studied in 2006. Most of the wetland plant species and communities widely distributed prior\\u000a to

M. A. Hamdan; T. Asada; F. M. Hassan; B. G. Warner; A. Douabul; M. R. A. Al-Hilli; A. A. Alwan

2010-01-01

49

Presence of indicator plant species as a predictor of wetland vegetation integrity  

USGS Publications Warehouse

We fit regression and classification tree models to vegetation data collected from Ohio (USA) wetlands to determine (1) which species best predict Ohio vegetation index of biotic integrity (OVIBI) score and (2) which species best predict high-quality wetlands (OVIBI score >75). The simplest regression tree model predicted OVIBI score based on the occurrence of three plant species: skunk-cabbage (Symplocarpus foetidus), cinnamon fern (Osmunda cinnamomea), and swamp rose (Rosa palustris). The lowest OVIBI scores were best predicted by the absence of the selected plant species rather than by the presence of other species. The simplest classification tree model predicted high-quality wetlands based on the occurrence of two plant species: skunk-cabbage and marsh-fern (Thelypteris palustris). The overall misclassification rate from this tree was 13 %. Again, low-quality wetlands were better predicted than high-quality wetlands by the absence of selected species rather than the presence of other species using the classification tree model. Our results suggest that a species’ wetland status classification and coefficient of conservatism are of little use in predicting wetland quality. A simple, statistically derived species checklist such as the one created in this study could be used by field biologists to quickly and efficiently identify wetland sites likely to be regulated as high-quality, and requiring more intensive field assessments. Alternatively, it can be used for advanced determinations of low-quality wetlands. Agencies can save considerable money by screening wetlands for the presence/absence of such “indicator” species before issuing permits.

Stapanian, Martin A.; Adams, Jean V.; Gara, Brian

2013-01-01

50

The Effect of Manning's Roughness Calibration on Flow and Sediment transport in Wetlands: Vegetation Drag Approach  

NASA Astrophysics Data System (ADS)

Wetland hydrology is one of the most complex and important factors that dictate landscape patterning in wetlands. Understanding factors that affect wetland hydrology are very important. Subtropical wetlands with low gradient, such as The Everglades in South Florida, are generally covered by various type of vegetation with area of highly vegetated and area with almost no plant density. Ridge and slough are one of the several major habitat types in the Everglades that are characterized by highly vegetated ridge with higher elevation and channelized slough with less dense vegetation. They are originally consisted of a peat - based systems of dense sawgrass ridges (Cladium jamaicense) interspersed with adjacent and relatively open sloughs. Because of vegetation dynamics, the hydrology is highly depends on vegetation drag force. Kadlec (1990) and Shi et al., 1995 stated that additional drag exerted by plants reduces the mean flow velocity and depth within the vegetated regions. Vegetation flexibility (flexible grasslike vs. rigid or less flexible bushes or trees) may affect flow resistance. In addition, total or partially submerged vegetation may also change the flow velocity. Most of vegetation in wetlands are partially submerged and therefore, flow resistance can be related to bed shear stress (Yen, 2002; Wu et al., 1999). The new modified Manning's coefficient expression estimates roughness value based on vegetation type, length, density, and vegetation being submerged/unsubmerged (Wu et al., 1999). This modification was applied to flow simulation in the study area at Loxahatchee Impoundment Landscape Assessment (LILA). Loxahatchee Impoundment Landscape Assessment (LILA) is living laboratory of The Everglades and is located at Boynton Beach, Florida and consists of 80 acres land divided into four macrocosms of 200 m × 400 m. Each macrocosm includes one ridge one slough and two tree islands. Two of the cells are non flowing cells and the others are constant flowing cells in LILA. The constant flowing cell, M2, was selected as the study area. Flow was simulated using FLO2D, a FEMA approved program that simulates flow depth and velocity by using modified manning's roughness coefficient based on vegetation drag approach. The result of this simulation will provide an improved understanding of the effect of vegetation dynamics on hydrology and how different vegetation type and density may change flow velocity and therefore sediment transport over time.

Mahmoudi, M.; Nalesso, M.; Garcia, R. F.; Miralles-Wilhelm, F.

2013-05-01

51

Efficiency of constructed wetland vegetated with Cyperus alternifolius applied for municipal wastewater treatment.  

PubMed

The treatment of municipal wastewater from Yazd city (center of Iran) by constructed wetland vegetated with Cyperus alternifolius was assessed. Two identical wetlands with a total working volume of 60 L and 10 cm sandy layer at the bottom were used. First wetland (W1) was control and had no Cyperus alternifolius plant. Second wetland (W2) had 100 Cyperus alternifolius shrubs with 40 cm height. Influent wastewater was provided from Yazd's septic tanks effluents and after a 4-day retention time in wetlands, reactors effluent was sampled for parameters analysis. Results show that chemical oxygen demand (COD), NO3 (-)-N, NH4 (+)-N, and PO4 (-3)-P in W1 were reduced to 72%, 88%, 32%, and 0.8%, and in W2, these parameters were removed in values of 83%, 81%, 47%, and 10%, respectively. In both wetlands, the highest and lowest removal efficiencies were related to COD and phosphorus, respectively. Also, the removed phosphorus can be released to stream when the soil saturated or influent phosphorus decreased and when the plant died. After a 4-day-retention time, the W2 wetland showed a statistically significantly lower COD and NH4 (+)-N in comparison with W2 wetland. PMID:24027589

Ebrahimi, Asghar; Taheri, Ensiyeh; Ehrampoush, Mohammad Hassan; Nasiri, Sara; Jalali, Fatemeh; Soltani, Rahele; Fatehizadeh, Ali

2013-01-01

52

Efficiency of Constructed Wetland Vegetated with Cyperus alternifolius Applied for Municipal Wastewater Treatment  

PubMed Central

The treatment of municipal wastewater from Yazd city (center of Iran) by constructed wetland vegetated with Cyperus alternifolius was assessed. Two identical wetlands with a total working volume of 60?L and 10?cm sandy layer at the bottom were used. First wetland (W1) was control and had no Cyperus alternifolius plant. Second wetland (W2) had 100 Cyperus alternifolius shrubs with 40?cm height. Influent wastewater was provided from Yazd's septic tanks effluents and after a 4-day retention time in wetlands, reactors effluent was sampled for parameters analysis. Results show that chemical oxygen demand (COD), NO3?–N, NH4+–N, and PO4?3–P in W1 were reduced to 72%, 88%, 32%, and 0.8%, and in W2, these parameters were removed in values of 83%, 81%, 47%, and 10%, respectively. In both wetlands, the highest and lowest removal efficiencies were related to COD and phosphorus, respectively. Also, the removed phosphorus can be released to stream when the soil saturated or influent phosphorus decreased and when the plant died. After a 4-day-retention time, the W2 wetland showed a statistically significantly lower COD and NH4+–N in comparison with W2 wetland.

Ebrahimi, Asghar; Taheri, Ensiyeh; Ehrampoush, Mohammad Hassan; Nasiri, Sara; Jalali, Fatemeh; Soltani, Rahele; Fatehizadeh, Ali

2013-01-01

53

Biomass estimation of wetland vegetation in Poyang Lake area using ENVISAT advanced synthetic aperture radar data  

NASA Astrophysics Data System (ADS)

Biomass estimation of wetlands plays a role in understanding dynamic changes of the wetland ecosystem. Poyang Lake is the largest freshwater lake in China, with an area of about 3000 km2. The lake's wetland ecosystem has a significant impact on leveraging China's environmental change. Synthetic aperture radar (SAR) data are a good choice for biomass estimation during rainy and dry seasons in this region. In this paper, we discuss the neural network algorithms (NNAs) to retrieve wetland biomass using the alternating-polarization ENVISAT advanced synthetic aperture radar (ASAR) data. Two field measurements were carried out coinciding with the satellite overpasses through the hydrological cycle in April to November. A radiative transfer model of forest canopy, the Michigan Microwave Canopy Scattering (MIMICS) model, was modified to fit to herbaceous wetland ecosystems. With both ASAR and MIMICS simulations as input data, the NNA-estimated biomass was validated with ground-measured data. This study indicates the capability of NNA combined with a modified MIMICS model to retrieve wetland biomass from SAR imagery. Finally, the overall biomass of Poyang Lake wetland vegetation has been estimated. It reached a level of 1.09×109, 1.86×108, and 9.87×108 kg in April, July, and November 2007, respectively.

Liao, Jingjuan; Shen, Guozhuang; Dong, Lei

2013-01-01

54

Experimental removal of wetland emergent vegetation leads to decreased methylmercury production in surface sediment  

USGS Publications Warehouse

We performed plant removal (devegetation) experiments across a suite of ecologically diverse wetland settings (tidal salt marshes, river floodplain, rotational rice fields, and freshwater wetlands with permanent or seasonal flooding) to determine the extent to which the presence (or absence) of actively growing plants influences the activity of the Hg(II)-methylating microbial community and the availability of Hg(II) to those microbes. Vegetated control plots were paired with neighboring devegetated plots in which photosynthetic input was terminated 4-8 months prior to measurements, through clipping aboveground biomass, severing belowground connections, and shading the sediment surface to prevent regrowth. Across all wetlands, devegetation decreased the activity of the Hg(II)-methylating microbial community (kmeth) by 38%, calculated MeHg production potential (MP) rates by 36%, and pore water acetate concentration by 78%. Decreases in MP were associated with decreases in microbial sulfate reduction in salt marsh settings. In freshwater agricultural wetlands, decreases in MP were related to indices of microbial iron reduction. Sediment MeHg concentrations were also significantly lower in devegetated than in vegetated plots in most wetland settings studied. Devegetation effects were correlated with live root density (percent volume) and were most profound in vegetated sites with higher initial pore water acetate concentrations. Densely rooted wetlands had the highest rates of microbial Hg(II)-methylation activity but often the lowest concentrations of bioavailable reactive Hg(II). We conclude that the exudation of labile organic carbon (e.g., acetate) by plants leads to enhanced microbial sulfate and iron reduction activity in the rhizosphere, which results in high rates of microbial Hg(II)-methyation and high MeHg concentrations in wetland sediment.

Windham-Myers, L.; Marvin-Dipasquale, M.; Krabbenhoft, D. P.; Agee, J. L.; Cox, M. H.; Heredia-Middleton, P.; Coates, C.; Kakouros, E.

2009-01-01

55

Vegetation study to assess the nutrient uptake potential of emergent macrophytes in semi-arid wetlands  

NASA Astrophysics Data System (ADS)

Arc GIS software and ground verification was used to map vegetation of a downstream riparian wetland in the Las Vegas Wash. Monogeneric stands of Phragmites australis dominated the spatial distribution of emergent macrophytes. This paper aims to evaluate the aboveground biomass production and nutrients (total nitrogen and total phosphorus) content to determine the maximum nutrient removal efficiency by harvesting Typha domingensis and P. australis during their highest growth rate, in a semi arid wetlands. The average aboveground biomass of T. domingensis (5.61to11.07 kg m-2) was significantly higher than P. australis (2.49-6.35 kg m-2) in the month of July 2010. Despite the high nutrient concentration measured in P. australis aboveground tissue, the net standing stock accumulation potential was still higher in T. domingensis. The net aboveground standing stock of nutrients in the Las Vegas Wash wetlands was measured (approximately 26418.7 kg N and 1264.1 kg P) for P. australis and (approximately 5183.8 kg N and 272.83 kg P) for T. domingensis. Harvesting aboveground biomass from both species would remove total nitrogen significantly from the system but not total phosphorus. Furthermore, harvesting P. australis during the peak growth period might positively impact the semi arid wetlands because it will provide more ground for T. domingensis extension. The comparative analysis of the emergent vegetation potential for biomass accumulation, nutrient concentration and standing stock was not significantly different among humid and semi arid wetlands. The humid and semi arid wetlands are characterized by a better understanding of the long term function and processes associated with the nutrient uptake potential of wetlands vegetation.

Adhikari, A. R.; Acharya, K.; Yu, Z.

2011-12-01

56

Experimental removal of wetland emergent vegetation leads to decreased methylmercury production in surface sediment  

NASA Astrophysics Data System (ADS)

We performed plant removal (devegetation) experiments across a suite of ecologically diverse wetland settings (tidal salt marshes, river floodplain, rotational rice fields, and freshwater wetlands with permanent or seasonal flooding) to determine the extent to which the presence (or absence) of actively growing plants influences the activity of the Hg(II)-methylating microbial community and the availability of Hg(II) to those microbes. Vegetated control plots were paired with neighboring devegetated plots in which photosynthetic input was terminated 4-8 months prior to measurements, through clipping aboveground biomass, severing belowground connections, and shading the sediment surface to prevent regrowth. Across all wetlands, devegetation decreased the activity of the Hg(II)-methylating microbial community (kmeth) by 38%, calculated MeHg production potential (MP) rates by 36%, and pore water acetate concentration by 78%. Decreases in MP were associated with decreases in microbial sulfate reduction in salt marsh settings. In freshwater agricultural wetlands, decreases in MP were related to indices of microbial iron reduction. Sediment MeHg concentrations were also significantly lower in devegetated than in vegetated plots in most wetland settings studied. Devegetation effects were correlated with live root density (percent volume) and were most profound in vegetated sites with higher initial pore water acetate concentrations. Densely rooted wetlands had the highest rates of microbial Hg(II)-methylation activity but often the lowest concentrations of bioavailable reactive Hg(II). We conclude that the exudation of labile organic carbon (e.g., acetate) by plants leads to enhanced microbial sulfate and iron reduction activity in the rhizosphere, which results in high rates of microbial Hg(II)-methyation and high MeHg concentrations in wetland sediment.

Windham-Myers, Lisamarie; Marvin-Dipasquale, Mark; Krabbenhoft, David P.; Agee, Jennifer L.; Cox, Marisa H.; Heredia-Middleton, Pilar; Coates, Carolyn; Kakouros, Evangelos

2009-06-01

57

Soil moisture and evapotranspiration of wetlands vegetation habitats retrieved from satellite images  

NASA Astrophysics Data System (ADS)

The research has been carried out in Biebrza Ramsar Convention test site situated in the N-E part of Poland. Data from optical and microwave satellite images have been analysed and compared to the detailed soil-vegetation ground truth measurements conducted during the satellite overpasses. Satellite data applied for the study include: ENVISAT.ASAR, ENVISAT.MERIS, ALOS.PALSAR, ALOS.AVNIR-2, ALOS.PRISM, TERRA.ASTER, and NOAA.AVHRR. Optical images have been used for classification of wetlands vegetation habitats and vegetation surface roughness expressed by LAI. Also, heat fluxes have been calculated using NOAA.AVHRR data and meteorological data. Microwave images have been used for the assessment of soil moisture. For each of the classified wetlands vegetation habitats the relationship between soil moisture and backscattering coefficient has been examined, and the best combination of microwave variables (wave length, incidence angle, polarization) has been used for mapping and monitoring of soil moisture. The results of this study give possibility to improve models of water cycle over wetlands ecosystems by adding information about soil moisture and surface heat fluxes derived from satellite images. Such information is very essential for better protection of the European sensitive wetland ecosystems. ENVISAT and ALOS images have been obtained from ESA for AO ID 122 and AOALO.3742 projects.

Dabrowska-Zielinska, K.; Budzynska, M.; Kowalik, W.; Turlej, K.

2010-08-01

58

Vegetation communities in continental boreal wetlands along a salinity gradient: Implications for oil sands mining reclamation  

Microsoft Academic Search

Oil sands mining is a major disturbance to boreal landscapes in north-eastern Alberta, Canada. Freshwater peatlands dominate the landscape prior to mining, but the post-mining reclamation landscape will have wetlands that span a salinity gradient. Little is known about the native vegetation communities in subsaline and saline marshes in the boreal region, yet these communities offer the best potential for

Marsha Trites; Suzanne E. Bayley

2009-01-01

59

Modeling Vegetation Dynamics in Response to Hydrological Changes in a Small Urban Tropical Freshwater Wetland  

NASA Astrophysics Data System (ADS)

Wetlands worldwide face drastic degradation from human-induced changes. A small freshwater wetland located within the dense urbanized island state of Singapore---the Nee Soon Wetland---is no exception. It is the only significant locality in Singapore of peat swamp forest and is home to a wide range of rare and endangered floral and faunal species. Unfortunately, changes in downstream land use and surrounding reservoirs' operations may pose threats to the coupled hydrological and vegetation systems. This study develops and applies coupled hydrological-vegetation models to understand the dynamic relationships between hydrology and vegetation systems, and simulates vegetation responses to hydrological changes in Nee Soon. The models combine a hydrological component with a vegetation component. The hydrological component accounts for both saturated and unsaturated flows, and incorporates evapotranspiration, rainfall infiltration and recharge from streams and reservoirs. The vegetation component is described by Lokta-Volterra equations that are tailored for plant growth, to simulate the vegetation dynamics of up to three species that thrive in different flooding conditions. Important findings include: (1) groundwater levels within Nee Soon are not highly sensitive to the operating levels of the surrounding reservoirs. However, (2) downstream drainage results in a localized zone of influence with significant adverse impacts, especially on the less flood-tolerant species. In addition, (3) the severely impacted less flood-tolerant species is unable to recover even when previous hydrological conditions are restored, unless the downstream drainage duration is reduced, or the plant characteristics such as maximum assimilation rates or competitiveness are increased. Finally, (4) hydrological conditions and species competitiveness supersede any other plant growth characteristics in determining the stable coexistence of different species. The developed models and modeling results simulation results help preservation efforts and guide conservation strategies in Nee Soon, as well as many wetlands worldwide.

Chui, T. M.; Palanisamy, B.; Mohanadas, H.

2011-12-01

60

Effect of climate fluctuations on long-term vegetation dynamics in Carolina bay wetlands  

USGS Publications Warehouse

Carolina bays and similar depression wetlands of the U.S. Southeastern Coastal Plain have hydrologic regimes that are driven primarily by rainfall. Therefore, climate fluctuations such as drought cycles have the potential to shape long-term vegetation dynamics. Models suggest two potential long-term responses to hydrologic fluctuations, either cyclic change maintaining open emergent vegetation, or directional succession toward forest vegetation. In seven Carolina bay wetlands on the Savannah River Site, South Carolina, we assessed hydrologic variation and vegetation response over a 15-year period spanning two drought and reinundation cycles. Changes in pond stage (water depth) were monitored bi-weekly to monthly each year from 1989?2003. Vegetation composition was sampled in three years (1989, 1993, and 2003) and analyzed in relation to changes in hydrologic conditions. Multi-year droughts occurred prior to the 1989 and 2003 sampling years, whereas 1993 coincided with a wet period. Wetland plant species generally maintained dominance after both wet and dry conditions, but the abundances of different plant growth forms and species indicator categories shifted over the 15-year period. Decreased hydroperiods and water depths during droughts led to increased cover of grass, upland, and woody species, particularly at the shallower wetland margins. Conversely, reinundation and longer hydroperiods resulted in expansion of aquatic and emergent species and reduced the cover of flood-intolerant woody and upland species. These semi-permanent Upper Coastal Plain bays generally exhibited cyclic vegetation dynamics in response to climate fluctuation, with wet periods favoring dominance by herbaceous species. Large basin morphology and deep ponding, paired with surrounding upland forest dominated by flood-intolerant pines, were features contributing to persistence of herbaceous vegetation. Drought cycles may promote directional succession to forest in bays that are smaller, shallower, or colonized by flood-tolerant hardwoods.

Stroh, C. L.; De Steven, D.; Guntenspergen, G.R.

2008-01-01

61

Effects of vegetation manipulation on breeding waterfowl in prairie wetlands--a literature review  

USGS Publications Warehouse

Literature on the effects of fire and grazing on the wetlands used by breeding prairie waterfowl is reviewed. Both dabbling and diving ducks and their broods prefer wetlands with openings in the marsh canopy. Decreased use is commonly associated with decreased habitat heterogeneity caused by tall, robust hydrophytes such as Typha spp. and other species adapted to form monotypes in the absence of disturbance. Nearly all previous studies indicate that reductions in height and density of tall, emergent hydrophytes by fire and grazing (unless very intensive) generally benefit breeding waterfowl. Such benefits are an increase in pair density, probably related to increased interspersion of cover and open water which decreases visibility among conspecific pairs, and improvements in their invertebrate food resources that result from increased habitat heterogeneity. Research needs are great because of the drastic changes that have accrued to prairie wetlands through fire suppression, cultivation, and other factors. The physical and biological environments preferred by species of breeding waterfowl during their seasonal and daily activities should be ascertained from future studies in wetland complexes that exist in the highest state of natural preservation. Long-term burning and grazing experiments should follow on specific vegetatively-degraded wetlands judged to be potentially important breeding areas. Seasonality, frequency, and intensity of treatments should be varied and combined and, in addition to measuring the response of the biotic community, the changes in the physical and chemical environment of the wetlands should be monitored to increase our knowledge of causative factors and possible predictive values.

Kantrud, H. A.

1986-01-01

62

Evaluation of multispatial scale measurements for monitoring wetland vegetation, Kushiro wetland, Japan: application of SPOT images, CASI data, airborne CNIR video images and balloon aerial photography  

Microsoft Academic Search

Our study was designed to evaluate the potential use for various spectral and spatial resolutions to classify the wetland vegetation into the species level. The objectives of our study is to investigate which combination of remote sensing systems is the most appropriate for delineating and mapping of specific and preservative vegetation. That is, to clarify appropriate remote sensing data and

M. Miyamoto; K. Kushida; K. Yoshino; T. Nagano; Y. Sato

2003-01-01

63

Surface-water transport of suspended matter through wetland vegetation of the Florida everglades  

NASA Astrophysics Data System (ADS)

The mobility of waterborne particulate matter plays an important role in the water quality, landscape evolution, and ecology of freshwater wetlands. In this work, we measured the surface-water transport of inorganic particles in a tracer experiment at a wetland in the Florida Everglades. Comparison of the results of this experiment to calculations of a three-dimensional transport model shows that dispersive mixing was small and that rate-limited mass-transfer reactions with emergent vegetation and periphyton substantially reduced water-column concentrations of particles.

Saiers, James E.; Harvey, Judson W.; Mylon, Steven E.

2003-10-01

64

Nitrogen detection in the vegetation of prototype constructed wetlands using chlorophyll fluorescence  

NASA Astrophysics Data System (ADS)

Constructed wetlands are a very efficient, clean and economical way to remove organic contaminants from waste water. In the whole water cleaning process, some other complex processes, such as physical sedimentation, filtration, chemical precipitation, and material absorption by vegetation, are involved. The Nitrogen absorption efficiency by heliconnia psitacorumm, was studied at laboratory scale in a small reactor simulating a subsurface flow constructed wetland. Chlorophyll increasing was measured by fluorescence, using blue LED, 460 [nm] as excitation light source. Besides, spectral differences were observed in the spectral signal and in its derivative, indicating changes in the plant physiological response.

Rosero, Edison; Plazas, Lucero; Solarte, Efraín; Fernández, Adrián; Peña, Enrique; Peña, Miguel

2009-08-01

65

Hydrologic, soil, and vegetation gradients in remnant and constructed riparian wetlands in west-central Missouri, 2001-04  

USGS Publications Warehouse

A study was conducted by the U.S. Geological Survey in cooperation with the Missouri Department of Conservation at the Four Rivers Conservation Area (west-central Missouri), between January 2001 and March 2004, to examine the relations between environmental factors (hydrology, soils, elevation, and landform type) and the spatial distribution of vegetation in remnant and constructed riparian wetlands. Vegetation characterization included species composition of ground, understory, and overstory layers in selected landforms of a remnant bottomland hardwood ecosystem, monitoring survival and growth of reforestation plots in leveed and partially leveed constructed wetlands, and determining gradients in colonization of herbaceous vegetation in a constructed wetland. Similar environmental factors accounted for variation in the distribution of ground, understory, and overstory vegetation in the remnant bottomland forest plots. The primary measured determining factors in the distribution of vegetation in the ground layer were elevation, soil texture (clay and silt content), flooding inundation duration, and ponding duration, while the distribution of vegetation in the understory layer was described by elevation, soil texture (clay, silt, and sand content), total flooding and ponding inundation duration, and distance from the Marmaton or Little Osage River. The primary measured determining factors in the distribution of overstory vegetation in Unit 1 were elevation, soil texture (clay, silt, and sand content), total flooding and ponding inundation duration, ponding duration, and to some extent, flooding inundation duration. Overall, the composition and structure of the remnant bottomland forest is indicative of a healthy, relatively undisturbed flood plain forest. Dominant species have a distribution of individuals that shows regeneration of these species with significant recruitment in the smaller size classes. The bottomland forest is an area whose overall hydrology has not been significantly altered; however, portions of the area have suffered from hydrologic alteration by a drainage ditch that is resulting in the displacement of swamp and marsh species by colonizing shrub and tree species. This area likely will continue to develop into an immature flood plain forest under the current (2004) hydrologic regime. Reforestation plots in constructed wetlands consisted of sampling survival and growth of multiple tree species (Quercus palustris, pin oak; Carya illinoiensis, pecan) established under several production methods and planted at multiple elevations. Comparison of survival between tree species and production types showed no significant differences for all comparisons. Survival was high for both species and all production types, with the highest mortality seen in the mounded root production method (RPM?) Quercus palustris (pin oak, 6.9 percent), while direct seeded Quercus palustris at middle elevation and bare root Quercus palustris seedlings at the low elevation plots had 100 percent survival. Measures of growth (diameter and height) were assessed among species, production types, and elevation by analyzing relative growth. The greatest rate of tree diameter (72.3 percent) and height (65.3 percent) growth was observed for direct seeded Quercus palustris trees planted at a middle elevation site. Natural colonized vegetation data were collected at multiple elevations within an abandoned cropland area of a constructed wetland. The primary measured determining factors in the distribution of herbaceous vegetation in this area were elevation, ponding duration, and soil texture. Richness, evenness, and diversity were all significantly greater in the highest elevation plots as a result of more recent disturbance in this area. While flood frequency and duration define the delivery mechanism for inundation on the flood plain, it is the duration of ponding and amount of 'topographic capture' of these floodwaters in fluvial lan

Heimann, David C.; Mettler-Cherry, Paige A.

2004-01-01

66

An assessment of vegetation and environmental controls in the 1970s of the Mesopotamian wetlands of southern Iraq  

Microsoft Academic Search

A vast ecosystem of wetlands and lakes once covered the Mesopotamian Plain of southern Iraq. Widespread drainage in the 1990s\\u000a nearly obliterated both components of the landscape. This paper reports the results of a study undertaken in 1972–1975 on\\u000a the vegetation of the wetlands prior to drainage and provides a unique baseline for gauging future restoration of the wetland\\u000a ecosystems

Majeed R. A. Al-Hilli; Barry G. Warner; Taro Asada; Ali Douabul

2009-01-01

67

Multitemporal classification of TerraSAR-X data for wetland vegetation mapping  

NASA Astrophysics Data System (ADS)

This paper is concerned with wetland vegetation mapping using multitemporal synthetic aperture radar imagery. Although wetlands play a key role in controlling flooding and nonpoint source pollution, sequestering carbon and providing an abundance of ecological services, knowledge of the flora and fauna of these environments is patchy, and understanding of their ecological functioning is still insufficient for a reliable functional assessment on areas larger than a few hectares. The aim of this paper is to evaluate multitemporal TerraSAR-X imagery to precisely map the distribution of vegetation formations considering flood duration. A series of six dual-polarization TerraSAR-X images (HH-VV) was acquired in 2012 during dry and wet seasons. One polarimetric parameter, the Shannon entropy (SE), and two intensity parameters (?° HH and ?° VV), which vary with wetland flooding status and vegetation roughness, were first extracted. These parameters were then classified using support vector machine techniques based on a specific kernel adapted to the comparison of time-series data, K-nearest neighbors, and decision tree (DT) algorithms. The results show that the vegetation formations can be identified very accurately (kappa index=0.85) from the classification of SE temporal profiles derived from the TerraSAR-X images. They also reveal the importance of the use of polarimetric parameters instead of backscattering coefficients alone (HH or VV) or combined (HH and VV).

Betbeder, Julie; Rapinel, Sébastien; Corpetti, Thomas; Pottier, Eric; Corgne, Samuel; Hubert-Moy, Laurence

2014-01-01

68

Bathymetry and Vegetation in Isolated March and Cypress Wetlands in the Northern Tampa Bay Area, 2000-2004.  

National Technical Information Service (NTIS)

The purpose of this report is to describe the bathymetry and vegetation of 10 isolated wetlands in the NTB area. Specifically, the report: (1) describes relations between wetland water level (stage), the area of inundation, and stored water volume; (2) co...

K. H. Haag T. M. Lee D. C. Herndon

2005-01-01

69

Effect of the Lower Kihansi Hydropower Project and post-project mitigation measures on wetland vegetation in Kihansi Gorge, Tanzania  

Microsoft Academic Search

Reduction in flow of the Lower Kihansi River, Tanzania, caused by implementation of a hydropower project in May 2000 has the potential to lead to changes in vegetation composition of spray maintained wetlands. These wetlands are the only known habitat for the Kihansi Spray Toad, Nectophrynoides\\u000aasperginis. In this paper, change over time is assessed by comparing samples taken in

C. H. Quinn; H. J. Ndangalasi; J. Gerstle; J. C. Lovett

2005-01-01

70

Drivers and feedbacks in spatial and temporal patterning of hydrology and vegetation in the Everglades wetlands  

NASA Astrophysics Data System (ADS)

Hosting a large variety of vegetal and animal species, many of which rare or endangered, wetlands are among the most rich and vulnerable ecosystems in the world. Throughout the past century, the growing climatic impact and the increasing anthropogenic pressure have seriously threatened their natural equilibrium and substantially deteriorated their ecosystems. For fragility, biodiversity and extension, the Everglades is probably one of the most iconic wetlands in the world. After decades of land seizing and exploitation following the southward march of development in Florida, awareness of the importance of the Everglades wetlands has recently risen, bringing it to the center of one of the largest and most ambitious restoration projects ever attempted. Wetlands equilibrium and biodiversity are crucially linked to the hydrologic regime. In the Everglades, hydroperiods (i.e. percent of time a site is inundated) exert a critical control in the creation of habitat niches for different plant species. However, the feedbacks between the hydrologic signature and the plant dynamics that ultimately yield the observed spatial vegetation patterns are unknown. We identify both the main hydrologic and local drivers of the vegetation species spatial configuration and use them within a robust modeling framework able to reproduce the vegetation structures currently observed in the Everglades. By including both exogenous (i.e. hydrologic) and endogenous (i.e. local interactions) forcings, we are able to describe the mechanisms yielding to the observed power law behavior of the cluster size distribution of vegetation species. Since power law clustering is often associated with self-organization and systems near critical transitions, these findings can be successfully used to quantitatively assess the impact of potential climatic shifts and the effect of habitat loss or deterioration due to human activity, and can assist policy makers in identifying case-specific ecosystems restoration and preservation measures.

Miralles-Wilhelm, F.; Foti, R.; Rinaldo, A.; Rodriguez-Iturbe, I.; Del Jesus, M.

2013-05-01

71

An ecohydrological model for studying groundwater-vegetation interactions in wetlands  

NASA Astrophysics Data System (ADS)

SummaryDespite their importance to the natural environment, wetlands worldwide face drastic degradation from changes in land use and climatic patterns. To help preservation efforts and guide conservation strategies, a clear understanding of the dynamic relationship between coupled hydrology and vegetation systems in wetlands, and their responses to engineering works and climate change, is needed. An ecohydrological model was developed in this study to address this issue. The model combines a hydrology component based on the Richards' equation for characterizing variably saturated groundwater flow, with a vegetation component described by Lotka-Volterra equations tailored for plant growth. Vegetation is represented by two characteristic wetland herbaceous plant types which differ in their flood and drought resistances. Validation of the model on a study site in the Everglades demonstrated the capability of the model in capturing field-measured water table and transpiration dynamics. The model was next applied on a section of the Nee Soon swamp forest, a tropical wetland in Singapore, for studying the impact of possible drainage works on the groundwater hydrology and native vegetation. Drainage of 10 m downstream of the wetland resulted in a localized zone of influence within half a kilometer from the drainage site with significant adverse impacts on groundwater and biomass levels, indicating a strong need for conservation. Simulated water table-plant biomass relationships demonstrated the capability of the model in capturing the time-lag in biomass response to water table changes. To test the significance of taking plant growth into consideration, the performance of the model was compared to one that substituted the vegetation component with a pre-specified evapotranspiration rate. Unlike its revised counterpart, the original ecohydrological model explicitly accounted for the drainage-induced plant biomass decrease and translated the resulting reduced transpiration toll back to the groundwater hydrology for a more accurate soil water balance. This study represents, to our knowledge, the first development of an ecohydrological model for wetland ecosystems that characterizes the coupled relationship between variably-saturated groundwater flow and plant growth dynamics.

Chui, Ting Fong May; Low, Swee Yang; Liong, Shie-Yui

2011-10-01

72

Influence of vegetation on the removal of heavy metals and nutrients in a constructed wetland.  

PubMed

A free water surface wetland was built to treat wastewater containing metals (Cr, Ni, Zn) and nutrients from a tool factory in Argentina. Water, sediment and macrophytes were sampled in the inlet and outlet area of the constructed wetland during three years. Three successive phases of vegetation dominance were developed and three different patterns of contaminant retention were observed. During the Eichhornia crassipes dominance, contaminants were retained in the macrophyte biomass; during the E. crassipes+Typha domingensis stage, contaminants were retained in the sediment and in the T. domingensis dominance stage, contaminants were retained in sediment and in the macrophyte biomass. Removal efficiency was not significantly different among the three vegetation stages, except for NH(4)(+) and i-P(diss). Because of its highest tolerance, T. domingensis is the best choice to treat wastewater of high pH and conductivity with heavy metals, a common result from many industrial processes. PMID:18079048

Maine, M A; Suñe, N; Hadad, H; Sánchez, G; Bonetto, C

2009-01-01

73

Relationship between hydraulic efficiency and phosphorus removal in a submerged aquatic vegetation-dominated treatment wetland  

Microsoft Academic Search

A tracer study (Rhodamine-WT dye) was performed on a 147-ha submerged aquatic vegetation (SAV)-dominated free-water surface treatment wetland in south Florida that received agricultural drainage waters (ADW). Two dimensional, time series plots of the dye concentrations revealed that a disproportionate amount of tracer flowed along the eastern and western levees of the cell. The tracer response curve developed from the

Forrest E. Dierberg; John J. Juston; Thomas A. DeBusk; Kathy Pietro; Binhe Gu

2005-01-01

74

Quantification strategies for human-induced and natural hydrological changes in wetland vegetation, southern Florida, USA  

NASA Astrophysics Data System (ADS)

An accurately dated peat profile from a mixed cypress swamp in the Fakahatchee Strand Preserve State Park (FSPSP, Florida, USA) has been examined for pollen and spores. The near-annual resolved pollen record shows a gradual shift from a wet to a relatively dry assemblage during the past 100 years. Timing of drainage activities in the region is accurately reflected by the onset and duration of vegetation change in the swamp. The reconstructed vegetation record has been statistically related to pollen assemblages from surface sediment samples. The response range of the FSPSP wetland to environmental perturbations could thus be determined and this allows better understanding of naturally occurring vegetation changes. In addition, the human impact on Florida wetlands becomes increasingly apparent. Superimposed high-frequency variation in the record suggests a positive correlation between winter-precipitation and pollen productivity of the dominant tree taxa. However, further high-resolution analysis is needed to confirm this relation. The response range of the FSPSP wetland to environmental perturbations on both annual- and decadal-scales documented in this study allows recognition and quantification of natural hydrological changes in older deposits from southwest Florida. The strong link between local hydrology and the El Niño Southern Oscillation makes the palynological record from FSPSP highly relevant for studying past El Niño—variability.

Donders, Timme H.; Wagner, Friederike; Visscher, Henk

2005-11-01

75

How vegetation and sediment transport feedbacks drive landscape change in the everglades and wetlands worldwide.  

PubMed

Mechanisms reported to promote landscape self-organization cannot explain vegetation patterning oriented parallel to flow. Recent catastrophic shifts in Everglades landscape pattern and ecological function highlight the need to understand the feedbacks governing these ecosystems. We modeled feedback between vegetation, hydrology, and sediment transport on the basis of a decade of experimentation. Results from more than 100 simulations showed that flows just sufficient to redistribute sediment from sparsely vegetated sloughs to dense ridges were needed for an equilibrium patterned landscape oriented parallel to flow. Surprisingly, although vegetation heterogeneity typically conveys resilience, in wetlands governed by flow/sediment feedbacks it indicates metastability, whereby the landscape is prone to catastrophic shifts. Substantial increases or decreases in flow relative to the equilibrium condition caused an expansion of emergent vegetation and loss of open-water areas that was unlikely to revert upon restoration of the equilibrium hydrology. Understanding these feedbacks is critical in forecasting wetland responses to changing conditions and designing management strategies that optimize ecosystem services, such as carbon sequestration or habitat provision. Our model and new sensitivity analysis techniques address these issues and make it newly apparent that simply returning flow to predrainage conditions in the Everglades may not be sufficient to restore historic landscape patterns and processes. PMID:20635883

Larsen, Laurel G; Harvey, Judson W

2010-09-01

76

Effects of different vegetation zones on CH4 and N2O emissions in coastal wetlands: a model case study.  

PubMed

The coastal wetland ecosystems are important in the global carbon and nitrogen cycle and global climate change. For higher fragility of coastal wetlands induced by human activities, the roles of coastal wetland ecosystems in CH4 and N2O emissions are becoming more important. This study used a DNDC model to simulate current and future CH4 and N2O emissions of coastal wetlands in four sites along the latitude in China. The simulation results showed that different vegetation zones, including bare beach, Spartina beach, and Phragmites beach, produced different emissions of CH4 and N2O in the same latitude region. Correlation analysis indicated that vegetation types, water level, temperature, and soil organic carbon content are the main factors affecting emissions of CH4 and N2O in coastal wetlands. PMID:24892044

Liu, Yuhong; Wang, Lixin; Bao, Shumei; Liu, Huamin; Yu, Junbao; Wang, Yu; Shao, Hongbo; Ouyang, Yan; An, Shuqing

2014-01-01

77

Effects of Different Vegetation Zones on CH4 and N2O Emissions in Coastal Wetlands: A Model Case Study  

PubMed Central

The coastal wetland ecosystems are important in the global carbon and nitrogen cycle and global climate change. For higher fragility of coastal wetlands induced by human activities, the roles of coastal wetland ecosystems in CH4 and N2O emissions are becoming more important. This study used a DNDC model to simulate current and future CH4 and N2O emissions of coastal wetlands in four sites along the latitude in China. The simulation results showed that different vegetation zones, including bare beach, Spartina beach, and Phragmites beach, produced different emissions of CH4 and N2O in the same latitude region. Correlation analysis indicated that vegetation types, water level, temperature, and soil organic carbon content are the main factors affecting emissions of CH4 and N2O in coastal wetlands.

Liu, Yuhong; Wang, Lixin; Bao, Shumei; Liu, Huamin; Yu, Junbao; Wang, Yu; Shao, Hongbo; Ouyang, Yan; An, Shuqing

2014-01-01

78

Vegetation survey of Pen Branch and Four Mile Creek wetlands  

SciTech Connect

One hundred-fifty plots were recently sampled (vegetational sampling study) at the Savannah River Site (SRS). An extensive characterization of the vascular flora, in four predetermined strata (overstory, Understory, shrub layer, and ground cover), was undertaken to determine dominance, co-dominance, and the importance value (I.V.) of each species. These results will be used by the Savannah River Laboratory (SRL) to evaluate the environmental status of Four Mile Creek, Pen Branch, and two upland pine stands. Objectives of this study were to: Describe in detail the plant communities previously mapped with reference to the topography and drainage, including species of plants present: Examine the successional trends within each sampling area and describe the extent to which current vegetation communities have resulted from specific earlier vegetation disturbances (e.g., logging and grazing); describe in detail the botanical field techniques used to sample the flora; describe the habitat and location of protected and/or rare species of plants; and collect and prepare plant species as herbarium quality specimens. Sampling was conducted at Four Mile Creek and Pen Branch, and in two upland pine plantations of different age growth.

Not Available

1992-10-01

79

Vegetation survey of Pen Branch and Four Mile Creek wetlands  

SciTech Connect

One hundred-fifty plots were recently sampled (vegetational sampling study) at the Savannah River Site (SRS). An extensive characterization of the vascular flora, in four predetermined strata (overstory, Understory, shrub layer, and ground cover), was undertaken to determine dominance, co-dominance, and the importance value (I.V.) of each species. These results will be used by the Savannah River Laboratory (SRL) to evaluate the environmental status of Four Mile Creek, Pen Branch, and two upland pine stands. Objectives of this study were to: Describe in detail the plant communities previously mapped with reference to the topography and drainage, including species of plants present: Examine the successional trends within each sampling area and describe the extent to which current vegetation communities have resulted from specific earlier vegetation disturbances (e.g., logging and grazing); describe in detail the botanical field techniques used to sample the flora; describe the habitat and location of protected and/or rare species of plants; and collect and prepare plant species as herbarium quality specimens. Sampling was conducted at Four Mile Creek and Pen Branch, and in two upland pine plantations of different age growth.

Not Available

1992-01-01

80

[Carbon storage and carbon fixation during the succession of natural vegetation in wetland ecosystem on east beach of Chongming Island].  

PubMed

Vegetation is an important biological factor in the ecological succession of wetland, and the main factor affecting the carbon storage and carbon fixation in wetland ecosystem. By the methods of field survey and lab analysis, this paper studied the carbon storage and carbon fixation during the succession of wetland vegetation on east beach of Chongming Island, and the results showed that there existed greater differences in the existing carbon storage and its allocation in wetland vegetation at its different succession stages. The existing carbon storage of the pioneer plant Scirpus mariqueter was much less than that of Phragmites australis, only accounted for about 13% of the latter. The underground rhizome of P. australis and the aboveground part of S. mariqueter were the main sites of existing carbon storage. P. australis at the later succession stage of wetland vegetation had a stronger capability of carbon fixation than S. mariqueter at the earlier succession stage of the vegetation, with the values being (1.63 +/- 0.39) kg x m(-2) x a(-1) and (0.63 +/- 0.28) kg x m(-2) x a(-1), respectively, suggesting that during the succession of S. mariqueter community to P. australis community, the carbon fixation capability of the wetland ecosystem became stronger. PMID:17615896

Mei, Xue-Ying; Zhang, Xiu-Feng

2007-04-01

81

Integrating field sampling, spatial statistics and remote sensing to map wetland vegetation in the Pantanal, Brazil  

NASA Astrophysics Data System (ADS)

To improve the protection of wetlands, it is imperative to have a thorough understanding of their structuring elements and of the identification of efficient methods to describe and monitor them. This article uses sophisticated statistical classification, interpolation and error propagation techniques, in order to describe vegetation spatial patterns, map plant community distribution and evaluate the capability of statistical approaches to produce high-quality vegetation maps. The approach results in seven vegetation communities with a known floral composition that can be mapped over large areas using remotely sensed data. The relations between remotely sensing data and vegetation patterns, captured in four factorial axes, were formalized mathematically in multiple linear regression models and used in a universal kriging procedure to reduce the uncertainty in mapped communities. Universal kriging has shown to be a valuable interpolation technique because parts of vegetation variability not explained by the images could be modeled as spatially correlated residuals, increasing prediction accuracy. Differences in spatial dependence of the vegetation gradients evidenced the multi-scale nature of vegetation communities. Cross validation procedures and Monte Carlo simulations were used to quantify the uncertainty in the resulting map. Cross-validation showed that accuracy in classification varies according with the community type, as a result of sampling density and configuration. A map of uncertainty resulted from Monte Carlo simulations displayed the spatial variation in classification accuracy, showing that the quality of classification varies spatially, even though the proportion and arrangement of communities observed in the original map is preserved to a great extent. These results suggested that mapping improvement could be achieved by increasing the number of field observations of those communities with a scattered and small patch size distribution; or by including new digital images as explanatory variables in the model. By comparing the resulting plant community map with a flood duration map, we verified that flooding duration is an important driver of vegetation zonation. We discuss our study in the context of developing a mapping approach that is able to integrate field point data and high-resolution remote sensing images, providing new basis to map wetland vegetation and allowing its future application in habitat management, conservation assessment and long-term ecological monitoring in wetland landscapes.

Arieira, J.; Karssenberg, D.; de Jong, S. M.; Addink, E. A.; Couto, E. G.; Nunes da Cunha, C.; Skøien, J. O.

2010-09-01

82

Wetland functional health assessment using remote sensing and other techniques: Literature search and overview. Technical memo  

SciTech Connect

Contents: introduction; remote sensing of wetland biomass and other wetland condition indicators; conceptual approaches in wetland assessment; wetland extent and type; landscape and wetland patterns; wetland biomass and productivity; wetland vegetation; wetland habitat quality; wetland hydrology; and conclusions and recommendations.

Patience, N.; Klemas, V.

1993-03-01

83

TTC Dyeing for Evaluation of Wetland Vegetation Activity in Sarobetsu Mire, Northern Japan  

NASA Astrophysics Data System (ADS)

Reduced groundwater levels cause drying and shrinkage of mires, resulting in rapid changes in wetland vegetation. To conserve pre-existing wetland vegetation, it is important to clarify its behavior in relation to groundwater level fluctuations. Sarobetsu Mire, the biggest high moor in Japan, is experiencing a transition of its wetland vegetation due to increased invasion by dwarf bamboo (Sasa (Eusasa)). Previous studies have been limited to qualitative assessment concluding that the reduction of wetland vegetation areas is taking place. The invasion of dwarf bamboo was found to be inhibited in areas with high groundwater levels, but few studies have sought to quantitatively assess the responses of individual plants to groundwater variations. Growth activity has often been measured using the triphenyl-tetrazolium-chloride (TTC) method, which is a simple approach. The purpose of this study is to develop a quantitative method to assess the response (in terms of activity) of wetland vegetation to groundwater levels. To examine the relationship between the two (i.e., whether plants are dead or alive), a pair of laboratory experiments was conducted using the TTC method and absorptimetry with dwarf bamboo collected from Sarobetsu Mire. The first experiment was to investigate the activity of wetland vegetation in an inundated environment, and the second was to investigate annual fluctuations in such activity. The results showed that the activity (in terms of absorbance) of dwarf bamboo continued to decrease immediately after collection, and that the absorbance peak at a wavelength of 480 nm was also smaller. However, after the submersion period exceeded 30 days, there were no significant changes in absorbance as the submersion period went on. This indicates that dwarf bamboo underwent activity loss and died when the submersion period exceeded 30 days. Dwarf bamboo was considered dead when absorbance (480 nm) was 0.2 or lower and the peak became unclear. Since the change in absorbance was the largest for dwarf bamboo at 480 nm, comparison at this wavelength was considered effective for activity judgment. This result indicated the feasibility of quantitative assessment for the activity of underground rhizomes of dwarf bamboo using TTC dyeing. The activity of dwarf bamboo is at its lowest in July, rises from July to December, is flat or shows a falling tendency from December to May, and falls sharply from June to July. The activity of rhizomes was low from June to August because their processes (in terms of nutrition) moved to the aerial parts of plants to supply nutrients to shoots. The growth of the aerial parts then subsided, suggesting that nutrients were stored in rhizomes from September onward. In the future, groundwater levels are expected to increase due to the restoration of river meanders as part of nature restoration projects, as well as in response to changes in hydrological environments caused by influences such as climate change. It will be necessary to verify the response of plant activity to groundwater levels using the TTC assessment method for various types of wetland vegetation and to promote verification in field tests.

Hayashida, K.; Murakami, Y.; Mizugaki, S.; Yano, M.

2011-12-01

84

Heavy metal contamination in vegetables cultivated on a major urban wetland inlet drainage system of Lake Victoria, Uganda  

Microsoft Academic Search

The population of the Ugandan capital, Kampala, located close to Lake Victoria, appears to be exposed to risk of ingesting the heavy metals Cadmium (Cd) and Lead (Pb) through vegetables in their diet. Lake Victoria is responsible for frequent torrential polluted runoffs in the city. The Nakivubo channel, the city’s major wetland drainage system, empties directly into the lake. Vegetables

Jolocam Mbabazi; J. Wasswa; J. Kwetegyeka; G. K. Bakyaita

2010-01-01

85

Coping with vegetation dynamics in low-land wetlands - Integration of RS derived interception into the rainfall-runoff model WetSpa  

NASA Astrophysics Data System (ADS)

The effective protection of wetlands demands knowledge of hydrological processes, which can be appropriately analysed using distributed models. It is eminent that the calibration and verification of distributed models of catchments with significant wetland coverage have to focus on wetland-specific issues such as the hydrological response of natural vegetation, i.e. parameterisation and dynamics of vegetation. An important and useful parameter describing vegetation canopy structure in terrestrial ecosystems is the Leaf Area Index (LAI), which is closely related to photosynthesis, net primary productivity, evapotranspiration and interception storage capacity. LAI can be estimated with remote sensing data, its suitability to derive the actual state of vegetation is high. This study focuses on improving the interception capacity calculation in the distributed hydrological model WetSpa. The main objective is to integrate seasonal LAI data. Not only field measurements, but also remote sensing derived LAI data is integrated into a WetSpa model for the Upper Biebrza catchment (northeast Poland). Biebrza National Park is characterized by a significant coverage of wetland and large variation in vegetation types. The use of remote sensing derived LAI values considerably improves the assessment of the actual status of vegetation and its seasonal dynamics. Landsat Thematic Mapper images are used to represent the different vegetation stages during the growing season (near LAI minimum and LAI maximum). They are analysed and processed to estimate the interception storage capacity of plant communities typical for Biebrza River valley. LAI of different plant communities has been measured using LAI-2000, and empirical relationships between these measurements and several spectral vegetation indices were established using linear and non-linear regression analysis. The vegetation indices with the highest correlation and the strongest linear relationship regarding LAI are NDVI (R2 = 0.72), SAVI (R2 = 0.72), MSI (R2 = 0.70) and MSR (R2 = 0.70). The minimum/maximum LAI maps are combined with the established equations to calculate spatially distributed hydrological parameter maps, i.e. minimum and maximum interception storage capacity. The model application yields considerable spatio-temporal differences in interception estimates for scenarios using interception maps calculated based on (1) LAI measurements and remote sensing data, compared to (2) the standard Corine Land Cover 2006 based data.

Jaros?aw, J.; Szporak, S.; Verbeiren, B.; Batelaan, O.

2012-04-01

86

Effect of pond shape and vegetation heterogeneity on flow and treatment performance of constructed wetlands  

NASA Astrophysics Data System (ADS)

A model framework is developed for nitrogen transformations in a constructed wetland by combining both hydraulics and chemical transformation of nitrogen species. The nitrogen concentration of the effluent water is represented in terms of a convolution between the probability density function of the hydraulic residence times and a chemical transformation function describing the rate of mass-removal of total nitrogen with time in the water as a first-order reaction. Closed-form solutions to the treatment efficiency is derived and related to the nitrogen reduction in wetland Alhagen in Nynäshamn, Sweden. Further, the model coefficients are explored by numerical simulations and expressed in terms of heterogeneity of the flow resistance, i.e. in vegetation, and the aspect ratio of the wetland. Heterogeneity in vegetation contributes to increasing the variance of the water residence time and this increases the effluent concentration of nitrogen. Based on the theory and the data from Alhagen, the residence time probability density function for water can have a significant influence on the treatment, and particularly the aspect ratio markedly affects the active water volume and the treatment efficiency.

Wörman, Anders; Kronnäs, Veronika

2005-01-01

87

Wind driven vertical transport in a vegetated, wetland water column with air-water gas exchange  

NASA Astrophysics Data System (ADS)

Flow around arrays of cylinders at low and intermediate Reynolds numbers has been studied numerically, analytically and experimentally. Early results demonstrated that at flow around randomly oriented cylinders exhibits reduced turbulent length scales and reduced diffusivity when compared to similarly forced, unimpeded flows (Nepf 1999). While horizontal dispersion in flows through cylinder arrays has received considerable research attention, the case of vertical dispersion of reactive constituents has not. This case is relevant to the vertical transfer of dissolved gases in wetlands with emergent vegetation. We present results showing that the presence of vegetation can significantly enhance vertical transport, including gas transfer across the air-water interface. Specifically, we study a wind-sheared air-water interface in which randomly arrayed cylinders represent emergent vegetation. Wind is one of several processes that may govern physical dispersion of dissolved gases in wetlands. Wind represents the dominant force for gas transfer across the air-water interface in the ocean. Empirical relationships between wind and the gas transfer coefficient, k, have been used to estimate spatial variability of CO2 exchange across the worlds’ oceans. Because wetlands with emergent vegetation are different from oceans, different model of wind effects is needed. We investigated the vertical transport of dissolved oxygen in a scaled wetland model built inside a laboratory tank equipped with an open-ended wind tunnel. Plastic tubing immersed in water to a depth of approximately 40 cm represented emergent vegetation of cylindrical form such as hard-stem bulrush (Schoenoplectus acutus). After partially removing the oxygen from the tank water via reaction with sodium sulfite, we used an optical probe to measure dissolved oxygen at mid-depth as the tank water re-equilibrated with the air above. We used dissolved oxygen time-series for a range of mean wind speeds to estimate the gas transfer coefficient, k, for both a vegetated condition and a control condition (no cylinders). The presence of cylinders in the tank substantially increased the rate of the gas transfer. For the highest wind speed, the gas transfer coefficient was several times higher when cylinders were present compared to when they were not. The gas transfer coefficient for the vegetated condition also proved sensitive to wind speed, increasing markedly with increasing mean wind speeds. Profiles of dissolved oxygen revealed well-mixed conditions in the bulk water column following prolonged air-flow above the water surface, suggesting application of the thin-film model is appropriate. The enhanced gas exchange observed might be explained by increased turbulent kinetic energy within the water column and the anisotropy of the cylinder array, which constrains horizontal motions more than vertical motions. Improved understanding of gas exchange in vegetated water columns may be of particularly use to investigations of carbon fluxes and soil accretion in wetlands. Reference: Nepf, H. (1999), Drag, turbulence, and diffusion in flow through emergent vegetation, Water Resour. Res., 35(2), 479-489.

Poindexter, C.; Variano, E. A.

2010-12-01

88

Synthesis and Study of the Roadside Vegetation Establishment Process.  

National Technical Information Service (NTIS)

The Texas Pollutant Discharge Elimination System (TPDES), which is administered and enforced by the Texas Commission on Environmental Quality (TCEQ), requires perennial vegetation to 70 percent of native or adjacent background vegetation before a Notice o...

A. P. Garza B. J. Storey C. Robinson G. G. Marek J. A. McFalls J. R. Schutt K. Heflin K. D. Jones T. A. Gaus W. J. Rogers

2011-01-01

89

Wetlands  

NSDL National Science Digital Library

This video segment explains why Native people regard wetlands not only for their important ecological function, but for their spiritual value as well. For many tribes, wetlands represent life. They consider wetlands to be sacred places that must be protected from external sources of pollution, such as runoff from landscaping businesses and municipal discharges. Included is a background essay that gives a history of wetlands and the destruction they are now facing from human development. The many benefits of wetlands, like their ability to protect property from flooding. There are four discussion questions about the importance of wetlands and their functions. There is a helpful section that shows you the standards for your state ranging from grades K-12, as well as links to related resources.

2010-01-01

90

Plant community, primary productivity, and environmental conditions following wetland re-establishment in the Sacramento-San Joaquin Delta, California  

Microsoft Academic Search

Wetland restoration can mitigate aerobic decomposition of subsided organic soils, as well as re-establish conditions favorable\\u000a for carbon storage. Rates of carbon storage result from the balance of inputs and losses, both of which are affected by wetland\\u000a hydrology. We followed the effect of water depth (25 and 55 cm) on the plant community, primary production, and changes in\\u000a two re-established

Robin L. Miller; Roger Fujii

2010-01-01

91

7 CFR 1410.11 - Farmable Wetlands Program.  

Code of Federal Regulations, 2010 CFR

...hydrology of the wetland and establishing vegetative cover (which may include emerging vegetation in water and bottomland hardwoods, cypress, and other appropriate tree species in shallow water areas), as determined by CCC. (f)...

2010-01-01

92

CHARACTERIZATION OF MICROTOPOGRAPHY AND ITS INFLUENCE ON VEGETATION PATTERNS IN CREATED WETLANDS  

Microsoft Academic Search

Created wetlands are increasingly used to mitigate wetland loss. Thus, identifying wetland creation methods that enhance ecosystem development might increase the likelihood of mitigation success. Noting that the microtopographic variation found in natural wetland settings may not commonly be found in created wetlands, this study explores relationships between induced microtopography, hydrology, and plant species richness\\/diversity in non-tidal freshwater wetlands, comparing

Kurt Moser; Gregory Noe

2007-01-01

93

Wetland methane emissions during the Last Glacial Maximum estimated from PMIP2 simulations: Climate, vegetation, and geographic controls  

Microsoft Academic Search

It is an open question to what extent wetlands contributed to the interglacial-glacial decrease in atmospheric methane concentration. Here we estimate methane emissions from glacial wetlands, using newly available PMIP2 simulations of the Last Glacial Maximum (LGM) climate from coupled atmosphere-ocean and atmosphere-ocean-vegetation models. These simulations apply improved boundary conditions resulting in better agreement with paleoclimatic data than earlier PMIP1

S. L. Weber; A. J. Drury; W. H. J. Toonen; M. van Weele

2010-01-01

94

COMPARISON OF LEVELS OF SULFOLANE AND DIISOPROPANOLAMINE IN NATURAL WETLAND VEGETATION EXPOSED TO GAS-CONDENSATE CONTAMINATED GROUND WATER  

Microsoft Academic Search

Groundwater containing the process chemicals sulfolane (tetrahydrothiophene 1,1-dioxide) and diisopropanolamine (DIPA) has contaminated a wetland in the vicinity of a sour-gas natural gas processing facility. Of concern is the extent of which these contaminants are taken up by vegetation and the associated risk to wildlife that may eat the plants. All sampled wetland plants contained detectable levels of sulfolane and

John V. Headley; Leslie C. Dickson; Kerry M. Peru

2002-01-01

95

Effects of hydraulic resistance by vegetation on stage dynamics of a stormwater treatment wetland  

NASA Astrophysics Data System (ADS)

SummaryThis work examined the potential effects of large-scale thinning of emergent vegetation on the stage dynamics in a very large (33.3 km2) constructed treatment wetland in South Florida. Dense vegetative biomass in treatment wetlands may restrict water flow and increase water levels, which may in turn have adverse effects on vegetative community structure. Here, we developed a physically-based, spatially-distributed hydrodynamic model of Stormwater Treatment Area 2, Cell 2 (STA2C2) to investigate the spatio-temporal variability of water level (stage) in response to management for thinning of emergent macrophytes (e.g., burning and/or herbicide treatments). The model was calibrated against stage measured at six monitoring stations for 1 year, and subsequently validated against 2 years of stage data from eight stations. Finally, the validated model was extended to simulate various vegetation management scenarios. The model provided an excellent fit to observed stage data in both calibration and validation periods (median model efficiency indices of 0.82 and 0.83, respectively). Higher stages in the treatment cell were dominantly associated with peak inflow magnitude and the timing of event intervals. Prolonged periods of sustained deep water conditions were observed when one flow peak was followed by consecutive peaks. A gradual stage gradient from the inlet to outlet was observed during peak flow periods, with a shift to a sharp gradient at approximately two-thirds distance from the inlet. Stages in the wetland were found to be controlled less by the hydraulic resistance, as indicated by a low sensitivity of simulated water levels for a ±50% perturbation in flow resistance parameter. Water depths were reduced by a maximum of 12 cm at the inlet region by thoroughly thinning the remaining emergent vegetation in STA2C2. Similarly, a maximum of only 2% of the total STA2C2 area was prevented from exceeding a water depth believed to be detrimental to Typha sp. (1.22 m) after the highest peak inflow. Collectively, our findings suggested that vegetation thinning may not be effective for minimizing deep water conditions in STA2C2.

Paudel, Rajendra; Grace, Kevin A.; Galloway, Stacey; Zamorano, Manuel; Jawitz, James W.

2013-03-01

96

Perspectives to establish knowledge linkages between acidic deposition and vegetation responses  

SciTech Connect

This paper provides perspective for present and planned research that seeks to establish a knowledge linkage between acidic deposition and vegetation responses. The paper can be divided into three sections: (1) experimental approaches necessary to establish knowledge linkages between acidic deposition and vegetation responses, (2) perspectives obtained from an established air pollutant (ozone) - vegetation (ponderosa pine) response linkage, and (3) current obstacles to overcome in order to establish an information linkage between acidic deposition and forest decline in the northern Appalachians.

Evans, L.S.; Lewin, K.F.

1985-01-01

97

Direct and Indirect Effects of Vegetation on Methylmercury Production in Wetlands as Assessed by Experimental Plant Removal  

NASA Astrophysics Data System (ADS)

Although vegetated wetlands are among the most active habitats for microbial methylmercury (MeHg) production, the relative influence of wetland vegetation itself is poorly understood. Plant physiology and biomass (live and dead) can modify both microbial populations and inorganic mercury (Hg(II)) bioavailability through a number of soil, water and atmospheric interactions. Alternatively, plant activity and structure can be simply a response to geochemical conditions that also favor Hg(II)-methylation. Linked studies within the San Francisco Bay watershed have demonstrated that habitat-specific biogeochemical characteristics are the dominant factors controlling MeHg production, and that differences in wetland plant biomass, root density, decomposition rates, can directly influence sediment mercury cycling. A vegetated:de-vegetated paired plot approach was used to directly assess the influence of live plant activities on surface sediment mercury dynamics and associated biogeochemistry in differing wetland settings: salt marshes, permanent and seasonal freshwater wetlands, a freshwater floodplain, and agricultural rice fields. Although results from several of these subhabitats are pending, the data thus far have illustrated linkages between wetland plants and microbial Hg(II)-methylation. De- vegetation strongly influenced sediment biogeochemistry (e.g. redox, dissolved organic content, and reduced sulfur pools) in high interior pickleweed (Sarcocornia pacifica) dominated saltmarshes, where the high rates of MeHg production (up to 1 ng g-1dry sed d-1) observed in vegetated plots were reduced to <10 pg g-1dry sed d-1 in de-vegetated plots. Further, plant root densities were positively correlated with the activity of Hg(II)-methylating bacteria in these interior saltmarsh settings. The pool size of mercury available for methylation ("reactive mercury") was not measurably influenced by this short-term de-vegetation experiment, but across field studies, rhizosphere biomass was often negatively correlated with reactive mercury concentration due to a corresponding increase in solid-phase reduced-sulfur compounds associated with this zone. Because mercury methylation is controlled by both the reactive mercury pool size and the microbial Hg(II)-methylation activity, the direct influence of wetland plants on both of these terms can be profound and reflect multiple, and potentially contrasting, mercury cycling pathways. Experimental field manipulations, in conjunction with comparative habitat and process studies, represent essential tools to elucidate the influence of wetland plant communities on Hg cycling.

Windham-Myers, L.; Marvin-Dipasquale, M.

2007-12-01

98

Seed-bank and vegetation development in a created tidal freshwater wetland on the Delaware River, Trenton, New Jersey, USA  

Microsoft Academic Search

The initial stages of seed-bank and vegetation development were documented in a newly created tidal freshwater wetland where\\u000a donor soils were not applied. The 32.3-ha site adjacent to the Delaware River in New Jersey, USA was completed in stages from\\u000a November 1993 to November 1994. Objectives of the study were to determine characteristics of the seed bank and vegetation\\u000a and

Mary Allessio Leck

2003-01-01

99

Controls on vegetative flow resistance in wetlands and low-gradient floodplains  

NASA Astrophysics Data System (ADS)

In low-gradient floodplains and wetlands, vegetation provides the primary resisting force for flow and hence can exert strong influence on flow velocities, water depth, and redistribution of sediments that affect the geomorphic evolution and ecological function of wetland landscapes. Critical research needs that remain for predicting flow in these environments include integration of data over multiple temporal and spatial scales as well as improved methods of estimating flow resistance. Existing relationships predict flow resistance as a function of stem diameter (d) and frontal area (a). Since these flow resistance parameters are difficult to quantify and generally not measured in the field, large-scale estimation of flow resistance requires a suitable proxy measurement that can be directly related to these parameters. Biomass is a parameter commonly obtained in field surveys and from remote sensing data. We use biomass to predict frontal area and stem diameter using empirical relations for vegetation quadrat data collected in the Everglades (Florida, USA). Biomass is directly related to frontal area (a) through a power function. This is generally true across various plant communities, but the relationship is strongest within individual plant communities. Biomass is linearly related to stem diameter (d) and biovolume (ad) in a manner independent of plant community. We found that species diversity, plant community, water depth, phosphorus concentration, and seasonality are important in governing the spatial and temporal variations in flow resistance parameters, specifically stem diameter and biovolume, as well as plant tissue density. We correlate unstratified quadrat biomass estimates to a remote sensing parameter, normalized difference vegetation index (NDVI), to address implications for scaling up quadrat data for integration into landscape-level processes. These results will improve parameterization of flow resistance for ongoing hydrologic modeling efforts, which will ultimately guide future restoration efforts in the heavily managed and degraded Everglades landscape.

Skalak, K.; Harvey, J. W.; Larsen, L. G.; Noe, G. B.; Rybick, N.; Jones, J.

2010-12-01

100

Late Quaternary climate and vegetation changes at Braamhoek wetland, South Africa  

NASA Astrophysics Data System (ADS)

This study contributes a continuous paleo-environmental record from Braamhoek wetland, eastern Free State, South Africa, covering the last 16 ka (16 000 cal yrs BP). The multi-proxy study includes analysis of microfossils (pollen, diatoms, phytoliths, charcoal fragments), stable isotopes (carbon and nitrogen) and lithological properties (carbon content, grain size). Braamhoek wetland is situated at an altitude of c. 1700 meters, a few kilometres north-west of the eastern escarpment, where the large difference in altitude results in orographic uplift of easterly air masses and annual rainfall is c. 1400 mm. The wetland is fed by ground-water springs, promoting continuous local wetness and organic preservation, which explains the accumulative conditions throughout Holocene and late Pleistocene. Analysis of fossil pollen suggests variations in vegetation patterns throughout the 16 ka period. The most important proxies for past vegetation are pollen of fynbos, forest trees, Poaceae and Asteraceae. Principal component analysis (PCA) was performed on 26 of the regional pollen taxa, yielding high positive loadings on forest trees and fynbos, which may reflect relatively moist conditions, particularly in combination with high representation of Poaceae pollen. The carbon isotope composition is a potential proxy for the relative abundance of C3 versus C4 grasses. The late Pleistocene carbon isotope values are probably an artefact of low carbon dioxide levels favouring C4 plants during late glacial conditions, while during the Holocene-Pleistocene transition and onwards, the isotopes probably reflect the local and regional C3/C4 grass ratio. The phytolith index gives additional information about environmental factors coupled to the grass distribution, while occurrences of planktonic diatoms indicate shifts in the moisture status within the wetland. We interpret depleted carbon isotope values, high PCA-score, high Poaceae/Asteraceae ratio, low phytolith index, as well as presence of planktonic diatoms, as a response to increased wetness, locally and/or regionally. The Braamhoek multi-proxy record suggests three major phases of increased wetness; c. 13.7-12.8 ka, 10.5-9.5 ka, 8.2-7.5 ka and 1.5-0.5 ka. Further, the decline in fynbos pollen representation after c. 9.5 ka and afromontane forest elements being prominent between c. 11 and 8 ka, infer a shift from cooler late glacial conditions, to warmer Holocene conditions at some stage between 11 and 8 ka. The inferred climate and environmental changes suggest a response to millennial scale astronomical forcing and latitudinal shifts in the major weather systems affecting the subcontinent.

Norström, E.; Scott, L.; Finné, M.; Risberg, J.; Partridge, T. C.; Holmgren, K.

2009-04-01

101

Characterization of microtopography and its influence on vegetation patterns in created wetlands  

Microsoft Academic Search

Created wetlands are increasingly used to mitigate wetland loss. Thus, identifying wetland creation methods that enhance ecosystem\\u000a development might increase the likelihood of mitigation success. Noting that the microtopographic variation found in natural\\u000a wetland settings may not commonly be found in created wetlands, this study explores relationships between induced microtopography,\\u000a hydrology, and plant species richness\\/diversity in non-tidal freshwater wetlands, comparing

Kurt Moser; Changwoo Ahn; Gregory Noe

2007-01-01

102

Effects of sediment removal on vegetation communities in Rainwater Basin playa wetlands.  

PubMed

Sedimentation from cultivated agricultural land use has altered the natural hydrologic regimes of depressional wetlands in the Great Plains. These alterations can negatively affect native wetland plant communities. Our objective was to determine if restored wetlands are developing plant communities similar to reference wetland conditions following hydrologic restoration. For this study, hydrology was restored via sediment removal. Thirty-four playa wetlands in reference, restored, and agricultural condition within the Rainwater Basin Region of Nebraska were sampled in 2008 and 2009. In 2008, reference and restored wetlands had higher species richness and more native, annual, and perennial species than agricultural wetlands. Restored wetlands had similar exotic species richness compared to reference and agricultural wetlands; however, reference wetlands contained more than agricultural wetlands. Restored wetlands proportion of exotics was 3.5 and 2 times less than agricultural wetlands and reference wetlands respectively. In 2009, reference and restored wetlands had higher species richness, more perennial species, and more native species than agricultural wetlands. Restored wetlands contained a greater number and proportion of annuals than reference and agricultural wetlands. Canonical Correspondence Analysis showed that reference, restored, and agricultural wetlands are dominated by different plant species and guilds. Restored wetland plant communities do not appear to be acting as intermediates between reference and agricultural wetland conditions or on a trajectory to reach reference conditions. This may be attributed to differing seed bank communities between reference and restored wetlands, dispersal limitations of perennial plant guilds associated with reference wetland conditions, and/or management activities may be preventing restored wetlands from reaching reference status. PMID:23786876

Beas, Benjamin J; Smith, Loren M; LaGrange, Theodore G; Stutheit, Randy

2013-10-15

103

A test of vegetation-related indicators of wetland quality in the prairie pothole region  

USGS Publications Warehouse

This study was part of an effort by the U.S. Environmental Protection Agency to quantitatively assess the environmental quality or 'health' of wetland resources on regional and national scales. During a two-year pilot study, we tested selected indicators of wetland quality in the U.S. portion of the prairie pothole region (PPR). We assumed that the amount of cropland versus non-cropland (mostly grassland) in the plots containing these basins was a proxy for their quality. We then tested indicators by their ability to discriminate between wetlands at the extremes of that proxy. Amounts of standing dead vegetation were greater in zones of greater water permanence. Depth of litter was greater in zones of greater water permanence and in zones of basins in poor-quality watersheds. Amounts of unvegetated bottom were greater in basins in poor-quality watersheds; lesser amounts occurred in all wetlands during a wetter year. Greater amounts of open water occurred during a wetter year and in zones of greater water permanence. When unadjusted for areas (ha) of communities, plant taxon richness was higher in wet-meadow and shallow-marsh zones in good-quality watersheds than in similar zones in poor-quality watersheds. Wet-meadow zones in good-quality watersheds had greater numbers of native perennials than those in poor-quality watersheds. This relation held when we eliminated all communities in good-quality watersheds larger than the largest communities in poor-quality watersheds from the data set. We conclude that although amounts of unvegetated bottom and plant taxon richness in wet-meadow zones were useful indicators of wetland quality during our study, the search for additional such indicators should continue. The value of these indicators may change with the notoriously unstable hydrological conditions in the PPR. Most valuable would be indicators that could be photographed or otherwise remotely sensed and would remain relatively stable under various hydrological conditions. An ideal set of indicators could detect the absence of stressors, as well as the presence of structures or functions, of known value to major groups of organisms.

Kantrud, H. A.; Newton, W. E.

1996-01-01

104

Hydrologic, Soil and Vegetation Gradients in Remnant and Constructed Riparian Wetlands in West-Central Missouri, 2001-04.  

National Technical Information Service (NTIS)

The purpose of this report is to characterize and relate hydrologic, soil, and vegetation gradients in remnant and constructed riparian wetlands in west-central Missouri from April 2001 to March 2004. Hydrologic data were collected at the Four Rivers Cons...

D. C. Heimann P. A. Mettler-Cherry

2004-01-01

105

Wetland vegetation and nutrient retention in Nakivubo and Kirinya wetlands in the Lake Victoria basin of Uganda  

Microsoft Academic Search

Wetlands form an important part of the catchment area of the African Great Lakes and protect water resources therein. One of the most important functions is the retention of nutrients from the inflowing water from the catchment, by wetland plants which store them in their phytomass. An assessment of the capacity in storing nutrients by dominant plants (Cyeprus papyrus, Miscanthus

P. Mugisha; F. Kansiime; P. Mucunguzi; E. Kateyo

2007-01-01

106

Vegetation, substrate and hydrology in floating marshes in the Mississippi river delta plain wetlands, USA  

USGS Publications Warehouse

In the 1940s extensive floating marshes (locally called 'flotant') were reported and mapped in coastal wetlands of the Mississippi River Delta Plain. These floating marshes included large areas of Panicum hemitomon-dominated freshwater marshes, and Spartina patens/Scirpus olneyi brackish marshes. Today these marshes appear to be quite different in extent and type. We describe five floating habitats and one non-floating, quaking habitat based on differences in buoyancy dynamics (timing and degree of floating), substrate characteristics, and dominant vegetation. All floating marshes have low bulk density, organic substrates. Nearly all are fresh marshes. Panicum hemitomon floating marshes presently occur within the general regions that were reported in the 1940's by O'Neil, but are reduced in extent. Some of the former Panicum hemitomon marshes have been replaced by seasonally or variably floating marshes dominated, or co-dominated by Sagittaria lancifolia or Eleocharis baldwinii. ?? 1996 Kluwer Academic Publishers.

Sasser, C. E.; Gosselink, J. G.; Swenson, E. M.; Swarzenski, C. M.; Leibowitz, N. C.

1996-01-01

107

A demonstration of wetland vegetation mapping in Florida from computer-processed satellite and aircraft multispectral scanner data  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Major vegetative classes identified by the remote sensing technique were cypress swamp, pine, wetland grasses, salt grass, mixed mangrove, black mangrove, Brazilian pepper. Australian pine and melaleuca were not satisfactorily classified from LANDSAT. Aircraft scanners provided better resolution resulting in a classification of finer surface detail. An edge effect, created by the integration of diverse spectral responses within boundary elements of digital data, affected the wetlands classification. Accuracy classification for aircraft was 68% and for LANDSAT was 74%.

Butera, M. K. (principal investigator)

1978-01-01

108

Revising vegetation scattering theories: Adding a rotated dihedral double bounce scattering to explain cross-polarimetric SAR observations over wetlands  

NASA Astrophysics Data System (ADS)

Common vegetation scattering theories indicate that short wavelength Synthetic Aperture Radar (SAR) observations (X- and C-band) measure mainly vegetation canopies as the short-wavelength radar signal interacts mainly with upper sections of the vegetation. Furthermore, these theories also suggest that SAR cross-polarization (cross-pol) observations reflect only volume scattering. Consequently most SAR decomposition techniques assume that the cross-pol signal represent solely volume scattering. However, short-wavelength and cross-pol observations from the Everglades wetlands, south Florida, suggest that a significant portion of the SAR signal scatters from the surface and not only from the upper sections of the vegetation. The indication for surface scattering in wetland environment is derived from phase observable processed using interferometric techniques. The interferometric SAR (InSAR) observations reveal coherent phase signal in all polarizations and all wavelengths, reflecting water level changes beneath the vegetation. This coherent phase signal cannot be explained by neither volume scattering nor radar signal interaction with the upper sections of the vegetations, because canopies and branches are frequently move by wind. The only way that such coherent signal can be maintained and represents surface water level changes is when a multiple bounce from the vegetation and surface occurs. The simplest multi-bounce scattering mechanism that generate cross-pol signal occurs by rotated dihedrals. Thus, we use the rotated dihedral mechanism to explain the InSAR wetland observations and to revise the current vegetation scattering theories to accounts also for double bounce component in cross-pol observations.

Hong, S.; Wdowinski, S.

2010-12-01

109

Vegetation mapping of Kushiro wetland in northeast Hokkaido, Japan: application of SPOT images, aerial balloon photographs and airborne color near infrared (CNIR) images for classification  

Microsoft Academic Search

Our study was designed to evaluate the potential of the utility for various spectral and spatial resolutions to classify the wetland vegetation into the species level. We investigated which combination is the most suitable for delineating and mapping specific vegetation types. The mission we employed had three main stages, (1) Making digital processed vegetation maps by manual interpretation of mosaicking

Michiru MIYAMOTO; Kunihiko YOSHINO; Keiji KUSHIDA

2002-01-01

110

Patch-scale effects of equine disturbance on arthropod assemblages and vegetation structure in subalpine wetlands.  

PubMed

Assessments of vertebrate disturbance to plant and animal assemblages often contrast grazed versus ungrazed meadows or other larger areas of usage, and this approach can be powerful. Random sampling of such habitats carries the potential, however, for smaller, more intensely affected patches to be missed and for other responses that are only revealed at smaller scales to also escape detection. We instead sampled arthropod assemblages and vegetation structure at the patch scale (400-900 m(2) patches) within subalpine wet meadows of Yosemite National Park (USA), with the goal of determining if there were fine-scale differences in magnitude and directionality of response at three levels of grazing intensity. Effects were both stronger and more nuanced than effects evidenced by previous random sampling of paired grazed and ungrazed meadows: (a) greater negative effects on vegetation structure and fauna in heavily used patches, but (b) some positive effects on fauna in lightly grazed patches, suggested by trends for mean richness and total and population abundances. Although assessment of disturbance at either patch or landscape scales should be appropriate, depending on the management question at hand, our patch-scale work demonstrated that there can be strong local effects on the ecology of these wetlands that may not be detected by comparing larger scale habitats. PMID:24715003

Holmquist, Jeffrey G; Schmidt-Gengenbach, Jutta; Ballenger, Elizabeth A

2014-06-01

111

Patch-Scale Effects of Equine Disturbance on Arthropod Assemblages and Vegetation Structure in Subalpine Wetlands  

NASA Astrophysics Data System (ADS)

Assessments of vertebrate disturbance to plant and animal assemblages often contrast grazed versus ungrazed meadows or other larger areas of usage, and this approach can be powerful. Random sampling of such habitats carries the potential, however, for smaller, more intensely affected patches to be missed and for other responses that are only revealed at smaller scales to also escape detection. We instead sampled arthropod assemblages and vegetation structure at the patch scale (400-900 m2 patches) within subalpine wet meadows of Yosemite National Park (USA), with the goal of determining if there were fine-scale differences in magnitude and directionality of response at three levels of grazing intensity. Effects were both stronger and more nuanced than effects evidenced by previous random sampling of paired grazed and ungrazed meadows: (a) greater negative effects on vegetation structure and fauna in heavily used patches, but (b) some positive effects on fauna in lightly grazed patches, suggested by trends for mean richness and total and population abundances. Although assessment of disturbance at either patch or landscape scales should be appropriate, depending on the management question at hand, our patch-scale work demonstrated that there can be strong local effects on the ecology of these wetlands that may not be detected by comparing larger scale habitats.

Holmquist, Jeffrey G.; Schmidt-Gengenbach, Jutta; Ballenger, Elizabeth A.

2014-06-01

112

Performance Variations of COD and Nitrogen Removal by Vegetated Submerged Bed Wetlands  

NASA Astrophysics Data System (ADS)

Vegetated submerged bed wetlands can supplement treatment of onsite wastewater systems. This study evaluated vegetation, media, and seasonal impacts on system performance in six meso scale rock plant filters with and without narrow leaf cattails (Typha augustifolia). Daily chemical oxygen demand (COD) reductions in planted cells averaged 85 percent and weekly total nitrogen (TN) reductions averaged 50 percent. Planted cells had 17 percent greater COD reduction and 76 percent greater TN reduction than unplanted cells, both significant differences. Media type affected COD reduction, particularly in unplanted cells. COD treatment in planted cells was highest for fine crushed limestone (87±13 percent) and least variable for coarse river gravel (85±11 percent). No significant difference in TN reduction was observed for different media types (48 to 51 percent range). Seasonal influences on treatment included a significant decrease during late fall and early spring and a significant increase with temperature. After a step increase in organic loading, treatment efficiency decreased sharply but returned to prior levels after an adaptation period of about one month. Planted cells not only exhibited higher treatment efficiency but also had a retarded organic matter breakthrough, appearing after three to seven times the period for a bromide tracer. This supports a hypothesis that retardation of contaminant movement through the treatment cells results in enhanced removal. These results support the use of rock plant filters, but demonstrate the need to account for performance variations in system design.

He, Qiang; Mankin, Kyle R.

2002-12-01

113

Mapping vegetation of a wetland ecosystem by fuzzy classification of optical and microwave satellite images supported by various ancillary data  

NASA Astrophysics Data System (ADS)

An approach to classification of satellite images aimed at vegetation mapping in a wetland ecosystem has been presented. The wetlands of the Biebrza Valley located in the NE part of Poland has been chosen as a site of interest. The difficulty of using satellite images for the classification of a wetland land cover lies in the strong variability of the hydration state of such ecosystem in time. Satellite images acquired by optical or microwave sensors depend heavily on the current water level which often masks the most interesting long-time scale features of vegetation. Therefore the images have to be interpreted in the context of various ancillary data related to the investigated site. In the case of Biebrza Valley the most useful information was obtained from the soil and hydration maps as well as from the old vegetation maps. The object oriented classification approach applied in eCognition software enabled simultaneous use of satellite images together with the additional thematic data. Some supplementary knowledge concerning possible plant cover changes was also introduced into the process of classification. The accuracy of the classification was assessed versus ground-truth data and results of visual interpretation of aerial photos. The achieved accuracy depends on the type of vegetation community in question and is better for forest or shrubs than for meadows.

Stankiewicz, Krystyna; Dabrowska-Zielinska, Katarzyna; Gruszczynska, Maryla; Hoscilo, Agata

2003-03-01

114

Evaluating the potential for created wetland establishment on restored surface mine sites. Final report  

SciTech Connect

The authors feel that (1) the design specifications presented in this report provide the guidance necessary for industry to implement wetland construction in contour surface mine reclamation, (2) the monitoring criteria represent conditions that are easily attainable prior to bond release, and (3) that the monitoring criteria allow regulatory agencies to perform field approval of constructed wetlands. However, this report also recommends that additional regulatory impediments to wetland construction in reclamation be addressed to encourage industry participation.

Carins, J.

1995-03-01

115

Hydrologic, vegetation, and soil data collected in selected wetlands of the Big River Management area, Rhode Island, from 2008 through 2010  

USGS Publications Warehouse

The Rhode Island Water Resources Board planned to develop public water-supply wells in the Big River Management Area in Kent County, Rhode Island. Research in the United States and abroad indicates that groundwater withdrawal has the potential to affect wetland hydrology and related processes. In May 2008, the Rhode Island Water Resources Board, the U.S. Geological Survey, and the University of Rhode Island formed a partnership to establish baseline conditions at selected Big River wetland study sites and to develop an approach for monitoring potential impacts once pumping begins. In 2008 and 2009, baseline data were collected on the hydrology, vegetation, and soil characteristics at five forested wetland study sites in the Big River Management Area. Four of the sites were located in areas of potential drawdown associated with the projected withdrawals. The fifth site was located outside the area of projected drawdown and served as a control site. The data collected during this study are presented in this report.

Borenstein, Meredith S.; Golet, Francis C.; Armstrong, David S.; Breault, Robert F.; McCobb, Timothy D.; Weiskel, Peter K.

2012-01-01

116

Wetland Functional Health Assessment Using Remote Sensing and Other Techniques: Literature Search and Overview.  

National Technical Information Service (NTIS)

Contents: Introduction; Remote sensing of wetland biomass and other wetland condition indicators; Conceptual approaches in wetland assessment; Wetland extent and type; Landscape and wetland patterns; Wetland biomass and productivity; Wetland vegetation; W...

N. Patience V. Klemas

1993-01-01

117

Early development of vascular vegetation of constructed wetlands in northwest Ohio receiving agricultural waters  

Microsoft Academic Search

Constructed wetlands are currently being explored for use in reducing non-point source (NPS) pollution. The Wetland Reservoir Subirrigation System (WRSIS) project links water management in agricultural fields, constructed wetlands and water storage reservoirs to enhance crop production and reduce delivery of agrichemicals and sediments to local waterways. Three WRSIS demonstration sites have been developed on prior converted cropland in the

Lee M Luckeydoo; N. R Fausey; L. C Brown; C. B Davis

2002-01-01

118

Vegetation, Invertebrate, and Wildlife Community Rankings and Habitat Analysis of Mitigation Wetlands in West Virginia  

Microsoft Academic Search

Numerous efforts have been made in West Virginia to construct and restore compensatory wetlands as mitigation for natural wetlands destroyed through highway development, timbering, mining, and other human activities. Because such little effort has been made to evaluate these wetlands, there is a need to evaluate the success of these systems. The objective of this study was to determine if

Collin K. Balcombe; James T. Anderson; Ronald H. Fortney; Walter S. Kordek

2005-01-01

119

Effect of temperature, HRT, vegetation and porous media on removal efficiency of pilot-scale horizontal subsurface flow constructed wetlands  

Microsoft Academic Search

In order to investigate the effect of temperature, hydraulic residence time (HRT), vegetation type and porous media material and grain size on the performance of horizontal subsurface flow (HSF) constructed wetlands treating wastewater, five pilot-scale units of dimensions 3m in length and 0.75m in width were operated continuously from January 2004 until January 2006 in parallel experiments. Three units contained

Christos S. Akratos; Vassilios A. Tsihrintzis

2007-01-01

120

Synergy between LIDAR and RADARSAT-2 images for the recognition of vegetation structures in the coastal wetlands of the Danube Delta  

NASA Astrophysics Data System (ADS)

Wetlands are among the most productive environments in the world and are characterized by exceptional biological diversity. Despite their indisputable importance, these environments remain among the most endangered ecosystems in the world due to drainage, drying out, pollution or overexploitation of resources. The Danube Delta, a coastal wetland of the Black Sea, cannot escape these dangers and, to preserve its resources, it has been declared a Biosphere Reserve (in 1993). The biodiversity of this area is remarkable and it possesses one of the largest reed in the world (a continuous 2,700 km² reed cover). The main goal of this project is to determine, characterize and derive functional descriptors of the vegetation structures, Phragmites australis species of the Danube Delta being the most prevalent. For this purpose, this project aims, on the one hand, at interpreting LIDAR measurements (acquired in May 2011) in conjunction with RADARSAT-2 satellite observations (acquired in early June 2011) and, on the other hand, at validating the results obtained by the introduction of the spectral measurements of the main vegetation classes into a Spectral Angle Mapper algorithm applied to a SPOT-5 image (May 2011). The LIDAR data allow the assessment of vegetation height with an accuracy of a few centimeters. Hence, the various vegetation layers can be accurately mapped. However, the differentiation of the various vegetation formations within a same layer requires the contribution of complementary data sources such as RADARSAT-2 data. The radar measurements are derived using the C band (? wavelength = 5.3 cm) providing additional information on the vegetation cover structure with regard to roughness, moisture and biomass. The simultaneous acquisition of HH, HV and VV polarizations allows the differentiation of the areas according to their response to different polarizations by establishing their polarimetric signatures. Based on these raw data, we were able to derive other indices such as, for instance, the intensity of the four polarizations, the span and the polarimetric entropy. Entropy is very sensitive to vegetation density; the thicker the vegetation, the higher the entropy becomes. The approach allowed us to obtain valuable information regarding different types of exploitation of the reed (cut or burned reed). Moreover, the exploitation of the SPOT 5 spectral information was made possible due to the calibration carried out using spectrometers to perform spectral measurements in the areas previously identified on the images.

Niculescu, Simona; Lardeux, Cédric; Grigoras, Ion; Hanganu, Jenica; David, Laurence

2014-05-01

121

Demonstration of wetland vegetation mapping in Florida from computer-processed satellite and aircraft multispectral scanner data  

NASA Technical Reports Server (NTRS)

The success of remotely mapping wetland vegetation of the southwestern coast of Florida is examined. A computerized technique to process aircraft and LANDSAT multispectral scanner data into vegetation classification maps was used. The cost effectiveness of this mapping technique was evaluated in terms of user requirements, accuracy, and cost. Results indicate that mangrove communities are classified most cost effectively by the LANDSAT technique, with an accuracy of approximately 87 percent and with a cost of approximately 3 cent per hectare compared to $46.50 per hectare for conventional ground survey methods.

Butera, M. K.

1979-01-01

122

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

USGS Publications Warehouse

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

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

1993-01-01

123

Isolated spring wetlands in the Great Basin and Mojave deserts, USA: potential response of vegetation to groundwater withdrawal.  

PubMed

Desert springs, often the sole sources of water for wildlife and cattle, support wetland and wetland/upland transition ecosystems including rare and endemic species. In the basin and range province in Nevada, USA, springs in the Great Basin and Mojave deserts are sustained by interconnected deep carbonate and shallow basin-fill aquifers which are threatened by proposed groundwater withdrawal to sustain rapidly expanding urban areas, a common problem in arid regions worldwide. This paper draws on historic groundwater data, groundwater modeling, and studies of environmental controls of spring ecosystems to speculate on the potential effects of groundwater withdrawal and water table decline on spring-supported vegetation. The focus is on springs in the Great Basin and Mojave deserts representative of those that may be affected by future, planned groundwater withdrawal. Groundwater withdrawal is expected to reduce spring discharge directly through reduced flows from the shallow basin-fill aquifer or through reduction of the hydraulic head of the deep carbonate aquifer. This flow reduction will truncate the outflow stream, reducing the areal cover of wetland and wetland/upland transition vegetation. Lowering the local water table may also reduce the amount of upland phreatophytic vegetation by causing water levels to drop below plant rooting depths. Percolation of salts to surface soils may be reduced, eventually altering desert shrub cover from halophytes to nonhalophytes. The extent of these effects will vary among springs, based on their distance from extraction sites and location relative to regional groundwater flow paths. On-site monitoring of biotic variables (including cover of selected hygrophytes and phreatophytes) should be a necessary complement to the planned monitoring of local hydrologic conditions. PMID:18060450

Patten, Duncan T; Rouse, Leigh; Stromberg, Juliet C

2008-03-01

124

Relationships among vegetation, geomorphology and hydrology in the Bananal Island tropical wetlands, Araguaia River basin, Central Brazil  

NASA Astrophysics Data System (ADS)

The Bananal Plain spreading on the Middle Araguaia River basin in Central Brazil at the Cerrado-Amazonia ecotone is a unique system that sustains the largest seasonal wetlands of the Cerrado biome. The huge Bananal Plain is an intracratonic sedimentary basin filled with Pleistocene sediments of the Araguaia formation. Covering approximately two million hectares, the Bananal Island is a major geomorphologic feature of the Bananal plain. Fieldwork and the analysis of a temporal series of MODIS-VI and Landsat ETM images allowed us to discriminate Cerrado phyto-physiognomies on the Bananal Island. Maps of vegetation and geomorphologic units were created, and from the correlation between landforms and vegetation types we identified morpho-vegetation units. Our approach allowed us to postulate that Pleistocene landforms strongly influence, if not dominate, the distribution of vegetation units. For example, the distribution of current gallery forest is not only controlled by active floodplains, but also by alluvial belts abandoned by avulsion. Additionally, arboreal Cerrado vegetation is supported by laterite developed on the sediments of the Araguaia Formation. Some of these inactive landforms are in part modified by the present day geomorphologic processes and colonized by successional vegetation that varies from alluvial forest to Cerrado. Characterized by a very flat landscape with a hindered drainage, the muddy sediments of the Araguaia Formation and the high seasonal rainfall favor the development of regional seasonal wetlands. The Bananal plain is a key area for understanding the Quaternary climatic and biogeographic changes in tropical South America. The control exerted by relict Quaternary landforms on the current vegetation units demonstrates the strong links between geomorphologic aspects of the landscape and ecological patterns. This multidisciplinary approach provides a better understanding of the biogeographic patterns in the Cerrado-Amazon ecotone, which is useful for identifying and designing areas for conservation.

Valente, C. R.; Latrubesse, E. M.; Ferreira, L. G.

2013-10-01

125

Changes in surface water table depth and soil physical properties after harvest and establishment of loblolly pine ( Pinus taeda L.) in Atlantic coastal plain wetlands of South Carolina  

Microsoft Academic Search

The surface water table is an important factor determining soil chemical, physical and biological processes, and thus affects the functions of forested wetlands. The objective of this study was to assess surface water table dynamics from timber harvesting through early forest plantation establishment in a coastal plain wetland area located in the southeastern United States. Simulated harvesting patterns included two

Yi-Jun Xu; James A Burger; W Michael Aust; Steven C Patterson; Masato Miwa; David P Preston

2002-01-01

126

Gas transfer velocities for quantifying methane, oxygen and other gas fluxes through the air-water interface of wetlands with emergent vegetation  

NASA Astrophysics Data System (ADS)

Empirical models for the gas transfer velocity, k, in the ocean, lakes and rivers are fairly well established, but there are few data to predict k for wetlands. We have conducted experiments in a simulated emergent marsh in the laboratory to explore the relationship between k, wind shear and thermal convection. Now we identify the implications of these results for gas transfer in actual wetlands by (1) quantifying the range of wind conditions in emergent vegetation canopies and the range of thermal convection intensities in wetland water columns, and (2) describing the non-linear interaction of these two stirring forces over their relevant ranges in wetlands. We measured mean wind speeds and wind speed variance within the shearless region of a Schoenoplectus-Typha marsh canopy in the Sacramento-San Joaquin Delta (Northern California, USA). The mean wind speed within this region, , is significantly smaller than wind above the canopy. Based on our laboratory experiments, for calm or even average wind conditions in this emergent marsh k600 is only on the order 0.1 cm hr-1 (for neutrally or stably stratified water columns). We parameterize unstable thermal stratification and the resulting thermal convection using the heat flux through the air-water interface, q. We analyzed a water temperature record for the Schoenoplectus-Typha marsh to obtain a long-term heat flux record. We used these heat flux data along with short-term heat flux data from other wetlands in the literature to identify the range of the gas transfer velocity associated with thermal convection in wetlands. The typical range of heat fluxes through water columns shaded by closed emergent canopies (-200 W m-2 to +200 W m-2) yields k600 values of 0.5 - 2.5 cm hr-1 according to the model we developed in the laboratory. Thus for calm or average wind conditions, the gas transfer velocity associated with thermal convection is significantly larger than the gas transfer velocity associated with wind shear. Because of the diurnal pattern in water column heat flux that follows the diurnal pattern in incoming solar radiation, this difference means gas transfer velocities are expected to vary diurnally during calm or average wind conditions, peaking late at night and early in the morning. Conversely for very windy conditions, alone may determine the gas transfer velocity even when high heat fluxes out of the water column are relatively high. For the calculation of k600 from , we developed an enhancement factor to account for the very high wind speed variance observed in the Schoenoplectus-Typha emergent canopy and likely seen in other emergent canopies as well. These wetland targeted gas transfer velocities will improve the accuracy of wetland gas flux measurements and models and enable the partitioning of net gas fluxes from wetlands into plant-mediated fluxes, ebullitive fluxes and fluxes due to the hydrodynamic transport of dissolved gases through the water column.

Poindexter, C.; Variano, E. A.

2012-12-01

127

Physical and Vegetative Characteristics of a Newly Constructed Wetland and Modified Stream Reach, Tredyffrin Township, Chester County, Pennsylvania, 2000-2006  

USGS Publications Warehouse

To compensate for authorized disturbance of naturally occurring wetlands and streams during roadway improvements to U.S. Highway 202 in Chester and Montgomery Counties, Pa., the Pennsylvania Department of Transportation (PennDOT) constructed 0.42 acre of emergent wetland and 0.94 acre of scrub-shrub/forested wetland and modified sections of a 1,600-foot reach of Valley Creek with woody riparian plantings and streambank-stabilization structures (including rock deflectors). In accordance with project permits and additional guidance issued by the U.S. Army Corps of Engineers, the U.S. Geological Survey (USGS), in cooperation with PennDOT, collected data from 2000 through 2006 to quantify changes in 1) the vegetation, soils, and extent of emergent and scrub-shrub/forested parts of the constructed wetland, 2) the profile, dimension, and substrate in the vicinity of rock deflectors placed at two locations within the modified stream reach, and 3) the woody vegetation within the planted riparian buffer. The data for this investigation were collected using an approach adapted from previous investigations so that technology and findings may be more easily transferred among projects with similar objectives. Areal cover by planted and non-planted vegetation growing within the emergent and scrub-shrub/forested parts of the constructed wetland exceeded 85 percent at the end of each growing season, a criterion in special condition 25c in the U.S. Army Corps of Engineers project permit. Areal cover of vegetation in emergent and scrub-shrub/forested parts of the constructed wetland exceeded 100 percent in all but one growing season. Frequent and long-lasting soil saturation favored obligate-wetland species like Typha latifolia (broadleaf cattail) and Scirpus validus (great bulrush), both of which maintained dominance in the emergent wetland throughout the study (percent cover was 20 and 78 percent, respectively, in 2006). Echinocloa crusgalli (barnyard grass), an annual invasive from Eurasia, initially established in the newly disturbed soils of the scrub-shrub/forested wetland (areal cover was 56 percent in 2000), but by 2002, E. crusgalli was not growing in any sample plots and other species including Agrostis stolonifera (creeping bent grass), Festuca rubra (red fescue), Cornus spp. (dogwood species), and Salix nigra (black willow) were becoming more common. Sal. nigra contributed 30-percent cover in the scrub-shrub/forested wetland part by fall 2003. Rapid colonization of this species in subsequent years increased annual cover through 2006, when 15- to 25-foot tall Sal. nigra trees dominated the tree/shrub stratum (48 percent of the areal cover in 2006). The understory of the scrub-shrub/forested wetland was mostly shaded because of the canopy of Sal. nigra trees. Herbaceous species growing under and near the margins of the canopy included Ag. stolonifera and Ty. latifolia (29- and 23-percent areal cover, respectively). Flows in Valley Creek are responsible for transporting sediment and shaping the channel. Annual mean streamflow during the period the modified stream reach was monitored ranged from 15.2 cubic feet per second (ft3/s) in the 2002 water year to 53.0 ft3/s in the 2004 water year. This is a range of about 55 percent lower to 58 percent higher than the annual mean streamflow for the period of record. Despite the variability in streamflow, longitudinal profiles surveyed near rock deflectors in two short (100-foot) reaches within the modified stream reach maintained a constant slope throughout the monitoring period, most likely because of the presence of bedrock control. Cross-section geometry in the upstream reach was virtually unchanged during the monitoring period but 10 feet of bank migration was measured downstream, leaving the rock deflectors in mid-stream. As indicated by the change in channel morphology at the downstream reach, it is apparent that the rock deflectors were ineffective at adequately protecting the bank

Chaplin, Jeffrey J.; White, Kirk E.; Olson, Leif E.

2009-01-01

128

Modelling wet weather sediment removal by stormwater constructed wetlands: Insights from a laboratory study  

Microsoft Academic Search

Constructed wetlands are now commonly used to control polluted urban stormwater discharges. A laboratory study was conducted to investigate the treatment of solids in these systems. Three mesocosm stormwater wetlands (vegetated with a well-established canopy of different densities) and one mesocosm non-vegetated pond were used, all sized to achieve particle fall number (Nf, a ratio between the times of the

Y. Li; A. Deletic; T. D. Fletcher

2007-01-01

129

Late Quaternary climate and vegetation changes at Braamhoek wetland, South Africa  

Microsoft Academic Search

This study contributes a continuous paleo-environmental record from Braamhoek wetland, eastern Free State, South Africa, covering the last 16 ka (16 000 cal yrs BP). The multi-proxy study includes analysis of microfossils (pollen, diatoms, phytoliths, charcoal fragments), stable isotopes (carbon and nitrogen) and lithological properties (carbon content, grain size). Braamhoek wetland is situated at an altitude of c. 1700 meters,

E. Norström; L. Scott; M. Finné; J. Risberg; T. C. Partridge; K. Holmgren

2009-01-01

130

Independent Wetland Vegetation Response to Climate Variability and Anthropogenic Hydrologic Control, Everglades, FL, USA  

NASA Astrophysics Data System (ADS)

The response of a wetland landscape composed of multiple, distinct, plant communities to a single stimulus, whether it results from natural climate variability or human alterations, should not be assumed to be uniform across the entire landscape. The Florida Everglades is such a landscape where elevated sawgrass ridges are immediately next to water lily dominated sloughs, known collectively as the sawgrass ridge and slough landscape (SRS). The distribution of the Everglades individual sawgrass ridge and slough plant communities within the SRS was altered by 20th century construction of water control structures (canals, levees, and dikes) and alteration of the natural hydrologic regime. Although restoration planning to stabilize the remaining ridge and slough habitats is underway, little is known about the landscape's origin and response to past hydrologic changes. Analysis of pollen assemblages from transects of piston cores collected across SRS indicate that sawgrass ridges and sloughs have been vegetationally distinct from one another since the mid Holocene. Modern sawgrass ridges formed from a marsh-like environment, whereas slough communities occupied their present sites throughout the history of the sites. Ridge formation was triggered by intervals of drier climate (i.e., the Medieval Warm Period and Little Ice Age) and changes in the mean position of the Intertropical Convergence Zone. The sloughs are temporarily composed of more marsh plants during drier conditions, but quickly return to their original state when precipitation increases. During the 20th century, sloughs appear to be strongly influenced by North Atlantic Oscillation (NAO) variability in spite of water management practices, while the sawgrass ridges respond primarily to [water management] anthropogenic changes in hydrology. Our evidence that, the sawgrass ridge and slough landscape communities can act independent of one another to changes in hydrology, indicates that restoring the pre-20th century hydrology may not restore all aspects of the pre-20th century landscape structure.

Bernhardt, C. E.; Willard, D. A.

2007-12-01

131

Control of reed canarygrass promotes wetland herb and tree seedling establishment in an upper Mississippi River Floodplain forest  

USGS Publications Warehouse

Phalaris arundinacea (reed canarygrass) is recognized as a problematic invader of North American marshes, decreasing biodiversity and persisting in the face of control efforts. Less is known about its ecology or management in forested wetlands, providing an opportunity to apply information about factors critical to an invader's control in one wetland type to another. In a potted plant experiment and in the field, we documented strong competitive effects of reed canarygrass on the establishment and early growth of tree seedlings. In the field, we demonstrated the effectiveness of a novel restoration strategy, combining site scarification with late fall applications of pre-emergent herbicides. Treatments delayed reed canarygrass emergence the following spring, creating a window of opportunity for the early growth of native plants in the absence of competition from the grass. They also allowed for follow-up herbicide treatments during the growing season. We documented greater establishment of wetland herbs and tree seedlings in treated areas. Data from small exclosures suggest, however, that deer browsing can limit tree seedling height growth in floodplain restorations. Slower tree growth will delay canopy closure, potentially allowing reed canarygrass re-invasion. Thus, it may be necessary to protect tree seedlings from herbivory to assure forest regeneration.

Thomsen, Meredith; Brownell, Kurt; Groshek, Matthew; Kirsch, Eileen

2012-01-01

132

Gas chromatographic-mass spectrometric determination of sulfolane in wetland vegetation exposed to sour gas-contaminated groundwater.  

PubMed

Described is a GC-MS method for the determination of the levels of sulfolane (tetrahydrothiophene 1,1-dioxide, C4H8O2S; a water miscible chemical used in the sweetening of sour gas) in wetland vegetation (roots, shoots, berries, seeds, grasses, and leaves). The technique was developed to provide positive detection of sulfolane in a variety of wetland vegetation and to determine the extent to which sulfolane may translocate within the plants. Vegetation samples collected at a sour gas processing facility were extracted using a two-stage process which utilized a back extraction of a water extract with toluene. The main advantages of this procedure were: good extraction efficiency (recovery of 80+/-12%), exclusion of most of the highly polar co-extractives during the toluene back extraction step, and a final extract well suited to routine GC-MS selected ion monitoring of sulfolane with a detection limit of 90 ng g(-1) (wet mass). In general, the method was rugged, based on a study period of 18 months in which over 175 runs were conducted. PMID:10563417

Headley, J V; Peru, K M; Dickson, L C

1999-10-22

133

Wetland chronosequence as a model of peatland development: Vegetation succession, peat and carbon accumulation  

NASA Astrophysics Data System (ADS)

Peatlands form currently a major terrestrial pool of organic matter (OM) and carbon (C). Dynamics of peat accumulation processes can be approached via models, which, however, need to be evaluated against real data. Land uplift coast with ongoing primary peatland formation is a unique setting to study the patterns and controls of peatland vegetation succession, development from fen to bog, and consequent changes in peat, carbon (C) and nitrogen (N) accumulation. Here we compared a chronosequence of peatlands with a vertical peat sequence and ran Holocene Peatland Model (HPM) simulations, and evaluated the simulation against the field observations. The modern vegetation from the emergent sea shore to a bog with age of about 3000 years formed a continuum from minerotrophic to ombrotrophic plant communities. Similar sequence of plant communities was found in historical vegetation data. Along the chronosequence the fen-bog transition stage was most diverse regarding to plant community types, but also to spatial variability in peat height and water table depth (WTD). The transition from meadow to fen communities was associated with the establishment of Sphagnum moss patches. Palaeobotanical evidence from the bog site showed a rapid and quite recent fen-bog transition indicated by coinciding decrease in minerotrophic plant functional types (sedge) and increase in ombrotrophic plant functional types (lawn or hummock Sphagna). Concurrent vegetation transition also in the cores from younger, a 700 year old, fen site suggests different pace of succession in these age cohorts, possibly due to external forcing. Evaluation of the HPM simulations indicated that the model is adjustable and it produced reasonable predictions despite temperature not being included directly in the model.

Juutinen, S.; Tuittila, E.; Frolking, S.; Väliranta, M.; Laine, A. M.; Miettinen, A.; Seväkivi, M.; Quillet, A.; Merilä, P.

2011-12-01

134

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

Microsoft Academic Search

We analyzed the transverse pattern of vegetation along a reach of the Fremont River in Capitol Reef National Park, Utah, USA\\u000a using models that support both delineation of wetland extent and projection of the changes in wetland area resulting from\\u000a upstream hydrologic alteration. We linked stage-discharge relations developed by a hydraulic model to a flow-duration curve\\u000a derived from the flow

Gregor T. Auble; Michael L. Scott; Jonathan M. Friedman

2005-01-01

135

High density biomass estimation for wetland vegetation using WorldView-2 imagery and random forest regression algorithm  

NASA Astrophysics Data System (ADS)

The saturation problem associated with the use of NDVI for biomass estimation in high canopy density vegetation is a well known phenomenon. Recent field spectroscopy experiments have shown that narrow band vegetation indices computed from the red edge and the NIR shoulder can improve the estimation of biomass in such situations. However, the wide scale unavailability of high spectral resolution satellite sensors with red edge bands has not seen the up-scaling of these techniques to spaceborne remote sensing of high density biomass. This paper explored the possibility of estimate biomass in a densely vegetated wetland area using normalized difference vegetation index (NDVI) computed from WorldView-2 imagery, which contains a red edge band centred at 725 nm. NDVI was calculated from all possible two band combinations of WorldView-2. Subsequently, we utilized the random forest regression algorithm as variable selection and a regression method for predicting wetland biomass. The performance of random forest regression in predicting biomass was then compared against the widely used stepwise multiple linear regression. Predicting biomass on an independent test data set using the random forest algorithm and 3 NDVIs computed from the red edge and NIR bands yielded a root mean square error of prediction (RMSEP) of 0.441 kg/m2 (12.9% of observed mean biomass) as compared to the stepwise multiple linear regression that produced an RMSEP of 0.5465 kg/m2 (15.9% of observed mean biomass). The results demonstrate the utility of WorldView-2 imagery and random forest regression in estimating and ultimately mapping vegetation biomass at high density - a previously challenging task with broad band satellite sensors.

Mutanga, Onisimo; Adam, Elhadi; Cho, Moses Azong

2012-08-01

136

Physical and vegetative characteristics of a relocated stream reach, constructed wetland, and riparian buffer, Upper Saucon Township, Lehigh County, Pennsylvania, 2000-04  

USGS Publications Warehouse

The U.S. Geological Survey, in cooperation with the Pennsylvania Department of Transportation, Engineering District 5-0, investigated physical and vegetative changes within a relocated stream reach, constructed wetland, and riparian buffer from September 2000 to October 2004. This report presents an evaluation of data collected using methods from multiple sources that have been adapted into a consistent approach. This approach is intended to satisfy a need for consistent collection of different types of data with the goal of transferring technology and findings to similar projects. Survey data indicate that adjustment of the upstream part of the relocated stream reach slowed over the monitoring period, but the downstream channel remains unstable as evidenced by excessive deposition. Upstream migration of a nick point has slowed or stopped altogether as of the 2003 assessment when this feature came in contact with the upstream-most part of the channel that is lined with riprap. Documented streambed erosion in the upstream cross sections, along with deposition downstream, has resulted in an overall decrease in slope of the stream channel over the monitoring period. Most streambed erosion took place prior to the 2002 assessment when annual mean streamflows were less than those in the final 2 years of monitoring. An abundance of fine sediment dominates the substrate of the relocated channel. Annual fluctuations of large particles within each cross section demonstrates the capacity of the relocated channel to transport the entire range of sediment. The substrate within the 0.28-acre constructed wetland (a mixture of soil from an off-site naturally occurring wetland and woodchips) supported a hydrophytic-vegetation community throughout the investigation. Eleocharis obtusa (spike rush), an obligate-wetland herb, was the most prevalent species, having a maximum areal cover of 90 percent in fall 2001 and a minimum of 23 percent in fall 2004. Drought-like conditions in water year 2002 (cumulative precipitation was 28.11 inches) allowed species like Panicum dichotomiflorum (witch grass), Salix sp. (willow), Leersia oryzoides (rice cutgrass), and Echinocloa crusgalli (barnyard grass) to become established by fall 2002. Above-average precipitation in water years 2003 and 2004 (58.55 and 53.17 inches, respectively) coincided with increased areal cover by E. obtusa in fall 2003 (56 percent) and decreased areal cover in fall 2004 (23 percent). Pond-like conditions that probably persisted throughout the 2004 growing season favored aquatic species like Alisma subcordatum (water plantain) to the detriment of many emergent species, including E. obtusa. Despite the pond-like conditions, L. oryzoides, an obligate-wetland grass, increased in areal cover (from 12 to 34 percent) between the 2003 and 2004 growing seasons because it was established in the higher elevations and the peripheral areas of the constructed wetland that were less prone to persistent inundation. Canopy development by trees and shrubs in the riparian buffer was initially (fall 2000) poor (39.7 percent), resulting in more available sunlight for the herbaceous understory than in any other growing season. As a result, areal cover of herbaceous species and trees and shrubs less than 1-meter tall was 108 percent in fall 2000 with Lolium perenne (perennial rye), Polygonum persicaria (lady's thumb), and Setaria faberi (foxtail) collectively contributing nearly half the cover (59.2 percent). Because of increases in canopy cover by trees and shrubs (39.7 percent in fall 2000 to 127 percent in fall 2004), herbaceous cover decreased to 76 percent by the fall of 2001 and varied between 72 and 77 percent for the rest of the study period. Tree density in the riparian buffer ranged from 3,078 and 4,130 plants per acre (fall 2000 and 2003, respectively) over the study period but essentially remained constant after fall 2001; computations reported each fall between fall 2001 and fall

Chaplin, Jeffrey J.; White, Kirk E.; Loper, Connie A.

2006-01-01

137

Mercury cycling in agricultural and managed wetlands of California, USA: seasonal influences of vegetation on mercury methylation, storage, and transport.  

PubMed

Plants are a dominant biologic and physical component of many wetland capable of influencing the internal pools and fluxes of methylmercury (MeHg). To investigate their role with respect to the latter, we examined the changing seasonal roles of vegetation biomass and Hg, C and N composition from May 2007-February 2008 in 3 types of agricultural wetlands (domesticated or white rice, wild rice, and fallow fields), and in adjacent managed natural wetlands dominated by cattail and bulrush (tule). We also determined the impact of vegetation on seasonal microbial Hg methylation rates, and Hg and MeHg export via seasonal storage in vegetation, and biotic consumption of rice seed. Despite a compressed growing season of ~3months, annual net primary productivity (NPP) was greatest in white rice fields and carbon more labile (leaf median C:N ratio=27). Decay of senescent litter (residue) was correlated with microbial MeHg production in winter among all wetlands. As agricultural biomass accumulated from July to August, THg concentrations declined in leaves but MeHg concentrations remained consistent, such that MeHg pools generally increased with growth. Vegetation provided a small, temporary, but significant storage term for MeHg in agricultural fields when compared with hydrologic export. White rice and wild rice seeds reached mean MeHg concentrations of 4.1 and 6.2ng gdw(-1), respectively. In white rice and wild rice fields, seed MeHg concentrations were correlated with root MeHg concentrations (r=0.90, p<0.001), suggesting transport of MeHg to seeds from belowground tissues. Given the proportionally elevated concentrations of MeHg in rice seeds, white and wild rice crops may act as a conduit of MeHg into biota, especially waterfowl which forage heavily on rice seeds within the Central Valley of California, USA. Thus, while plant tissues and rhizosphere soils provide temporary storage for MeHg during the growing season, export of MeHg is enhanced post-harvest through increased hydrologic and biotic export. PMID:23809880

Windham-Myers, Lisamarie; Marvin-DiPasquale, Mark; Kakouros, Evangelos; Agee, Jennifer L; Kieu, Le H; Stricker, Craig A; Fleck, Jacob A; Ackerman, Josh T

2014-06-15

138

Mercury cycling in agricultural and managed wetlands of California: seasonal influences of vegetation on mercury methylation, storage, and transport  

USGS Publications Warehouse

Plants are a dominant biologic and physical component of many wetland capable of influencing the internal pools and fluxes of methylmercury (MeHg). To investigate their role with respect to the latter, we examined the changing seasonal roles of vegetation biomass and Hg, C and N composition from May 2007-February 2008 in 3 types of agricultural wetlands (domesticated or white rice, wild rice, and fallow fields), and in adjacent managed natural wetlands dominated by cattail and bulrush (tule). We also determined the impact of vegetation on seasonal microbial Hg methylation rates, and Hg and MeHg export via seasonal storage in vegetation, and biotic consumption of rice seed. Despite a compressed growing season of ~ 3 months, annual net primary productivity (NPP) was greatest in white rice fields and carbon more labile (leaf median C:N ratio = 27). Decay of senescent litter (residue) was correlated with microbial MeHg production in winter among all wetlands. As agricultural biomass accumulated from July to August, THg concentrations declined in leaves but MeHg concentrations remained consistent, such that MeHg pools generally increased with growth. Vegetation provided a small, temporary, but significant storage term for MeHg in agricultural fields when compared with hydrologic export. White rice and wild rice seeds reached mean MeHg concentrations of 4.1 and 6.2 ng gdw- 1, respectively. In white rice and wild rice fields, seed MeHg concentrations were correlated with root MeHg concentrations (r = 0.90, p < 0.001), suggesting transport of MeHg to seeds from belowground tissues. Given the proportionally elevated concentrations of MeHg in rice seeds, white and wild rice crops may act as a conduit of MeHg into biota, especially waterfowl which forage heavily on rice seeds within the Central Valley of California, USA. Thus, while plant tissues and rhizosphere soils provide temporary storage for MeHg during the growing season, export of MeHg is enhanced post-harvest through increased hydrologic and biotic export.

Windham-Myers, Lisamarie; Marvin-DiPasquale, Mark C.; Kakouros, Evangelos; Agee, Jennifer L.; Kieu, Le H.; Stricker, Craig A.; Fleck, Jacob A.; Ackerman, Josh T.

2013-01-01

139

Catastrophic Shifts in Wetland Geomorphology and Ecology in Response to Hydrology-Vegetation-Sediment Transport Feedbacks (Invited)  

NASA Astrophysics Data System (ADS)

Coastal marshes and long-hydroperiod floodplain wetlands exhibit strong bi-directional feedback between hydrology, vegetation, and sediment that impacts landscape dynamics and ecosystem services. In these ecosystems, vegetation responds to and also influences the distribution of topography, with effects on habitat provision, biological diversity, landscape connectivity, surface-subsurface exchange, and microbial and redox reactions. Topography evolves both autogenically and allogenically. Autogenically, peat accretes under reducing conditions as a function of local water levels, vegetation community, and nutrient concentrations. Concurrently, an allogenic sediment redistribution feedback process involves erosion of sediment from low, sparsely vegetated areas and deposition of sediment within dense vegetation that resists flow. It is well documented that these feedback processes are dominantly responsible for evolution of tidal marsh morphology and response of coastal marshes to sea level rise. Less well understood is the role these feedbacks play in the evolution of more slowly flowing interior marshes and in the response of these systems to perturbations in flow velocity as well as water level. We developed a cellular automata model that physically simulates both sediment redistribution and differential peat accretion feedbacks. Because of the efficiency of this simplified modeling technique, we ran the model over a broad range of environmental conditions in a generalized sensitivity analysis. As a result of the two feedback processes, simulated landscapes reflected a variety of morphologies found in coastal and interior wetlands worldwide, with differences attributable to relative dominance of physical (e.g., surface-water flow, water level) or biological (e.g., vegetation productivity and colonization) drivers. Significantly, under moderate surface-water flow velocities (4-6 cm s-1), a class of patterned wetlands with regular ridges and sloughs oriented parallel to the dominant flow direction emerged, which mimics the patterned, flow-parallel topography found in the Florida Everglades. Sediment redistribution and differential peat accretion feedbacks constitute the first description of a viable mechanism for formation of this ecologically important landscape structure and provide guidance for restoration efforts. We show that because of vegetative resistance to flow, this patterned landscape structure is prone to shift to an alternate stable state, dominated by a monoculture of emergent vegetation, under changes in surface-water flow velocity or water level. Results suggest that twentieth-century degradation of the Everglades ridge and slough landscape is attributable primarily to changes in water level and, secondarily, to diminished surface-water flow velocities. Because hydrology-vegetation-sediment feedbacks cause hysteresis in landscape evolution trajectories, restoration of historic flow velocities and water levels will not necessarily produce a return to historic landscape structure. Understanding the dynamics of sediment redistribution and differential peat accretion feedbacks will be essential in predicting how wetlands worldwide will respond to changes in climate or water management.

Larsen, L. G.; Harvey, J. W.

2010-12-01

140

FLUE GAS DESULFURIZATION SLUDGE: ESTABLISHMENT OF VEGETATION ON PONDED AND SOIL-APPLIED WASTE  

EPA Science Inventory

The report gives results of research to identify and evaluate forms of vegetation and methods of their establishment for reclaiming retired flue gas desulfurization sludge ponds. Also studied were the soil liming value of limestone scrubber sludge (LSS) and plant uptake and perco...

141

Biological indicators of wetland health: Comparing qualitative and quantitative vegetation measures with anuran measures  

Microsoft Academic Search

Understanding wetland responses to human perturbations is essential to the effective management of Florida's surface and ground water resources. Southwest Florida Water Management District (SWFWMD) Rules (Chapter 40D-2.301(c) FAC) prohibit adverse environmental effects to wetlands, fish and wildlife caused by groundwater withdrawal. Numerous studies have documented the responses of biological attributes across taxa and regions to human disturbance. Biological assessment

Shannon M Gonzalez

2004-01-01

142

Landscape object-based analysis of wetland plant functional types: the effects of spatial scale, vegetation classes and classifier methods  

NASA Astrophysics Data System (ADS)

Remote sensing-based vegetation classifications representing plant function such as photosynthesis and productivity are challenging in wetlands with complex cover and difficult field access. Recent advances in object-based image analysis (OBIA) and machine-learning algorithms offer new classification tools; however, few comparisons of different algorithms and spatial scales have been discussed to date. We applied OBIA to delineate wetland plant functional types (PFTs) for Poyang Lake, the largest freshwater lake in China and Ramsar wetland conservation site, from 30-m Landsat TM scene at the peak of spring growing season. We targeted major PFTs (C3 grasses, C3 forbs and different types of C4 grasses and aquatic vegetation) that are both key players in system's biogeochemical cycles and critical providers of waterbird habitat. Classification results were compared among: a) several object segmentation scales (with average object sizes 900-9000 m2); b) several families of statistical classifiers (including Bayesian, Logistic, Neural Network, Decision Trees and Support Vector Machines) and c) two hierarchical levels of vegetation classification, a generalized 3-class set and more detailed 6-class set. We found that classification benefited from object-based approach which allowed including object shape, texture and context descriptors in classification. While a number of classifiers achieved high accuracy at the finest pixel-equivalent segmentation scale, the highest accuracies and best agreement among algorithms occurred at coarser object scales. No single classifier was consistently superior across all scales, although selected algorithms of Neural Network, Logistic and K-Nearest Neighbors families frequently provided the best discrimination of classes at different scales. The choice of vegetation categories also affected classification accuracy. The 6-class set allowed for higher individual class accuracies but lower overall accuracies than the 3-class set because individual classes differed in scales at which they were best discriminated from others. Main classification challenges included a) presence of C3 grasses in C4-grass areas, particularly following harvesting of C4 reeds and b) mixtures of emergent, floating and submerged aquatic plants at sub-object and sub-pixel scales. We conclude that OBIA with advanced statistical classifiers offers useful instruments for landscape vegetation analyses, and that spatial scale considerations are critical in mapping PFTs, while multi-scale comparisons can be used to guide class selection. Future work will further apply fuzzy classification and field-collected spectral data for PFT analysis and compare results with MODIS PFT products.

Dronova, I.; Gong, P.; Wang, L.; Clinton, N.; Fu, W.; Qi, S.

2011-12-01

143

Coastal wetlands  

SciTech Connect

This book presents an overview of coastal wetlands, mainly focusing on the Great Lakes ecosystem. Topics covered include the following: the effects of water level fluctuations on Great Lakes coastal marshes; environmental influences on the distribution and composition of wetlands in the Great Lakes Basin; vegetation dynamics, buried seeds, and water level fluctuations on the shorelines of the Great Lakes; preliminary observations on the flux of carbon, nitrogen, and phosphorous in a Great Lakes coastal marsh; nutrient cycling by wetlands and possible effects of water levels; and Avain wetland habitat functions affected by water level fluctuations.

Prince, H.H.; d'Itri, F.M.

1986-01-01

144

Vegetation mapping from medium-density discrete echo Airborne Laser Scanning data: a case study of the Lake Balaton wetlands  

NASA Astrophysics Data System (ADS)

Airborne Laser Scanning (ALS) is mainly used for collecting information on geomorphology, but the high spatial resolution and accuracy and especially the sensitivity to vertical structure are also proven to be valuable in vegetation mapping. Point cloud datasets acquired for regional or country-wide ALS surveys have strong potential as an easily accessible basis for consistent automatic vegetation mapping across large areas. However, automatized classification on the basis of multivariate analysis algorithms is not widely applied to moderate resolution discrete echo point clouds that these surveys typically produce. The number of relevant independent variables that can be derived from these datasets is often considered insufficient for multivariate classification-based detection of species or vegetation health, but in some cases it can be enhanced to a level sufficient for vegetation mapping. Although in conventional (single-wavelength) ALS the radiometric information produced is restricted to a single band, the differences of the radiometric parameters of the surveyed vegetation can considerably aid discrimination. In most cases, the horizontal distribution of the scanned points holds no information as this is governed by the sensor scan pattern. However, the horizontal distribution of points with specific radiometric intensity can add to the number of independent variables. In our case study of a lake shore and wetland area (ca. 100 km2 of wetlands distributed in a surveyed area of 1000 km2) a raster-based approach was used to average vertical structural parameters across cells occupied by several points. The information present in the position of the points relative to each other was thus exploited. Radiometric calibration of the echo amplitude also provided valuable information on vegetation type. Given a sufficient amount of pre-surveyed ground truth areas, a straightforward decision tree classification of LIDAR data mapped not only land cover categories, but also the main vegetation genera and the health of the dominant species. The decision tree algorithm was set up on the basis of a signature analysis comparing the histograms of each ALS-derived variable within the ground truth areas, and separating the classes based on histogram differences. This has proven robust enough to work across the full study area, and artefacts were relatively easy to recognize and understand. Classification accuracies produced by this study are between 60% and 92%, with an overall accuracy of 83% for all categories. While this is clearly below the maximum accuracy achievable by hyperspectral surveys of small areas, it is comparable to many passive multispectral or fused passive multispectral and ALS vegetation surveys and also the accuracies of ALS-based forest monitoring. Since the method itself is not specific for wetlands, it is believed that such an approach could provide valid vegetation classification results in other areas. As shown by this case study, medium-density discrete echo ALS datasets similar to those collected during European region-wide surveys can successfully be used to map vegetation classes relevant for ecology and conservation.

Zlinszky, A.; Mücke, W.; Lehner, H.; Briese, C.; Pfeifer, N.

2012-04-01

145

Gas exchange in wetlands with emergent vegetation: The effects of wind and thermal convection at the air-water interface  

NASA Astrophysics Data System (ADS)

Methane, carbon dioxide, and oxygen are exchanged between wetlands and the atmosphere through multiple pathways. One of these pathways, the hydrodynamic transport of dissolved gas through the surface water, is often underestimated in importance. We constructed a model wetland in the laboratory with artificial emergent plants to investigate the mechanisms and magnitude of this transport. We measured gas transfer velocities, which characterize the near-surface stirring driving air-water gas transfer, while varying two stirring processes important to gas exchange in other aquatic environments: wind and thermal convection. To isolate the effects of thermal convection, we identified a semiempirical model for the gas transfer velocity as a function of surface heat loss. The laboratory results indicate that thermal convection will be the dominant mechanism of air-water gas exchange in marshes with emergent vegetation. Thermal convection yielded peak gas transfer velocities of 1 cm h-1. Because of the sheltering of the water surface by emergent vegetation, gas transfer velocities for wind-driven stirring alone are likely to exceed this value only in extreme cases.

Poindexter, Cristina M.; Variano, Evan A.

2013-07-01

146

Monitoring of wetlands Ecosystems using satellite images  

NASA Astrophysics Data System (ADS)

Wetlands are very sensitive ecosystems, functioning as habitat for many organisms. Protection and regeneration of wetlands has been the crucial importance in ecological research and in nature conservation. Knowledge on biophysical properties of wetlands vegetation retrieved from satellite images will enable us to improve monitoring of these unique areas, very often impenetrable. The study covers Biebrza wetland situated in the Northeast part of Poland and is considered as Ramsar Convention test site. The research aims at establishing of changes in biophysical parameters as the scrub encroachment, lowering of the water table, and changes of the farming activity caused ecological changes at these areas. Data from the optical and microwave satellite images collected for the area of Biebrza marshland ecosystem have been analysed and compared with the detailed soil-vegetation ground measurements conducted in conjunction with the overflights. Satellite data include Landsat ETM, ERS-2 ATSR and SAR, SPOT VEGETATION, ENVISAT MERIS and ASAR, and NOAA AVHRR. From the optical data various vegetation indices have been calculated, which characterize the vegetation surface roughness, its moisture conditions and stage of development. Landsat ETM image has been used for classification of wetlands vegetation. For each class of vegetation various moisture indices have been developed. Ground data collected include wet and dry biomass, LAI, vegetation height, and TDR soil moisture. The water cloud model has been applied for retrieval of soil vegetation parameters taking into account microwave satellite images acquired at VV, HV and HH polarisations at different viewing angles. The vegetation parameters have been used for to distinguish changes, which occurred at the area. For each of the vegetation class the soil moisture was calculated from microwave data using developed algorithms. Results of this study will help mapping and monitoring wetlands with the high spatial and temporal resolution for better management and protection of this ecosystems. The research has been conducted under AO ID-122 ESA Project

Dabrowska-Zielinska, K.; Gruszczynska, M.; Yesou, H.; Hoscilo, A.

147

Mercury cycling in agricultural and managed wetlands of California: experimental evidence of vegetation-driven changes in sediment biogeochemistry and methylmercury production  

USGS Publications Warehouse

The role of live vegetation in sediment methylmercury (MeHg) production and associated biogeochemistry was examined in three types of agricultural wetlands (domesticated or white rice, wild rice, and fallow fields) and adjacent managed natural wetlands (cattail- and bulrush or tule-dominated) in the Yolo Bypass region of California's Central Valley, USA. During the active growing season for each wetland, a vegetated:de-vegetated paired plot experiment demonstrated that the presence of live plants enhanced microbial rates of mercury methylation by 20 to 669% (median = 280%) compared to de-vegetated plots. Labile carbon exudation by roots appeared to be the primary mechanism by which microbial methylation was enhanced in the presence of vegetation. Pore-water acetate (pw[Ac]) decreased significantly with de-vegetation (63 to 99%) among all wetland types, and within cropped fields, pw[Ac] was correlated with both root density (r = 0.92) and microbial Hg(II) methylation (kmeth. r = 0.65). Sediment biogeochemical responses to de-vegetation were inconsistent between treatments for “reactive Hg” (Hg(II)R), as were reduced sulfur and sulfate reduction rates. Sediment MeHg concentrations in vegetated plots were double those of de-vegetated plots (median = 205%), due in part to enhanced microbial MeHg production in the rhizosphere, and in part to rhizoconcentration via transpiration-driven pore-water transport. Pore-water concentrations of chloride, a conservative tracer, were elevated (median = 22%) in vegetated plots, suggesting that the higher concentrations of other constituents around roots may also be a function of rhizoconcentration rather than microbial activity alone. Elevated pools of amorphous iron (Fe) in vegetated plots indicate that downward redistribution of oxic surface waters through transpiration acts as a stimulant to Fe(III)-reduction through oxidation of Fe(II)pools. These data suggest that vegetation significantly affected rhizosphere biogeochemistry through organic exudation and transpiration-driven concentration of pore-water constituents and oxidation of reduced compounds. While the relative role of vegetation varied among wetland types, macrophyte activity enhanced MeHg production.

Windham-Myers, Lisamarie; Marvin-DiPasquale, Mark; Stricker, Craig A.; Agee, Jennifer L.; Kieu, Le H.; Kakouros, Evangelos

2014-01-01

148

Mercury cycling in agricultural and managed wetlands of California, USA: experimental evidence of vegetation-driven changes in sediment biogeochemistry and methylmercury production.  

PubMed

The role of live vegetation in sediment methylmercury (MeHg) production and associated biogeochemistry was examined in three types of agricultural wetlands (domesticated or white rice, wild rice, and fallow fields) and adjacent managed natural wetlands (cattail- and bulrush or tule-dominated) in the Yolo Bypass region of California's Central Valley, USA. During the active growing season for each wetland, a vegetated:de-vegetated paired plot experiment demonstrated that the presence of live plants enhanced microbial rates of mercury methylation by 20 to 669% (median=280%) compared to de-vegetated plots. Labile carbon exudation by roots appeared to be the primary mechanism by which microbial methylation was enhanced in the presence of vegetation. Pore-water acetate (pw[Ac]) decreased significantly with de-vegetation (63 to 99%) among all wetland types, and within cropped fields, pw[Ac] was correlated with both root density (r=0.92) and microbial Hg(II) methylation (kmeth. r=0.65). Sediment biogeochemical responses to de-vegetation were inconsistent between treatments for "reactive Hg" (Hg(II)R), as were reduced sulfur and sulfate reduction rates. Sediment MeHg concentrations in vegetated plots were double those of de-vegetated plots (median=205%), due in part to enhanced microbial MeHg production in the rhizosphere, and in part to rhizoconcentration via transpiration-driven pore-water transport. Pore-water concentrations of chloride, a conservative tracer, were elevated (median=22%) in vegetated plots, suggesting that the higher concentrations of other constituents around roots may also be a function of rhizoconcentration rather than microbial activity alone. Elevated pools of amorphous iron (Fe) in vegetated plots indicate that downward redistribution of oxic surface waters through transpiration acts as a stimulant to Fe(III)-reduction through oxidation of Fe(II)pools. These data suggest that vegetation significantly affected rhizosphere biogeochemistry through organic exudation and transpiration-driven concentration of pore-water constituents and oxidation of reduced compounds. While the relative role of vegetation varied among wetland types, macrophyte activity enhanced MeHg production. PMID:23809881

Windham-Myers, Lisamarie; Marvin-DiPasquale, Mark; A Stricker, Craig; Agee, Jennifer L; H Kieu, Le; Kakouros, Evangelos

2014-06-15

149

Camera derived vegetation greenness index as proxy for gross primary production in a low Arctic wetland area  

NASA Astrophysics Data System (ADS)

The Arctic is experiencing disproportionate warming relative to the global average, and the Arctic ecosystems are as a result undergoing considerable changes. Continued monitoring of ecosystem productivity and phenology across temporal and spatial scales is a central part of assessing the magnitude of these changes. This study investigates the ability to use automatic digital camera images (DCIs) as proxy data for gross primary production (GPP) in a complex low Arctic wetland site. Vegetation greenness computed from DCIs was found to correlate significantly (R2 = 0.62, p < 0.001) with a normalized difference vegetation index (NDVI) product derived from the WorldView-2 satellite. An object-based classification based on a bi-temporal image composite was used to classify the study area into heath, copse, fen, and bedrock. Temporal evolution of vegetation greenness was evaluated and modeled with double sigmoid functions for each plant community. GPP at light saturation modeled from eddy covariance (EC) flux measurements were found to correlate significantly with vegetation greenness for all plant communities in the studied year (i.e., 2010), and the highest correlation was found between modeled fen greenness and GPP (R2 = 0.85, p < 0.001). Finally, greenness computed within modeled EC footprints were used to evaluate the influence of individual plant communities on the flux measurements. The study concludes that digital cameras may be used as a cost-effective proxy for potential GPP in remote Arctic regions.

Westergaard-Nielsen, Andreas; Lund, Magnus; Hansen, Birger Ulf; Tamstorf, Mikkel Peter

2013-12-01

150

Removal of ammoniacal nitrogen and oxidised nitrogen in landfill leachate using vegetated constructed wetland with continuous flow through different filter media  

Microsoft Academic Search

Performance of the vegetated horizontal subsurface-flow constructed wetland was evaluated for the removal of ammoniacal nitrogen (AN), total oxidized nitrogen (TNOx-N) and nitrite nitrogen (NO2-N) from landfill leachate. Four reactors were used, RI (granite without vegetation), RII and RIII which consists of granite and gravel with different sizes respectively and RIV contained sand and 67.5 L of charcoal. RII, RIII

Lim Chin Shiam; Suryani Soetardjo; H. P. S. A. Khalil

2010-01-01

151

Uncoupling of the Pathway of Methanogenesis in Northern Wetlands: Connection to Vegetation, and Implications for Variability and Predictability.  

NASA Astrophysics Data System (ADS)

Typical methanogenic decomposition pathways include near terminal carbon intermediates that turn over rapidly with small pool sizes. However, incubation and field experiments demonstrated that these organic intermediates accumulate in northern wetlands due to the lack of consumption by methanogenic bacteria. Acetate is the major organic end product of decomposition rather than CH4, and methanogenesis can be insignificant. The ratio of CO2:acetate:CH4 varied with vegetation type, and habitats dominated by non-vascular plants (Sphagnum) produced more acetate-C than CO2 or CH4. This ratio correlated well with stable C isotope alpha values used to delineate the path of CH4 formation. We suggest that methanogenesis in general is inhibited in oligotrophic wetlands, but that the conversion of acetate to CH4 is more sensitive, which increases the importance of the conversion of H2/CO2 to CH4. The relative importance of CH4 as an end product increased greatly in sites containing even small populations of Carex compared to sites inhabited only by Sphagnum, suggesting that subtle vegetation changes expected to occur during warming could lead to changes in the path of methanogenesis, increasing production. In addition, depth profiles revealed an active surficial (0-7 cm) C cycle that is sensitive to hydrology that may also greatly affect variability of CH4 formation. Acetate production represented a terminal process and was a sink for a large portion of metabolized C whose ultimate fate was aerobic oxidation to CO2. C destined for CH4 is thus bypassed to CO2 and does not contribute to atmospheric CH4. However, the connection and sensitivity of the pathway of methanogenesis to even small vegetation changes suggests that pathways can be mapped, they vary greatly over small distances, and they can change drastically with relatively small temperature increases.

Hines, M. E.; Duddleston, K. N.; Chanton, J. P.

2006-12-01

152

The importance of hydrology in restoration of bottomland hardwood wetland functions  

USGS Publications Warehouse

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.

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

2008-01-01

153

Development and testing of an index of biotic integrity based on submersed and floating vegetation and its application to assess reclamation wetlands in Alberta's oil sands area, Canada.  

PubMed

We developed and tested a plant-based index of biological integrity (IBI) and used it to evaluate the existing reclamation wetlands in Alberta's oil sands mining region. Reclamation plans call for >15,000 ha of wetlands to be constructed, but currently, only about 25 wetlands are of suitable age for evaluation. Reclamation wetlands are typically of the shallow open water type and range from fresh to sub-saline. Tailings-contaminated wetlands in particular may have problems with hydrocarbon- and salt-related toxicity. From 60 initial candidate metrics in the submersed aquatic and floating vegetation communities, we selected five to quantify biological integrity. The IBI included two diversity-based metrics: the species richness of floating vegetation and the percent of total richness contributed by Potamogeton spp. It also included three relative abundance-based metrics: that of Ceratophyllum demersum, of floating leafed species and of alkali-tolerant species. We evaluated the contribution of nonlinear metrics to IBI performance but concluded that the correlation between IBI scores and wetland condition was not improved. The method used to score metrics had an influence on the IBI sensitivity. We conclude that continuous scoring relative to the distribution of values found in reference sites was superior. This scoring approach provided good sensitivity and resolution and was grounded in reference condition theory. Based on these IBI scores, both tailings-contaminated and tailings-free reclamation wetlands have significantly lower average biological integrity than reference wetlands (ANOVA: F(2,59) = 34.7, p = 0.000000000107). PMID:21484300

Rooney, Rebecca C; Bayley, Suzanne E

2012-01-01

154

[The establishment of Holocene vegetation belts: quite near to a complete model of a solid mass].  

PubMed

Pollen and macro-remains were analysed in a sixth site (La Gouille 1,800 m) of the Chaîne des Hurtières (northern French Alps). Nine A.M.S. dates support the chronology. Thus, the establishment of the vegetation belt of a massif can be modelled in the northern French Alps. Betula invaded sub-Alpine grasslands as early as 10,000 14C BP. Around 9,600 14C BP shrublands with Corylus, Alnus and Sorbus were established before the spread of Abies at the site approximately 8,200 14C BP. A decrease in Abies prior to 8,100 14C BP occurred during the Venediger climatic oscillation. At around 2,940 14C BP, a strong regression of Abies due to human action is noted with the expansion of Alnus viridis. Recently, a second Abies retraction led to the present sparce P. cembra and Alnus viridis vegetation cover. PMID:11291314

David, F

2001-03-01

155

Bioavailability and uptake of arsenic by wetland vegetation: Effects on plant growth and nutrition  

Microsoft Academic Search

This study reports on the uptake, potential bioavailability and phytotoxicity of arsenic (As) to an important wetland plant species growing in the vicinity of produced water discharge. The effects caused by As chemical form and concentration on growth, tissue concentrations and distribution of As and nutrient elements were studied in Spartina patens, growing in hydroponic conditions. A 4 × 3

A. A. Carbonell; M. A. Aarabi; R. D. DeLaune; R. P. Gambrell; W. H. Patrick Jr

1998-01-01

156

Vegetation effects on fecal bacteria, BOD, and suspended solid removal in constructed wetlands treating domestic wastewater  

Microsoft Academic Search

Constructed wetlands have emerged as a viable alternative for secondary treatment of domestic wastewater in areas with landscape limitations, poor soil conditions, and high water tables, which limit installation of full-scale adsorption fields. Existing information on the effects of macrophytes on treatment performance is contradictory and mostly derived from greenhouse mesocosm experiments. This study investigated the removal efficiency of fecal

A. D. Karathanasis; C. L. Potter; M. S. Coyne

2003-01-01

157

Impacts of vegetation changes on the hydraulic and sediment transport characteristics in Guandu mangrove wetland  

Microsoft Academic Search

Excessive mangrove spreading causes a significant impact upon the ecosystem and flood control operations in the Guandu mangrove wetland (Guandu Natural Reserve), Taiwan. Aerial photos, taken between 1978 and 1994, reveal that marsh habitats, dominated by Cyperus malaccensis Lam. and Phragmites communis (L.) Trin., have changed into a swamp habitat, dominated by Kandelia candel (L.) Druce. The coverage area of

Hong-Yuan Lee; Shang-Shu Shih

2004-01-01

158

The Influence of Vegetation on Sedimentation and Resuspension of Soil Particles in Small Constructed Wetlands  

Microsoft Academic Search

their influence on water turbidity and their ability to adsorb phosphorus (Sharpley, 1980), heavy metals (Ka- When initiatives to mitigate soil erosion are insufficient or fail, bata-Pendias and Pendias, 1984), and pesticides (Leo- constructed surface flow wetlands (CWs) could be a final buffer to 22 . Results show that macrophytes stimulate sediment resuspension or new erosion of sediments under storm

B. C. Braskerud

2001-01-01

159

Multisite comparison of drivers of methane emissions from wetlands in the European Arctic: influence of vegetation community and water table.  

NASA Astrophysics Data System (ADS)

Arctic and sub arctic wetlands are a major source of atmospheric CH4 and therefore have the potential to be important in controlling global radiative forcing. Furthermore, the strong links between wetland CH4 emissions and vegetation community, hydrology and temperature suggest potentially large feedbacks between climate change and future emissions. Quantifying current emissions over large spatial scales and predicting future climatic feedbacks requires a fundamental understanding of the ground based drivers of plot scale emissions. The MAMM project (Methane in the Arctic: Measurements and Modelling) aims to understand and quantify current CH4 emissions and future climatic impacts by combining both ground and aircraft measurements across the European Arctic with regional computer modelling. Here we present results from the ground-based MAMM measurement campaigns, analysing chamber-measured CH4 emissions from two sites in the European Arctic/Sub-Arctic region (Sodankylä, Finland; Stordalen Mire, Sweden) from growing seasons in 2012 and 2013. A total of 85 wetland static chambers were deployed across the two field sites; 39 at Sodankylä (67° 22'01' N, 26° 3'06' E) in 2012 and 46 at Stordalen Mire (68° 21'20' N, 19° 02'56' E) in 2013. Chamber design, protocol and deployment were the same across both sites. Chambers were located at sites chosen strategically to cover the local range of water table depths and vegetation communities. A total of 18 and 15 repeated measurements were made at each chamber in Sodankylä and Stordalen Mire, respectively, over the snow-free season. Preliminary results show a large range of CH4 fluxes across both sites ranging from a CH4 uptake of up to 0.07 and 0.06 mg CH4-C m-2 hr-1 to emissions of 17.3 and 44.2 mg CH4-C m-2 hr-1 in Sodankylä and Stordalen Mire, respectively. Empirical models based on vegetation community, water table depth, temperature and soil nutrient availability (Plant Root Simulator Probes, PRSTM) have been constructed with the aim of understanding the drivers of chamber scale fluxes. By combining measurements made at two different sites, >300km apart, using the same experimental setup, we are uniquely able to investigate whether CH4 emissions are driven by common parameters. Furthermore we are able to determine if plot scale empirical models and parameterisations can be used effectively to upscale emissions to landscape and whole Arctic scale.

Dinsmore, Kerry; Drewer, Julia; Leeson, Sarah; Skiba, Ute; Levy, Pete; George, Charles

2014-05-01

160

Integrated field lysimetry and porewater sampling for evaluation of chemical mobility in soils and established vegetation.  

PubMed

Potentially toxic chemicals are routinely applied to land to meet growing demands on waste management and food production, but the fate of these chemicals is often not well understood. Here we demonstrate an integrated field lysimetry and porewater sampling method for evaluating the mobility of chemicals applied to soils and established vegetation. Lysimeters, open columns made of metal or plastic, are driven into bareground or vegetated soils. Porewater samplers, which are commercially available and use vacuum to collect percolating soil water, are installed at predetermined depths within the lysimeters. At prearranged times following chemical application to experimental plots, porewater is collected, and lysimeters, containing soil and vegetation, are exhumed. By analyzing chemical concentrations in the lysimeter soil, vegetation, and porewater, downward leaching rates, soil retention capacities, and plant uptake for the chemical of interest may be quantified. Because field lysimetry and porewater sampling are conducted under natural environmental conditions and with minimal soil disturbance, derived results project real-case scenarios and provide valuable information for chemical management. As chemicals are increasingly applied to land worldwide, the described techniques may be utilized to determine whether applied chemicals pose adverse effects to human health or the environment. PMID:25045915

Matteson, Audrey R; Mahoney, Denis J; Gannon, Travis W; Polizzotto, Matthew L

2014-01-01

161

Analysis of LANDSAT ETM and TM multi-temporal data for IPCI-based wetland vegetation condition classes in the prairie pothole region of North Dakota  

NASA Astrophysics Data System (ADS)

In this study, geographic information systems (GIS), FRAGSTATS (landscape pattern analysis program), and satellite classification land cover data were used to (1) explore, quantify, and compare the spatial pattern of landscapes surrounding seasonal and temporary wetlands in the Prairie Pothole Region (PPR) of North Dakota; (2) determine the relationship of landscape metrics to the Index of Plant Community Integrity (IPCI); and (3) develop a landscape-level wetland condition prediction model. Patch-based statistics, derived from multi-temporal (LANDSAT TM and ETM+) land cover data, were summarized at the class and landscape-level and used to characterize landscape spatial pattern. Non-Metric Multidimensional Scaling ordination was used to evaluate the dissimilarity in landscape metric space of wetlands of differing IPCI values. Statistical analysis confirmed differences in spatial patterns surrounding wetlands. Strong associations were also discovered between the IPCI condition of wetlands and 13 landscape metrics, largely among seasonal wetlands (landscapes with relatively minimal human disturbance). The associations were relatively weaker among temporary wetlands (landscapes subjected to repeated and considerable agricultural management). A data-driven model, the Landscape Wetland Analysis Model (LWAM), was developed and validated for rapid quantitative assessment of landscape structure, and prediction of potential wetland plant community condition. The modeling approach was based on (1) identification of metrics that displayed reasonable relationship(s) with wetland condition classes, (2) establishment of threshold levels that significantly and consistently separated the IPCI wetland conditions, and (3) the development of decision rules for obtaining wetland modeled condition class membership. Three landscape metrics were retained for model development: (1) grassland percent core area of landscape (C%LAND), (2) grassland largest patch index (LPI), and (3) the number of patches per unit area (NPA). The model provides two decision-making options for landscape-level assessment, understanding, and ultimately managing PPR wetlands: (1) three-level condition classification approach (i.e., poor, intermediate, and good: derived when two decision rules are applied), and (2) two-level classification approach (i.e., poor and good: derived when all decision rules are applied). Two aspects of the PPR landscape were discovered as important in this study contributing to the structure and plant community condition of wetland ecosystems: (1) grasslands, and (2) landscape fragmentation.

Mita, Dath Kakole

162

The influence of topography and vegetation self-organization over resource fluxes in wetland ecosystems  

NASA Astrophysics Data System (ADS)

While it is recognized that topography and vegetation self-organization (SO) are both first order controls over ecosystem dynamics, the discrete contributions that these two controls have over ecosystem functioning have not been studied in any rigorous way. This work is focused on systematically isolating the separate and combined impacts of topography and SO over vegetation dynamics. We simulate the steady state and transient dynamics of nitrogen-limited patterned peat vegetation observed in the bogs of northern Siberia. We do so across a realistic range of land slopes, nutrient limitation values, and rainfall amounts. Simulation results show that on relatively shallow slopes, vegetation SO is a primary control over the spatial arrangement of vegetation, and that such self-organized arrangements yield the most efficient capture of ecosystem resources. However, as slope increases, and or resource limitation is low, topography begins to exert its control over the temporal and spatial dynamics. As will be discussed, these results suggest a simple continuum framework, valid across biomes, for understanding the interplay between these two first order controls. Specifically, as resources (e.g., water, nutrients) increase, ecosystem dynamics shift towards topographic control, while when resources are reduced, ecosystem dynamics shift towards vegetation SO control.

Stieglitz, Marc; Cheng, Yiwei; Truk, Greg; Engel, Victor; Ross, Joshua

2014-05-01

163

Current Issues in Alaska Wetland Management.  

National Technical Information Service (NTIS)

Although wetlands cover over half of Alaska, the status, management and regulation of these areas is problematic. The technical literature on Alaskan wetland vegetation, soils and hydrology is abundant, but the application of the literature to wetland man...

C. H. Racine

1994-01-01

164

Effects of river hydrology and fluvial processes on riparian vegetation establishment, growth, and survival  

NASA Astrophysics Data System (ADS)

Stream hydrology, sediment, and geology interact to determine the spatial and temporal availability of river bottomland substrates on which plants establish and grow. Collectively, these surfaces comprise a mosaic of landscape patches with associated plant communities that fall along key gradients of physical disturbance and water availability. Aspects of flow such as magnitude, frequency, timing, and rate of change of floods and magnitude and duration of low flows, interact with sediment flux and plant traits to determine plant distribution and fitness in different parts of the bottomland. Flow and sediment dynamics can influence different aspects of the plant life cycle such as germination, establishment, growth, and survival. Feedbacks between plants and fluvial processes, such as increased surface roughness and associated reductions in flow velocity and potential for aggradation, can determine differential survival of plant species depending on their tolerance of high velocity flow and associated shear stress, dislodgement, or burial by sediment. We present an overview of some key relationships between flow, sediment, plant traits, and riparian vegetation responses, and provide specific examples from our research on rivers in the semi-arid western U.S., including unaltered systems, dam-altered systems, and in the context of development of environmental flows to restore native riparian vegetation communities. Further, we describe the riparian response guilds framework and demonstrate how it can facilitate both an understanding of vegetation response to changing flow, sediment, and disturbance regimes and the development of priorities for flow management. Through understanding how guilds of species respond to variations in flow and sediment regimes, we are be better able to anticipate and predict biotic change in response to human-caused and climate-driven flow alteration.

Shafroth, P. B.; Merritt, D. M.; Wilcox, A. C.

2012-12-01

165

[Spatial variation of soil moisture/salinity and the relationship with vegetation under natural conditions in Yancheng coastal wetland].  

PubMed

Taking the core part of Yancheng national nature reserve as the study area, according to soil sampling analysis of coastal wetlands in April and May 2011 land the 2011 ETM + remote sensing image, the spatial difference characteristic of coastal wetlands soil moisture and salinity, and the relationship with vegetation under natural conditions, were investigated with the model of correspondence analysis (CCA), linear regression simulation and geo-statistical method. The results showed: Firstly, the average level of the soil moisture was fluctuating between 36.820% and 46.333% , and the soil salinity was between 0.347% and 1.328% , in a more detailed sense, the Spartina swamp was the highest, followed by the mudflats swamp, the Suaeda salsa swamp, and the Reed marsh. Secondly, the spatial variation of soil moisture was consistent with that of the salinity, and the degree of variation in the east-west direction was greater than that in the north-south. The maximum soil moisture and salinity were found in the southwest Spartina swamp. The minimum was in the Reed swamp. The soil moisture and salinity were divided into 5 levels, from I to V. Level IV occupied the highest proportion, which were 36.156% and 28.531% , respectively. Finally, different landscape types with the combination of soil moisture and salinity showed a common feature that the moisture and salinity were from both high to low. The soil moisture value of Reed marshes was lower than 40.116% and the salinity value was lower than 0. 676% . The soil moisture value of Suaeda salsa marshes was between 38. 162% and 46. 403% and the salinity value was between 0.417% and 1.295%. The soil moisture value of Spartina swamp was higher than 43.214% and the salinity was higher than 1.090%. The soil moisture value of beach was higher than 43.214% and the salinity was higher than 0.677%. PMID:23668120

Zhang, Hua-Bing; Liu, Hong-Yu; Li, Yu-Feng; An, Jing; Xue, Xing-Yu; Hou, Ming-Hang

2013-02-01

166

Hydrogeology of wetlands  

USGS Publications Warehouse

A collection of 10 papers presented at the Hydrogeology of Wetlands Symposium, 28th International Geological Congress in Washington, DC, in July 1989. The purpose of the symposium was to assemble papers describing hydrogeologic studies of wetlands representative of different geographic regions, wetland types, and study approaches. The papers presented at the Symposium ranged geographically from wetlands in the Arctic to the Subtropics. Different wetland types included coastal, riverine, depressional glacial terrane, and dunal depressions. Different study approaches included regional syntheses, analyses of groundwater flow systems, wetland-river interaction, and geomorphology-vegetation interaction. -from Editors

Winter, T. C.; Llamas, M. R.

1993-01-01

167

Ground-cover vegetation in wetland forests of the lower Suwannee River floodplain, Florida, and potential impacts of flow reductions  

USGS Publications Warehouse

Ground-cover vegetation was surveyed in wetland forests in the lower Suwannee River floodplain, Florida, in a study conducted by the U.S. Geological Survey in cooperation with the Suwannee River Water Management District from 1996 to 1999. Increased water use in the basin, supplied primarily from ground water, could reduce ground-water discharge to the river and flows in the lower Suwannee River. Many of the 282 ground-cover species found in wetland forests of the floodplain have distributions that are related to flow-dependent hydrologic characteristics of forest types, and their distributions would change if flows were reduced. Overall species diversity in the floodplain might decrease, and the composition of ground-cover vegetation in all forest types might change with flow reductions. The study area included forests within the 10-year floodplain of the lower Suwannee River from its confluence with the Santa Fe River to the lower limit of forests near the Gulf of Mexico. The floodplain is divided into three reaches (riverine, upper tidal, and lower tidal) due to variations in hydrology, vegetation, and soils with proximity to the coast. The riverine (non-tidal) reach had the greatest number of total species (203) and species unique to that reach (81). Mitchella repens, Toxicodendron radicans, and Axonopus furcatus were the most frequently dominant species in riverine bottomland hardwoods. Free-floating aquatic species, such as Spirodela punctata and Lemna valdiviana, were the dominant species in the wettest riverine swamps. The upper tidal reach had the lowest number of total species (116), only two species unique to that reach, and the lowest density of ground cover (26 percent). Panicum commutatum and Crinum americanum were frequent dominant species in upper tidal forests. The lower tidal reach had the highest ground-cover density (43 percent) and the second highest number of total species (183) and number of species unique to that reach (55). Saururus cernuus and species of Carex were frequently dominant in lower tidal swamps. Lower tidal hammocks, the most elevated lower tidal forests, were dominated by Osmunda cinnamomea and Chasmanthium laxum. Flow reductions in the lower Suwannee River could change the flow-dependent hydrologic characteristics of wetland forests. Decreases in inundation and saturation in riverine forests could result in a decrease in the number and extent of semi-permanently inundated ponds. As a result, several species of free-floating, aquatic plants that grow only in riverine floodplain ponds might decrease in abundance or disappear if flows were reduced. Decreases in inundation and saturation could also result in a shift to more upland species in all riverine forests and upper tidal bottomland hardwoods. Upland species and some exotic species might increase in abundance in the floodplain, invading forests where hydrologic conditions have been altered by flow reductions. Depth and duration of inundation due to river flooding could decrease in all riverine and upper tidal forests, probably resulting in a shift of species to those that are typically found in forests with shallower, shorter-duration floods. Salinity in the lower tidal reach and adjacent areas of the upper tidal reach might increase with flow reductions, and the distribution of species might change due to varying tolerances of salinity among species. Species with low salt-tolerance unique to the lower tidal reach might disappear from the floodplain, and species with high salinity tolerance could increase in abundance, replacing less salt-tolerant species.

Darst, Melanie R.; Light, Helen M.; Lewis, Lori J.

2002-01-01

168

Vegetation and proximity to the river control amorphous silica storage in a riparian wetland (Biebrza National Park, Poland)  

Microsoft Academic Search

Wetlands can modify and control nutrient fluxes between terrestrial and aquatic ecosystems, yet little is known of their potential as biological buffers and sinks in the biogeochemical silica cycle. We investigated the storage of amorphous silica (ASi) in a central-European riparian wetland. The variation in storage of ASi in the soil of an undisturbed wetland was significantly controlled by two

E. Struyf; W. Opdekamp; H. Backx; S. Jacobs; D. J. Conley; P. Meire

2009-01-01

169

How well do we know northern land cover? Comparison of four global vegetation and wetland products with a new ground-truth database for West Siberia  

Microsoft Academic Search

currently available land cover classification products are remarkably poor indicators of vegetation type and water body extent in this northern wetland environment. The ground-truth data are compared with (1) the Global Land Cover Characteristics database derived from Advanced Very High Resolution Radiometer data (GLCC.AVHRR), (2) the Global Land Cover Classification derived from Moderate Resolution Imaging Spectroradiometer data (GLCC.MODIS), (3) the

Karen E. Frey; Laurence C. Smith

2007-01-01

170

Snohomish Estuary Wetlands Study. Volume IV. Delineation of Wetland Boundaries.  

National Technical Information Service (NTIS)

Wetlands boundaries in the Snohomish River Basin were delineated according to Army Corps of Engineers (Corps) definition presented in Corps permit regulations (33 CFR 323.2). These definitions are based primarily on occurrence of wetland vegetation and co...

M. E. Boule G. B. Shea

1978-01-01

171

Defining Hydrophytes for Wetland Identification and Delineation.  

National Technical Information Service (NTIS)

The presence of hydrophytic vegetation is an essential ingredient in the definition of wetlands. The National Technical Committee for Wetland Vegetation was, among other things, charged with reviewing the concept of a hydrophyte and constructing a definit...

R. W. Tiner

2012-01-01

172

Assessment of acreage and vegetation change in Florida's Big Bend tidal wetlands using satellite imagery  

USGS Publications Warehouse

Fluctuations in sea level and impending development on the west coast of Florida have aroused concern for the relatively pristine tidal marshes of the Big Bend. Landsat Thematic Mapper (TM) images for 1986 and 1995 are processed and evaluated for signs of change. The images cover 250 km of Florida's Big Bend Gulf Coast, encompassing 160,000 acres of tidal marshes. Change is detected using the normalized difference vegetation index (NDVI) and land cover classification. The imagery shows negligible net loss or gain in the marsh over the 9-year period. However, regional changes in biomass are apparent and are due to natural disturbances such as low winter temperatures, fire, storm surge, and the conversion of forest to march. Within the marsh, the most prominent changes in NDVI and in land cover result from the recovery of mangroves from freezes, a decline of transitional upland vegetation, and susceptibility of the marsh edge and interior to variations in tidal flooding.

Raabe, Ellen A.; Stumpf, Richard P.

1997-01-01

173

Germination in Baltic coastal wetland meadows: similarities and differences between vegetation and seed bank  

Microsoft Academic Search

The abundance and variety of seedlings in Baltic coastal grasslands was studied in cattle grazed and ungrazed areas in seashore\\u000a and delta on the western coast of Finland. The vegetation, seed bank and environmental conditions of the same sites were also\\u000a studied. Altogether 4609 seedlings were observed in 79 field plots (20 cm 20 cm) making an average of 1458.54

Heli M. Jutila

2003-01-01

174

Effects of vegetative propagule pressure on the establishment of an introduced clonal plant, Hydrocotyle vulgaris  

PubMed Central

Some introduced clonal plants spread mainly by vegetative (clonal) propagules due to the absence of sexual reproduction in the introduced range. Propagule pressure (i.e. total number of propagules) may affect the establishment and thus invasion success of introduced clonal plants, and such effects may also depend on habitat conditions. A greenhouse experiment with an introduced plant, Hydrocotyle vulgaris was conducted to investigate the role of propagule pressure on its invasion process. High (five ramets) or low (one ramet) propagule pressure was established either in bare soil or in an experimental plant community consisting of four grassland species. H. vulgaris produced more total biomass under high than under low propagule pressure in both habitat conditions. Interestingly, the size of the H. vulgaris individuals was smaller under high than under low propagule pressure in bare soil, whereas it did not differ between the two propagule pressure treatments in the grassland community. The results indicated that high propagule pressure can ensure the successful invasion in either the grass community or bare soil, and the shift in the intraspecific interaction of H. vulgaris from competition in the bare soil to facilitation in the grassland community may be a potential mechanism.

Liu, Ruihua; Chen, Qiuwen; Dong, Bicheng; Yu, Feihai

2014-01-01

175

Effects of vegetative propagule pressure on the establishment of an introduced clonal plant, Hydrocotyle vulgaris.  

PubMed

Some introduced clonal plants spread mainly by vegetative (clonal) propagules due to the absence of sexual reproduction in the introduced range. Propagule pressure (i.e. total number of propagules) may affect the establishment and thus invasion success of introduced clonal plants, and such effects may also depend on habitat conditions. A greenhouse experiment with an introduced plant, Hydrocotyle vulgaris was conducted to investigate the role of propagule pressure on its invasion process. High (five ramets) or low (one ramet) propagule pressure was established either in bare soil or in an experimental plant community consisting of four grassland species. H. vulgaris produced more total biomass under high than under low propagule pressure in both habitat conditions. Interestingly, the size of the H. vulgaris individuals was smaller under high than under low propagule pressure in bare soil, whereas it did not differ between the two propagule pressure treatments in the grassland community. The results indicated that high propagule pressure can ensure the successful invasion in either the grass community or bare soil, and the shift in the intraspecific interaction of H. vulgaris from competition in the bare soil to facilitation in the grassland community may be a potential mechanism. PMID:24981102

Liu, Ruihua; Chen, Qiuwen; Dong, Bicheng; Yu, Feihai

2014-01-01

176

Application of remote sensing techniques at different scales of observation on wetland evapotranspiration  

NASA Astrophysics Data System (ADS)

The establishment and maintenance of the structure and functions in wetland ecosystems is greatly influenced by hydrologic conditions. Evapotranspiration (ET) is the major output component in the hydrologic water budget. Therefore, in order to provide efficient information for water resources management and the conservation of wetland ecosystems, research on ET is urgently needed. Moreover, to overcome the variable spatial vegetation distribution and the temporal change of wetlands, appropriate remote sensing techniques are also greatly needed. The goal of this research was to study fundamental wetland ET and then with the aid of remote sensing techniques from the micro scale to the macro scale to develop useful wetland ET estimation methods. The study site was located in the Ft. Drum Marsh, Upper St. John's River Basin in Indian River County, Florida. The site is a freshwater marsh with southern cattail ( Typha domingensis Pers.) and sawgrass (Cladium jamaicense Crantz) as the dominant vegetation species. There were four stages of the study: (1) a fundamental ET study with a lysimeter system, (2) ground measurements and analyses of spectral responses of wetland vegetation using a field spectroradiometer, (3) wetland vegetation mapping using aerial hyperspectral images, and (4) application of satellite images to delineate wetland vegetation and estimate marsh-wide ET. The results of the fundamental ET study showed the various important vegetation parameters of sawgrass and cattail. A more appropriate estimation method of canopy resistance for sawgrass and cattail was proposed. Among the various ET estimation methods, the Priestley-Taylor method was found to be most applicable. The ground spectral response measurements of sawgrass and cattail demonstrated a distinguishable difference in red wavebands and normalized difference vegetation index (NDVI), which indicated the spectral separability of the two wetland species. Leaf area index and stomatal resistance displayed a high correlation to spectral reflectance. Aerial hyperspectral imaging proved very successful in the identification of wetland vegetation species. Among all 64 wavebands, the separability tests revealed that the wavebands in the blue-green, red edge, and near-infrared spectral regions are the most important contributors for the identification of wetland vegetation species. The satellite image was applied to map wetland vegetation using the knowledge based classification method. Integrating the results from the four stages of study, the marsh-wide ET was estimated. The results of this research can have extensive application to wetland ET, wetland delineation, and remote sensing techniques.

Juan, Chung-Hsin

177

The role of terrestrial vegetation in mercury deposition: fate of stable mercury isotopes applied to upland and wetland forest canopies during the METAALICUS experiment (Invited)  

NASA Astrophysics Data System (ADS)

Methylmercury (MeHg) is an organic, neurotoxic form of mercury (Hg) that is responsible for fish consumption advisories in North American freshwaters. It is generally believed that increases in anthropogenic Hg emissions have resulted in high MeHg concentrations of fish. However, a direct relationship between deposition of inorganic Hg(II) and concentrations of MeHg in fish has been difficult to demonstrate because of our inability to distinguish newly-deposited Hg from Hg accumulated historically in ecosystems. The Mercury Experiment to Assess Atmospheric Loading In Canada and the US (METAALICUS) increased atmospheric inputs of mercury (Hg) to a small lake and its watershed to levels comparable to those in more industrialized regions. Between 2001 and 2006, three different enriched stable isotopes of Hg (spikes) were loaded to the watershed, one each to the surface of the lake (200Hg), the wetland (198Hg) and the forested upland (202Hg) areas of the catchment to determine the relative contribution of these sources to fish MeHg concentrations. Terrestrial vegetation often represents the first landscape compartment that new atmospheric Hg contacts upon deposition, and plants act as conduits of atmospheric Hg to the landscape. We will present pools and fluxes of spike Hg within upland and wetland canopy and ground vegetation compartments. Our Geographical Information Systems-based modeling approach to calculating spike pools used aircraft spray tracks, regressions between spike application rate and concentrations of spike in vegetation, a LiDAR-derived Leaf Area Index (LAI) map and relationships between LAI and canopy biomass. We observed that 30-50% of spike Hg applied to the upland and wetland was initially intercepted by the forest canopy. Average half lives of spike Hg on deciduous (110±30 days) and coniferous (180±40 days) forest canopy and ground vegetation (890±620 days) indicated that retention of new atmospheric Hg(II) on terrestrial vegetation delays downward transport of new atmospheric Hg(II) into the soil profile and delivery of this Hg(II) to methylating zones in wetlands and lakes. Measurements of re-emission of spike Hg from tree foliage using an Hg(0) flux chamber suggested that 40-70% of the spike initially retained in the forest canopy was photoreduced and re-emitted to the atmosphere. ~20% of the initial canopy spike pool was deposited in throughfall over the course of the growing season and a similar proportion was accounted for in litterfall. Spike Hg was still detectable on coniferous foliage the following spring (~2-8% of the initial pool), indicating that wet deposited Hg may contribute to foliar Hg concentrations.

Graydon, J. A.; St. Louis, V. L.; Lindberg, S. E.; Sandilands, K.; Krabbenhoft, D. P.; Tate, M. T.; Harris, R.; Emmerton, C. A.; Richardson, M.; Asmath, H.

2009-12-01

178

Transpiration of gaseous elemental mercury through vegetation in a subtropical wetland in florida  

SciTech Connect

Four seasonal sampling campaigns were carried out in the Florida Everglades to measure elemental Hg vapor (Hg{sup o}) fluxes over emergent macrophytes using a modified Bowen ratio gradient approach. The predominant flux of Hg{sup o} over both invasive cattail and native sawgrass stands was emission; mean day time fluxes over cattail ranged from {approx}20 (winter) to {approx}40 (summer) ng m{sup -2} h{sup -1}. Sawgrass fluxes were about half those over cattail during comparable periods. Emission from vegetation significantly exceeded evasion of Hg{sup o} from the underlying water surface ({approx}1-2 ng m{sup -2} h{sup -1}) measured simultaneously using floating chambers. Among several environmental factors (e.g. CO{sub 2} flux, water vapor flux, wind speed, water, air and leaf temperature, and solar radiation), water vapor exhibited the strongest correlation with Hg{sup o} flux, and transpiration is suggested as an appropriate term to describe this phenomenon. The lack of significant Hg{sup o} emissions from a live, but uprooted (floating) cattail stand suggests that a likely source of the transpired Hg{sup o} is the underlying sediments. The pattern of Hg{sup o} fluxes typically measured indicated a diel cycle with two peaks, possibly related to different gas exchange dynamics: one in early morning related to lacunal gas release, and a second at midday related to transpiration; nighttime fluxes approached zero.

Lindberg, Steven Eric [ORNL; Dong, Weijin [ORNL; Meyers, Tilden [NOAA, Oak Ridge, TN

2002-07-01

179

The effects of size of opening in vegetation and litter cover on seedling establishment of goldenrods ( Solidago spp.)  

Microsoft Academic Search

We investigated the effects of size of opening in the vegetation and litter cover on seedling establishment of two species of goldenrods (Solidago spp.) in an abandoned field in southwestern Michigan, U.S.A. Seeds of S. canadensis and S. juncea were sown into clipped plots, ranging from 0 cm (control, unclipped) to 100 cm in diameter, with and without litter. Seedling

Deborah E. Goldberg; Patricia A. Werner

1983-01-01

180

Assessment of compost application to coal ash disposal sites to promote the rapid vegetation establishment  

NASA Astrophysics Data System (ADS)

In the city of Tuzla, located in Bosnia and Herzegovina, a coal fired thermo electric power plant is operated by the company JP ELEKTROPRIVERDA BIH TERMOELEKTRANA "TUZLA". High amounts of ash are produced by the power plant, which are currently disposed into settlement ponds bordered by dams in natural valleys. A total of four ash disposal sites covering an area of approx. 170 ha have been established during the last decades. Due to the fact that residual ash from coal combustion was found to contain a variety of trace elements (Ni, Cr, As, B), it must be assumed that ash disposal of that magnitude constitutes an environmental problem which is investigated within the EU-FP6 / STREP project "Reintegration of Coal Ash Disposal Sites and Mitigation of Pollution in the West Balkan Area" RECOAL. The main hazards relate to soil and groundwater contamination due to leaching toxins, dust dispersion, and toxins entering the food chain as these disposal sites are used for agricultural purposes. In order to rapidly establish a vegetation cover on barren ash dumps that particularly would prevent dust erosion we assessed the applicability of compost, produced from locally available municipal and industrial organic residues as an amendment to ash to improve substrate fertility. The envisaged remediation technology was considered to be a low cost, easy applicable and rapid method capable of substantially enhancing living conditions of residents in the vicinity of the abandoned disposal sites. Various compost application rates were evaluated in the field on experimental site Divkovici I in Tuzla and additionally in the greenhouse environment at Brandenburg Technical University Cottbus. Field and laboratory tests revealed that plant growth and cover rate can substantially be improved by mixing compost into the upper ash layer to a maximum depth of approx. 20 cm. Besides direct growth observations in the field analysis of soil parameters gave evidence that the fertility of ashy substrates amended with compost produced from locally available sewage sludge and saw dust can be improved. The metal content of grass grown in the various treatments was considered to be elevated compared to normal contents. However, metal uptake in compost treatments was lower than in untreated plots. A preliminary cost assessment, comparing the remediation technology tested on site Divkovici with a standard soil covering technique revealed financial benefits for the compost method due to significant lower application rates.

Repmann, F.; Slazak, A.; Babic, M.; Schneider, B. U.; Schaaf, W.; Hüttl, R. F.

2009-04-01

181

Reducing sedimentation of depressional wetlands in agricultural landscapes  

USGS Publications Warehouse

Depressional wetlands in agricultural landscapes are easily degraded by sediments and contaminants accumulated from their watersheds. Several best management practices can reduce transport of sediments into wetlands, including the establishment of vegetative buffers. We summarize the sources, transport dynamics, and effect of sediments, nutrients, and contaminants that threaten wetlands and the current knowledge of design and usefulness of grass buffers for protecting isolated wetlands. Buffer effectiveness is dependent on several factors, including vegetation structure, buffer width, attributes of the surrounding watershed (i.e., area, vegetative cover, slope and topography, soil type and structure, soil moisture, amount of herbicides and pesticides applied), and intensity and duration of rain events. To reduce dissolved contaminants from runoff, the water must infiltrate the soil where microbes or other processes can break down or sequester contaminants. But increasing infiltration also diminishes total water volume entering a wetland, which presents threats to wetland hydrology in semi-arid regions. Buffer effectiveness may be enhanced significantly by implementing other best management practices (e.g., conservation tillage, balancing input with nutrient requirements for livestock and crops, precision application of chemicals) in the surrounding watershed to diminish soil erosion and associated contaminant runoff. Buffers require regular maintenance to remove sediment build-up and replace damaged or over-mature vegetation. Further research is needed to establish guidelines for effective buffer width and structure, and such efforts should entail a coordinated, regional, multi-scale, multidisciplinary approach to evaluate buffer effectiveness and impacts. Direct measures in "real-world" systems and field validations of buffer-effectiveness models are crucial next steps in evaluating how grass buffers will impact the abiotic and biotic variables attributes that characterize small, isolated wetlands. ?? 2008 The Society of Wetland Scientists.

Skagen, S. K.; Melcher, C. P.; Haukos, D. A.

2008-01-01

182

Ecohydraulics and Estuarine Wetland Rehabilitation  

Microsoft Academic Search

The hydraulics or water flow in wetlands is known to be a key factor influencing ecosystem development in estuarine wetland environments. The relationship is indirect, with the hydraulics of wetlands influencing a host of factors including soil salinity, waterlogging, sediment transport, sediment chemistry, vegetation dispersal and growth and nutrient availability and cycling. The relationship is also not one way, with

J. F. Rodriguez; A. Howe; N. Saintilan; J. Spencer

2004-01-01

183

Investigation of Soil Properties effects on Establishment of Vegetation Types (Case Study: Sabzdasht, Bafgh)  

NASA Astrophysics Data System (ADS)

This research was conducted to investigate the relationships between soil (Organic Matter, potassium, phosphorous, sodium, Fine gravel, soil texture, EC, Lime, Gypsum, Nitrogen) and environmental (Elevation, Slope) factors with distribution of vegetation types in rangelands of Sabzdasht, located in Bafgh, Yazd province at 2012. For this purpose, four vegetation types were selected as follows: Artemisia sieberi; Artemisia sieberi, Stipa barbata, Eurotia ceratoides; Dorema ammoniacum, Artemisia sieberi, Eurotia ceratoides; and Hammada salicornica.Minimal area was determined using nested plots. Afterward, vegetation factors were measured and five soil profiles were dug randomly in minimal area. In each profile, data for depths of 0-10 and 10-80 cm were recorded. Principal Component Analysis was applied to analyze the data. Results showed that soil texture, potassium, phosphorous, EC and lime had the most impact on variation and distribution of vegetation types. Keywords: Environmental Factors, Principal Component Analysis, Minimal Area, Bafgh, Yazd

Sadeghi Nia, Majid; jafari, Mohammad; Zahedi Amiri, Ghavomoldin; Baghestani Maybodi, Naser; Tavili, Ali

2013-04-01

184

Isolated Spring Wetlands in the Great Basin and Mojave Deserts, USA: Potential Response of Vegetation to Groundwater Withdrawal  

Microsoft Academic Search

Desert springs, often the sole sources of water for wildlife and cattle, support wetland and wetland\\/upland transition ecosystems\\u000a including rare and endemic species. In the basin and range province in Nevada, USA, springs in the Great Basin and Mojave\\u000a deserts are sustained by interconnected deep carbonate and shallow basin-fill aquifers which are threatened by proposed groundwater\\u000a withdrawal to sustain rapidly

Duncan T. Patten; Leigh Rouse; Juliet C. Stromberg

2008-01-01

185

Hydrologic gradient and vegetation controls on CH 4 and CO 2 fluxes in a spring-fed forested wetland  

Microsoft Academic Search

Four different habitats in a spring-fed forested wetland (Clear Springs Wetland, Panola County, Mississippi, USA) varying\\u000a in hydrologic regime were examined for methane and carbon dioxide fluxes from soils over 15 and 9 months, respectively. There\\u000a was an increasing gradient of CH4 flux rates from an unflooded upper-elevation forest site to an occasionally flooded bottomland forest site to a shallow permanently

Hong-Suk Koh; Clifford A. Ochs; Kewei Yu

2009-01-01

186

Vegetation and proximity to the river control amorphous silica storage in a riparian wetland (Biebrza National Park, Poland)  

NASA Astrophysics Data System (ADS)

Wetlands can modify and control nutrient fluxes between terrestrial and aquatic ecosystems, yet little is known of their potential as biological buffers and sinks in the biogeochemical silica cycle. We investigated the storage of amorphous silica (ASi) in a central-European riparian wetland. The variation in storage of ASi in the soil of an undisturbed wetland was significantly controlled by two factors: dominance of sedges and grasses and distance to the river (combined R2=78%). Highest ASi storage was found near the river and in sites with a dominance of grasses and sedges, plants which are well known to accumulate ASi. The management practice of mowing reduced the amount of variation attributed to both factors (R2=51%). Although ASi concentrations in soils were low (between 0.1 and 1% of soil dry weight), ASi controlled the availability of dissolved silica (DSi) in the porewater, and thus potentially the exchange of DSi with the nearby river system through both diffusive and advective fluxes. A depth gradient in ASi concentrations, with lower ASi in the deeper layers, indicates dissolution. Our results show that storage and recycling of ASi in wetland ecosystems can differ significantly on small spatial scales. Human management interferes with the natural control mechanisms. Our study demonstrates that wetlands have the potential to modify the fluxes of both DSi and ASi along the land-ocean continuum and supports the hypothesis that wetlands are important ecosystems in the biogeochemical cycling of silica.

Struyf, E.; Opdekamp, W.; Backx, H.; Jacobs, S.; Conley, D. J.; Meire, P.

2009-01-01

187

Vegetation and proximity to the river control amorphous silica storage in a riparian wetland (Biebrza National Park, Poland)  

NASA Astrophysics Data System (ADS)

Wetlands can modify and control nutrient fluxes between terrestrial and aquatic ecosystems, yet little is known of their potential as biological buffers and sinks in the biogeochemical silica cycle. We investigated the storage of amorphous silica (ASi) in a central-European riparian wetland. The variation in storage of ASi in the soil of an undisturbed wetland was significantly controlled by two factors: dominance of sedges and grasses and distance to the river (combined (R2=78%). Highest ASi storage was found near the river and in sites with a dominance of grasses and sedges, plants which are well known to accumulate ASi. The management practice of mowing reduced the amount of variation attributed to both factors (R2=51%). Although ASi concentrations in soils were low (between 0.1 and 1% of soil dry weight), ASi controlled the availability of dissolved silica (DSi) in the porewater, and thus potentially the exchange of DSi with the nearby river system through both diffusive and advective fluxes. A depth gradient in ASi concentrations, with lower ASi in the deeper layers, indicates dissolution. Our results show that storage and recycling of ASi in wetland ecosystems can differ significantly on small spatial scales. Human management interferes with the natural control mechanisms. Our study demonstrates that wetlands have the potential to modify the fluxes of both DSi and ASi along the land-ocean continuum and supports the hypothesis that wetlands are important ecosystems in the biogeochemical cycling of silica.

Struyf, E.; Opdekamp, W.; Backx, H.; Jacobs, S.; Conley, D. J.; Meire, P.

2009-04-01

188

Establishing Minimum Flow Requirements Based on Benthic Vegetation: What are Some Issues Related to Identifying Quantity of Inflow and Tools Used to Quantify Ecosystem Response?  

NASA Astrophysics Data System (ADS)

Establishing minimum flow requirements in aquatic ecosystems is one way to stipulate controls on water withdrawals in a watershed. The basis of the determination is to identify the amount of flow needed to sustain a threshold ecological function. To develop minimum flow criteria an understanding of ecological response in relation to flow is essential. Several steps are needed including: (1) identification of important resources and ecological functions, (2) compilation of available information, (3) determination of historical conditions, (4) establishment of technical relationships between inflow and resources, and (5) identification of numeric criteria that reflect the threshold at which resources are harmed. The process is interdisciplinary requiring the integration of hydrologic and ecologic principles with quantitative assessments. The tools used quantify the ecological response and key questions related to how the quantity of flow influences the ecosystem are examined by comparing minimum flow determination in two different aquatic systems in South Florida. Each system is characterized by substantial hydrologic alteration. The first, the Caloosahatchee River is a riverine system, located on the southwest coast of Florida. The second, the Everglades- Florida Bay ecotone, is a wetland mangrove ecosystem, located on the southern tip of the Florida peninsula. In both cases freshwater submerged aquatic vegetation (Vallisneria americana or Ruppia maritima), located in areas of the saltwater- freshwater interface has been identified as a basis for minimum flow criteria. The integration of field studies, laboratory studies, and literature review was required. From this information we developed ecological modeling tools to quantify and predict plant growth in response to varying environmental variables. Coupled with hydrologic modeling tools questions relating to the quantity and timing of flow and ecological consequences in relation to normal variability are addressed.

Hunt, M. J.; Nuttle, W. K.; Cosby, B. J.; Marshall, F. E.

2005-05-01

189

Operational actual wetland evapotranspiration estimation for the Everglades using MODIS imagery  

NASA Astrophysics Data System (ADS)

Wetlands are one of the most important ecosystems with varied functions and structures. Humans have drained wetlands and altered the structure and functions of wetlands for various uses. Wetland restoration efforts require assessment of the level of ecohydrological restoration for the intended functions. Among the various indicators of success in wetland restoration, achieving the desired water level (hydrology) is the most important, faster to achieve and easier to monitor than the establishment of the hydric soils and wetland vegetation. Monitoring wetland hydrology using remote sensing based evapotranspiration (ET) is a useful tool and approach since point measurements for understanding the temporal (before and after restoration) and spatial (impacted and restored) parts of the wetland are not effective for large areas. Evapotranspiration accounts over 80% of the water budget of the wetlands necessitating the need for spatiotemporal monitoring of ET flux. A study employing remotely sensed data from Moderate Resolution Imaging Spectroradiometer (MODIS) and modeling tools was conducted for a weekly spatial estimation of Everglades ET. Weekly surface temperature data were generated from the MODIS thermal band and evaporative fraction was estimated using the simplified surface energy balance (SSEB) approach. Based on the Simple Method, potential ET (PET) was estimated. Actual weekly wetland ET was computed as the (product of the PET and evaporative fraction). The ET product will be useful information for environmental restoration and wetland hydrology managers. The on-going restoration and monitoring work in the Everglades will benefit from this product and assist in evaluating progress and success in the restoration.

Melesse, Assefa; Cereon, Cristobal

2014-05-01

190

Effects of a Long-Term Disturbance on Arthropods and Vegetation in Subalpine Wetlands: Manifestations of Pack Stock Grazing in Early versus Mid-Season  

PubMed Central

Conclusions regarding disturbance effects in high elevation or high latitude ecosystems based solely on infrequent, long-term sampling may be misleading, because the long winters may erase severe, short-term impacts at the height of the abbreviated growing season. We separated a) long-term effects of pack stock grazing, manifested in early season prior to stock arrival, from b) additional pack stock grazing effects that might become apparent during annual stock grazing, by use of paired grazed and control wet meadows that we sampled at the beginning and end of subalpine growing seasons. Control meadows had been closed to grazing for at least two decades, and meadow pairs were distributed across Sequoia National Park, California, USA. The study was thus effectively a landscape-scale, long-term manipulation of wetland grazing. We sampled arthropods at these remote sites and collected data on associated vegetation structure. Litter cover and depth, percent bare ground, and soil strength had negative responses to grazing. In contrast, fauna showed little response to grazing, and there were overall negative effects for only three arthropod families. Mid-season and long-term results were generally congruent, and the only indications of lower faunal diversity on mid-season grazed wetlands were trends of lower abundance across morphospecies and lower diversity for canopy fauna across assemblage metrics. Treatment x Season interactions almost absent. Thus impacts on vegetation structure only minimally cascaded into the arthropod assemblage and were not greatly intensified during the annual growing season. Differences between years, which were likely a response to divergent snowfall patterns, were more important than differences between early and mid-season. Reliance on either vegetation or faunal metrics exclusively would have yielded different conclusions; using both flora and fauna served to provide a more integrative view of ecosystem response.

Holmquist, Jeffrey G.; Schmidt-Gengenbach, Jutta; Haultain, Sylvia A.

2013-01-01

191

Effects of irrigation on seed production and vegetative characteristics of four moist-soil plants on impounded wetlands in California  

USGS Publications Warehouse

We examined the effects of irrigation on 4 moist-soil plants commonly managed for waterfowl in the Sacramento Valley, California. Irrigation resulted in taller and heavier swamp timothy (Heleochloa schoenoides), pricklegrass (Crypsis niliaca), and sprangletop (Leptochloa fasicularis). Barnyardgrass (Echinochloa crusgalli) grew taller in irrigated wetlands, but no significant difference in weight was detected. Only sprangletop yielded larger seed masses in response to irrigation. Without irrigation, swamp timothy and pricklegrass assumed a typical prostrate growth form, but with irrigation, they assumed a vertical growth form. Irrigation did not significantly affect plant density. Because of rising water costs, wetland managers should consider wildlife management objectives and plant responses before implementing irrigation practices.

Mushet, D. M.; Euliss, N. H., Jr.; Harris, S. W.

1992-01-01

192

Establishing critical levels of air pollutants for protecting East Asian vegetation — A challenge  

Microsoft Academic Search

Critical levels of ozone (O3) and sulfur dioxide (SO2) for protecting European forests are not evaluated to apply to East Asian vegetation. Based on the results obtained from the long-term experimental studies on the effects of chronic exposure to O3or SO2on 30 young potted grown tree species using open-top chambers, we analyzed dose-response relationships between the whole-plant dry mass increment

Yoshihisa Kohno; Hideyuki Matsumura; Takashi Ishii; Takeshi Izuta

193

An integrated approach to assess broad-scale condition of coastal wetlands - The Gulf of Mexico Coastal Wetlands pilot survey  

USGS Publications Warehouse

The Environmental Protection Agency (EPA) and U.S. Geological Survey (USGS) initiated a two-year regional pilot survey in 2007 to develop, test, and validate tools and approaches to assess the condition of northern Gulf of Mexico (GOM) coastal wetlands. Sampling sites were selected from estuarine and palustrine wetland areas with herbaceous, forested, and shrub/scrub habitats delineated by the US Fish and Wildlife Service National Wetlands Inventory Status and Trends (NWI S&T) program and contained within northern GOM coastal watersheds. A multi-level, stepwise, iterative survey approach is being applied to multiple wetland classes at 100 probabilistically-selected coastal wetlands sites. Tier 1 provides information at the landscape scale about habitat inventory, land use, and environmental stressors associated with the watershed in which each wetland site is located. Tier 2, a rapid assessment conducted through a combination of office and field work, is based on best professional judgment and on-site evidence. Tier 3, an intensive site assessment, involves on-site collection of vegetation, water, and sediment samples to establish an integrated understanding of current wetland condition and validate methods and findings from Tiers 1 and 2. The results from this survey, along with other similar regional pilots from the Mid-Atlantic, West Coast, and Great Lakes Regions will contribute to a design and implementation approach for the National Wetlands Condition Assessment to be conducted by EPA's Office of Water in 2011. ?? Springer Science+Business Media B.V. 2008.

Nestlerode, J. A.; Engle, V. D.; Bourgeois, P.; Heitmuller, P. T.; Macauley, J. M.; Allen, Y. C.

2009-01-01

194

Flue gas desulfurization sludge: establishment of vegetation on ponded and soil-applied waste. Final report January 1977-September 1981  

SciTech Connect

The report gives results of research to identify and evaluate forms of vegetation and methods of their establishment for reclaiming retired flue gas desulfurization sludge ponds. Also studied were the soil liming value of limestone scrubber sludge (LSS) and plant uptake and percolation losses of some chemical nutrients in the sludge. Several vegetation schemes were evaluated between 1977 and 1982 for covering and stabilizing LSS at Colbert Steam Plant, Cherokee, AL, and Shawnee Steam Plant, Paducah, KY. Eleven tree and 10 grass or legume species were tested for adaptability and survival when planted directly in LSS or in LSS amended with soil, municipal sewage sludge, or standard potting mix. Other studies indicated that LSS apparently has sufficient unreacted limestone to be a satisfactory soil liming agent.

Giordano, P.M.; Mays, D.A.; Soileau, J.M.

1984-01-01

195

Wetland restoration and compliance issues on the Savannah River site  

SciTech Connect

Operation of the nuclear production reactors on the Savannah River Site has faced potential conflicts with wetland regulations on several occasions. This paper provides two examples in which regulatory compliance and restoration research have been meshed, providing both compliance and better knowledge to aid future regulatory needs. The decision to restart the L reactor required the mitigation of thermal effluents under Sec. 316 of the Clean Water Act. The National Pollutant Discharge Elimination System, permit for the selected mitigation alternative, a 405-ha once-through cooling reservoir, required the establishment of a balanced biological community (BBC) within the lake. To promote the development of a BBC, the reservoir was seeded with water from an existing BBC (Par Pond) and stocked with fish and had artificial reefs constructed. The US Department of Energy (DOE) also requested that the Savannah River Ecology Laboratory establish littoral/wetland vegetation along the shoreline to provide aquatic and wildlife habitat, shoreline stabilization, and a good faith effort toward the establishment of a BBC. The development of wetland vegetation was deemed important to the successful development of a BBC within L Lake. However, in a similar cooling reservoir system constructed in 1957 (Par Pond), wetland vegetation successfully developed without any planting effort. Other than the good faith effort toward a BBC, there is no reason to assume a littoral/wetland community would not develop of its own accord. However, research conducted at L Lake indicates that the planting of wetland vegetation at L Lake accelerated the process of natural selection over that of areas that were not planted.

Wein, G.R.; McLeod, K.W.; Sharitz, R.R. (Savannah River Ecology Lab., Aiken, SC (United States))

1993-01-01

196

Nitrogen removal from wastewater in vertical flow constructed wetlands containing LWA\\/gravel layers and reed vegetation  

Microsoft Academic Search

The influence of light weight aggregates made of fly ash from sewage sludge thermal treatment (FASSTT LWA) on the nitrogen removal efficiency from artificial wastewater in constructed wetlands (CW) with vertical flow reed bed was investigated. Thirty lysimeters with six different double-layer bed constructions (upper layer of FASSTT LWA with thicknesses of: 0cm, 12cm, 25cm, 50cm, and 100cm of the

Andrzej Bia?owiec; Wojciech Janczukowicz; Peter F. Randerson

2011-01-01

197

Establishment of woody riparian vegetation in relation to annual patterns of streamflow, Bill Williams River, Arizona  

Microsoft Academic Search

Previous studies have revealed the close coupling of components of annual streamflow hydrographs and the germination and establishment\\u000a ofPopulus species. Key hydrograph components include the timing and magnitude of flood peaks, the rate of decline of the recession\\u000a limb, and the magnitude of base flows. In this paper, we retrospectively examine establishment of four woody riparian species\\u000a along the Bill

Patrick B. Shafroth; Gregor T. Auble; Juliet C. Stromberg; Duncan T. Patten

1998-01-01

198

Design and implementation of functional wetland mitigation: Case studies in Ohio and South Carolina  

Microsoft Academic Search

Wetland development offers the opportunity to replace and enhance ecological functions lost through permitted wetland impacts. Components necessary for the restoration and creation of wetlands are presented and examples of wetland construction are described to illustrate the application of wetland design. Land contours, top soil, hydrology and vegetation were manipulated to develop wooded wetlands at sites in Ohio and South

Sue Ann McCuskey; Allen W. Conger; Hilburn O. Hillestad

1994-01-01

199

Effects of vegetative-periodic-induced rhizosphere variation on the uptake and translocation of metals in Phragmites australis (Cav.) Trin ex. Steudel growing in the Sun Island Wetland.  

PubMed

To evaluate the vegetative periodic effect of rhizosphere on the patterns of metal bioaccumulation, the concentrations of Mg, K, Ca, Mn, Zn, Fe, Cu, Cr, Ni, Cd and Pb in the corresponding rhizosphere soil and tissues of Phragmites australis growing in the Sun Island wetland (Harbin, China) were compared. The concentrations of Zn, Fe, Cu, Cr, Ni, Cd and Pb in roots were higher than in shoots, suggesting that roots are the primary accumulation organs for these metals and there exists an exclusion strategy for metal tolerance. In contrast, the rest of the metals showed an opposite trend, suggesting that they were not restricted in roots. Harvesting would particularly be an effective method to remove Mn from the environment. The concentrations of metals in shoots were generally higher in autumn than in summer, suggesting that Ph. australis possesses an efficient root-to-shoot translocation system, which is activated at the end of the growing season and allows more metals into the senescent tissues. Furthermore, metal bioaccumulation of Ph. australis was affected by vegetative periodic variation through the changing of physicochemical and microbial conditions. The rhizospheric microbial characteristics were significantly related to the concentrations of Mg, K, Zn, Fe and Cu, suggesting that microbial influence on metal accumulation is specific and selective, not eurytopic. PMID:23455898

Wu, Jieting; Wang, Li; Ma, Fang; Yang, Jixian; Li, Shiyang; Li, Zhe

2013-05-01

200

Testing wetland features to increase amphibian reproductive success and species richness for mitigation and restoration.  

PubMed

Aquatic habitat features can directly influence the abundance, species richness, and quality of juvenile amphibians recruited into adult populations. We examined the influences of within-wetland slope, vegetation, and stocked mosquito fish (Gambusia affinis) on amphibian metamorph production and species richness during the first two years post-construction at 18 experimental wetlands in northeast Missouri (U.S.A.) grasslands. We used an information theoretic approach (AICc) to rank regression models representing total amphibian metamorph production, individual amphibian species metamorph production, and larval amphibian species richness. Total amphibian metamorph production was greatest at shallow-sloped, fish-free wetlands during the first year, but shallow-sloped wetlands with high vegetation cover were best the second year. Species richness was negatively associated with fish and positively associated with vegetation in both survey years. Leopard frog (Rana blairi/sphenocephala complex) metamorph quality, based on average metamorph size, was influenced by slope and the number of cohorts in the wetland. However, the tested variables had little influence on the size of American toads (Bufo americanus) or boreal chorus frogs (Pseudacris maculata). Our results indicate that wetlands designed to act as functional reproductive habitat for amphibians should incorporate shallows, high amounts of planted or naturally established vegetation cover, and should be fish-free. PMID:22908722

Shulse, Christopher D; Semlitsch, Raymond D; Trauth, Kathleen M; Gardner, James E

2012-07-01

201

Wetland 101  

NSDL National Science Digital Library

This online course provides an introduction to wetland ecology, types of wetlands, wetland functions and values, and wetlands management. Topics include how a wetland is defined, wetland hydrology, seasonal and other fluctuations in water levels, and wetland soils and plants. The course consists of a series of slide presentations with self-quizzes and an online final quiz. Registration and log-in are required.

202

Vegetation  

Microsoft Academic Search

Lamto vegetation encompasses savanna areas with contrasting tree densities, mixed with moist and dry forest areas. The different\\u000a savanna types are roughly organized according to topographical transects. The grass layer is dominated by grass tussock species\\u000a from the Andropogonaea family, whereas four species dominate the tree layer. Herbaceous species exhibit different phenological\\u000a patterns. In contrast, trees are all deciduous but

Jean-Claude Menaut; Luc Abbadie

203

The role of plant type and salinity in the selection for the denitrifying community structure in the rhizosphere of wetland vegetation.  

PubMed

Coastal wetlands, as transient links from terrestrial to marine environments, are important for nitrogen removal by denitrification. Denitrification strongly depends on both the presence of emergent plants and the denitrifier communities selected by different plant species. In this study, the effects of vegetation and habitat heterogeneity on the community of denitrifying bacteria were investigated in nine coastal wetlands in two preserved areas of Spain. Sampling locations were selected to cover a range of salinity (0.81 to 31.3 mS/cm) and nitrate concentrations (0.1 to 303 ?M NO3-), allowing the evaluation of environmental variables that select for denitrifier communities in the rhizosphere of Phragmites sp., Ruppia sp., and Paspalum sp. Potential nitrate reduction rates were found to be dependent on the sampling time and plant species and related to the denitrifier community structure, which was assessed by terminal restriction fragment length polymorphism analysis of the functional genes nirS, nirK and nosZ. The results showed that denitrifier community structure was also governed by plant species and salinity, with significant influences of other variables, such as sampling time and location. Ruppia sp. and Phragmites sp. selected for certain communities, whereas this was not the case for Paspalum sp. The plant species effect was strongest on nirK-type denitrifiers, whereas water carbon content was a significant factor defining the structure of the nosZ-harboring community. The differences recognized using the three functional gene markers indicated that different drivers act on denitrifying populations capable of complete denitrification, compared to the overall denitrifier community. This finding may have implications for emissions of the greenhouse gas nitrous oxide. PMID:22847270

Bañeras, Luís; Ruiz-Rueda, Olaya; López-Flores, Rocío; Quintana, Xavier D; Hallin, Sara

2012-06-01

204

Controls on wetland loss during large magnitude storms: a case study in Breton Sound, LA  

NASA Astrophysics Data System (ADS)

In 2005, the storm surge and wave field associated with Hurricanes Katrina and Rita eroded 527 km^2 of wetlands within the Louisiana coastal plain. Low salinity wetlands were preferentially eroded, while higher salinity wetlands remained largely intact and unchanged. Field studies were undertaken in Breton Sound, Louisiana, where both the low and high salinity wetlands experienced very similar hydrodynamic conditions during Hurricane Katrina. This site provides a natural case to study the causes of the observed land loss patterns. We observe geotechnical differences between soil profiles in high and low salinity wetlands, as controlled by vegetation, and which result in differential erosion. Low salinity wetlands contain a weak zone at a depth of ~30 cm below the marsh surface; this coincides with the base of rooting and has shear strengths as low as 500-1450 Pa. High salinity wetlands display deeper rooting, have no identifiable weak zone, and shear strengths exceed 4500 Pa throughout the upper soil profile. Results from a model (STWAVE-ADCIRC) are used to establish the hydrodynamic conditions during Hurricane Katrina (storm surge, wave height, and wave period). We calculate the potential shear stresses exerted by waves, accounting for the interaction between the oscillatory flow and the vegetation. Calculated shear stresses were in the range 425-3600 Pa, values sufficient to cause widespread erosion of the low salinity wetlands, but not the high salinity wetlands, corresponding with the observed patterns of land loss. A conceptual model is developed to illustrate the influence of rooting type and depth on the strength profile of wetlands soils and their susceptibility to erosion during large magnitude storms. These findings have implications for wetland restoration schemes involving freshwater diversions.

Howes, N. C.; Hughes, Z. J.; Fitzgerald, D.; Georgiou, I. Y.; Kulp, M. A.; Miner, M. D.; Smith, J. M.; Barras, J. A.

2010-12-01

205

USE OF WETLANDS BY UPLAND WILDUFE  

Microsoft Academic Search

Seasonal use of wetlands by upland wildlife is common; when uplands are dis­ turbed. wildlife may use we I lands year·round. The structure and form of vegetation in wetlands is more important than species composition 10 upland wildlife. Wetlands may provide upland wildlife with food. escape cover. protection from inclement weather. and reproductive habitat. There has been little documentation of

Frank Schiloskey. Jr

206

The biogeochemistry of nitrogen in freshwater wetlands  

Microsoft Academic Search

The biogeochemistry of N in freshwater wetlands is complicated by vegetation characteristics that range from annual herbs to perennial woodlands; by hydrologic characteristics that range from closed, precipitation-driven to tidal, riverine wetlands; and by the diversity of the nitrogen cycle itself. It is clear that sediments are the single largest pool of nitrogen in wetland ecosystems (100's to 1000's g

William B. Bowden

1987-01-01

207

THE INTEGRATED CONSTRUCTED WETLANDS (ICW) CONCEPT  

Microsoft Academic Search

The free surface flow Integrated Constructed Wetlands (ICW) concept explicitly combines the objectives of cleansing and managing water flow from farmyards with that of integrating the wetland infrastructure into the landscape and enhancing its biological diversity. This leads to system robustness and sustainability. Hydraulic dissipation, vegetation interception, and evapotranspiration create an additional freeboard at the outlet of each wetland segment

Miklas Scholz; Rory Harrington; P aul Carroll; Atif Mustafa

2007-01-01

208

Assessment of Vegetation Establishment on Tailings Dam at an Iron Ore Mining Site of Suburban Beijing, China, 7 Years After Reclamation with Contrasting Site Treatment Methods  

NASA Astrophysics Data System (ADS)

Strip-mining operations greatly disturb soil, vegetation and landscape elements, causing many ecological and environmental problems. Establishment of vegetation is a critical step in achieving the goal of ecosystem restoration in mining areas. At the Shouyun Iron Ore Mine in suburban Beijing, China, we investigated selective vegetation and soil traits on a tailings dam 7 years after site treatments with three contrasting approaches: (1) soil covering (designated as SC), (2) application of a straw mat, known as "vegetation carpet", which contains prescribed plant seed mix and water retaining agent (designated as VC), on top of sand piles, and (3) combination of soil covering and application of vegetation carpet (designated as SC+VC). We found that after 7 years of reclamation, the SC+VC site had twice the number of plant species and greater biomass than the SC and VC sites, and that the VC site had a comparable plant abundance with the SC+VC site but much less biodiversity and plant coverage. The VC site did not differ with the SC site in the vegetation traits, albeit low soil fertility. It is suggested that application of vegetation carpet can be an alternative to introduction of topsoil for treatment of tailings dam with fine-structured substrate of ore sands. However, combination of topsoil treatment and application of vegetation carpet greatly increases vegetation coverage and plant biodiversity, and is therefore a much better approach for assisting vegetation establishment on the tailings dam of strip-mining operations. While application of vegetation carpet helps to stabilize the loose surface of fine-structured mine wastes and to introduce seed bank, introduction of fertile soil is necessary for supplying nutrients to plant growth in the efforts of ecosystem restoration of mining areas.

Yan, Demin; Zhao, Fangying; Sun, Osbert Jianxin

2013-09-01

209

Wetlands Protection.  

National Technical Information Service (NTIS)

The bibliography serves as a tool for understanding wetlands and the regulations, policies and activities that form the current framework for protection or degradation and loss. It is organized according to the following topics: Wetland types; Wetland cha...

1988-01-01

210

NUTRIENT AND HABITAT INDICATORS FOR CRITERIA DEVELOPMENT IN GREAT LAKES COASTAL WETLANDS  

EPA Science Inventory

EPA's Mid-Continent Ecology Division is testing indicators and establishing stressor - response relationships to support development of nutrient and habitat criteria for Great Lakes coastal wetlands. Our focus is on water quality changes, food web shifts, and vegetation loss as ...

211

Mitigation bank promotes research on restoring Coastal Plain depression wetlands (South Carolina).  

SciTech Connect

Barton, Christopher, D., Diane DeSteven and John C. Kilgo. 2004. Mitigation bank promotes research on restoring Coastal Plain depression wetlands (South Carolina). Ecol. Rest. 22(4):291-292. Abstract: Carolina bays and smaller depression wetlands support diverse plant communities and provide critical habitat for semi-aquatic fauna throughout the Coastal Plain region of the southeastern United States. Historically, many depression wetlands were altered or destroyed by surface ditching, drainage, and agricultural or silviculture uses. These important habitats are now at further risk of alteration and loss following a U.S. Supreme Court decision in 2001 restricting federal regulation of isolated wetlands. Thus, there is increased attention towards protecting intact sites and developing methods to restore others. The U.S. Department of Energy's (DOE) 312-mi2 (800-km2) Savannah River Site (SRS) in west-central South Carolina includes about 350 Carolina bays and bay-like wetland depressions, of which about two-thirds were degraded or destroyed prior to federal acquisition of the land. Although some of the altered wetlands have recovered naturally, others still have active active drainage ditches and contain successional forests typical of drained sites. In 1997, DOE established a wetland mitigation bank to compensate for unavoidable wetland impacts on the SRS. This effort provided an opportunity fir a systematic research program to investigate wetland restoration techniques and ecological responses. Consequently, research and management staffs from the USDA Forest Service, Westinghouse Savannah River Corporation, the Savannah River Technology Center, the Savannah River Ecology Laboratory (SREL) and several universities developed a collaborative project to restore degraded depression wetlands on the SRS. The mitigation project seeks cost-effective methods to restore the hydrology and vegetation typical of natural depression wetlands, and so enhance habitats for wetland-dependent wildlife. We present a brief summary of this project and the research studies now underway.

Barton, Christopher D.; DeSteven, Diane; Kilgo, John C.

2004-12-31

212

Assessing coastal plain wetland composition using advanced spaceborne thermal emission and reflection radiometer imagery  

NASA Astrophysics Data System (ADS)

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.

Pantaleoni, Eva

213

Spatio-Temporal Variation in Contrasting Effects of Resident Vegetation on Establishment, Growth and Reproduction of Dry Grassland Plants: Implications for Seed Addition Experiments  

PubMed Central

Successful establishment of plants is limited by both biotic and abiotic conditions and their interactions. Seedling establishment is also used as a direct measure of habitat suitability, but transient changes in vegetation might provide windows of opportunity allowing plant species to colonize sites which otherwise appear unsuitable. We aimed to study spatio-temporal variability in the effects of resident vegetation on establishment, growth and reproduction of dry grassland species in abandoned arable fields representing potentially suitable habitats. Seeds were sown in disturbed (bare of vegetation and roots) and undisturbed plots in three fields abandoned in the last 20 years. To assess the effects of temporal variation on plant establishment, we initiated our experiments in two years (2007 and 2008). Seventeen out of the 35 sown species flowered within two years after sowing, while three species completely failed to become established. The vegetation in the undisturbed plots facilitated seedling establishment only in the year with low spring precipitation, and the effect did not hold for all species. In contrast, growth and flowering rate were consistently much greater in the disturbed plots, but the effect size differed between the fields and years of sowing. We show that colonization is more successful when site opening by disturbance coincide with other suitable conditions such as weather or soil characteristics. Seasonal variability involved in our study emphasizes the necessity of temporal replication of sowing experiments. Studies assessing habitat suitability by seed sowing should either involve both vegetation removal treatments and untreated plots or follow the gradient of vegetation cover. We strongly recommend following the numbers of established individuals, their sizes and reproductive success when assessing habitat suitability by seed sowing since one can gain completely different results in different phases of plant life cycle.

Knappova, Jana; Knapp, Michal; Munzbergova, Zuzana

2013-01-01

214

Spatio-temporal variation in contrasting effects of resident vegetation on establishment, growth and reproduction of dry grassland plants: implications for seed addition experiments.  

PubMed

Successful establishment of plants is limited by both biotic and abiotic conditions and their interactions. Seedling establishment is also used as a direct measure of habitat suitability, but transient changes in vegetation might provide windows of opportunity allowing plant species to colonize sites which otherwise appear unsuitable. We aimed to study spatio-temporal variability in the effects of resident vegetation on establishment, growth and reproduction of dry grassland species in abandoned arable fields representing potentially suitable habitats. Seeds were sown in disturbed (bare of vegetation and roots) and undisturbed plots in three fields abandoned in the last 20 years. To assess the effects of temporal variation on plant establishment, we initiated our experiments in two years (2007 and 2008). Seventeen out of the 35 sown species flowered within two years after sowing, while three species completely failed to become established. The vegetation in the undisturbed plots facilitated seedling establishment only in the year with low spring precipitation, and the effect did not hold for all species. In contrast, growth and flowering rate were consistently much greater in the disturbed plots, but the effect size differed between the fields and years of sowing. We show that colonization is more successful when site opening by disturbance coincide with other suitable conditions such as weather or soil characteristics. Seasonal variability involved in our study emphasizes the necessity of temporal replication of sowing experiments. Studies assessing habitat suitability by seed sowing should either involve both vegetation removal treatments and untreated plots or follow the gradient of vegetation cover. We strongly recommend following the numbers of established individuals, their sizes and reproductive success when assessing habitat suitability by seed sowing since one can gain completely different results in different phases of plant life cycle. PMID:23755288

Knappová, Jana; Knapp, Michal; Münzbergová, Zuzana

2013-01-01

215

Modeling the suitability of potential wetland mitigation sites with a geographic information system.  

SciTech Connect

Wetland mitigation is frequently required to compensate for unavoidable impacts to wetlands. Site conditions and landscape context are critical factors influencing the functions that created wetlands perform. We developed a spatial model and used a geographic information system (GIS) to identify suitable locations for wetland mitigation sites. The model used six variables to characterize site conditions: hydrology, soils, historic condition, vegetation cover, adjacent vegetation, and land use. For each variable, a set of suitability scores was developed that indicated the wetland establishment potential for different variable states. Composite suitability scores for individual points on the landscape were determined from the weighted geometric mean of suitability scores for each variable at each point. These composite scores were grouped into five classes and mapped as a wetland mitigation suitability surface with a GIS. Sites with high suitability scores were further evaluated using information on the feasibility of site modification and project cost. This modeling approach could be adapted by planners for use in identifying the suitability of locations as wetland mitigation sites at any site or region.

Van Lonkhuyzen, R. A.; LaGory, K. E.; Kuiper, J. A.; Environmental Assessment

2004-03-01

216

Effect of litter, leaf cover and cover of basal internodes of the dominant species Molinia caerulea on seedling recruitment and established vegetation  

NASA Astrophysics Data System (ADS)

The effects of litter removal, leaf cover of established plants and cover of basal internodes of a dominant species Molinia caerulea on seedling germination and the dynamics of established plants were studied in a field experiment in an oligotrophic wet meadow. Although the negative influence of litter on total seedling number and seedling species composition was non-significant, litter significantly affected the dynamics of the established vegetation and caused inhibition of total leaf cover development. The effects of total leaf cover of established plants on seedling establishment changed during the vegetation season. Whereas the effect of total leaf cover was positive at the start and in the middle of the vegetation season, at the end the total leaf cover negatively affected seedling establishment. Both total leaf cover and cover of basal internodes affected seedling composition. Effects of these two variables were statistically separable suggesting that they are based on different mechanisms. The response of seedling establishment to these factors was species specific and, consequently, our data support the hypothesis that that biotically generated spatial heterogeneity can promote species co-existence through the differentiation of species regeneration niches.

Jane?ek, Št?pán; Lepš, Jan

2005-09-01

217

The Necessity for Multidisciplinary Approaches to Wetland Design and Adaptive Management: The Case of Wetland Channels  

Microsoft Academic Search

\\u000a The need for a multidisciplinary approach to the design and adaptive management of constructed wetlands is illustrated by\\u000a case examples of channel form and function in a variety of wetland types. Channels in wetland systems are typically viewed\\u000a simply as conduits of water inflow and outflow. However, there are dynamic interrelationships amongst vegetation, hydrology\\/hydraulics,\\u000a and substrate in wetland channel systems

Marjorie L. Zeff

218

The importance of subsurface geology for water source and vegetation communities in Cherokee Marsh, Wisconsin  

USGS Publications Warehouse

Restoration of disturbed wetland systems is an important component of wetland mitigation, yet uncertainty remains about how hydrologic processes affect biologic processes and wetlands patterns. To design more effective restoration strategies and re-establish native plant communities in disturbed wetlands, it is imperative to understand undisturbed systems. A site within Cherokee Marsh located in Madison, Wisconsin, USA, contains a relatively undisturbed area of wetland consisting of plant communities common within the prairie landscape including a fen, sedge meadow, and shallow marsh. These distinct communities are found within an area of minimal topographic relief, yet transitions from one community to the next occur over short distances. This study sought to characterize the geologic, hydrologic, and chemical gradients associated with these shifts in vegetation to gain insight into the factors controlling the spatial differences in dominant plant species, which could be critical for restoration success. Vegetation analyses revealed a transition of dominant sedge species, which appeared to correspond to changes in hydrology from a ground-water dominated to a surface-water dominated system (as determined by water isotopes). Along the same vegetation transect, subsurface coring results show a heterogeneous composition of peat and till with lateral and vertical variations in stratigraphy, which relates to variability in ground-water discharge as evidenced by hydroperiods and stable isotope composition. Applications of this type of approach throughout the glaciated terrains of the midwestern and northeastern United States and Canada can improve future wetland restoration and management. ?? 2007, The Society of Wetland Scientists.

Kurtz, A. M.; Bahr, J. M.; Carpenter, Q. J.; Hunt, R. J.

2007-01-01

219

Restoring biodiversity in the Gwydir Wetlands through environmental flows.  

PubMed

As part of the Water Reforms process, environmental flow rules have been progressively implemented in New South Wales rivers. The Integrated Monitoring of Environmental Flows (IMEF) is a major project established to better understand how rivers and associated wetlands respond to environmental water allocations. The results presented here represent the vegetation data collected for the testing of the hypothesis that "protecting or restoring a portion of freshes and high flows and otherwise maintaining natural flow variability will replenish anabranches and riverine wetlands, restoring their biodiversity". The study site is the Ramsar listed Gwydir Wetlands, located on the Gingham and Gwydir (Big Leather) Watercourses in the Lower Gwydir Valley, 100 km west of Moree. The expansion of irrigated agriculture in the lower Gwydir valley has severely altered flow regimes in the wetlands. The spread of the weed Phyla canescens (Lippia) is of major concern to landholders in the Gwydir Wetlands. Results indicate that Paspalum distichum (Water couch) and Eleocharis plana (Ribbed spike-rush) can maintain dominance over Phyla canescens if flooding occurs on a semi-regular basis. Conversely, Eichhornia crassipes (Water hyacinth) is a rampant noxious weed of open water in the Gwydir Wetlands, and has quickly spread in areas that are inundated for long periods. Management of this weed requires periodic drying of the wetlands to cause desiccation and death of the plants. The flooding requirement of individual species and plant associations in the Gwydir Wetlands are currently not fully understood. By providing better information on the consequence of different flows, the IMEF project will help to develop better management strategies to shift the dominance from introduced species such as P. canescens and E. crassipes to more desirable native plant species. PMID:14653636

Mawhinney, W A

2003-01-01

220

Wetlands stewardship  

SciTech Connect

Wetlands have important ecological values and functions. It is estimated that 80 percent of the Nation's coastal fisheries are dependent on wetlands for spawning, nursery areas, and food sources. Both coastal and inland wetlands provide essential breeding, nesting, feeding, and predator escape habitats for millions of waterfowl, other birds, mammals, and reptiles. Well over one-third of the 564 plant and animal species listed as threatened or endangered in the United States utilize wetland habitats during some portion of their life cycle. Wetlands Stewardship is intended as a resource for everyone interested in wetlands protection.

Whelan, J.M.

1992-04-01

221

Impact of standing vegetation on early establishment of willow cuttings in the flooded area of the Parana River Delta (Argentina)  

Microsoft Academic Search

We assessed the growth and survival of a willow clone (Salix matsudana × Salix alba ‘A 13\\/44’) growing under different vegetation management in the flooded area of the Parana River Delta (Argentina) during\\u000a the first 2 years after planting. Treatments consisted in a combination of practices applied in the row and in the inter-row.\\u000a In the row (1-m wide) vegetation was manually cut

Ana M. Garau; Fernando D. Caccia; Ana B. Guarnaschelli

2008-01-01

222

The establishment of heathland vegetation on ex-arable land: the response of Calluna vulgaris to soil acidification  

Microsoft Academic Search

The UK Biodiversity Action Plan has identified the creation of lowland heathland as an important objective. Heathland restoration studies have identified soil pH, elevated soil nutrients and large weed seed banks as major problems in the restoration of heathland vegetation on ex-arable land. Heathland vegetation is usually found on nutrient-poor acidic soils. Creating acidic soil conditions on ex-arable sites thus

Clare S. Lawson; Martin A. Ford; Jonathan Mitchley; John M. Warren

2004-01-01

223

Reconstruction of Anacostia wetlands: success?  

USGS Publications Warehouse

Historically, the tidal Anacostia River in Washington, D.C. had been an extensive system of freshwater tidal marshes replete with a full array of wetland vegetation dominated by wild rice. The local Nacochtank Indians had found the abundant fish and wildlife sufficient to sustain their daily lives. White man's intrusion upon the landscape gradually brought about deterioration of the natural (and associated cultural) system. Total demise followed mid-20th century dredge and fill channelization, which was conducted from the confluence of the Anacostia with the Potomac near the heart of Washington, D.C. to the terminus of the tidal regime at Bladensburg, Maryland. The National Park Service (NPS) became the manager for much of the land along the Anacostia, particularly the eastern bank. As part of its planning effort, the NPS envisioned returning portions of the Anacostia under its control to a natural system as a vignette. The concept was based on bringing back as comprehensive a collection of vegetation and wildlife as possible through the reestablishment of tidal marshes at Kenilworth and Kingman. The resultant wetlands were to be made accessible to the public both logistically and through a well designed interpretative program. In fact, this vision has been realized due to an impressive cooperative effort among a number of Federal and local agencies and organizations. In 1993, 32 acres of freshwater tidal marsh were reconstructed at Kenilworth. Based upon the 5-year monitoring program that has been in place since reconstruction, several generalizations may be made concerning the degree of success of the marsh reconstruction. Water quality in the marsh system and nearby tidal waters has not been noticeably improved. The poor quality may be clue to the overwhelmingly high loads (e.g., sediment, nutrients, etc.) brought in on the twice daily tidal cycle from the Anacostia and to the relatively small volume of water which actually interacts with the emergent marsh. Revegetation, which is a product of direct plantings (16 species comprised of 350,000 plants) and by establishment of volunteer plants, must be considered successful. Remarkably, full vegetation cover was achieved by the end of the first year (1993). Species diversity is high with 100-130 wetland species occupying portions of the wetland. Good species differentiation (incipient plant communities) can be noted at areas of sediment elevation differences. There is a good range of predominant species (five to eight) with rice cutgrass (Leersia oryzoides) initially being dominant but in later years becoming codominant. Even the native wild rice (Zizania aquatica) is making a substantive comeback. Invasive plants such as purple loosestrife (Lythrum salicaria) and phragmites (Phragmites australis) are being watched and dealt with as appropriate. There has been important habitat creation, and a resulting increase in fauna can be expected, particularly as the acreage reconstructed at Kenilworth has more than doubled with similarly reconstructed wetlands at Kingman Lake (42 acres), which were completed during the summer of 2000, just a quarter of a mile down river. One of the challenges with the Kingman marsh reconstruction has been protecting against the grazing pressure of native Canada geese (Branm canadensis). In the long run, these revived Anacostia wetlands are bound to improve local conditions and will contribute to a rejuvenated Chesapeake Bay system.

Hammerschlag, R.S.

2002-01-01

224

Wetland Mitigation Monitoring at the Fernald Preserve - 13200  

SciTech Connect

The U.S. Department of Energy is responsible for 7.2 hectares (17.8 acres) of mitigation wetland at the Fernald Preserve, Ohio. Remedial activities affected the wetlands, and mitigation plans were incorporated into site-wide ecological restoration planning. In 2008, the Fernald Natural Resource Trustees developed a comprehensive wetland mitigation monitoring approach to evaluate whether compensatory mitigation requirements have been met. The Fernald Preserve Wetland Mitigation Monitoring Plan provided a guideline for wetland evaluations. The Ohio Environmental Protection Agency (Ohio EPA) wetland mitigation monitoring protocols were adopted as the means for compensatory wetland evaluation. Design, hydrologic regime, vegetation, wildlife, and biogeochemistry were evaluated from 2009 to 2011. Evaluations showed mixed results when compared to the Ohio EPA performance standards. Results of vegetation monitoring varied, with the best results occurring in wetlands adjacent to forested areas. Amphibians, particularly ambystomatid salamanders, were observed in two areas adjacent to forested areas. Not all wetlands met vegetation performance standards and amphibian biodiversity metrics. However, Fernald mitigation wetlands showed substantially higher ratings compared to other mitigated wetlands in Ohio. Also, soil sampling results remain consistent with other Ohio mitigated wetlands. The performance standards are not intended to be 'pass/fail' criteria; rather, they are reference points for use in making decisions regarding future monitoring and maintenance. The Trustees approved the Fernald Preserve Wetland Mitigation Monitoring Report with the provision that long-term monitoring of the wetlands continues at the Fernald Preserve. (authors)

Powell, Jane [Fernald Preserve Site Manager, DOE Office of Legacy Management, Harrison, Ohio (United States)] [Fernald Preserve Site Manager, DOE Office of Legacy Management, Harrison, Ohio (United States); Bien, Stephanie; Decker, Ashlee; Homer, John [Environmental Scientist, S.M. Stoller Corporation, Harrison, Ohio (United States)] [Environmental Scientist, S.M. Stoller Corporation, Harrison, Ohio (United States); Wulker, Brian [Intern, S.M. Stoller Corporation, Harrison, Ohio (United States)] [Intern, S.M. Stoller Corporation, Harrison, Ohio (United States)

2013-07-01

225

Physical and Vegetative Characteristics of a Relocated Stream Reach, Constructed Wetland, and Riparian Buffer, Upper Saucon Township, Lehigh County, Pennsylvania, 2000-04.  

National Technical Information Service (NTIS)

This report presents an evaluation of data collected within a relocated stream reach, constructed wetland, and riparian buffer during seven post-construction monitoring events from September 2000 through October 2004. The evaluation pro-vides PennDOT and ...

2006-01-01

226

Tidal Wetlands Impacts Data Homepage  

NSDL National Science Digital Library

A cooperative effort between the Virginia Institute of Marine Science (VIMS) and the US Environmental Protection Agency (EPA), this site was designed "to assist resource managers, academicians, students, politicians, and the general public in the areas of research, education, environmental management, and policy ... about human impacts on tidal wetlands in Virginia." Non-interactive sections include the Overview of the VIMS Program, describing data collection methods; Overview of Management, describing the history and current status of tidal wetlands management; Nontidal wetlands impacts information, summarizing impacts to nontidal wetlands; and General Data Summaries, offering display tables and graphs. Two searchable sections provide for select examination of the data: Design a query for 1993-1997 and Design a query for 1988-1992 enable viewers to examine data by year, activity category, and watershed. Results are presented in tabular form and "display impacts to vegetated and nonvegetated wetlands by square footage." Photographs accompany the summary data.

227

What Are Wetlands are Where Are They?  

NASA Astrophysics Data System (ADS)

The first empirical models of methane emission from natural wetlands were developed in the late 1980s and early 1990s following the first field measurements of wetland methane fluxes. Since the mid-1990s, a suite of empirical, ecosystem, and process-based models of increasing complexity have been developed to simulate methane emissions from wetlands. Inputs to these models typically include climate variables, and vegetation and soil characteristics; they simulate soil temperature/thaw, water-table position, carbon supply and processes of production, transport, oxidation and emission of methane. A standard approach has been to apply the CH4 models to an externally-defined wetland data set due to the difficulty of modeling the distribution of wetlands themselves. More recently, researchers have begun characterizing methane-producing environments based on, inter alia, modeled soil hydrological dynamics and satellite-derived surface inundation. However, modeling the distribution and dynamics of methane-producing wetlands remains a fundamental challenge in understanding the role of wetlands in the global methane cycle under past, current and future climates. The wide spectrum of vegetation, hydrological regime, chemistry, soils, and seasonality means that defining wetlands is not straightforward and, although multiple systems describing local and regional wetland environments exist, none encompasses their global diversity particularly with regard to methane-relevant characteristics. Recent work by Petrescu et al. (Glob. Biogeochem. Cycl., 24/4, 2010) highlights the sensitivity of modeled emissions to uncertainties in wetland distributions. We hypothesize that differences among wetland distributions can be explained primarily by the methods, purposes and instruments used to produce the distributions. The lack of a comprehensive definition of wetlands for methane studies, together with approaches with different strengths and weaknesses for identifying the spectrum of wetland variability, constitutes a major uncertainty in modeling wetlands and their methane emissions. We illustrate the problem with examples of tropical and boreal wetlands.

Matthews, E.

2011-12-01

228

Climate Change and Intertidal Wetlands  

PubMed Central

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.

Ross, Pauline M.; Adam, Paul

2013-01-01

229

Climate change and intertidal wetlands.  

PubMed

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

Ross, Pauline M; Adam, Paul

2013-01-01

230

The Integrated Constructed Wetlands (ICW) concept  

Microsoft Academic Search

The free surface flow Integrated Constructed Wetlands (ICW) concept explicitly combines the objectives of cleansing and managing\\u000a water flow from farmyards with that of integrating the wetland infrastructure into the landscape and enhancing its biological\\u000a diversity. This leads to system robustness and sustainability. Hydraulic dissipation, vegetation interception, and evapotranspiration\\u000a create an additional freeboard at the outlet of each wetland segment

Miklas Scholz; Rory Harrington; Paul Carroll; Atif Mustafa

2007-01-01

231

Control of hardwood regeneration in restored carolina bay depression wetlands.  

SciTech Connect

Carolina bays are depression wetlands located in the coastal plain region of the eastern United States. Disturbance of this wetland type has been widespread, and many sites contain one or more drainage ditches. Restoration of bays is of interest because they are important habitats for rare flora and fauna. Previous bay restoration projects have identified flood-tolerant woody competitors in the seedbank and re-sprouting as impediments to the establishment of desired herbaceous wetland vegetation communities. We restored 3 bays on the Savannah River Site, South Carolina, by plugging drainage ditches, harvesting residual pine/hardwood stands within the bays, and monitoring the vegetative response of the seedbank to the hydrologic change. We applied a foliar herbicide on one-half of each bay to control red maple (Acerrubrum), sweetgum (Liquidambar styraciflua), and water oak (Quercus nigra) sprouting, and we tested its effectiveness across a hydrologic gradient in each bay. Hardwood regeneration was partially controlled by flooding in bays that exhibited long growing season hydroperiods. The findings also indicated that herbicide application was an effective means for managing hardwood regeneration and re-sprouting in areas where hydrologic control was ineffective. Herbicide use had no effect on species richness in the emerging vegetation community. In late-season drawdown periods, or in bays where hydroperiods are short, more than one herbicide application may be necessary.

Moser, Lee, J.; Barton, Christopher, D.; Blake, John, I.

2012-06-01

232

Estimating relative wetland values for regional planning  

Microsoft Academic Search

A numeric method is described for establishing the relative values of wetlands in regional planning. The method combines qualitative\\u000a understanding of how local wetlands function with assessments of their regional values. The method, called the IVA (Indicator\\u000a Value Assessment), is a rapid assessment method based on the assumption that wetlands having specific environmental indicators\\u000a perform a wetland function better than

Thomas Hruby; William E. Cesanek; Keith E. Miller

1995-01-01

233

Some aspects of natural vegetation establishment on abandoned underground coal mine refuse areas in illinois. Final report  

Microsoft Academic Search

Inventories of lands affected by surface and underground mining for coal in Illinois have identified gob a coarse coal refuse (5,000 acres) and slurry (3,991 acres) disposal areas designated as problem sites. This study was designed to characterize the chemical and physical parameters of 36 naturally well-vegetated (26 unburned gob, 5 burned gob, 5 slurry) disposal sites, to relate those

J. R. DAntuono; W. D. Klimstra

1979-01-01

234

Flow patterns of dairy wastewater constructed wetlands in a cold climate  

Microsoft Academic Search

Conservative tracer experiments, and spatial temperature and dissolved oxygen mapping within four subsurface treatment wetlands employed in this study demonstrated the importance of supplemental aeration and vegetation in reducing preferential flows in cold climate treatment wetlands. Four constructed wetlands, employing horizontal subsurface flow were used to treat dairy wastewater in a 2×2 factorial design consisting of two wetland cells with

Pete Muñoz; Aleksandra Drizo; W. Cully Hession

2006-01-01

235

Effect of constructed wetlands receiving agricultural return flows on disinfection byproduct precursors  

Microsoft Academic Search

The effects of wetland treatment on disinfection byproduct precursors were evaluated for six constructed wetlands receiving agricultural return flows in the Central Valley of California. Wetlands varied in size, age, vegetation, hydrologic residence time (0.9–20days) and water management (continuous flow vs. flood pulse). The effects of wetland treatment were determined by analyzing input and outflow waters for dissolved organic carbon

Francisco J. Díaz; Alex T. Chow; Anthony T. O’Geen; Randy A. Dahlgren; Po-Keung Wong

2009-01-01

236

Methane Fluxes from Subtropical Wetlands  

NASA Astrophysics Data System (ADS)

It is well documented that green house gas concentrations have risen at unequivocal rates since the industrial revolution but the disparity between anthropogenic sources and natural sources is uncertain. Wetlands are one example of a natural ecosystem that can be a substantial source or sink for methane (CH4) depending on climate conditions. Due to strict anaerobic conditions required for CH4-generating microorganisms, natural wetlands are one of the main sources for biogenic CH4. Although wetlands occupy less than 5% of total land surface area, they contribute approximately 20% of total CH4 emissions to the atmosphere. The processes regulating CH4 emissions are sensitive to land use and management practices of areas surrounding wetlands. Variation in adjacent vegetation or grazing intensity by livestock can, for example, alter CH4 fluxes from wetland soils by altering nutrient balance, carbon inputs and hydrology. Therefore, understanding how these changes will affect wetland source strength is essential to understand the impact of wetland management practices on the global climate system. In this study we quantify wetland methane fluxes from subtropical wetlands on a working cattle ranch in central Florida near Okeechobee Lake (27o10'52.04'N, 81o21'8.56'W). To determine differences in CH4 fluxes associated with land use and management, a replicated (n = 4) full factorial experiment was designed for wetlands where the surrounding vegetation was (1) grazed or un-grazed and (2) composed of native vegetation or improved pasture. Net exchange of CH4 and CO2 between the land surface and the atmosphere were sampled with a LICOR Li-7700 open path CH4 analyzer and Li-7500A open path CO2/H20 analyzer mounted in a 1-m3 static gas-exchange chamber. Our results showed and verified that CH4 emissions from subtropical wetlands were larger when high soil moisture was coupled with high temperatures. The presence of cattle only amplified these results. These results help quantify GHG emissions from subtropical wetlands while demonstrating the differences in these fluxes based on the surrounding ecosystem.

DeLucia, N.; Gomez-Casanovas, N.; Bernacchi, C.

2013-12-01

237

Identification and characterization of wetlands in the Bear Creek watershed  

SciTech Connect

The primary objective of this study was to identify, characterize, and map the wetlands in the Bear Creek watershed. A preliminary wetland categorization system based on the Cowardin classification system (Cowardin et al. 1979) with additional site-specific topographic, vegetation, and disturbance characteristic modifiers was developed to characterize the type of wetlands that exist in the Bear Creek watershed. An additional objective was to detect possible relationships among site soils, hydrology, and the occurrence of wetlands in the watershed through a comparison of existing data with the field survey. Research needs are discussed in the context of wetland functions and values and regulatory requirements for wetland impact assessment and compensatory mitigation.

Rosensteel, B.A. [JAYCOR, Oak Ridge, TN (United States); Trettin, C.C. [Oak Ridge National Lab., TN (United States)

1993-10-01

238

Hydrology and Hydraulic Design Criteria for the Creation and Restoration of Wetlands.  

National Technical Information Service (NTIS)

Hydrology is generally accepted as the single most important factor governing the successful establishment and maintenance of specific wetlands types and wetland processes. Long before the study of wetlands was a separate field of science, early scholars ...

1993-01-01

239

Dune development and migration to damage long established vegetation colonies in the lahar deposition zone of Ruapehu Volcano, New Zealand  

NASA Astrophysics Data System (ADS)

This study reports migration of dunes that mainly originate from lahar deposits and gully erosion, in the Rangipo Desert on the skirts of the Ruapehu Volcano, New Zealand. Although the Rangipo Desert is not a dry desert (average annual rainfall: 1100mm), the occasional supply of volcanic materials from Ruapehu, strong wind (average maximum speed in a day: 12 m/s) together with low winter temperatures has created a desert-like landscape. The study site consists of a flood plain with sporadic tussock and alpine to sub-alpine vegetation colonies which often form mound-like structures and sand dunes on terraces on the flanks of the volcano. The accretionary mounds and dunes comprise layers of tephra and pumice of various ages, together with interstitial wind-blown materials. While shrubs thrive on these terrace tops, it was observed that migrating dunes of 3 m in height have progressively buried and killed vegetation at two sites. Aerial photographs taken in 2000 and 2011 indicated that the dunes originated from pockets of lahar deposits and gully out-wash materials on the flood plain and were migrating in the major leeward wind direction (Northeast), or towards the sites. The migration rate at one site was estimated at 5 m/year from the photography. The flood plain pockets had formed at points where the floor slope changed from steep to gentle. As they contain finer materials than their surroundings, they have produced a series of sequential dunes. The exposed floor between the dunes comprises pumice layers of low infiltration capacity, suggesting that dunes migrate and develop as they strip off floor deposits. Subsequent exposure of the layers induces surface flow concentration in wet weather to cause gully incision. In conclusion, lahar occurrence is a major controlling factor in development in the landscape of the Rangipo Desert, by not only directly flowing at times into the flood plain, but also by producing migrating dunes that impact on existing vegetation colonies and helping to stimulate gully development long after their occurrence.

Ohno, Y.; Kasai, M.; Marutani, T.

2012-04-01

240

ERTS-1 investigation of wetlands ecology  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Data from aircraft can be used for large scale mapping where detailed information is necessary, whereas Landsat-1 data are useful for rapid mapping of gross wetland boundaries and vegetative composition and assessment of seasonal change plant community composition such as high and low growth forms of Spartina alterniflora, Juncus roemarianus, and Spartina cynosuroides. Spoil disposal and wetland ditching activities may also be defined. Wetland interpretation is affected by tidal stage; drainage patterns are more easily detected at periods of low water. Species discrimination is easier at periods of high water during the growing season; upper wetland boundaries in fresh water tidal marshes are more easily delineated during the winter months when marsh vegetation is largely dead or dormant. Fresh water discharges from coastal streams may be inferred from the species composition of contiguous wetlands.

Anderson, R. R. (principal investigator); Carter, V.; Mcginness, J.

1975-01-01

241

Systematic Study of Cutthroat Grass Wetland Reclamation through Ditch Filling  

NASA Astrophysics Data System (ADS)

Landscape evolution is often driven by the site hydrology, particularly in the case of wetlands. Biodiversity seems to favor slow changes in water conditions, which facilitate adaptation by a broad array of species. Restoration of impacted areas, if performed too rapidly may not result in the simple reversal of the adverse evolution. A systematic wetland reclamation study is underway to analyze the manner in which drained wetlands in the scrub area of Highlands County, Florida can be effectively rehydrated to yield properly functioning wetlands. Ten wetlands, comprising a total area of 130 acres, located in the Lake Placid Scrub Wildlife & Environmental Area (3150 acres) are involved. All but one have been drained through ditching approximately twenty years ago. The predominant species is cutthroat grass (Panicum abscissum). The drained wetlands are significantly invaded with upland species, such as slash pine (Pinus elliottii). During year one of the study, ditches affecting six of the wetlands have been filled. Water levels are being recorded daily at nine locations corresponding to groundwater wells in the scrub regions and groundwaterstilling wells inside selected wetlands, including the natural remnant, "restored" wetlands, and ditched wetlands. Ditches for the three wetlands not restored during year one will be filled during year two of the study. Hydrologic monitoring will continue at least for a period of two years. Yearly, vegetation surveys will document the progression of the ten wetlands. Initially, the metric for success will be comparison to the natural remnant wetland both for hydrologic and vegetative indicators.

Wise, W. R.

2001-12-01

242

Remote sensing of coastal wetlands  

NASA Technical Reports Server (NTRS)

Various aircraft and satellite sensors for detecting and mapping wetlands properties are examined. The uses of color IR photography to map coastal vegetation, and of Landsat MSS and TM and SPOT data to quantify biomass and productivity for large wetland areas are discussed. For spectral estimation of biomass and productivity, the relation between radiance and biomass needs to be studied; the quantity and orientation of dead biomass and the amount of soil reflectance in comparison with vegetation reflectance in a given target area affect the spectral estimation of biomass. The radiometric evaluation of brackish wetland, and remote sensing in mangroves are described. The collection of images in narrow, contiguous spectral band using imaging spectrometry is considered.

Hardisky, M. A.; Klemas, V.; Gross, M. F.

1986-01-01

243

Exploring Wetlands.  

ERIC Educational Resources Information Center

Presents a wetlands education model for secondary education students. Students monitor a wetland, participate in decision-making, and take actions to protect it. In a series of six steps, the model guides students through the process of defining a problem; envisioning solutions; evaluating appropriate solutions based on environmental, economic and…

Kerr, Elizabeth; Harrison, Gordon

1996-01-01

244

Freshwater Wetlands.  

ERIC Educational Resources Information Center

Provides descriptions about freshwater wetlands, such as marshes, swamps, and bogs. Contains three learning activities which deal with unusual wetland plants, the animals and plants in a typical marsh, and the effects of a draught on a swamp. Included are reproducible handouts and worksheets for two of the activities. (TW)

Naturescope, 1986

1986-01-01

245

Study of Panjin wetlands along Bohai coast: (I) the information system of wetlands based on 3S technique  

Microsoft Academic Search

Based on previous studies on Panjin wetlands along the coast of the Bohai Sea, this paper adopts RS, GIS and GPS techniques\\u000a and establishes the information system for Panjin wetlands. The system involves many functions, such as identification and\\u000a classification of wetlands, calculation of the area of wetlands and storage of the information of the wetland management.\\u000a Moreover, our study

Tieliang Wang; Linfei Zhou; Peiqi Yang; Bo Zhao

2008-01-01

246

Impact of land use on vegetation composition, diversity, and selected soil properties of wetlands in the southern Drakensberg mountains, South Africa  

Microsoft Academic Search

Wetlands provide the ecosystem services of enhancing water quality, attenuating floods, sequestrating carbon and supporting\\u000a biodiversity. In southern Africa, the pattern and intensity of land use is influenced by whether land tenure is public (state),\\u000a private (individual ownership), or communal (shared agricultural and grazing resources). The influence of land tenure and\\u000a its associated use on service provision was compared for

D. J. J. Walters; D. C. Kotze; T. G. O’Connor

2006-01-01

247

Organic carbon oxidation and suppression of methane production by microbial Fe(III) oxide reduction in vegetated and unvegetated freshwater wetland sediments  

Microsoft Academic Search

High concentrations (20-75 pmol cm-3) of amorphous Fe(III) oxide were observed in unvegetated surface and Juncus eflusus rhizosphere sediments of a freshwater wetland in the southeastern United States. Incu- bation experiments demonstrated that microbial Fe(III) oxide reduction suppressed sulfate reduction and methanogenesis in surface scdimcnts and mediated 240% of depth-integrated (O-10 cm) unvegetated sedi- ment carbon metabolism, compared to I

Eric E. Roden; Robert G. Wetzel

1996-01-01

248

Predicting friction factor in herbaceous emergent wetlands  

NASA Astrophysics Data System (ADS)

Over 53% of all wetlands in the US have been lost since the mid-1780s; to counteract wetland losses, wetland land area is being replaced through wetland restoration and mitigation. Development of the target wetland hydroperiod is critical to restoration success. For wetlands in which outflow is a component of the water budget, such as in riparian wetlands, surface water stage is controlled all or in part by the hydraulic resistance within the wetland, requiring accurate simulation of hydraulic resistance due to vegetation. Hydraulic models that consider vegetation rely on an accurate determination of a resistance parameter such as a friction factor or drag coefficient. At low Reynolds numbers typical of flows in wetlands, hydraulic resistance is orders of magnitude higher than fully turbulent flows and resistance parameters are functions of the flow regime as well as the vegetation density and structure. The exact relationship between hydraulic resistance, flow regime, and vegetation properties at the low-Reynolds number flows remains unclear. Prior research has typically involved laboratory studies of flow through idealized, individual stems. However, emergent wetland vegetation frequently grows as clumps. The goals of this research were to investigate the effect of clumping vegetation on flow resistance and to develop a prediction equation for use in wetland design. A 6-m by 1-m by 0.4-m recirculating flume was planted with mature common rush, Juncus effusus, a common emergent wetland plant. Three different flow rates (3, 4, and 5 L/s) and three different tailgate heights (0, 2.5, and 5 cm) were used to simulate a range of flow conditions. Plant spacing and clump diameter were varied (20 and 25 cm, 8 and 12 cm, respectively). Friction factors ranged from 9 to 40 and decreased with increasing plant density. Non-dimensional parameters determined through Buckingham Pi analysis were used in a regression analysis to develop a prediction model. Results of the regression analysis showed that the fraction of vegetated occupied area was most significant factor in determining friction factor.

Wynn-Thompson, T.; Hall, K.

2012-12-01

249

Measuring Above Ground Biomass and Vegetation Structure in the South Florida Everglades Wetland Ecosystem with X-, C-, and L-band SAR data and Ground-based LiDAR  

NASA Astrophysics Data System (ADS)

Worldwide, anthropogenic activities are disturbing and disrupting nutrient rich bio-diverse wetland ecosystems. Disturbance of the South Florida Everglades has been particularly acute, but difficult to quantify given its limited accessibility. Successful ecosystem monitoring requires the use of remote sensing. We used space-based Synthetic Aperture Radar (SAR) observations to estimate vegetation structure and above-ground biomass and track their changes over time. Our study leveraged three different SAR wavelengths that interact with different aspects of the vegetation. The short wavelength X-band (3.2 cm) signal interacts mainly with canopies; the intermediate wavelength C-band (5.6 cm) signal interacts with both canopies and branches; and the long wavelength L-band (24 cm) signal interacts with both the surface and lower portion of the vegetation. We used dual- and quadruple-polarization observations acquired from the TerraSAR-X, RadarSAT-2, and ALOS satellites. Different polarization data reflect radar signal interaction with different sections of the vegetation due to different scattering mechanisms. In order to calibrate the multi-wavelength and multi-polarization SAR observations, we conducted field measurement in three vegetation communities: hammock, pine and cypress. Our ground measurements included both traditional forestry surveys and state-of-the-art Terrestrial Laser Scanning (TLS), a.k.a. ground based LiDAR surveys. A week long TLS survey was conducted in the Everglades National Park in the three calibrations sites using a Leica ScanStation C10 TLS instrument which utilizes a narrow, green (532 nm) laser beam. During this week we collected a total of 29 scans (33 GB of data). The TLS surveys provided centimeter resolution 3-D point clouds of the ground surface and below-canopy vegetation. Initial analysis of the data has provided detailed 3-D estimates of the vegetation structure and above ground biomass. A comparative analysis of the ability of the three bands of SAR to quantify above ground biomass in the different communities is presented. We also determine the essential bands needed to most efficiently estimate biomass. We find that the performance of SAR differs by community types. More rigorous data processing will provide important quantitative measures that will allow careful calibration of the remote sensing SAR data.

Feliciano, E. A.; Wdowinski, S.; Potts, M.; Chin, S.; Phillips, D. A.

2010-12-01

250

Results of preliminary reconnaissance trip to determine the presence of wetlands in wet forest habitats on the Island of Hawaii as part of the Hawaii Geothermal Project, October 1993  

SciTech Connect

In October 1993, the authors sampled soils, vegetation, and hydrology at eight sites representing a range of substrates, elevations, soil types, and plant community types within rainforest habitats on the Island of Hawaii. Their purpose was to determine whether any of these habitats were wetlands according to the 1987 Corps of Engineers Wetlands Delineation Manual. None of the rainforest habitats they sampled was wetland in its entirety. However, communities established on pahoehoe lava flows contained scattered wetlands in depressions and folds in the lava, where water could accumulate. Therefore, large construction projects, such as that associated with proposed geothermal energy development in the area, have the potential to impact a significant number and/or area of wetlands. To estimate those impacts more accurately, they present a supplementary scope of work and cost estimate for additional sampling in the proposed geothermal project area.

Wakeley, J.S.; Sprecher, S.W.; Lichvar, R.

1994-02-25

251

Opposing environmental gradients govern vegetation zonation in an intermountain playa  

USGS Publications Warehouse

Vegetation zonation was investigated at an intermountain playa wetland (Mishak Lakes) in the San Luis Valley (SLV) of southern Colorado. Plant composition and abiotic conditions were quantified in six vegetation zones. Reciprocal transplants were performed to test the importance of abiotic factors in governing zonation. Abiotic conditions differed among several vegetation zones. Prolonged inundation led to anaerobic soils in the Eleocharis palustris and the submerged aquatics zones, on the low end of the site's 1.25 m elevation gradient. On the high end of the gradient, soil salinity and sodicity (a measure of exchangeable sodium) were high in the Distichlis spicata zone (electrical conductivity, EC = 5.3 dS/m, sodium absorption ratio, SAR = 44.0) and extreme in the Sarcobatus vermiculatus zone (EC = 21 dS/m, SAR = 274). Transplanted species produced maximum biomass in the zone where they originated, not in any other higher or lower vegetation zone. The greatest overall transplant effect occurred for E. palustris, which experienced a ??? 77% decline in productivity when transplanted to other zones. This study provides evidence that physical factors are a major determinant of vegetation zone composition and distribution across the entire elevation gradient at Mishak Lakes. Patterns at Mishak Lakes arise from counter-directional stress gradients: a gradient from anaerobic to well-oxygenated from basin bottom to upland and a gradient from extremely high salinity to low salinity in the opposing direction. Because abiotic conditions dominate vegetation zonation, restoration of the altered hydrologic regime of this wetland to a natural hydrologic regime may be sufficient to re-establish many of the natural biodiversity functions provided by these wetlands. ?? 2008 The Society of Wetland Scientists.

Sanderson, J. S.; Kotliar, N. B.; Steingraeber, D. A.

2008-01-01

252

High and Mid-Latitude Wetlands, Climate Change, and Carbon Storage  

NASA Technical Reports Server (NTRS)

Pollen and macrofossil stratigraphy from wetlands associated with AMS chronology provides a vegetational and climatic history over thousands of years. From these records we establish a record of climate change which can be compared with independent records of carbon accumulation rates in these same wetlands. In this way, inferences can be made concerning carbon storage during different climatic regimes. One focus of our research has been high-latitude regions such as Alaskan and Siberian tundra, from which we have paleorecords which span the last 10,000 years. We will present records from the Malaspina Glacier region, Alaska and the Pur-Taz region of Western Siberia. A second focus of our research is in mid-latitude eastern North America. We will present paleorecords from wetlands in Vermont, New York, and Virginia showing the relationship between carbon accumulation rates and climatic changes since the late Pleistocene.

Peteet, Dorothy

2000-01-01

253

Contiguity and edge characteristics of wetlands in five coastal counties of north Carolina, USA  

Microsoft Academic Search

Wetland contiguity and edge were determined with a geographic information system (GIS) for five coastal counties in North\\u000a Carolina. USA. The digital database was created from wetlands digitized from U.S. Fish and Wildlife Service National Wetlands\\u000a Inventory maps. The GIS analysis was based on three classes of information: 1) all wetlands as one class; 2) wetlands separated\\u000a by dominant vegetative

Kevin K. Moorhead

1999-01-01

254

Modelling wet weather sediment removal by stormwater constructed wetlands: Insights from a laboratory study  

NASA Astrophysics Data System (ADS)

SummaryConstructed wetlands are now commonly used to control polluted urban stormwater discharges. A laboratory study was conducted to investigate the treatment of solids in these systems. Three mesocosm stormwater wetlands (vegetated with a well-established canopy of different densities) and one mesocosm non-vegetated pond were used, all sized to achieve particle fall number ( Nf, a ratio between the times of the particle travel in horizontal and vertical directions) and Particle Shear Velocity Reynolds Number, Re?, which are reflective of full-scale systems. The mesocosm vegetated systems had also similar turbulent Reynolds Numbers ( ReT) to those funds in full-scale systems. Ten groups of steady-state experiments were carried out, all with different hydraulic loadings and sediment inflow concentrations (also maintained within the ranges found in real systems during wet weather). Samples were taken along the mesocosms and analysed for Total Suspended Solids concentrations (TSS) and Particle Size Distribution (PSD). It was found that both Re? and ReT do not significantly influence the trapping of sediments, and therefore the particle re-suspension induced by water flow is not important for sedimentation in constructed stormwater wetlands. Vegetation density was found not to be an important factor, while particle diameter, and flow characteristics (e.g., flow rate and velocity) do influence trapping efficiency of particles. It was concluded that sediment trapping correlates strongly with particle fall number, Nf, and therefore can be explained by this single non-dimensional number. A simple non-linear two-parameter regression model is proposed for prediction of particle trapping efficiency in constructed stormwater wetlands. However, further work is needed before the method can be used in practice. The aim of the ongoing work is to test whether the proposed model could be used across a number of real stormwater constructed wetlands without any further calibration. The data collected from a number of stormwater treatment systems in Melbourne, Australia, will be used in this study.

Li, Y.; Deletic, A.; Fletcher, T. D.

2007-05-01

255

Restoring coastal wetlands that were ditched for mosquito control: A preliminary assessment of hydro-leveling as a restoration technique  

USGS Publications Warehouse

The wetlands surrounding Tampa Bay, Florida were extensively ditched for mosquito control in the 1950s. Spoil from ditch construction was placed adjacent to the wetlands ditches creating mound-like features (spoil-mounds). These mounds represent a loss of 14% of the wetland area in Tampa Bay. Spoil mounds interfere with tidal flow and are locations for non-native plants to colonize (e.g., Schinus terebinthifolius). Removal of the spoil mounds to eliminate exotic plants, restore native vegetation, and re-establish natural hydrology is a restoration priority for environmental managers. Hydro-leveling, a new technique, was tested in a mangrove forest restoration project in 2004. Hydro-leveling uses a high pressure stream of water to wash sediment from the spoil mound into the adjacent wetland and ditch. To assess the effectiveness of this technique, we conducted vegetation surveys in areas that were hydro-leveled and in non-hydro-leveled areas 3 years post-project. Adult Schinus were reduced but not eliminated from hydro-leveled mounds. Schinus seedlings however were absent from hydro-leveled sites. Colonization by native species was sparse. Mangrove seedlings were essentially absent (???2 m-2) from the centers of hydro-leveled mounds and were in low density on their edges (17 m-2) in comparison to surrounding mangrove forests (105 m-2). Hydro-leveling resulted in mortality of mangroves adjacent to the mounds being leveled. This was probably caused by burial of pneumatophores during the hydro-leveling process. For hydro-leveling to be a useful and successful restoration technique several requirements must be met. Spoil mounds must be lowered to the level of the surrounding wetlands. Spoil must be distributed further into the adjacent wetland to prevent burial of nearby native vegetation. Finally, native species may need to be planted on hydro-leveled areas to speed up the re-vegetation process. ?? Springer Science+Business Media B.V. 2007.

Smith, III, T. J.; Tiling, G.; Leasure, P. S.

2007-01-01

256

Coastal wetlands: Proceedings of First Great Lakes Wetlands Colloquium, November 1984, East Lansing, Michigan  

SciTech Connect

This book explores the wetlands of the Great Lakes. Topics considered include the effects of water level fluctuations on Great Lakes coastal marshes; environmental influences on the distribution and composition of wetlands in the Great Lakes Basin; vegetation dynamics, buried seeds, and water level fluctuations on the shoreline of the Great Lakes; preliminary observations on the flux of carbon, nitrogen, and phosphorous in a Great Lakes coastal marsh; nutrient cycling by wetlands and possible effects of water levels; and avian wetland habitat functions affected by water level fluctuations.

Prince, H.H.; D'Itri, F.M.

1986-01-01

257

Late Holocene to present climatic and anthropogenic drivers affecting wetland plant communities, Florida Everglades, USA  

NASA Astrophysics Data System (ADS)

We synthesize the paleoecological results of dozens of sediment cores to evaluate the complex interactions of regional climate variability and anthropogenic modifications during the late Holocene affecting the development, stability, and resilience of the Florida Everglades wetlands. The Everglades is a mosaic of wetland types whose distributions are controlled by water depth, hydroperiod, fire, and substrate. External stressors could trigger shifts in the vegetation composition and change the community structure. Episodic severe periods of aridity during the late Holocene caused regional shifts in vegetation including the initiation and development of tree islands and sawgrass ridges, which became established during abrupt drought events. While the timing varies site to site, most droughts occurred during well-documented global climate events like the Medieval Climate Anomaly and the Little Ice Age. However, slough vegetation is more resilient to climate variability and quickly returns to its original composition after droughts. Twentieth century modification to the natural Everglades hydrology saw the distribution wetlands severely altered. The response was not homogeneous. Some communities were drowned by prolonged hydroperiods whereas other communities, such as marl prairies became drier. However, slough vegetation in the ridge and slough landscape did not respond to 20th century land use but instead has been sensitive to changes in precipitation associated with the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation.

Bernhardt, C. E.; Willard, D. A.

2011-12-01

258

What Makes a Wetland a Wetland?  

ERIC Educational Resources Information Center

Provides descriptions of and activities about various kinds of wetlands. Contains seven learning activities ranging from creating wetland scenes with picture cutouts to actually exploring a wetland. Includes reproducible handouts and worksheets for several of the activities. (TW)

Naturescope, 1986

1986-01-01

259

Vegetation dynamics  

USGS Publications Warehouse

Intro paragraph: A disturbance can be defined as 'any relatively discrete event in time that disrupts ecosystem, community, or population structure and changes resources, substrate availability, or the physical environment' (Pickett and White 1985). Vegetation dynamics are a function of the temporal and spatial patterns of the disturbance regime. Natural disturbance regimes support the highest biological diversity; therefore, forest management practices that most closely mimic natural disturbances are expected to sustain the highest biological diversity within a given area (Denslow 1980). In southern forested wetlands, flooding is the dominant disturbance factor, thus plant species are usually distributed along a gowing-season flood gradient (Franz and Bassas 1977).

King, S.L.; Burke, M.K.; Antrobus, T.J.; Billups, S.

2000-01-01

260

Application of EPA wetland research program approach to a floodplain wetland restoration assessment.  

SciTech Connect

Kolka, R.K., C.C. Trettin, E.A. Nelson, C.D. Barton, and D.E. Fletcher. 2002. Application of the EPA Wetland Research Program Approach to a floodplain wetland restoration assessment. J. Env. Monitoring & Restoration 1(1):37-51. Forested wetland restoration assessment is difficult because of the timeframe necessary for the development of a forest ecosystem. The development of a forested wetland ecosystem includes the recovery of hydrology, soils, vegetation, and faunal communities. To assess forested wetland restoration projects, measures need to be developed that are sensitive to early changes in community development and are predictive of future conditions. In this study we apply the EPS's Wetland Research Program's (WRP) approach to assess the recovery of two thermally altered riparian wetland systems in South Carolina. In one of the altered wetland systems, approximately 75% of the wetland was planted with bottomland tree seedlings in an effort to hasten recovery. Individual studies addressing hydrology, soils, vegetation, and faunal communities indicate variable recovery responses.

Kolka, R., K.; Trettin, C., C.; Nelson, E., A.; Barton, C., D.; Fletcher, D., E.

2002-01-01

261

Remote Sensing and Wetland Ecology: a South African Case Study  

PubMed Central

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.

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

2008-01-01

262

Mitigation of micropollutants inside wetland systems: Impacts of season and flow conditions  

NASA Astrophysics Data System (ADS)

The important role of wetlands for retention and mitigation of micropollutants has been documented by numerous studies. Natural wetlands in stream eco-systems comprise different elements, e.g. open water bodies, densely vegetated areas and riparian zones with fluctuating water tables, where different biogeochemical conditions prevail. However, our main knowledge on the mitigation potential of these wetlands stems from input-output balances established for constructed systems and from controlled lab-scale experiments. Less is known about internal processes occurring in natural wetlands. The ability of hydrological tracers to serve as a reference for the transport of aquatic pollutants has been shown for a variety of micropollutants. In this study we used a set of hydrological tracers with different physico-chemical properties to assess the retention potential of a recently restored wetland that comprises a variety of internal flowpaths and wetland elements. We conducted our experiments during summer and winter to document the impacts of different seasons and flow conditions. As such we aimed to shed light on real-world retention capabilities of different wetland elements as a guideline for wetland (re-) construction. On a clear winter day (0°C, runoff 21 l/s) we injected 1kg of sodium bromide (NaBr), 1g of uranine (UR) and 1g of sulphorhodamine (SRB). Tracers were measured continuously by field fluorometers and conductivity meters complemented by manual and automatic sampling for laboratory analysis. In accordance with the constructional setup the Multi-Flow Dispersion Model (MDM) enabled us to numerically separate the existing three main flowpaths (FPs). Approximately 25% of the injected tracers traveled through FP1, which only comprised straight channel sections and narrow riparian zones. Approximately 65% of the tracers followed FP2, which contained one small open water body. The remaining tracers (approximately 10%) made their way through a large water body with a diffuse outlet through a densely vegetated zone. A comparison between conservative (NaBr) and non-conservative tracers (UR, SRB) yielded different retention capabilities for the three different FPs and hence wetland elements. During summer (20°C, runoff 0.8 l/s) we repeated the tracer injections using the same protocol. Then the entire wetland was densely vegetated and we expected higher tracer retention due to enhanced biological activity and longer residence times at low flow conditions. However, we observed the opposite, since only one flowpath (FP1) was active and all open water bodies were disconnected due to wetland succession. Regarding retention of micropollutants in our restored wetland we conclude that (a) retention in deep water bodies is decisive, (b) straight sections show relative small retention capabilities, (c) vegetation activity (summer/winter) seems less important for treatment than for flow path development, and (d) in our case photolysis is overall more effective than sorption. These findings highlight the importance of open water bodies for wetland restoration. This study was financed by the PhytoRet-Project (C.21) of the European INTERREG IV program Upper Rhine.

Lange, Jens; Herbstritt, Barbara; Schuetz, Tobias

2014-05-01

263

A method for improving the management of controversial wetland.  

PubMed

Valley bottom wetlands in agricultural landscapes often are neglected in national and regional wetland inventories. Although these areas are small, located in the bottomlands of the headwater catchments, and scattered in the rural landscape, they strongly influence hydrology, water quality, and biodiversity over the whole catchment area. Valley bottom wetlands often are considered as controversial wetlands. Awareness of the functional role of wetlands is increasing, in parallel with their progressive disappearance in intensive farming landscapes. The need to improve tools for controlling wetland management is a primary consideration for decision makers and land users. This article proposes a method for the inventory of valley bottom wetlands. The method is based on the functional analysis of potential, existing, and efficient valley bottom wetlands (the PEEW approach). Several indicators are proposed for checking the validity of such an approach. Potential wetlands are delineated by means of a topographic index using topographic and pedoclimatic criteria computed from a Digital Elevation Model and easily accessible databases. Existing wetlands are identified from observed surface moisture, the presence of specific wetland vegetation, or soil feature criteria. Efficient wetlands are defined through a given function, such as flow or pollutant regulation or biodiversity control. An analysis of areas at the limits between potential, existing, and efficient wetlands highlights land cultivated or drained in the past, which currently represents negotiating areas in which rehabilitation and other intended management actions can be implemented. PMID:16273326

Merot, Philippe; Hubert-Moy, Laurence; Gascuel-Odoux, Chantal; Clement, Bernard; Durand, Patrick; Baudry, Jacques; Thenail, Claudine

2006-02-01

264

Development and testing of an index of biotic integrity based on submersed and floating vegetation and its application to assess reclamation wetlands in Alberta’s oil sands area, Canada  

Microsoft Academic Search

We developed and tested a plant-based index of biological integrity (IBI) and used it to evaluate the existing reclamation\\u000a wetlands in Alberta’s oil sands mining region. Reclamation plans call for >15,000 ha of wetlands to be constructed, but currently,\\u000a only about 25 wetlands are of suitable age for evaluation. Reclamation wetlands are typically of the shallow open water type\\u000a and range

Rebecca C. Rooney; Suzanne E. Bayley

265

Feedbacks on Convection from an African Wetland  

NASA Astrophysics Data System (ADS)

The Niger Inland Delta in Mali floods every year late in the wet season. This is in response to rainfall many hundreds of kilometres upstream. Once flooded, the wetland produces a strong mesoscale contrast in surface fluxes. The ready availability of water for evaporation within the wetland contrasts with the strongly moisture-limited sparse vegetation in the surrounding region. This study examines the impact of the wetland on convection in the region using a satellite thermal infra-red (TIR) dataset spanning 24 years. The temporal variability in the wetland extent is quantified using cloud-free data by estimating the morning warming rate of the surface. The same TIR dataset is also used to examine the diurnal cycle of cold (<233K) cloud in the region. Compared with wet season conditions prior to inundation, there is a 54% increase in the daytime initiation of new convective storms in the region of the wetland. This feature is consistent with a hypothesised "wetland breeze" effect driven by the contrast in sensible heat flux. This can produce daytime divergence over the wetland, and strong convergence in the vicinity, particularly on the upwind side of the wetland. A signal of enhanced cloud cover is also found to propagate hundreds of kilometres westwards when the wetland is present. This is made up of increased numbers of long-lived Mesoscale Convective Systems emanating from the wetland region. The study provides observational evidence of a remote hydrological feedback. Rainfall in the Soudanian zone of West Africa flows down the Niger and its tributaries, producing a wetland of varying extent and timing depending on upstream conditions. Via the processes highlighted here, the wetland then affects both local and regional rainfall. This feedback raises the possibility that changes in upstream water use, for example through large-scale hydroelectric schemes, could have a climatic impact over a wide area.

Taylor, Christopher

2010-05-01

266

Hardwood re-sprout control in hydrologically restored Carolina Bay depression wetlands.  

SciTech Connect

Carolina bays are isolated depression wetlands located in the upper coastal plain region of the eastern Unites States. Disturbance of this wetland type has been widespread, and many sites contain one or more drainage ditches as a result of agricultural conversion. Restoration of bays is of interest because they are important habitats for rare flora and fauna species. Previous bay restoration projects have identified woody competitors in the seedbank and re-sprouting as impediments to the establishment of herbaceous wetland vegetation communities. Three bays were hydrologically restored on the Savannah River Site, SC, by plugging drainage ditches. Residual pine/hardwood stands within the bays were harvested and the vegetative response of the seedbank to the hydrologic change was monitored. A foliar herbicide approved for use in wetlands (Habitat® (Isopropylamine salt of Imazapyr)) was applied on one-half of each bay to control red maple (Acer rubrum L.), sweet gum (Liquidambar styraciflua L.), and water oak (Quercus nigra L.) sprouting. The effectiveness of the foliar herbicide was tested across a hydrologic gradient in an effort to better understand the relationship between depth and duration of flooding, the intensity of hardwood re-sprout pressure, and the need for hardwood management practices such as herbicide application.

Moser, Lee, Justin

2009-06-01

267

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)

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.

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

2013-12-01

268

Subtropical reservoir shorelines have reduced plant species and functional richness compared with adjacent riparian wetlands  

NASA Astrophysics Data System (ADS)

Dam construction has large negative effects on biodiversity in river and riparian ecosystems worldwide. This study aimed to determine whether reservoir shorelines had lower plant species diversity and functional diversity than unregulated or lightly regulated riparian wetlands and to examine the responses of plant diversity and functional traits to reservoir shoreline environmental gradients. We surveyed 146, 44, and 67 plots on reservoir shorelines and in mainstem and tributary riparian wetlands, respectively, in a subtropical river-reservoir system. Species richness, functional richness, evenness, and divergence were calculated to reflect the species and functional diversity of plant communities. Environmental factors including elevation above water level, slope, landform type, substrate, disturbance, and cover were measured. The results showed that both species and functional richness were significantly lower on reservoir shorelines than in riparian wetlands. The relative species number of clonal plants and relative cover of annual plants were both negatively related to slope and elevation. Structural equation modeling and other statistical analyses indicated that most environmental factors had significant effects on species and functional richness on reservoir shorelines but had no significant effect on functional evenness and divergence. Our findings suggest that reservoir shoreline wetlands formed by damming rivers and inundating pre-existing riparian wetlands can be a biodiversity coldspot in regulated rivers at the plot level. Topographic factors are important in determining the plant diversity and vegetation establishment on reservoir shorelines in the Yangtze River basin.

Liu, Wenzhi; Liu, Guihua; Liu, Hui; Song, Yu; Zhang, Quanfa

2013-12-01

269

Is wetland mitigation successful in Southern California?  

NASA Astrophysics Data System (ADS)

Wetlands perform many vital functions within their landscape position; they provide unique habitats for a variety of flora and fauna and they act as treatment systems for upstream natural and anthropogenic waste. California has lost an estimated 91% of its wetlands. Despite the 1989 "No Net Loss" policy and mitigation requirements by the regulatory agencies, the implemented mitigation may not be offsetting wetlands losses. The "No Net Loss" policy is likely failing for numerous reasons related to processes in the wetlands themselves and the policies governing their recovery. Of particular interest is whether these mitigation sites are performing essential wetlands functions. Specific questions include: 1) Are hydric soil conditions forming in mitigation sites; and, 2) are the water quality-related chemical transformations that occur in natural wetlands observed in mitigation sites. This study focuses on success (or lack of success) in wetlands mitigation sites in Southern California. Soil and water quality investigations were conducted in wetland mitigation sites deemed to be successful by vegetation standards. Observations of the Standard National Resource Conservation Service field indicators of reducing conditions were made to determine whether hydric soil conditions have developed in the five or more years since the implementation of mitigation plans. In addition, water quality measurements were performed at the inlet and outlet of these mitigation sites to determine whether these sites perform similar water quality transformations to natural wetlands within the same ecosystem. Water quality measurements included nutrient, trace metal, and carbon species measurements. A wetland location with minimal anthropogenic changes and similar hydrologic and vegetative features was used as a control site. All sites selected for study are within a similar ecosystem, in the interior San Diego and western Riverside Counties, in Southern California.

Cummings, D. L.; Rademacher, L. K.

2004-12-01

270

Landsat classification of coastal wetlands in Texas  

NASA Technical Reports Server (NTRS)

Through a multiagency study of Landsat imagery applications, an analysis of Texas coastal wetlands shows that five Level III categories of wetlands can be delineated using image interpretation: topographically low marshes, topographically high marshes, tidal flats, sea grass and algal flats, and vegetated dredged material. Image interpretation involves optical enlargement of 1:1,000,000 scale, Landsat transparencies to a scale of 1:125,000 and mapping on a stable film base. Digital classification procedures, resulting in 1:24,000 scale line printer maps as output, require several iterations to display welands effectively. Accuracies of 65% were achieved for all wetland categories combined.

Finley, R. J.; Mcculloch, S.; Harwood, P.

1981-01-01

271

Final Report: Five years of monitoring reconstructed freshwater tidal wetlands in the urban Anacostia River (2000-2004)  

USGS Publications Warehouse

The Anacostia River in Washington, D.C. USA consisted of over 809 hectares (2000 acres) of freshwater tidal wetlands before mandatory dredging removed most of them in the first half of the 20th century. Much of this13 kilometer (8 mile) reach was transferred to the National Park Service (NPS). Planning processes in the 1980?s envisioned a restoration (rejuvenation) of some wetlands for habitat, aesthetics, water quality and interpretative purposes. Subsequently, the U.S. Army Corps of Engineers in a cost share agreement with the District of Columbia reconstructed wetlands on NPS lands at Kenilworth - 12.5 hectares (1993), Kingman - 27 hectares (2000), a Fringe Marsh - 6.5 hectares (2003) and is currently constructing Heritage Marsh - 2.5 hectares (2005/2006). The USGS Patuxent Wildlife Research Center in conjunction with the University of Maryland Biological Engineering Department was contracted to conduct post-reconstruction monitoring (2000-2004) to document the relative success and progress of the Kingman Marsh reconstruction primarily based on vegetative response but also in conjunction with seed bank and soil characteristics. Results from Kingman were compared to Kenilworth Marsh (reconstructed 7 years prior), Dueling Creek Marsh (last best remaining freshwater tidal wetland bench in the urbanized Anacostia watershed) and Patuxent River Marsh (in a more natural adjacent watershed). Vegetation establishment was initially strong at Kingman, but declined rapidly as measured by cover, richness, diversity , etc. under grazing pressure from resident Canada geese and associated reduction in sediment levels. This decline did not occur at the other wetlands. The decline occurred despite a substantial seed bank that was sustained primarily be water born propagules. Soil development, as true for most juvenile wetlands, was slow with almost no organic matter accumulation. By 2004 only two of 7 planted species remained (mostly Peltandra virginica) at Kingman which did provide almost 50% of the approximately 1/3 total vegetation cover remaining.

Hammerschlag, R.S.; Baldwin, A.H.; Krafft, C.C.; Neff, K.P.; Paul, M.M.; Brittingham, K.D.; Rusello, K.; Hatfield, J. S.

2006-01-01

272

Wetland Bioblitz  

NSDL National Science Digital Library

This activity (located on page 3 of the PDF) is a full inquiry investigation into biodiversity of a given habitat. Groups of learners will work in pairs or small groups and conduct a bioblitz of a wetland, carefully observing, identifying and recording a list of as many plant and animal species as they can find. Data from all groups will be pooled to determine the âspecies richness,â the total number of species and to make a bar graph to compare numbers of each type of organism. Relates to linked video, DragonflyTV GPS: Wetlands.

Twin Cities Public Television, Inc.

2007-01-01

273

Wetlands ecology  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. The ERTS imagery analyzed provides approximately 2/3 coverage of the test site. Analysis was made using visual methods, density slicing, and multispectral analysis. Preliminary conclusions reached are that most, if not all, of the investigation objectives can be met. Saline and near-saline wetlands can be delineated from ERTS-1 images as the wetland-upland boundaries and land-water interface are clearly defined. Major plant species or communities such as Spartina alterniflora (high and low vigor forms), Spartina patens/Distichlis spicata, and Juncus roemarianus can be discriminated and spoil disposal areas identified.

Anderson, R. R. (principal investigator); Carter, V. L.; Mcginness, J. W., Jr.

1972-01-01

274

Effects of wetlands on quality of runoff entering lakes in the Twin Cities Metropolitan Area, Minnesota  

USGS Publications Warehouse

Four wetlands were compared with respect to their effectiveness in decreasing suspended solids and nutrient concentrations in runoff to lakes immediately downstream from the wetlands. An artificial impoundment in one of the wetlands increased settling of suspended solids. A decrease of nutrients in this wetland was probably the result of high assimilation rates associated with a dense stand of cattails. Two of the other three wetlands consist of open water and land areas, both of which contain abundant vegetation. Drainage from land areas within the wetlands may have lowered the overall effectiveness of the wetlands in decreasing sediment and nutrient concentrations. The third wetland was a constructed wetland that was ineffective in decreasing sediment or nutrient concentrations because its storage capacity was too small to prevent frequent flushing of accumulated sediment. Sediment concentrations in discharge from this wetland were as much as 22 times greater than the already high sediment concentrations in the inflow. (Author 's abstract)

Brown, R. G.

1985-01-01

275

Multi-Objective Environmental Management in Constructed Wetlands  

Microsoft Academic Search

We examined multi-objective environmental management as applied to pursuing concurrent goals of water treatment, biodiversity and promotion of recreation in constructed wetlands. A case study of a wetland established to treat landfill leachate, increase biodiversity, and promote recreation was evaluated. The study showed that attempts to combine pollution management with activities promoting biodiversity or recreation are problematic in constructed wetlands.

Michelle Benyamine; Mattias Bäckström; Per Sandén

2004-01-01

276

Regional Management Philosophy Variations within Virginia's Local Wetlands Management Program  

Microsoft Academic Search

In Virginia, local governments may establish wetlands boards to manage wetlands within their jurisdictions in accordance with general statewide standards. A survey of Virginia's local wetlands boards was conducted to assess the variation in management philosophies among boards. Both individual member philosophies and composite board philosophies indicate significant differences among some boards. The potential this creates for inconsistent decisions within

C. Hershner; N. Theberge

1986-01-01

277

Urban Wetland Resource Investigation in Jinan Urban Parks of China based on QUICKBIRD Data  

Microsoft Academic Search

Wetlands in urban are important part of environment. The state of wetland is tightly related with the security and sustainable development of ecosystem and society. This study is about wetland investigation in park of Jinan city which having been famous for its springs based on high spatial resolution remote sensing QUICKBIRD data. Through study, we conclude that :(1) the vegetation

Gao Xiang-wei; Fei Xian-yun; Zhang Zhi-guo; Qiu Li

2006-01-01

278

Methane emission from natural wetlands: Global distribution, area, and environmental characteristics of sources  

Microsoft Academic Search

A global data base of wetlands at 1 degree resolution was developed from the integration of three independent global, digital sources: (1) vegetation, (2) soil properties and (3) fractional inundation in each 1 degree cell. The integration yielded a global distribution of wetland sites identified with in situ ecological and environmental characteristics. The wetland sites were classified into five major

Elaine Matthews; Inez Fung

1987-01-01

279

Restored wetlands as filters to remove nitrogen  

Microsoft Academic Search

Four wetlands established in abandoned ricefields and dominated by Phragmites australis, Typha latifolia and Scirpus lacustris were used to improve the quality of agricultural runoff in the Ebro Delta (NE Spain) in 1993, 1994 and 1995. The wetlands were continuously flooded with water from a ricefield irrigation network during the growing season and received water with between 5 and 200

Jose A. Romero; Francisco A. Comín; Carmen García

1999-01-01

280

Differential assessment of designations of wetland status using two delineation methods.  

PubMed

Two different methods are commonly used to delineate and characterize wetlands. The U.S. Army Corps of Engineers (ACOE) delineation method uses field observation of hydrology, soils, and vegetation. The U.S. Fish and Wildlife Service's National Wetland Inventory Program (NWI) relies on remote sensing and photointerpretation. This study compared designations of wetland status at selected study sites using both methods. Twenty wetlands from the Wetland Boundaries Map of the Ausable-Boquet River Basin (created using the revised NWI method) in the Ausable River watershed in Essex and Clinton Counties, NY, were selected for this study. Sampling sites within and beyond the NWI wetland boundaries were selected. During the summers of 2008 and 2009, wetland hydrology, soils, and vegetation were examined for wetland indicators following the methods described in the ACOE delineation manual. The study shows that the two methods agree at 78 % of the sampling sites and disagree at 22 % of the sites. Ninety percent of the sampling locations within the wetland boundaries on the NWI maps were categorized as ACOE wetlands with all three ACOE wetland indicators present. A binary linear logistic regression model analyzed the relationship between the designations of the two methods. The outcome of the model indicates that 83 % of the time, the two wetland designation methods agree. When discrepancies are found, it is the presence or absence of wetland hydrology and vegetation that causes the differences in delineation. PMID:24748237

Wu, Meiyin; Kalma, Dennis; Treadwell-Steitz, Carol

2014-07-01

281

Differential Assessment of Designations of Wetland Status Using Two Delineation Methods  

NASA Astrophysics Data System (ADS)

Two different methods are commonly used to delineate and characterize wetlands. The U.S. Army Corps of Engineers (ACOE) delineation method uses field observation of hydrology, soils, and vegetation. The U.S. Fish and Wildlife Service's National Wetland Inventory Program (NWI) relies on remote sensing and photointerpretation. This study compared designations of wetland status at selected study sites using both methods. Twenty wetlands from the Wetland Boundaries Map of the Ausable-Boquet River Basin (created using the revised NWI method) in the Ausable River watershed in Essex and Clinton Counties, NY, were selected for this study. Sampling sites within and beyond the NWI wetland boundaries were selected. During the summers of 2008 and 2009, wetland hydrology, soils, and vegetation were examined for wetland indicators following the methods described in the ACOE delineation manual. The study shows that the two methods agree at 78 % of the sampling sites and disagree at 22 % of the sites. Ninety percent of the sampling locations within the wetland boundaries on the NWI maps were categorized as ACOE wetlands with all three ACOE wetland indicators present. A binary linear logistic regression model analyzed the relationship between the designations of the two methods. The outcome of the model indicates that 83 % of the time, the two wetland designation methods agree. When discrepancies are found, it is the presence or absence of wetland hydrology and vegetation that causes the differences in delineation.

Wu, Meiyin; Kalma, Dennis; Treadwell-Steitz, Carol

2014-07-01

282

COMPARISON OF CREATED AND NATURAL FRESHWATER EMERGENT WETLANDS IN CONNECTICUT  

EPA Science Inventory

Five three- to four-year old created palustrine/emergent wetland sites were compared with five nearby natural wetlands of comparable size and type. ydrologic, soil and vegetation data were compiled over a nearly two-year period (1988-90). reated sites, which were located along ma...

283

Denitrification Potentials in Restored and Natural Bottomland Hardwood Wetlands  

Microsoft Academic Search

functioning in a restored wetland when compared with its natural counterpart. We used the denitrification en- Wetland restoration projects are frequently evaluated by their hy- zyme activity (DEA) assay, a measure of the potential of drologic roles and vegetation characteristics, but their success in re- a microbial population to produce the nitrate reductase storing biogeochemical processes, such as denitrification, is

Rachael G. Hunter; Stephen P. Faulkner

2001-01-01

284

Wetland retention of lead from a hazardous waste site  

Microsoft Academic Search

Wetland sediment, vegetation, and surface water samples were collected for total Pb analyses from locations designated on the site map (Fig. 1), with the results to be used to evaluate the storage of Pb in the wetland ecosystem. The soil and sediment samples were also treated by sequential chemical extractions (SCE) to fractionate the chemical forms. The distribution of the

Shanshin Ton; Joseph J. Delfino; Howard T. Odum

1993-01-01

285

PREDICTABILITY OF PRIMARY SUCCESSIONAL WETLANDS ON PUMICE, MOUNT ST. HELENS  

Microsoft Academic Search

This study describes wetland vegetation developing on young volcanic surfaces at Mount St. Helens. Canonical correspondence analysis (CCA) revealed that habitat types reflecting moisture regimes were the best predictors of species composition and that elevation and geographical position were also significant predictors. Explained variation was significant and had increased from 19% to 31% in the five years since these wetlands

ROGER DEL MORAL

286

Responses of wetland plants to ammonia and water level  

Microsoft Academic Search

Constructed wetland systems receiving animal wastewater may enhance water quality when designed, operated, and maintained properly. In the case of wetlands designed to treat animal waste, system effectiveness may be limited by high ammonia concentrations and inundation, conditions that can adversely affect macrophytic vegetation. We conducted a 4-month greenhouse experiment to assess the impact of ammonia concentration and water level

Ernest Clarke; Andrew H. Baldwin

2002-01-01

287

Mercury in Wetlands, Adirondack Region of New York State  

Microsoft Academic Search

Wetlands play a prominent role in the cycling of mercury by harboring bacteria that transform mercury into methyl mercury, a neurotoxin, and by having high concentrations of dissolved organic carbon (DOC) that interact with mercury transport. We are measuring total mercury and methyl mercury in vegetation, soil, surface water, and ground water in the Sunday Lake watershed, in which wetlands

J. B. Yavitt; M. Kalicin; C. T. Driscoll; R. Newton; R. Munson

2001-01-01

288

Saltwater Wetlands.  

ERIC Educational Resources Information Center

Provides information about saltwater wetlands. Contains seven learning activities which deal with "making" a mud snail, plants and animals of mangroves, and the effects of tides on salt marshes. Included are reproducible handouts and worksheets for several of the activities. (TW)

Naturescope, 1986

1986-01-01

289

Coastal Wetlands.  

ERIC Educational Resources Information Center

This material includes student guide sheets, reference materials, and tape script for the audio-tutorial unit on Inland Wetlands. A set of 35mm slides and an audio tape are used with the materials. The material is designed for use with Connecticut schools, but it can be adapted to other localities. The unit materials emphasize the structure,…

Area Cooperative Educational Services, New Haven, CT. Environmental Education Center.

290

Wetland Delineation  

NSDL National Science Digital Library

Learning how to delineate a wetland using official criteria can be an enlightening experience for students and teachers. The objective of this investigation is for students to delineate the boundaries of an area in a watershed and categorize it as a wetla

Van Faasen, Carl; Peaslee, Graham; Soukhome, Jennifer; Statema, William

2009-04-01

291

What are wetlands and where are they? Part 2: Why are wetland areas and methane emissions so different among wetland-methane models and data sets?  

NASA Astrophysics Data System (ADS)

Natural wetlands are central to understanding current and future interactions between climate and carbon cycling. They are the world's largest source of methane (CH4) to the atmosphere and their distribution and emissions are sensitive to interannual and longer-term variations in climate. Field observations confirm heterogeneous responses of CH4 emissions to climate variations governed by interacting influences of vegetation, climate, and environmental characteristics that differ among wetland ecosystems. Therefore, improving models of wetland-CH4 emission requires characterizing methane-relevant information across the spectrum of wetland variability. Modeling wetland extent and type--inextricably entwined with predicting methane emissions--remains ad hoc such that improvements in both are needed to increase predictive capability especially under future climate. Wetland distributions from data sets, and simulated or prescribed in wetland-methane models, diverge widely in part because no consensus exists on what and where wetlands are, i.e., wetlands are an ill-defined modeling target. Simulated wetland-methane fluxes also vary widely in magnitude, seasonality and geography due in part to wetland definition but also because few of the ~800 published CH4 flux observations have been used to develop and verify the models. Finally, no approach exists to link methane fluxes of wetland ecosystems represented in the literature to the global distribution of those ecosystems. We diagnose underlying causes for differences in wetland areas and distributions in models and data sets, and quantify their impact on modeled methane emissions. We present initial results from a coordinated effort to codify and amplify methane-relevant wetland data and to link the large body of methane fluxes observed in wetland ecosystems to the global distribution of those ecosystems.

Matthews, E.; Bruhwiler, L.

2013-12-01

292

Application of Systems Model and Remote Sensing Images to Improve Wetland Management  

NASA Astrophysics Data System (ADS)

Wetlands are complex ecosystem that involves interaction among hydrological, ecological and spatial-temporal considerations. Also, water shortages and invasive vegetation are common problems in wetlands. The present paper has the purpose to contribute with the solution of these problems: (i) Providing a tool to wetland managers to monitor changes in vegetation cover and wetland hydrology over time; (ii) Finding a relationship between vegetation response and key hydrological attributes in wetlands and (iii) Incorporating these relationship in an optimization model to recommend water allocation and invasive vegetation control to improve wetland management. This research is applied at the Bear River Migratory Bird Refuge (the Refuge), located on the northeast side of Great Salt Lake, Utah. The Refuge constitutes one of the most important habitats for migratory birds for the Pacific Flyway of North America. Water measures and coverage vegetation collected in-situ at the Refuge has been used to calibrate and evaluate the effects on wetland plant communities to the process of flooding and drought in wetland units during different years. A MATLAB-based algorithm has been developed to process LandSat images to estimate the interaction between flooded areas and invasive vegetation cover. These interactions are embedded in a system optimization model to recommend water allocations and vegetation control actions among diked wetland units that improve wetland habitat for wildlife species. This modeling effort identify the interaction between invasive vegetation and flood wetland areas and embed those interactions in a systems model that wetland managers can use to make informed decisions about allocation of water and manage vegetation cover.

Alminagorta, O.; Torres-Rua, A. F.

2013-05-01

293

AVIRIS spectra of California wetlands  

NASA Technical Reports Server (NTRS)

Spectral data gathered by the AVIRIS from wetlands in the Suisun Bay area of California on 13 October 1987 were analyzed. Spectra representing stands of numerous vegetation types (including Sesuvium verrucosum, Scirpus acutus and Scirpus californicus, Xanthium strumarium, Cynadon dactylon, and Distichlis spicata) and soil were isolated. Despite some defects in the data, it was possible to detect vegetation features such as differences in the location of the chlorophyll red absorption maximum. Also, differences in cover type spectra were evident in other spectral regions. It was not possible to determine if the observed features represent noise, variability in canopy architecture, or chemical constituents of leaves.

Gross, Michael F.; Ustin, Susan L.; Klemas, Vytautas

1988-01-01

294

WETLAND DETECTION METHODS INVESTIGATION  

EPA Science Inventory

The purpose of this investigation was to research and document the application of remote sensing technology for wetlands detection. arious sensors and platforms are evaluated for: suitability to monitor specific wetland systems; effectiveness of detailing wetland extent and capab...

295

Our Valuable Wetlands.  

ERIC Educational Resources Information Center

Defines wetlands and lists several types of wetland habitat. Describes explorations that can be done with secondary school students including the baby boom, a food pyramid, and microenvironments. Includes a classroom poster with text on the variety of wetlands. (CW)

Texley, Juliana

1988-01-01

296

PLANT DIVERSITY, COMPOSITION, AND INVASION OF RESTORED AND NATURAL PRAIRIE POTHOLE WETLANDS: IMPLICATIONS FOR RESTORATION  

Microsoft Academic Search

Hundreds of wetlands comprising thousands of hectares have been restored in the Midwestern United States. In nearly all cases, restoration consisted of simply restoring wetland hydrology. For this reason, the success of these restorations relies on natural colonization. We compared the structure and composition of the vegetation in two types of wetlands: 10 natural wetlands and 17 five-to-seven-year-old restored wet-

Eric W. Seabloom; Arnold G. van der Valk

2003-01-01

297

Comparison of created and natural freshwater emergent wetlands in Connecticut (USA)  

Microsoft Academic Search

Five three- to four-year old created palustrine\\/emergent wetland sites were compared with five nearby natural wetlands of comparable size and type. Hydrologic, soil and vegetation data were compiled over a nearly two-year period (1988-90). Created sites, which were located along major highways, exhibited more open water, greater water depth, and greater fluctuation in water depth than natural wetlands. Typical wetland

Sheri R. Confer; William A. Niering

1992-01-01

298

Building spectral libraries for wetlands land cover classification and hyperspectral remote sensing  

Microsoft Academic Search

Recent advances in remote sensing provide opportunities to map plant species and vegetation within wetlands at management relevant scales and resolutions. Hyperspectral imagers, currently available on airborne platforms, provide increased spectral resolution over existing space-based sensors that can document detailed information on the distribution of vegetation community types, and sometimes species. Development of spectral libraries of wetland species is a

R. J. Zomer; A. Trabucco; S. L. Ustin

2009-01-01

299

Geomorphic and hydrogeologic controls on wetland distribution in the New South Wales Southern Highlands, south east Australia: prioritising natural resource management investment.  

NASA Astrophysics Data System (ADS)

Strategic investment of public funds in wetland conservation on the New South Wales (NSW) Southern Tablelands, in south east Australia, is impeded by poor understanding of the distribution of wetlands and their geomorphic and hydrogeologic setting. Appropriate investment and management is also unclear in the face of climate change. This research detailed: the spatial configuration, the hydrogeological setting, and intrinsic ecological value of the wetlands. Using this modelling, potential impact of climate change on wetlands was examined. Previous work developed a draft typology for Southern Tablelands wetlands, expanded techniques for representing spatial variability in wetland biodiversity (using generalised dissimilarity models) and explored methods of modelling wetland location through integration of hydrology, terrain and geological features. This new work integrated the mapping of the spatial distribution of a range of wetland types with a hydrogeological landscape (HGL) framework in order to better understand the movement of water through wetland landscapes. The process of HGL determination relies on the integration of a number of factors including: geology, soils, slope, regolith thickness, vegetation and climate. If the distribution of regolith materials, fractured rock and barriers to flow are characterised, an understanding of surface and sub-surface fluid pathways can be established. Contextualising a study of wetlands in an HGL framework is useful because it provides information about the biophysical controls that influence why wetlands occur in some parts of the landscape and not others. Each HGL unit spatially defines areas with similar controls on movement of water and hence similar patterns of surface and groundwater connectivity. The NSW Southern Highland landscape was divided into 34 HGL units, based on derived spatial information and field observations. Each HGL unit had an associated conceptual model, identifying potential surface water and groundwater pathways. These models were then field tested by collating and interpreting the widest possible range of biophysical parameters, in order to enhance the rigour of the models. In parallel, wetland mapping identified 4 main wetland types: upland hanging swamps, upland bogs or fens, upland freshwater lakes and riverine wetlands. The wetland types were linked with their contemporary geomorphic setting and then integrated with the HGL framework enabling identification of the wetland 'plumbing' context. These integrated wetland HGL units were evaluated with respect to the NSW Climate Impact Profile for the south east NSW region (min. T increase 1-3°C; max T. increase 2-3°C; rainfall 20-50% summer increase, 20-50% winter decrease; 10-20% evaporation increase). This scenario-based modelling provides an accurate measure of sensitivity of the wetlands to change and allows evaluation of the capacity for a wetland to adapt to change. If landscape variation, the biophysical character of wetlands, the hydrogeological context, and hence the influences of surface and groundwater systems are understood, then we can identify NRM hazards and prioritise wetland management. The premise is that if we understand the natural processes that result in particular outcomes in a landscape, then strategic decisions about whether to intervene, how to intervene, or whether it is worth doing so, can be made.

Cowood, Alie; Moore, Leah

2014-05-01

300

Issues related to wetland delineation of a Texas, USA bottomland hardwood forest  

Microsoft Academic Search

Methods of wetland delineation require presence of three parameters: hydric soils, wetland hydrology, and hydrophytic vegetation.\\u000a Currently accepted methods to assess these parameters often have inconsistent agreement among the parameters in bottomland\\u000a hardwood forested wetlands. This study characterized soil morphology, hydrology, and vegetative composition in a bottomland\\u000a hardwood forest in east Texas, USA. Alternate methods for assessment of the three

Janet C. Dewey; Stephen H. Schoenholtz; James P. Shepard; Michael G. Messina

2006-01-01

301

Hydrologic considerations in defining isolated wetlands  

USGS Publications Warehouse

Wetlands that are not connected by streams to other surface-water bodies are considered to be isolated. Although the definition is based on surface-water connections to other water bodies, isolated wetlands commonly are integral parts of extensive ground-water flow systems, and isolated wetlands can spill over their surface divides into adjacent surface-water bodies during periods of abundant precipitation and high water levels. Thus, characteristics of ground-water flow and atmospheric-water flow affect the isolation of wetlands. In general, the degree that isolated wetlands are connected through the ground-water system to other surface-water bodies depends to a large extent on the rate that ground water moves and the rate that hydrologic stresses can be transmitted through the ground-water system. Water that seeps from an isolated wetland into a gravel aquifer can travel many kilometers through the ground-water system in one year. In contrast, water that seeps from an isolated wetland into a clayey or silty substrate may travel less than one meter in one year. For wetlands that can spill over their surface watersheds during periods of wet climate conditions, their isolation is related to the height to a spill elevation above normal wetland water level and the recurrence interval of various magnitudes of precipitation. The concepts presented in this paper indicate that the entire hydrologic system needs to be considered in establishing a definition of hydrologic isolation.

Winter, T. C.; LaBaugh, J. W.

2003-01-01

302

Artificial Wetlands  

NSDL National Science Digital Library

Golf courses are known as places of recreation. But some of them could someday double as water treatment facilities. Water hazards on golf courses can be used to control environmental hazards. That's according to Purdue University soil microbiologist Ron Turco. He says the artificial wetlands can also control flooding in surrounding communities, by collecting excess water. This Science Update looks at the research, which leads to these findings and offers links to other resources for further inquiry.

American Association for the Advancement of Science (;)

2005-04-11

303

Primary production control of methane emission from wetlands  

NASA Technical Reports Server (NTRS)

Based on simultaneous measurements of CO2 and CH4 exchange in wetlands extending from subarctic peatlands to subtropical marshes, a positive correlation between CH4 emission and net ecosystem production is reported. It is suggested that net ecosystem production is a master variable integrating many factors which control CH4 emission in vegetated wetlands. It is found that about 3 percent of the daily net ecosystem production is emitted back to the atmosphere as CH4. With projected stimulation of primary production and soil microbial activity in wetlands associated with elevated atmospheric CO2 concentration, the potential for increasing CH4 emission from inundated wetlands, further enhancing the greenhouse effect, is examined.

Whiting, G. J.; Chanton, J. P.

1993-01-01

304

Emissions of sulfur gases from wetlands  

NASA Technical Reports Server (NTRS)

Data on the emissions of sulfur gases from marine and freshwater wetlands are summarized with respect to wetland vegetation type and possible formation mechanisms. The current data base is largest for salt marshes inhabited by Spartina alterniflora. Both dimethyl sulfide (DMS) and hydrogen sulfide (H2S) dominate emissions from salt marshes, with lesser quantities of methyl mercaptan (MeSH), carbonyl sulfide (COS), carbon disulfide (CS2) and dimethyl disulfide (DMDS) being emitted. High emission rates of DMS are associated with vegetation that produces the DMS precursor dimethylsulfonionpropionate (DMSP). Although large quantities of H2S are produced in marshes, only a small percentage escapes to the atmosphere. High latitude marshes emit less sulfur gases than temperate ones, but DMS still dominates. Mangrove-inhabited wetlands also emit less sulfur than temperate S. alterniflora marshes. Few data are available on sulfur gas emissions from freshwater wetlands. In most instances, sulfur emissions from temperate freshwater sites are low. However, some temperate and subtropical freshwater sites are similar in magnitude to those from marine wetlands which do not contain vegetation that produces DMSP. Emissions are low in Alaskan tundra but may be considerably higher in some bogs and fens.

Hines, Mark E.

1992-01-01

305

Effect of earthworm Eisenia fetida and wetland plants on nitrification and denitrification potentials in vertical flow constructed wetland.  

PubMed

The response of nitrification potentials, denitrification potentials, and N removal efficiency to the introduction of earthworms and wetland plants in a vertical flow constructed wetland system was investigated. Addition of earthworms increased nitrification and denitrification potentials of substrate in non-vegetated constructed wetland by 236% and 8%, respectively; it increased nitrification and denitrification potentials in rhizosphere in vegetated constructed wetland (Phragmites austrail, Typha augustifolia and Canna indica), 105% and 5%, 187% and 12%, and 268% and 15% respectively. Denitrification potentials in rhizosphere of three wetland plants were not significantly different, but nitrification potentials in rhizosphere followed the order of C. indica>T. augustifolia>P. australis when addition of earthworms into constructed wetland. Addition of earthworms to the vegetated constructed significantly increased the total number of bacteria and fungi of substrates (P<0.05). The total number of bacteria was significantly correlated with nitrification potentials (r=913, P<0.01) and denitrification potentials (r=840, P<0.01), respectively. The N concentration of stems and leaves of C. indica were significantly higher in the constructed wetland with earthworms (P<0.05). Earthworms had greater impact on nitrification potentials than denitrification potentials. The removal efficiency of N was improved via stimulated nitrification potentials by earthworms and higher N uptake by wetland plants. PMID:23591133

Xu, Defu; Li, Yingxue; Howard, Alan; Guan, Yidong

2013-06-01

306

Wetland resources investigation based on 3S technology  

NASA Astrophysics Data System (ADS)

Wetland is a special ecosystem between land and water . It can provide massive foods, raw material, water resources and habitat for human being, animals and plants, Wetlands are so important that wetlands' development, management and protection have become the focus of public attention ."3S" integration technology was applied to investigate wetland resources in Shandong Province ,the investigation is based on remote sensing(RS) information, combining wetlandrelated geographic information system(GIS) data concerning existing geology, hydrology, land, lakes, rivers, oceans and environmental protection, using the Global Positioning System (GPS) to determine location accurately and conveniently , as well as multi-source information to demonstrate each other based on "3S" integration technology. In addition, the remote sensing(RS) interpretation shall be perfected by combining house interpretation with field survey and combining interpretation results with known data.By contrasting various types of wetland resources with the TM, ETM, SPOT image and combining with the various types of information, remote sensing interpretation symbols of various types of wetland resources are established respectively. According to the interpretation symbols, we systematically interpret the wetland resources of Shandong Province. In accordance with the purpose of different work, we interpret the image of 1987, 1996 and 2000. Finally, various interpretation results are processed by computer scanning, Vectored, projection transformation and image mosaic, wetland resources distribution map is worked out and wetland resources database of Shandong Province is established in succession. Through the investigation, wetland resource in Shandong province can be divided into 4 major categories and 17 sub-categories. we have ascertained the range and area of each category as well as their present utilization status.. By investigating and calculating, the total area of wetland in Shandong Province is 1,712,200 hm2,which accounts for 7.58% of the total area of land in Shandong Province (not including the wetland in the shallow waters along the coast). Among them, area of river wetland is 286,746 hm2, area of lakes wetland is143,490 hm2, area of reservoir and pond wetland is 118,693 hm2, area of offshore and coastal wetland is 994,100 hm2, and area of other wetland is 169,171 hm2. On the basis of this, we can analyze the dynamic changes trend and the reasons: steady degenerating for natural wetlands, increasing year by year for artificial wetland, and the distribution pattern takes shape that the existing natural wetlands are being protected and the increase of new artificial wetlands is in conformity with the social development, so the situation of the wetland resources is developing towards a virtuous circle direction.

Lin, Hui; Jing, Haitao; Zhang, Lianpeng

2008-10-01

307

PREDICTABILITY OF PRIMARY SUCCESSIONAL WETLANDS ON PUMICE  

Microsoft Academic Search

ABSTRACT This study describes wetland vegetation developing on young volcanic surfaces at Mount St. Helens. Canonical correspondence analysis (CCA) revealed that habitat types reflecting moisture regimes were the best predictors of species ,composition ,and that elevation and geographical position were also significant predictors. Explained variation was significant and had increased from 19% to 31% in the five years since these

Del Moral; Primary Successional Wetland; Mount St. Helens; Roger Del Moral

308

Wetlands of Central America  

Microsoft Academic Search

The wetlands of seven Central American countries – Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, and Panamá – are reviewed. The region's wetlands are classified into five systems: marine, estuarine, riverine, lacustrine, and palustrine. At a minimum, wetlands cover ˜40,000 km2 (˜8%) of the land area of Central America. These wetlands support high levels of biological diversity, especially of

Aaron M. Ellison

2004-01-01

309

Physiological Ecology and Ecohydrology of Coastal Forested Wetlands  

USGS Publications Warehouse

The form, function, and productivity of wetland communities are influenced strongly by the hydrologic regime of an area. Wetland ecosystems persist by depending upon surpluses of rainfall, evapotranspiration, soil moisture, and frequency and amplitude of water-level fluctuations. Yet, wetland vegetation can also influence ecosystem water economy through conservative water- and carbon-use strategies at several organizational scales. Scientists have described leaf-level water-use efficiency in coastal mangrove forests as being among the highest of any ecosystem. These forested wetlands occur in intertidal areas and often persist under flooded saline conditions. Are these same strategies used by other types of coastal forested wetlands? Do conservative water-use strategies reflect a consequence of salt balance more than efficiency in water use per se? At what organizational scales do these strategies manifest? These are just a few of the questions being answered by physiological and landscape ecologists at the U.S. Geological Survey National Wetlands Research Center (NWRC).

Krauss, Ken W.

2007-01-01

310

Exploring Microbial Iron Oxidation in Wetland Soils  

NASA Astrophysics Data System (ADS)

Iron is one of the most abundant elements on earth and is essential for life. Because of its importance, iron cycling and its interaction with other chemical and microbial processes has been the focus of many studies. Iron-oxidizing bacteria (FeOB) have been detected in a wide variety of environments. Among those is the rhizosphere of wetland plants roots which release oxygen into the soil creating suboxic conditions required by these organisms. It has been reported that in these rhizosphere microbial iron oxidation proceeds up to four orders of magnitude faster than strictly abiotic oxidation. On the roots of these wetland plants iron plaques are formed by microbial iron oxidation which are involved in the sequestering of heavy metals as well organic pollutants, which of great environmental significance.Despite their important role being catalysts of iron-cycling in wetland environments, little is known about the diversity and distribution of iron-oxidizing bacteria in various environments. This study aimed at developing a PCR-DGGE assay enabling the detection of iron oxidizers in wetland habitats. Gradient tubes were used to enrich iron-oxidizing bacteria. From these enrichments, a clone library was established based on the almost complete 16s rRNA gene using the universal bacterial primers 27f and 1492r. This clone library consisted of mainly ?- and β-Proteobacteria, among which two major clusters were closely related to Gallionella spp. Specific probes and primers were developed on the basis of this 16S rRNA gene clone library. The newly designed Gallionella-specific 16S rRNA gene primer set 122f/998r was applied to community DNA obtained from three contrasting wetland environments, and the PCR products were used in denaturing gradient gel electrophoresis (DGGE) analysis. A second 16S rRNA gene clone library was constructed using the PCR products from one of our sampling sites amplified with the newly developed primer set 122f/998r. The cloned 16S rRNA gene sequences all represented novel culturable iron oxidizers most closely related to Gallionella spp. Based on their nucleotide sequences four groups could be identified, which were comparable to the DGGE banding pattern obtained before with the gradient tubes enrichments. The above mentioned nested PCR-DGGE method was used to study the distribution and community composition of Gallionella-like iron-oxidizing bacteria under the influence of plants species, soil depth, as well as season. Soil samples from Appels, Belgium, an intertidal, freshwater marsh known to hold intensive iron cycling, were taken from 5 different vegetation types in April, July and October 2007. Soil cores were sliced at 1-cm intervals and subjected to chemical and molecular analyses. The DGGE patterns showed that the community of iron-oxidizing bacteria differed with vegetation type, and sediment depth. Samples taken in autumn held lower diversity in Gallionella-related iron oxidizers than those sampled in spring and summer.

Wang, J.; Muyzer, G.; Bodelier, P. L. E.; den Oudsten, F.; Laanbroek, H. J.

2009-04-01

311

Zambia Wetland  

... and are influenced by terrain, vegetation structure, soil type and soil moisture content. Wet surfaces or areas with standing water ... NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed ...

2013-04-16

312

Riparian Vegetation Response to the March 2008 Short-Duration, High-Flow Experiment-Implications of Timing and Frequency of Flood Disturbance on Nonnative Plant Establishment Along the Colorado River Below Glen Canyon Dam  

USGS Publications Warehouse

Riparian plant communities exhibit various levels of diversity and richness. These communities are affected by flooding and are vulnerable to colonization by nonnative species. Since 1996, a series of three high-flow experiments (HFE), or water releases designed to mimic natural seasonal flooding, have been conducted at Glen Canyon Dam, Ariz., primarily to determine the effectiveness of using high flows to conserve sediment, a limited resource. These experiments also provide opportunities to examine the susceptibility of riparian plant communities to nonnative species invasions. The third and most recent HFE was conducted from March 5 to 9, 2008, and scientists with the U.S. Geological Survey's Grand Canyon Monitoring and Research Center examined the effects of high flows on riparian vegetation as part of the overall experiment. Total plant species richness, nonnative species richness, percent plant cover, percent organic matter, and total carbon measured from sediment samples were compared for Grand Canyon riparian vegetation zones immediately following the HFE and 6 months later. These comparisons were used to determine if susceptibility to nonnative species establishment varied among riparian vegetation zones and if the timing of the HFE affected nonnative plant establishment success. The 2008 HFE primarily buried vegetation rather than scouring it. Percent nonnative cover did not differ among riparian vegetation zones; however, in the river corridor affected by Glen Canyon Dam operations, nonnative species richness showed significant variation. For example, species richness was significantly greater immediately after and 6 months following the HFE in the hydrologic zone farthest away from the shoreline, the area that represents the oldest riparian zone within the post-dam riparian area. In areas closer to the river channel, tamarisk (Tamarix ramosissima X chinensis) seedling establishment occurred (<2 percent cover) in 2008 but not to the extent reported in either 2000, a year when experimental summer flows coincided with tamarisk seed production, or in 1986, a year following several years of sustained flooding. The results from the 2008 HFE suggest that riparian vegetation zones subject to intermittent disturbance and near the river under normal dam operations are more susceptible to nonnative species introductions following a disturbance. This study also finds that the timing of an HFE affects the types of species that can become established. For example, HFEs conducted in March are associated with reduced tamarisk seedling establishment compared to disturbances later in the season. Additionally, early season, short-duration flooding that results in vegetation burial may favor clonal species. Along the Colorado River many of these clonal species are native; these species include arrowweed (Pluchea sericea), coyote willow (Salix exigua), and rivercane (Phragmites australis).

Ralston, Barbara E.

2010-01-01

313

Five years (2000-2004) of post-reconstruction monitoring of freshwater tidal wetlands in the urban Anacostia River, Washington, D.C. USA  

USGS Publications Warehouse

The Anacostia River in Washington, D.C. USA consisted of over 809 hectares (2000 acres) of freshwater tidal wetlands before mandatory dredging removed most of them in the first half of the 20th century. Much of this13 kilometer (8 mile) reach was transferred to the National Park Service (NPS). Planning processes in the 1980's envisioned a restoration (rejuvenation) of some wetlands for habitat, aesthetics, water quality and interpretative purposes. Subsequently, the U.S. Army Corps of Engineers in a cost share agreement with the District of Columbia reconstructed wetlands on NPS lands at Kenilworth - 12.5 hectares (1993), Kingman 27 hectares (2000), a Fringe Marsh - 6.5 hectares (2003) and is currently constructing Heritage Marsh - 2.5 hectares (2005/2006). The USGS Patuxent Wildlife Research Center in conjunction with the University of Maryland Biological Engineering Department was contracted to conduct post-reconstruction monitoring (2000-2004) to document the relative success and progress of the Kingman Marsh reconstruction primarily based on vegetative response but also in conjunction with seed bank and soil characteristics. Results from Kingman were compared to Kenilworth Marsh (reconstructed 7 years prior), Dueling Creek Marsh (last best remaining freshwater tidal wetland bench in the urbanized Anacostia watershed) and Patuxent River Marsh (in a more natural adjacent watershed). Vegetation establishment was initially strong at Kingman, but declined rapidly as measured by cover, richness, diversity, etc. under grazing pressure from resident Canada geese and associated reduction in sediment levels. This decline did not occur at the other wetlands. The decline occurred despite a substantial seed bank that was sustained primarily be water born propagules. Soil development, as true for most juvenile wetlands, was slow with almost no organic matter accumulation. By 2004 only two of 7 planted species remained (mostly Peltandra virginica) at Kingman which did provide almost 50% of the approximately 1/3 total vegetation cover remaining.

Hammerschlag, D.; Krafft, C.

2006-01-01

314

Study of Panjin wetlands along Bohai coast: (I) the information system of wetlands based on 3S technique  

NASA Astrophysics Data System (ADS)

Based on previous studies on Panjin wetlands along the coast of the Bohai Sea, this paper adopts RS, GIS and GPS techniques and establishes the information system for Panjin wetlands. The system involves many functions, such as identification and classification of wetlands, calculation of the area of wetlands and storage of the information of the wetland management. Moreover, our study indicates that remote sensing technique is a useful tool for great macrography, speediness and accuracy to carry out the extraction, analysis, management and handling of information together with geography information system, which has prospective applications in similar kinds of research.

Wang, Tieliang; Zhou, Linfei; Yang, Peiqi; Zhao, Bo

2008-11-01

315

Understanding wetlands  

NSDL National Science Digital Library

Students collect soil cores (~12 inches) from one or more wetlands, describe the color and other physical features they can observe. Section each core according to grain size or color, weigh each section, dry in oven for 24 hours (can use microwave if the soil is fairly sandy). Use sieve machine to sieve each section and weigh each size fraction (sand...coarse, medium, fine, very fine, silt/clay). The activity gives students practice in making good observation, measuring, interpreting and analyzing data, and to propose a probable source region for the soil materials. Have students plo Has minimal/no quantitative component

Isiorho, Solomon

316

Wetlands Transects  

NSDL National Science Digital Library

Field work on local sites has many benefits. Often students are surprised to discover thriving ecosystems in the most familiar and ordinary places. In this activity students will lay out transect lines beside a local stream or river. There they will record species of plants and insects living around the stream. By doing so, students will learn how to use transect sampling techniques, use a variety of methods to sample species, and compare species diversity and density between parallel transects. This activity helps students gain experience in problem-solving, scientific processes, and communication and introduces the terms transect, wetland indicator plants, diversity, and sampling.

317

Pipeline corridors through wetlands -- Impacts on plant communities: Norris Brook Crossing Peabody, Massachusetts  

SciTech Connect

The goal of the Gas Research Institute Wetland Corridors Program is to document impacts of existing pipelines on the wetlands they traverse. To accomplish this goal, 12 existing wetland crossings were surveyed. These sites varied in elapsed time since pipeline construction, wetland type, pipeline installation techniques, and right-of-way (ROW) management practices. This report presents the results of a survey conducted August 17--19, 1992, at the Norris Brook crossing in the town of Peabody, Essex County, Massachusetts. The pipeline at this site was installed during September and October 1990. A backhoe was used to install the pipeline. The pipe was assembled on the adjacent upland and slid into the trench, after which the backhoe was used again to fill the trench and cover the pipeline. Within two years after pipeline construction, a dense vegetative community, composed predominantly of native perennial species, had become established on the ROW. Compared with adjacent natural areas undisturbed by pipeline installation, there was an increase in purple loosestrife and cattail within the ROW, while large woody species were excluded from the ROW. As a result of the ROW`s presence, habitat diversity, edge-type habitat, and species diversity increased within the site. Crooked-stem aster, Aster prenanthoides (a species on the Massasschusetts list of plants of special concern), occurred in low numbers in the adjacent natural areas and had reinvaded the ROW in low numbers.

Shem, L.M.; Van Dyke, G.D.; Zimmerman, R.E. [Argonne National Lab., IL (United States)

1994-12-01

318

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

Microsoft Academic Search

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

Chris Wright; Alisa Gallant

2007-01-01

319

Does Facilitation of Faunal Recruitment Benefit Ecosystem Restoration? An Experimental Study of Invertebrate Assemblages in Wetland Mesocosms  

Microsoft Academic Search

We used wetland mesocosms (1) to experimentally as- sess whether inoculating a restored wetland site with vegetation\\/sediment plugs from a natural wetland would alter the development of invertebrate commu- nities relative to unaided controls and (2) to determine if stocking of a poor invertebrate colonizer could fur- ther modify community development beyond that due to simple inoculation. After filling mesocosms

Valerie J. Brady; Bradley J. Cardinale; Joseph P. Gathman; Thomas M. Burton

2002-01-01

320

Losing function through wetland mitigation in central Pennsylvania, USA.  

PubMed

In the United States, the Clean Water Act requires mitigation for wetlands that are negatively impacted by dredging and filling activities. During the mitigation process, there generally is little effort to assess function for mitigation sites and function is usually inferred based on vegetative cover and acreage. In our study, hydrogeomorphic (HGM) functional assessment models were used to compare predicted and potential levels of functional capacity in created and natural reference wetlands. HGM models assess potential function by measurement of a suite of structural variables and these modeled functions can then be compared to those in natural, reference wetlands. The created wetlands were built in a floodplain setting of a valley in central Pennsylvania to replace natural ridge-side slope wetlands. Functional assessment models indicated that the created sites differed significantly from natural wetlands that represented the impacted sites for seven of the ten functions assessed. This was expected because the created wetlands were located in a different geomorphic setting than the impacted sites, which would affect the type and degree of functions that occur. However, functional differences were still observed when the created sites were compared with a second set of reference wetlands that were located in a similar geomorphic setting (floodplain). Most of the differences observed in both comparisons were related to unnatural hydrologic regimes and to the characteristics of the surrounding landscape. As a result, the created wetlands are not fulfilling the criteria for successful wetland mitigation. PMID:17265110

Hoeltje, S M; Cole, C A

2007-03-01

321

Springs as Ecosystems: Clarifying Groundwater Dependence and Wetland Status (Invited)  

NASA Astrophysics Data System (ADS)

Springs ecosystems are among the most productive, biologically diverse and culturally important ecosystems on Earth. Net annual productivity of some springs exceeds 5 kg/m^2/yr. Springs support an estimated 19% of the endangered species and numerous rare taxa in the United States. Springs serve as keystone ecosystems in arid regions, and as cornerstones of indigenous cultural well-being, history, economics, and aesthetics. Despite their significance, the ecosystem ecology and stewardship of springs have received scant scientific and public attention, resulting in loss or impairment of 50-90% of the springs in many regions, both arid and temperate. Six reasons contribute to the lack of attention to springs. Springs are poorly mapped because: 1) their generally small size is less than the pixel area of most remote sensing analyses and they are overlooked; and 2) springs detection is often limited by emergence on cliff faces, beneath heavy vegetation cover, or under water. In addition, 3) high levels of ecosystem complexity at springs require multidisciplinary team approaches for inventory, assessment, and research, but collaboration between the fields of hydrogeology and ecology has been limited. 4) Protectionism by land owners and organizations that manage springs limits the availability information, preventing regional assessment of status. 5) Prior to recent efforts, the absence of a descriptive lexicon of springs types has limited discussion about variation in ecological characteristics and processes. 6) Neither regarded entirely as groundwater or as surface water, springs fall 'between jurisdictional cracks' and are not subject to clear legal and regulatory oversight. With regards to the latter point, two jurisdictional phrases have reduced scientific understanding and stewardship of springs ecosystems: 'jurisdictional wetlands' and 'groundwater-dependent ecosystems' (GDEs). Most springs have insufficient monitoring data to establish perenniality or the range of natural variation in flow, and many of the 12 springs types do not develop hydric soils or wetland vegetation. These factors and their normally small size preclude springs as jurisdictional wetlands by U.S. Environmental Protection Agency and Army Corps of Engineers criteria. Helocrenes (springfed wet meadows, cienegas, and some fens) are considered as wetlands, but the other 11 types of terrestrial springs often are not. The use of the phrase 'GDE' applies to any aquatic ecosystem supported by groundwater, and the utility of this phrase as a descriptor of springs is diluted by its application to all subterranean and surface aquatic habitats. The failure to recognize the importance of springs ecosystems has become a quiet but global crisis, in part due to inappropriate conceptual understanding and poor jurisdictional terminology. We clarify relationships between these concepts and terms to establish effective, consistent monitoring, assessment, restoration, management, and monitoring goals and protocols for improving springs stewardship.

Stevens, L.; Springer, A. E.; Ledbetter, J. D.

2013-12-01

322

A compound method for automatically extracting plateau wetlands from satellite imagery  

NASA Astrophysics Data System (ADS)

Timely information on wetland distribution can be effectively acquired by means of remote sensing. A Landsat TM image recorded on 17 July 2009 (row: 36; column: 134) at a spatial resolution of 30 m was used to map wetlands in Maduo County of northwestern Qinghai Province with a combined method of thresholding, tassled cap transformation and vegetation indexing. The wetlands found in the study area fall into two broad types, I and II. Type I wetlands are characterized by a close proximity to water bodies. Type II wetlands are characterized by a higher vegetative component that obscures their morphology. Thresholding was used to map type I wetlands from TM5. Tasseled Cap transformation was used to map type II wetlands. With the assistance of NDVI, snow was then removed, leaving only grassland and type II wetland to be separate. Type 1 wetland was mapped at 832 km2. The second type of wetland was mapped at 422.97 km2. A total of 1254.97 km2 wetlands were mapped. Comparison with the raw color composite of the same image reveals that the mapping has been accomplished quite accuracy. More research will be undertaken to compare the classified results with those obtained with supervised and unsupervised results. Both thresholding and Tassled cap transformation are found to be effective at detecting different types of wetlands in the plateau environment

Li, Huan; Gao, Jay

2012-10-01

323

FORT BELKNAP WETLANDS MANAGEMENT PROGRAM  

EPA Science Inventory

The product activities include: 1) Conducting wetland inventories and wetland assessments in the Milk River Watershed. This will include wetland delineations, and the collection of vascular plants and plant identification. Currently there is no baseline data of wetland activite...

324

Forms of organic phosphorus in wetland soils  

NASA Astrophysics Data System (ADS)

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 ?g P gvegetation 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.

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

2014-06-01

325

Protect Your Wetlands  

NSDL National Science Digital Library

This resource explains how to create a wetlands awareness program and how to protect wetlands through the regulatory process. In addition, it explains the federal programs designed to protect wetlands and how to procure state and local protection for wetlands. It is part of a module that aims to help students get to know the complexities of wetlands, discover wildlife, enjoy the experience of being outdoors, and learn how necessary wetlands are to the health of our environment. For educators and their middle school students, it suggests ways to study wetland characteristics, why wetlands are important, and how students and teachers can help protect a local wetland in any part of the country. An associated set of activities is also available.

326

Impacts of water development on aquatic macroinvertebrates, amphibians, and plants in wetlands of a semi-arid landscape  

USGS Publications Warehouse

We compared the macroinvertebrate and amphibian communities of 12 excavated and 12 natural wetlands in western North Dakota, USA, to assess the effects of artificially lengthened hydroperiods on the biotic communities of wetlands in this semi-arid region. Excavated wetlands were largely unvegetated or contained submergent and deep-marsh plant species. The natural wetlands had two well-defined vegetative zones populated by plant species typical of wet meadows and shallow marshes. Excavated wetlands had a richer aquatic macroinvertebrate community that included several predatory taxa not found in natural wetlands. Taxa adapted to the short hydroperiods of seasonal wetlands were largely absent from excavated wetlands. The amphibian community of natural and excavated wetlands included the boreal chorus frog, northern leopard frog, plains spadefoot, Woodhouse's toad, and tiger salamander. The plains spadefoot occurred only in natural wetlands while tiger salamanders occurred in all 12 excavated wetlands and only one natural wetland. Boreal chorus frogs and northern leopard frogs were present in both wetland types; however, they successfully reproduced only in wetlands lacking tiger salamanders. Artificially extending the hydroperiod of wetlands by excavation has greatly influenced the composition of native biotic communities adapted to the naturally short hydroperiods of wetlands in this semi-arid region. The compositional change of the biotic communities can be related to hydrological changes and biotic interactions, especially predation, related to excavation.

Euliss, N. H., Jr.; Mushet, D. M.

2004-01-01

327

Establishment of a Food-Processing Department at Jampro, Jamaica. Technical Report: The Agro-Industry System of Fruits and Vegetables. Analysis and Recommendations.  

National Technical Information Service (NTIS)

The expert report on the agro-industry system of fruit and vegetables in Jamaica covers: (1) project background; (2) regulation by short-term, atomized markets; variability in levels of prices, mainly as results of seasonal differences; marketing; (3) glo...

D. Perraud

1991-01-01

328

How the Energy and Water Development Appropriations Act of 1993 has impacted the constitutional dynamics of federal wetlands delineation and regulation  

SciTech Connect

A reliable source of specific criteria for recognizing a wetland, as defined for regulatory purposes would be valuable. In 1987 the Army Corps of Engineers developed a technical manual for identifying wetlands (1987 Wetlands Manual). An interagency manual (1989 Wetlands Manual) was later developed. This manual has been used to identify wetlands according to three evidentiary factors: vegetation, hydrology, and soil. This paper addresses the development of criteria to delineate wetlands, and describes some of the logic used by federal courts to uphold the limited constitutional use of the 1989 Wetlands Manual.

Johnson, J.J.S.; Logan, W.L.

1995-12-31

329

Canada's Wetland Habitats  

NSDL National Science Digital Library

This detailed information on the wetlands of Canada begins with an introduction defining wetlands and their locations along with details about their value and human and biological threats. The second chapter provides a summary of the Canadian wetland classification system with descriptions on the five classes of wetlands which are bogs, fens, swamps, marshes, and shallow open water. Chapter three gives an opportunity to explore the seven major wetland regions in Canada, which are classified as arctic, subarctic, boreal, prairie, temperate, oceanic, and mountain. The Ramsar internatioinal convention on wetlands and Canadian Ramsar sites are outlined in the last chapter.

330

Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan. Topical report, October 1990--August 1992  

SciTech Connect

This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth wetland sites mapped Lenawee soils were selected in Midland County, Michigan: Site 1, a younger stand subjected to recent selective logging, and Site 2, a more mature stand. The collection of ecological data to analyze plant succession on the right-of-way (ROW) and the effects of the developing ROW plant communities on adjacent forest communities was initiated in 1989. Cover class estimates were made for understory and ROW plant species on the basis of 1 {times} 1{minus}m quadrats. Individual stem diameters and species counts were recorded for overstory plants in 10{minus}m quadrats. Although long-term studies have not been completed, firm baseline data were established for comparative analyses with future sampling. Current data indicate that vegetation became well-established on the ROW within one year and subsequently increased in coverage. About 65% of the species were wetland indicators, and the dominants included seeded and natural invading species; nevertheless, some elements of the original flora regenerated and persist. The plants of the ecotone understories of both sites changed from their original composition as a result of the installation of the gas pipeline. Although some forest species persist at both sites, the ecotone of Site I was influenced more by the seeded species, whereas the natural invaders were more important at Site 2.

Rastorfer, J.R. [Chicago State Univ., IL (United States). Dept. of Biological Sciences; Van Dyke, G.D.; Zellmer, S.D.; Wilkey, P.L. [Argonne National Lab., IL (United States)

1995-04-01

331

Experiences with constructed wetland systems in Korea  

NASA Astrophysics Data System (ADS)

In spite of the low temperature during the winter season and the high land environment, the wetland treatment system is gaining popularity in Korea because of its lower construction cost and simplicity in operation and maintenance. Many different types of wetland treatment systems have been built during the last 10 years, among which the free water surface wetland has been predominant. Most of the large-scale systems are government projects for improving the water quality of the streams flowing into the estuary dikes and reservoirs. The covering plants used in this system are different in different areas but cattails and reeds or their combinations are common. Constructed wetlands in Korea can be characterized by their shallow depths and short hydraulic residence times. There is no established flow pattern and configuration rules for constructing wetlands, but many efforts have been made with a view to improving their ecological function. Flow control is the most difficult problem in designing a riverbed or riparian wetland. There have been scores of flow rate control devices developed for wetlands, but none of them guarantee wetlands’ safety against flooding. In earlier wetland construction, the building materials were mainly soil. Recently, strong and durable building materials such as rocks, gravel beds, concrete and steel are used at vulnerable places to protect them from erosion. Our investigation indicated that the wetland system would be an appropriate technology because it is not only cheaper to construct, but also requires less maintenance work. However, we suffer from the reduced effectiveness in performance during the winter. We need to evaluate the partial treatment accomplished during 6 to 7 months per year.

Youngchul, Kim; Gilson, Hwang; Jin-Woo, Lee; Je-Chul, Park; Dong-Sup, Kim; Min-Gi, Kang; in-Soung, Chang

2006-10-01

332

Constructed wetland design: The first generation  

SciTech Connect

A recent inventory, sponsored by the U.S. EPA Risk Reduction Engineering Laboratory in Cincinnati, OH documented the presence of over 150 constructed wetlands systems in the U.S., for the treatment of municipal and industrial wastewaters. The total flow received by these systems is about 400,000 cu m/d (100 mgd). This paper summarizes some of the results from the inventory, including: location, type, vegetation, design flow, loading rates, and costs for wetland systems where this information was available. The paper also discusses some 'lessons learned' from site visits to several of the systems.

Reed, S.C.; Brown, D.S.

1992-01-01

333

Constructing a Baseline Model of Alpine Wetlands of the Uinta Mountains, Utah, USA  

NASA Astrophysics Data System (ADS)

Alpine wetlands of the Uinta Mountains, northeastern Utah, contain a variety of groundwater-dependent ecosystems. Unlike their counterparts in other areas of the Rocky Mountains, these systems have been relatively unstudied. The Reader Lakes area on the southern slope of the range was selected for detailed study because of its variety of wetland plant communities, homogenous bedrock geology, and minimal human impact. The primary goal of this interdisciplinary study is to establish the functional links between the geomorphology and hydrogeology of these high mountain wetlands and their constituent plant communities. In addition to traditional field studies and water chemistry, geospatial technologies are being used to organize and analyze both field data (water chemistry and wetland vegetation) and archived multispectral imagery (2006 NAIP images). The hydrology of these wetlands is dominated by groundwater discharge and their surface is dominated by string-and-flark morphology of various spatial scales, making these montane wetlands classic patterned fens. The drainage basin is organized into a series of large-scale stair-stepping wetlands, bounded by glacial moraines at their lower end. Wetlands are compartmentalized by a series of large strings (roughly perpendicular to the axial stream) and flarks. This pattern may be related to small ridges on the underlying ground moraine and possibly modified by beaver activity along the axial stream. Small-scale patterning occurs along the margins of the wetlands and in sloping-fen settings. The smaller-scale strings and flarks form a complex; self-regulating system in which water retention is enhanced and surface flow is minimized. Major plant communities have been identified within the wetlands for example: a Salix planifolia community associated with the peaty strings; Carex aquatilis, Carex limosa, and Eriophorum angustifolium communities associated with flarks; as well as a Sphagnum sp.- rich hummocky transition zone between wetland and non-wetland areas. On-going analyses of water-chemistry data will be used to identify discrete water sources and to characterize the degree of horizontal and vertical water mixing within the system, as well as to help identify the biochemical requirements of the different plant communities. Results indicate that the chemical composition of the main creek reflects the accumulative effect that the peaty flarks have on the creek as it passes through the wetland system, with pH overall decreasing from 7.3 to 7.0, dissolved oxygen decreasing from 9400 to 8400 micrograms per liter and total dissolved solids increasing from 9 mg/L to 13 mg/L. String ground water is characterized by relatively high pH (ranging from 6.0 to 7.1), high oxidizing-reducing potential (ORP) (ranging from 50 mV to 180 mV), high dissolved oxygen (from 2500 ?g/L to 9600 ?g /L) while flark ground water has relatively lower pH (5.6 to 6.8), low oxidizing reducing potential (ORP) (ranging from -66 mV to 150 mV), low dissolved oxygen (from 900 ?g /L to 9000 ?g /L).

Matyjasik, M.; Ford, R. L.; Bartholomew, L. M.; Welsh, S. B.; Hernandez, M.; Koerner, D.; Muir, M.

2008-12-01

334

Copper stable isotopes to trace copper behavior in wetland systems.  

PubMed

Wetlands are reactive zones of the landscape that can sequester metals released by industrial and agricultural activities. Copper (Cu) stable isotope ratios (?(65)Cu) have recently been used as tracers of transport and transformation processes in polluted environments. Here, we used Cu stable isotopes to trace the behavior of Cu in a stormwater wetland receiving runoff from a vineyard catchment (Alsace, France). The Cu loads and stable isotope ratios were determined in the dissolved phase, suspended particulate matter (SPM), wetland sediments, and vegetation. The wetland retained >68% of the dissolved Cu and >92% of the SPM-bound Cu, which represented 84.4% of the total Cu in the runoff. The dissolved Cu became depleted in (65)Cu when passing through the wetland (?(65)Cuinlet-outlet from 0.03‰ to 0.77‰), which reflects Cu adsorption to aluminum minerals and organic matter. The ?(65)Cu values varied little in the wetland sediments (0.04 ± 0.10‰), which stored >96% of the total Cu mass within the wetland. During high-flow conditions, the Cu flowing out of the wetland became isotopically lighter, indicating the mobilization of reduced Cu(I) species from the sediments and Cu reduction within the sediments. Our results demonstrate that the Cu stable isotope ratios may help trace Cu behavior in redox-dynamic environments such as wetlands. PMID:24787375

Babcsányi, Izabella; Imfeld, Gwenaël; Granet, Mathieu; Chabaux, François

2014-05-20

335

Advection, dispersion, and filtration of fine particles within emergent vegetation of the Florida Everglades  

Microsoft Academic Search

(1) The movement of particulate matter within wetland surface waters affects nutrient cycling, contaminant mobility, and the evolution of the wetland landscape. Despite the importance of particle transport in influencing wetland form and function, there are few data sets that illuminate, in a quantitative way, the transport behavior of particulate matter within surface waters containing emergent vegetation. We report observations

Yong H. Huang; James E. Saiers; Judson W. Harvey; Gregory B. Noe; Steven Mylon

2008-01-01

336

Wetland Characteristics and Denitrification  

EPA Science Inventory

This presentation serves as an initial summary of our wetland field work's watershed characteristics hydrologic characteristics, water quality measurements, and denitrification assays. We present our measurement results in the context of wetland type (Estuarine, Freshwater Mars...

337

Ecological outcomes and evaluation of success in passively restored southeastern depressional wetlands.  

SciTech Connect

Abstract: Depressional wetlands may be restored passively by disrupting prior drainage to recover original hydrology and relying on natural revegetation. Restored hydrology selects for wetland vegetation; however, depression geomorphology constrains the achievable hydroperiod, and plant communities are influenced by hydroperiod and available species pools. Such constraints can complicate assessments of restoration success. Sixteen drained depressions in South Carolina, USA, were restored experimentally by forest clearing and ditch plugging for potential crediting to a mitigation bank. Depressions were assigned to alternate revegetation methods representing desired targets of herbaceous and wet-forest communities. After five years, restoration progress and revegetation methods were evaluated. Restored hydroperiods differed among wetlands, but all sites developed diverse vegetation of native wetland species. Vegetation traits were influenced by hydroperiod and the effects of early drought, rather than by revegetation method. For mitigation banking, individual wetlands were assessed for improvement from pre-restoration condition and similarity to assigned reference type. Most wetlands met goals to increase hydroperiod, herb-species dominance, and wetland-plant composition. Fewer wetlands achieved equivalence to reference types because some vegetation targets were incompatible with depression hydroperiods and improbable without intensive management. The results illustrated a paradox in judging success when vegetation goals may be unsuited to system constraints.

De Steven, Diane; Sharitz, Rebecca R.; Barton, Christopher, D.

2010-11-01

338

Wetlands for Wastewater Treatment  

Microsoft Academic Search

\\u000a This chapter discusses the use of natural and constructed wetlands for treatment of wastewaters. Mechanisms of treatment processes\\u000a for wetlands were described. Function, roles, types, and selection of wetland plants were discussed. This chapter also covers\\u000a design, monitoring, and maintenance of wetland treatment systems for wastewater. Case studies in Malaysia and UK were discussed.

Azni Idris; Abdul Ghani Liew Abdullah; Yung-Tse Hung; Lawrence K. Wang

339

Create a Wetland Scene  

NSDL National Science Digital Library

In this lesson plan students will learn about the importance of wetlands. They will learn about the different types of freshwater wetlands and the things that threaten their health. Finally, they will study specific examples of wetland areas of the U.S. and what is being done to protect them.

340

Predicting wetland water storage  

Microsoft Academic Search

A conceptual wetland model was developed to describe the interactions between a wetland, the surrounding catchment, and the local groundwater. Numerical evaluation of the wetland water balance was achieved by applying a bucket model. The model required little calibration and used physically based catchment properties and recorded climatic data sets. Model flexibility lends itself to application across a broad range

A. L. Krasnostein; C. E. Oldham

2004-01-01

341

Wetlands, Wildlife, and People.  

ERIC Educational Resources Information Center

Discusses the problems created when wetlands are drained or altered by humans. Provides a brief case study of the Everglades as an example of the effects of human intervention. Presents four learning activities (along with reproducible worksheets) that deal with the benefits of wetlands, and some debated issues over wetlands. (TW)

Naturescope, 1986

1986-01-01

342

Are isolated wetlands isolated?  

USGS Publications Warehouse

While federal regulations during the past 10 years have treated isolated wetlands as unconnected to aquatic resources protected by the Clean Water Act, they provide critical ecosystem services to society that extend well beyond their wetland boundaries. The authors offer well-documented examples from the scientific literature on some of the ecosystem services provided by isolated wetlands to society and other ecosystems.

Smith, Loren M.; Euliss, Ned H., Jr.; Haukos, David A.

2011-01-01

343

Impacts of freshwater wetlands on water quality: A landscape perspective  

NASA Astrophysics Data System (ADS)

In this article, we suggest that a landscape approach might be useful in evaluating the effects of cumulative impacts on freshwater wetlands. The reason for using this approach is that most watersheds contain more than one wetland, and effects on water quality depend on the types of wetlands and their position in the landscape. Riparian areas that border uplands appear to be important sites for nitrogen processing and retention of large sediment particles. Fine particles associated with high concentrations of phosphorus are retained in downstream wetlands, where flow rates are slowed and where the surface water passes through plant litter. Riverine systems also may play an important role in processing nutrients, primarily during flooding events. Lacustrine wetlands appear to have the least impact on water quality, due to the small ratio of vegetated surface to open water. Examples are given of changes that occurred when the hydrology of a Maryland floodplain was altered.

Whigham, Dennis F.; Chitterling, Carin; Palmer, Brian

1988-09-01

344

Modeling Wetland Vegetation using Polarimetric SAR  

NASA Technical Reports Server (NTRS)

A three-year project to study small-scale topographic changes and relict geomorphic features on barrier islands using synthetic aperture radar (SAR) is described. A study area on the Texas coast consisting of Galveston Island and Bolivar Peninsula was overflown by the NASA/JPL DC 8 AIRSAR in April 1995. Data was acquired in the fully polarimetric mode using C-, L-, and P-bands and in the TOPSAR configuration with C- and L-bands in interferometric mode. The study area will be overflown again in late spring 1996. The data will be registered to global positioning system (GPS) surveyed points to form high resolution digital elevation models (DEM) and then analyzed to investigate possible topographic changes.

Slatton, K. Clint; Crawford, Melba M.; Gibeaut, James C.; Gutierrez, Roberto O.

1996-01-01

345

Carbon and water cycles in tropical papyrus wetlands  

Microsoft Academic Search

Highly productive papyrus (Cyperus papyrus L.) wetlands dominate many permanently flooded areas of tropical East Africa; however, the cycling of carbon and water within\\u000a these ecosystems is poorly understood. The objective of this study was to utilise Eddy Covariance (EC) techniques to measure\\u000a the fluxes of carbon dioxide and water vapour between papyrus vegetation and the atmosphere in a wetland

M. J. Saunders; M. B. Jones; F. Kansiime

2007-01-01

346

Annual monitoring report for the Gunnison, Colorado, wetlands mitigation plan  

SciTech Connect

The US Department of Energy (DOE) administers the Uranium Mill Tailings Remedial Action (UMTRA) Project to clean up uranium mill tailings and other surface contamination at 24 abandoned uranium mill sites in 10 states. One of these abandoned mill sites is near the town of Gunnison, Colorado; surface remediation and the environmental impacts of remedial action are described in the Gunnison environmental assessment (EA) (DOE, 1992). Remedial action resulted in the elimination of 4.3 acres (ac) 1.7 hectares (ha) of wetlands and mitigation of this loss of wetlands is being accomplished through the enhance of 18.4 ac (7.5 ha) of riparian plant communities in six spring feed areas on Bureau of Land Management (BLM) land. The description of the impacted and mitigation wetlands is provided in the Mitigation and Monitoring Plan for Impacted Wetlands at the Gunnison UMTRA Project Site, Gunnison, Colorado (DOE, 1994), which is attached to the US Army corps of Engineers (USACE) Section 404 Permit. As part of the wetlands mitigation plan, the six mitigation wetlands were fenced in the fall of 1993 to exclude livestock grazing. Baseline of grazed conditions of the wetlands vegetation was determined during the summer of 1993 (DOE, 1994). A 5-year monitoring program of these six sites has been implemented to document the response of vegetation and wildlife to the exclusion of livestock. This annual monitoring report provides the results of the first year of the 5-year monitoring period.

NONE

1995-10-01

347

Ecosystem attributes related to tidal wetland effects on water quality.  

PubMed

Biogeochemical functioning of ecosystems is central to nutrient cycling, carbon balance, and several ecosystem services, yet it is not always clear why levels of function might vary among systems. Wetlands are widely recognized for their ability to alter concentrations of solutes and particles as water moves through them, but we have only general expectations for what attributes of wetlands are linked to variability in these processes. We examined changes in several water quality variables (dissolved oxygen, dissolved organic carbon, nutrients, and suspended particles) to ascertain which constituents are influenced during tidal exchange with a range of 17 tidal freshwater wetlands along the Hudson River, New York, USA. Many of the constituents showed significant differences among wetlands or between flooding and ebbing tidal concentrations, indicating wetland-mediated effects. For dissolved oxygen, the presence of even small proportional cover by submerged aquatic vegetation increased the concentration of dissolved oxygen in water returned to the main channel following a daytime tidal exchange. Nitrate concentrations showed consistent declines during ebbing tides, but the magnitude of decline varied greatly among sites. The proportional cover by graminoid-dominated high intertidal vegetation accounted for over 40% of the variation in nitrate decline. Knowing which water-quality alterations are associated with which attributes helps suggest underlying mechanisms and identifies what functions might be susceptible to change as sea level rise or salinity intrusion drives shifts in wetland vegetation cover. PMID:23600246

Findlay, S; Fischer, D

2013-01-01

348

Wetlands Reserve Program  

NSDL National Science Digital Library

Recognizing that the health of the nation's wetlands depends on the fate of private (as well as public-owned) wetlands, the Wetlands Reserve Program is an important, voluntary initiative led by the USDA Natural Resources Conservation Service (NRCS) to provide "technical and financial support" to help private landowners restore their wetlands. This straightforward site describes the Wetlands Reserve Program (WRP), including a map showing national WRP acreage, several question/ answer fact sheets, state programs and contacts, and a slide show (PowerPoint) entitled Producing Wildlife Habitat Results. Although the site targets the general public, students and educators will find it useful and instructive.

349

Performance of a Natural Wetland Treating Acid Mine Drainage in Arid Conditions  

Microsoft Academic Search

A wetland naturally formed in the discharge from a copper mine tailing impoundment in Rajasthan, India. The wetland is abundantly vegetated. This study investigated changes that occurred in the seepage as it travelled 180 and 380 m (P1 and P2) through the wetland. The pH increased from 6.17 to 7.10 at P1 and 7.34 at P2 in the pre-monsoon season,

A. S. Sheoran

2005-01-01

350

Ecological Threats and Agricultural Opportunities of the Aquatic Cane-Like Grass Phragmites australis in Wetlands  

Microsoft Academic Search

\\u000a Wetlands are some of the most biologically productive and dynamic natural ecosystems with multiple value for man and nature.\\u000a Indeed wetlands provide goods and service such as water storing, floodwater trapping, and trapping of sediment and pollutants.\\u000a Wetlands also affect climate change by absorbing CO2,?storing and releasing heat, and harnessing sunlight using a rich variety of vegetation that supports animal

Andreas P. Mamolos; Anna E. Nikolaidou; Athina K. Pavlatou-Ve; Sofia K. Kostopoulou; Kiriaki L. Kalburtji

351

Comparison of Constructed Wetland Mesocosms Designed for Treatment of Copper-Contaminated Wastewater  

Microsoft Academic Search

This study compared the performance of two constructed wetland mesocosms used to model a full-scale wetland system designed for treatment of copper-contaminated wastewater. One mesocosm (designated site-specific) was built near the construction site of the full-scale wetland using on-site soil, commercially available vegetation [Scirpus californicus (C.A. Meyer) Steud.], and water from the targeted wastestream. A second mesocosm (designated generic) was

Gladden

2001-01-01

352

Response of ducks to glyphosate-induced habitat alterations in wetlands  

Microsoft Academic Search

The effects of glyphosate herbicide-induced changes in wetland emergent vegetation (largely cattails,Typha spp.) on densities of ducks (Anatinae) were assessed in northeastern North Dakota. In 1990 and 1991, 17 cattail-dominated\\u000a wetlands were randomly assigned to 0% (reference wetlands), 50%, 70%, or 90% areal spray coverages with glyphosate herbicide.\\u000a Densities of green-winged teal (Anas crecca), bluewinged teal (Anas discors), gadwalls (Anas

George M. Linz; Dage C. Blixt; David L. Bergman; William J. Bleier

1996-01-01

353

Design and Construction of Wetlands for Aqueous Transfers and Transformations of Selected Metals  

Microsoft Academic Search

Two pilot-scale wetland cells (6.1 × 30.5 m) were integratively designed and constructed to emphasize and enhance transfers and transformations of selected metals (Cu, Pb, and Zn) in an aqueous matrix. A series of preliminary experiments and analyses were conducted to select macrofeatures (hydroperiod, hydrosoil, and vegetation) of the constructed wetland system. These wetland cells were designed to operate in

W. Bradley Hawkins; John H. Rodgers; W. B. Gillespie; A. W. Dunn; P. B. Dorn; M. L. Cano

1997-01-01

354

Benthic macroinvertebrate populations of urban freshwater tidal wetlands in the Anacostia River, Washington D.C  

Microsoft Academic Search

This study characterizes the benthic communities establishing themselves on recently reconstructed urban freshwater tidal wetlands along the Anacostia River in Washington, D.C. in comparison to a similar relic wetland as well as to a reference wetland in the adjacent Patuxent River watershed. The study's focus is the two main areas of Kingman Marsh, which were reconstructed from Anacostia dredge material

K. D. Brittingham

2005-01-01

355

The growing season water balance and controls on evapotranspiration in wetland reclamation test cells Fort McMurray, Alberta  

NASA Astrophysics Data System (ADS)

In the oil sands mining region near Fort McMurray, Alberta, efforts to establish specific wetland reclamation techniques are underway. During the 2010 growing season, the water balance of 12 plots (cells) of different soil and vegetation treatments were studied with emphasis on understanding the controls on evapotranspiration (ET) and the effects of construction techniques. Cell hydrologic behaviour was distinct from natural wetlands due to frequent artificial irrigation. ET ranged from ˜0 6 mm day-1 to ˜8.2 mm day-1 with a mean of ˜3.2 mm day-1 and variation among the cells was attributed to the construction techniques used, specifically placement period and soil depth. ET was weakly correlated to individual environmental variables; however, multivariate statistical models revealed complex interactions among environmental variables that acted to control ET. Cumulative water balances indicated certain construction techniques produced ET rates comparable to natural wetlands, which may be an important factor in improving the long-term sustainability of reclaimed wetlands.

Faubert, Jean-Pascal R.

356

Using dual classifications in the development of avian wetland indices of biological integrity for wetlands in West Virginia, USA.  

PubMed

Considerable resources are being used to develop and implement bioassessment methods for wetlands to ensure that "biological integrity" is maintained under the United States Clean Water Act. Previous research has demonstrated that avian composition is susceptible to human impairments at multiple spatial scales. Using a site-specific disturbance gradient, we built avian wetland indices of biological integrity (AW-IBI) specific to two wetland classification schemes, one based on vegetative structure and the other based on the wetland's position in the landscape and sources of water. The resulting class-specific AW-IBI was comprised of one to four metrics that varied in their sensitivity to the disturbance gradient. Some of these metrics were specific to only one of the classification schemes, whereas others could discriminate varying levels of disturbance regardless of classification scheme. Overall, all of the derived biological indices specific to the vegetative structure-based classes of wetlands had a significant relation with the disturbance gradient; however, the biological index derived for floodplain wetlands exhibited a more consistent response to a local disturbance gradient. We suspect that the consistency of this response is due to the inherent nature of the connectivity of available habitat in floodplain wetlands. PMID:19401811

Veselka, Walter; Anderson, James T; Kordek, Walter S

2010-05-01

357

FUNDAMENTAL INVESTIGATION ON CONSTRUCTED WETLAND DESIGN FOR WASTE WATER PURIFICATION  

NASA Astrophysics Data System (ADS)

In designing a constructed wetland for water purification, a homogeneous vegetation bed is often adopted in order to prevent short circuit which reduces the efficiency of SS trapping. However, vegetation naturally becomes inhomogeneous under the action of water flow, causing unexpected short circuit. This paper discusses a possibility to design a channel for a "stable short circuit", which distributes SS to vegetation zones by large horizontal eddies between the channel and vegetation zones. A series of numerical experiments show that even one slightly bended channel can distribute a high ratio of SS supplied through the channel to vegetation zones with the aid of horizontal eddies. This fact suggests that hydraulic design of artificial short circuit can be an alternative strategy for design of constructed wetlands.

Ishikawa, Tadaharu; Gao, Shuang

358

SYNERGISTIC USE OF OPTICAL AND RADAR REMOTE SENSING FOR MAPPING AND MONITORING FLOODING SYSTEM IN KAFUE FLATS WETLAND OF SOUTHERN ZAMBIA  

Microsoft Academic Search

These Wetlands are lands with characteristics between aquatic and terrestrial ecosystems. They generally consist of grasslands, swamps, marshes, peat bogs, willows, mangroves, etc. Some wetlands are found in shallow slow flowing or percolating waters with hydric soils and hydrophytic vegetation. These characteristics ensure the biological diversity and uniqueness of wetland ecosystems. However, as population increases there is increased need to

Michael Aduah; Ben Maathuis; Yousif Ali Hussin

359

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

USGS Publications Warehouse

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

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

2009-01-01

360

Conservative and reactive solute transport in constructed wetlands  

Microsoft Academic Search

(1) The transport of bromide, a conservative tracer, and rhodamine WT (RWT), a photodegrading tracer, was evaluated in three wastewater-dependent wetlands near Phoenix, Arizona, using a solute transport model with transient storage. Coupled sodium bromide and RWT tracer tests were performed to establish conservative transport and reactive parameters in constructed wetlands with water losses ranging from (1) relatively impermeable (15%),

Steffanie H. Keefe; Larry B. Barber; Robert L. Runkel; Joseph N. Ryan; Diane M. McKnight; Roland D. Wass

2004-01-01

361

Design Methodology of Free Water Surface Constructed Wetlands  

Microsoft Academic Search

Simple criteria, guidelines and models are established for free water surface (FWS) constructed wetland selection and preliminary sizing. The analysis employs models for FWS constructed wetland design, considering simultaneously the removal requirements and the hydraulics of the system. On the basis of these models, a step-by-step methodology is developed outlining the design procedure for new and performance evaluation for existing

Maria A. Economopoulou; Vassilios A. Tsihrintzis

2004-01-01

362

Use of macroinvertebrates to identify cultivated wetlands in the Prairie Pothole Region  

USGS Publications Warehouse

We evaluated the use of macroinvertebrates as a potential tool to identify dry and intensively farmed temporary and seasonal wetlands in the Prairie Pothole Region. The techniques we designed and evaluated used the dried remains of invertebrates or their egg banks in soils as indicators of wetlands. For both the dried remains of invertebrates and their egg banks, we weighted each taxon according to its affinity for wetlands or uplands. Our study clearly demonstrated that shells, exoskeletons, head capsules, eggs, and other remains of macroinvertebrates can be used to identify wetlands, even when they are dry, intensively farmed, and difficult to identify as wetlands using standard criteria (i.e., hydrology, hydrophytic vegetation, and hydric soils). Although both dried remains and egg banks identified wetlands, the combination was more useful, especially for identifying drained or filled wetlands. We also evaluated the use of coarse taxonomic groupings to stimulate use of the technique by nonspecialists and obtained satisfactory results in most situations.

Euliss, N. H., Jr.; Mushet, D. M.; Johnson, D. H.

2001-01-01

363

A comparison of sampling techniques to estimate number of wetlands  

USGS Publications Warehouse

Service use annual estimates of the number of ponded wetlands to estimate duck production and establish duck hunting regulations. Sampling techniques that minimize bias may provide more reliable estimates of annual duck production. Using a wetland geographic information system (GIS), we estimated number of wetlands using standard counting protocol with belt transects and samples of square plots. Estimates were compared to the known number of wetlands in the GIS to determine bias. Bias in transect-derived estimates ranged from +67-87% of the known number of wetlands, compared to bias of +3-6% in estimates from samples of 10.24-km2 plots. We recommend using samples of 10.24-km2 plots stratified by wetland density to decrease bias.

Johnson, R. R.; Higgins, K. F.; Naugle, D. E.; Jenks, J. A.

1999-01-01

364

Wetlands Assessment for site characterization, Advanced Neutron Source (ANS)  

SciTech Connect

This Wetlands Assessment has been prepared in accordance with the Department of Energy`s (DOE) Code of Federal Regulations (CFR) 10 CFR 1022, Compliance with Floodplain/Wetlands Environmental Review Requirements, which established the policy and procedure for implementing Executive Order 11990, Protection of Wetlands. The proposed action is to conduct characterization activities in or near wetlands at the ANS site. The proposed action will covered under a Categorical Exclusion, therefore this assessment is being prepared as a separate document [10 CFR 1022.12(c)]. The purpose of this Wetlands Assessment is to fulfill the requirements of 10 CFR 1022.12(a) by describing the project, discussing the effects of the proposed action upon the wetlands, and considering alternatives to the proposed action.

Wade, M.C.; Socolof, M.L. [Oak Ridge National Lab., TN (United States). Energy Div.; Rosensteel, B.; Awl, D. [JAYCOR, Vienna, VA (United States)

1994-10-01

365

Wetland Loss and Biodiversity Conservation  

Microsoft Academic Search

Most species of wetland-dependent organisms live in multiple local populations sustained through occasional migration. Retention of minimum wetland densities in human-dominated landscapes is funda- mental to conserving these organisms. An analysis of wetland mosaics was performed for two regions of the northeastern United States to assess the degree to which historical wetland loss alters the metrics of wetland mosaics and

James P. Gibbs

2000-01-01

366

Using aquatic invertebrates to delineate seasonal and temporary wetlands in the Prairie Pothole Region of North America  

USGS Publications Warehouse

Tillage can destroy or greatly disturb indicators of hydric soils and hydrophytic vegetation, making delineation of tilled wetlands difficult. The remains of aquatic invertebrates (e.g., shells, drought-resistant eggs, and trichopteran cases) are easily identifiable and persist in wetland substrates even when wetlands are dry. Additionally, these remains are not easily destroyed by mechanical tillage. To test the feasibility of using invertebrate remains to delineate wetlands, we used two methods to identify the wetland edge of ten seasonal and ten temporary wetlands, evenly divided between grassland and cropland landscapes. First, we identified the wetland edge using hydric soil and vegetation indicators along six evenly spaced transects in each wetland (our standard delineation). We then identified the wetland edge along the same transects using aquatic invertebrate remains as our indicator. In grassland landscapes, delineations of the wetland edge made using invertebrate remains were consistently at the same location or closer to the wetland center as the standard delineations for both seasonal and temporary wetlands. In cropland landscapes, however, many of our invertebrate delineations of seasonal and temporary wetlands were on the upland side of our standard delineations. We attribute the differences to movement of remains during tillage, increased maximum pool levels in cropland wetlands, and disturbance of hydric soils and plants. We found that the elevations of the wetland edge indicated by invertebrate remains were more consistent within a wetland than elevations determined by standard delineations. Aquatic invertebrate remains can be useful in delineating wetlands when other indicators have been destroyed or severely disturbed by tillage.

Euliss, N. H., Jr.; Mushet, D. M.; Johnson, D. H.

2002-01-01

367

AN INVESTIGATION ON THE PARK AND PEOPLE PROBLEMS: SPECIAL EMPHASIS ON THE IMPACT ON WETLAND SURROUNDING VEGETATION DUE TO OVERGRAZING OF LIVESTOCK IN KOSHI TAPPU WILDLIFE RESERVE, NEPAL. (A Case Study of Kusaha VDC)  

Microsoft Academic Search

Koshi Tappu Wildlife Reserve (KTWR) is an important wetland area in the floodplain of Sapta Koshi River in the east terai of Nepal. It covers about 150 km2 area. It is decorated by a total of 515 species of plants consisting submerged, floating species as well as grassland\\/subannah and riverine forest. The study was carried out to investigate the impact

Anu Shrestha; Rana Bahadur Chhetri; Sanjay Nath

368

Conservation of waterbirds in the Hadejia-Nguru Wetlands, Nigeria: current efforts and problems  

Microsoft Academic Search

Akinsola, O.A., Ezealor, A.U. & Polet, G. 2000. Conservation of waterbirds in the Hadejia-Nguru Wetlands, Nigeria: current efforts and problems. Ostrich 71 (1 & 2): 118–121.The ornithological importance of the Hadejia-Nguru wetlands at both national and international levels is well known. Current efforts at conserving the avifauna of the wetlands started with the establishment of the Hadejia-Nguru Wetlands Conservation Project

Olumide A. Akinsola; Augustine U. Ezealor; Gert Polet

2000-01-01

369

Hydrology and history: land use changes and ecological responses in an urban wetland  

Microsoft Academic Search

The impacts of changing land use on hydrology and dominant plant species from 1850–1990 were investigated in a palustrine wetland in southern Wisconsin, USA. Aerial photographs, historic maps and water levels of the area were used to determine changes in land use, wetland vegetation, and groundwater and surface flows over time. Piezometers and water table wells were monitored weekly for

C. R. Owen

1999-01-01

370

INTEGRATING MULTI-SOURCE INFORMATION VIA FUZZY CLASSIFICATION METHOD FOR WETLAND GRASS MAPPING  

Microsoft Academic Search

Late greening vegetation has been regarded as significant indicator of flood recessional wetlands ecosystem in the Poyang lake natural reserve (PLNNR). Mapping the wetlands, especially the distribution of late greening grassland is of great importance for PLNNR managers and decision makers either for ecosystem dynamic monitoring or habitat sustainability assessment. The aim of this paper is to explore the use

X. Zhao; A. Stein

371

Reporting on ecological condition and ecosystem services for the 2011 National Wetland Condition Assessment  

EPA Science Inventory

The first-ever National Wetland Condition Assessment (NWCA) was conducted by the U.S. Environmental Protection Agency (USEPA) in 2011. Vegetation, algae, soil, water chemistry, and hydrologic data were collected at ~900 wetland points across the contiguous United States. The NW...

372

Ecological risk assessment of the herbicide tebuthiuron in northern Australian wetlands1  

Microsoft Academic Search

The herbicide tebuthiuron has been used widely in the Northern Territory of Australia for control of the wetland weed, Mimosa pigra (Mimosa), since the late 1980s. Mimosa is an opportunistic and aggressive weed, forming dense mono-specific stands in tropical wetland habitats and replacing native vegetation (Lonsdale et al 1995). Thus, there is a need to effectively control and manage Mimosa

RA van Dam; C Camilleri; CJ Turley; SJ Markich

373

Nitrogen removal efficiencies in a free water surface constructed wetland in relation to plant coverage  

Microsoft Academic Search

Vegetation coverage is considered to be a key factor controlling nitrogen removal in wetlands. We describe the use of newly designed stainless steel incubation chambers to detect shifts in the in situ nitrate reduction activities associated to areas covered with common reed (Phragmites australis) and cattail (Typha latifolia) in the sediment of a free water surface constructed wetland (FWS-CW). Activities

A. García-Lledó; O. Ruiz-Rueda; A. Vilar-Sanz; L. Sala; L. Bañeras

2011-01-01

374

Treatment of Domestic Wastewater by Three Plant Species in Constructed Wetlands  

Microsoft Academic Search

Three common Appalachian plant species (Juncus effusus L., Scirpus validus L., and Typha latifolia L.) were planted into small-scale constructed wetlands receivingprimary treated wastewater. The experimental design includedtwo wetland gravel depths (45 and 60 cm) and five plantingtreatments (each species in monoculture, an equal mixture of the three species, and controls without vegetation), with two replicates per depth × planting

Jerry Coleman; Keith Hench; Keith Garbutt; Alan Sexstone; Gary Bissonnette; Jeff Skousen

2001-01-01

375

Agricultural Encroachment: Implications for Carbon Sequestration in Tropical African Wetlands  

NASA Astrophysics Data System (ADS)

Tropical wetlands have been shown to exhibit high rates of net primary productivity and may therefore play an important role in global climate change mitigation through carbon assimilation and sequestration. Many permanently flooded areas of tropical East Africa are dominated by the highly productive C4 emergent macrophyte sedge, Cyperus papyrus L. (papyrus). However, increasing population densities around wetland margins in East Africa are reducing the extent of papyrus coverage due to the planting of subsistence crops such as Cocoyam (Colocasia esculenta). We have assessed the impact of this land use change on the carbon cycle in theis wetland environment. Eddy covariance techniques were used, on a campaign basis, to measure fluxes of carbon dioxide over both papyrus and cocoyam dominated wetlands located on the Ugandan shore of Lake Victoria. The integration of flux data over the annual cycle shows that papyrus wetlands have the potential to act as a sink for significant amounts of carbon, in the region of 10 t C ha-1 yr-1. The cocoyam vegetation was found to assimilate ~7 t C ha-1 yr-1 but when carbon exports from crop biomass removal were taken into account these wetlands represent a significant net loss of carbon of similar magnitude. The development of sustainable wetland management strategies are therefore required in order to promote the dual wetland function of crop production and the mitigation of greenhouse gas emissions especially under future climate change scenarios.

Jones, M. B.; Saunders, M.; Kansiime, F.

2013-12-01

376

Classifying and mapping wetlands and peat resources using digital cartography  

USGS Publications Warehouse

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.

Cameron, Cornelia, C.; Emery, David, A.

1992-01-01

377

Vulnerability of Northern Prairie Wetlands to Climate Change  

NSDL National Science Digital Library

This peer reviewed article from Bioscience journal is on the effect of climate change on northern prairie wetlands. The prairie pothole region (PPR) lies in the heart of North America and contains millions of glacially formed, depressional wetlands embedded in a landscape matrix of natural grassland and agriculture. These wetlands provide valuable ecosystem services and produce 50% to 80% of the continent's ducks. We explored the broad spatial and temporal patterns across the PPR between climate and wetland water levels and vegetation by applying a wetland simulation model (WETSIM) to 18 stations with 95-year weather records. Simulations suggest that the most productive habitat for breeding waterfowl would shift under a drier climate from the center of the PPR (the Dakotas and southeastern Saskatchewan) to the wetter eastern and northern fringes, areas currently less productive or where most wetlands have been drained. Unless these wetlands are protected and restored, there is little insurance for waterfowl against future climate warming. WETSIM can assist wetland managers in allocating restoration dollars in an uncertain climate future

W. CARTER JOHNSON, BRUCE V. MILLETT, TAGIR GILMANOV, RICHARD A. VOLDSETH, GLENN R. GUNTENSPERGEN, and DAVID E. NAUGLE (;)

2005-11-01

378

Influence of vegetation in mitigation of methyl parathion runoff  

Microsoft Academic Search

A pesticide runoff event was simulated on two 10m×50m constructed wetlands (one non-vegetated, one vegetated) to evaluate the fate of methyl parathion (MeP) (Penncap-M®). Water, sediment, and plant samples were collected at five sites downstream of the inflow for 120d. Semi-permeable membrane devices (SPMDs) were deployed at each wetland outflow to determine exiting pesticide load. MeP was detected in water

M. T. Moore; E. R. Bennett; C. M. Cooper; S. Smith Jr.; J. L. Farris; K. G. Drouillard; R. Schulz

2006-01-01

379

Restoration of a forested wetland ecosystem in a thermally impacted stream corridor  

SciTech Connect

The Savannah River Swamp is a 3,020 Ha forested wetland on the floodplain of the Savannah River and is located on the Department of Energy`s Savannah River Site (SRS). Major impacts to the swamp hydrology occurred with the completion of the production reactors and one coal-fired powerhouse at the SRS in the early 1950`s. Water was pumped from the Savannah River, through secondary heat exchangers of the reactors, and discharged into three of the tributary streams that flow into the swamp. This continued from 1954 to 1988 at various levels. The sustained increases in water volume resulted in overflow of the original stream banks and the creation of additional floodplains. Accompanying this was considerable erosion of the original stream corridor and deposition of a deep silt layer on the newly formed delta. Heated water was discharged directly into Pen Branch and water temperature in the stream often exceeded 50 C. The nearly continuous flood of the swamp, the thermal load of the water, and the heavy silting resulted in complete mortality of the original vegetation in large areas of the floodplain. Research has been ongoing to determine methods to reintroduce tree species characteristic of more mature forested wetlands. The goal of the restoration is to create structural and biological diversity in the forest canopy by establishing a mix of species typically present in riparian and wetland forests of the area.

Nelson, E.A. [Westinghouse Savannah River Corp., Aiken, SC (United States). Savannah River Technology Center; McKee, W.H. Jr.; Dulohery, C.J. [Forest Service, Charleston, SC (United States). Center for Forested Wetlands Research

1995-09-01

380

Estimation model of soil freeze-thaw erosion in Silingco watershed wetland of Northern Tibet.  

PubMed

The freeze-thaw (FT) erosion is a type of soil erosion like water erosion and wind erosion. Limited by many factors, the grading evaluation of soil FT erosion quantities is not well studied. Based on the comprehensive analysis of the evaluation indices of soil FT erosion, we for the first time utilized the sensitivity of microwave remote sensing technology to soil moisture for identification of FT state. We established an estimation model suitable to evaluate the soil FT erosion quantity in Silingco watershed wetland of Northern Tibet using weighted summation method of six impact factors including the annual FT cycle days, average diurnal FT phase-changed water content, average annual precipitation, slope, aspect, and vegetation coverage. Finally, with the support of GIS, we classified soil FT erosion quantity in Silingco watershed wetland. The results showed that soil FT erosion are distributed in broad areas of Silingco watershed wetland. Different soil FT erosions with different intensities have evidently different spatial and geographical distributions. PMID:23935427

Kong, Bo; Yu, Huan

2013-01-01

381

Casco Bay Watershed Wetlands Characterization.  

National Technical Information Service (NTIS)

This report describes a pilot project to develop a watershed-based wetlands characterization using digital data and GIS technology for the state of Maine. The Casco Bay Watershed Wetlands Characterization Method determines relative significance of wetland...

E. Hertz J. Sartoris

2001-01-01

382

WATER QUALITY AND AQUATIC MACROINVERTEBRATES IN 3 TYPES OF REFERENCE LIMESINK WETLANDS IN SOUTHWEST GEORGIA  

Microsoft Academic Search

In SW Georgia, three wetlands types have been classified based on vegetation and soils: marshes dominated by herbaceous vegetation, open savannas with an overstory canopy of cypress, and forested swamps composed of cypress\\/hardwoods. We sampled 28 relatively unimpacted limesink wetlands for water quality at eight different times during 1997-98, and sampled invertebrates using a D-frame sweep net at early, mid,

Juliann Battle; Stephen W. Golladay