Science.gov

Sample records for wetland vegetation establishment

  1. Wetland vegetation establishment in L-Lake

    SciTech Connect

    Kroeger, S.R.

    1990-07-01

    Wetland vegetation was transplanted from PAR Pond to L-Lake between January and August, 1987. Approximately 100,000 individual plants representing over 40 species were transplanted along the southern shoreline. Three zones of vegetation were created: (1) submersed/floating-leaved, (2) emergent, (3) upper emergent/shrub. During the summers of 1987, 1988, 1989, the Savannah River Ecology Laboratory sampled the vegetation in 54 permanent transects located in planted (N=32) and unplanted areas (N=22). The 1989 vegetation data from L-Lake were compared to 1985 data from PAR Pond.

  2. Seed bank and established vegetation in the last remnants of the Mexican Central Plateau wetlands: the Lerma marshes.

    PubMed

    Zepeda, Carmen; Lot, Antonio; Nemiga, Xanat Antonio; Manjarrez, Javier

    2014-06-01

    Seed banks play a central role in vegetation dynamics of many wetlands. Therefore, knowledge of seed reservoirs in the soils of aquatic communities should provide useful tools for conservation and restoration efforts. This study was conducted in the Lerma marshes, one of the last remnants of the vast wetlands that were once in the Mexican Central Plateau. The main objective was to determine the composition and abundance of seed bank and its relationship with established vegetation of the three Lerma marshes. In each marsh, we systematically selected 18 to 40 sampling sites. In each site, the composition of vascular plant vegetation was evaluated in two 10m lines perpendicular to the shore. Every 0.5m, we determined the coverage of species by measuring the intercepted length for each plant or group of plants. At each sampling site where we had evaluated the established vegetation, we collected a sample of the top 10cm of sediment; the soil cores were divided into an upper layer (0-5cm) and a lower layer (5-10cm). These samples were used to evaluate the seed bank by the seedling emergence method. All samples were placed in a greenhouse at 20-25 degrees C and remained flooded for 15 weeks. Forty-nine species were recorded in the vegetation. Chiconahuapan had the richest and most diverse flora and the greatest number of perennial species. A life-forms analysis showed that perennial herbs, especially rooted-emergent hydrophytes, dominated in the three wetlands. Sixty-one species were identified in the total seed bank; Chimaliapan had the most diverse total seed bank, whereas the mean seedling density was higher in Chignahuapan. Only two species of the total seed bank of each marsh had a density greater than 10% of the total, and more than half were uncommon. The upper layer of sediment (0-5cm) contained two times more seeds/m2 and species per sample than the lower layer (5-10cm), and there was a significant decrease of seed density with depth. The detrended

  3. 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

    Atekwana, E.A. . Dept. of Geology); Agendia, P.L. . Dept. of Plant Biology)

    1994-04-01

    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.

  4. Textural signatures for wetland vegetation

    NASA Technical Reports Server (NTRS)

    Whitman, R. I.; Marcellus, K. L.

    1973-01-01

    This investigation indicates that unique textural signatures do exist for specific wetland communities at certain times in the growing season. When photographs with the proper resolution are obtained, the textural features can identify the spectral features of the vegetation community seen with lower resolution mapping data. The development of a matrix of optimum textural signatures is the goal of this research. Seasonal variations of spectral and textural features are particularly important when performing a vegetations analysis of fresh water marshes. This matrix will aid in flight planning, since expected seasonal variations and resolution requirements can be established prior to a given flight mission.

  5. Flooding Frequency Alters Vegetation in Isolated Wetlands

    USGS Publications Warehouse

    Haag, Kim H.; Lee, Terrie M.

    2006-01-01

    Many isolated wetlands in central Florida occur as small, shallow depressions scattered throughout the karst topography of the region. In these wetlands, the water table approaches land surface seasonally, and water levels and flooding frequency are largely determined by differences between precipitation and evapotranspiration. Because much of the region is flat with little topographic relief, small changes in wetland water levels can cause large changes in wetland surface area. Persistent changes in wetland flooding frequencies, as a result of changes in rainfall or human activity, can cause a substantial change in the vegetation of thousands of acres of land. Understanding the effect that flooding frequency has on wetland vegetation is important to assessing the overall ecological status of wetlands. Wetland bathymetric mapping, when combined with water-level data and vegetation assessments, can enable scientists to determine the frequency of flooding at different elevations in a wetland and describe the effects of flooding frequency on wetland vegetation at those elevations. Five cypress swamps and five marshes were studied by the U.S. Geological Survey (USGS) during 2000-2004, as part of an interdisciplinary study of isolated wetlands in central Florida (Haag and others, 2005). Partial results from two of these marshes are described in this report.

  6. Disturbance metrics predict a wetland Vegetation Index of Biotic Integrity

    USGS Publications Warehouse

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

    2013-01-01

    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.

  7. 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...

  8. 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...

  9. Does prescribed fire benefit wetland vegetation?

    USGS Publications Warehouse

    Flores, C.; Bounds, D.L.; Ruby, D.E.

    2011-01-01

    The effects of fire on wetland vegetation in the mid-Atlantic region of the United States are poorly known, despite the historical use of fire by federal, state, and private landowners in the Chesapeake Bay Region. Prescribed fire is widely used by land managers to promote vegetation that is beneficial to migratory waterfowl, muskrats, and other native wildlife and to reduce competition from less desirable plant species. We compared vegetative response to two fire rotations, annual burns and 3-year burns, and two control sites, Control 1 and Control 2. We tested the effects of fire within six tidal marsh wetlands at Blackwater National Wildlife Refuge and Fishing Bay Wildlife Management Area in Maryland. We examined changes in total live biomass (all species), total stem density, litter, and changes in live biomass and stem density of four dominant wetland plant species (11 variables). Our results suggest that annual prescribed fires will decrease the accumulation of litter, increase the biomass and stem densities of some wetland plants generally considered less desirable for wildlife, and have little or no effect on other wetland plants previously thought to benefit from fire. ?? 2011 US Government.

  10. Simulation of wetlands forest vegetation dynamics

    USGS Publications Warehouse

    Phipps, R.L.

    1979-01-01

    A computer program, SWAMP, was designed to simulate the effects of flood frequency and depth to water table on southern wetlands forest vegetation dynamics. By incorporating these hydrologic characteristics into the model, forest vegetation and vegetation dynamics can be simulated. The model, based on data from the White River National Wildlife Refuge near De Witt, Arkansas, "grows" individual trees on a 20 x 20-m plot taking into account effects on the tree growth of flooding, depth to water table, shade tolerance, overtopping and crowding, and probability of death and reproduction. A potential application of the model is illustrated with simulations of tree fruit production following flood-control implementation and lumbering. ?? 1979.

  11. Vegetation survey of PEN Branch wetlands

    SciTech Connect

    Not Available

    1991-01-01

    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.

  12. Effects of dominant species on vegetation change in Carolina bay wetlands following a multi-year drought.

    SciTech Connect

    Mulhouse, John, M.; De Steven, Diane; Lide, Robert, F.; Sharitz, Rebecca, R.

    2005-05-01

    Wetland vegetation is strongly dependent upon climate-influenced hydrologic conditions, and plant composition responds in generally consistent ways to droughts. However, the extent of species composition change during drought may be influenced by the pre-existing structure of wetland vegetation. We characterized the vegetation of ten herbaceous Carolina bay wetlands on the South Carolina Upper Coastal Plain during a period of average rainfall and again near the end of a four-year drought. We hypothesized that, as a group, bays dominated by less robust plant species (characteristic of open-water pond and depression meadow vegetation types) would show greater compositional change than bays dominated by dense, robust-form clonal graminoids (characteristic of grass and sedge marsh vegetation types). Aquatic species decreased during the drought in all wetlands, regardless of vegetation group. Compared to grass/sedge marshes, pond/meadow wetlands acquired more species, particularly non-wetland species, during the drought. Pond/meadow wetlands also had greater increases in the abundances of species that require unflooded conditions to establish. Prior to the drought, all wetlands were ponded almost continuously, but during drought the pond/meadow wetlands had shorter and more variable hydroperiods than the grass/sedge marshes. Thus, vegetation change may be partly confounded with hydrologic conditions that provide greater opportunities for species recruitment in pond/meadow bays. The results suggest that Carolina bay vegetation dynamics may differ as a function of dominant vegetation and climate driven variation in wetland hydrologic condition.

  13. Correspondence between vegetation and soils in wetlands and nearby uplands

    USGS Publications Warehouse

    Scott, Michael L.; Slauson, William L.; Segelquist, Charles A.; Auble, Gregor T.

    1989-01-01

    The association between vegetation and soils from a geographically broad sampling of wetlands and adjoining uplands is reported for 38 hydric and 26 nonhydric soils, as recognized in the hydric soils list of the Soil Conservation Service. Wetlands represented in the study include estuaries, pitcher plant bogs, prairie depressional wetlands, and western riparian lands. The agreement between vegetation and soils is clear with few exceptions. In general, hydric soils support hydrophytic plant communities, and nonhydric soils support upland communities. Only 10% of the hydric soils sampled support upland communities and only 15% of the nonhydric soils support wetland communities. Exceptions to the correspondence between vegetation and soils are discussed; local hydrology, the transitional nature of some soils, and other determinants of wetland vegetation structure (e.g., salinity, disturbance) seem to account for many of the observed discrepancies. A method that simplifies the complexity of soils and vegetation cannot be expected to represent accurately all details of their interrelations.

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

    SciTech Connect

    Zimmerman, R.E.; Shem, L.M.; Gowdy, M.J.; Van Dyke, G.D.; Hackney, C.T.

    1992-07-01

    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.

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

    SciTech Connect

    Zimmerman, R.E.; Shem, L.M.; Gowdy, M.J. ); Van Dyke, G.D. ); Hackney, C.T. )

    1992-01-01

    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.

  16. TerraSAR-X dual-pol time-series for mapping of wetland vegetation

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

    Mapping vegetation formations at a fine scale is crucial for assessing wetland functions and for better landscape management. Identification and characterization of vegetation formations is generally conducted at a fine scale using ecological ground surveys, which are limited to small areas. While optical remotely sensed imagery is limited to cloud-free periods, SAR time-series are used more extensively for wetland mapping and characterization using the relationship between distribution of vegetation formations and flood duration. The aim of this study was to determine the optimal number and key dates of SAR images to be classified to map wetland vegetation formations at a 1:10,000 scale. A series of eight dual-polarization TerraSAR-X images (HH/VV) was acquired in 2013 during dry and wet seasons in temperate climate conditions. One polarimetric parameter was extracted first, the Shannon entropy, which varies with wetland flooding status and vegetation roughness. Classification runs of all the possible combinations of SAR images using different k (number of images) subsets were performed to determine the best combinations of the Shannon entropy images to identify wetland vegetation formations. The classification runs were performed using Support Vector Machine techniques and were then analyzed using the McNemar test to investigate significant differences in the accuracy of all classification runs based on the different image subsets. The results highlight the relevant periods (i.e. late winter, spring and beginning of summer) for mapping vegetation formations, in accordance with ecological studies. They also indicate that a relationship can be established between vegetation formations and hydrodynamic processes with a short time-series of satellite images (i.e. 5 dates). This study introduces a new approach for herbaceous wetland monitoring using SAR polarimetric imagery. This approach estimates the number and key dates required for wetland management (e

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

    SciTech Connect

    Bergman, C.L.; LaGory, K.

    2004-01-01

    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.

  18. Remote sensing for identification and classification of wetland vegetation

    USGS Publications Warehouse

    Cowardin, L.M.; Myers, V.I.

    1974-01-01

    Multispectral photography and ground truth were obtained on an area 12 miles (19.3 km) east of Bemidji, Minnesota, to identify and map wetlands less than 2 acres (0.8 hectare) in size, to map emergent vegetation in lakes, and to explore the feasibility of classifying vegetation from aerial photographs. Wetlands less than 2 acres in size were identified on photography taken in May 1971, and emergent vegetation was recorded on purposely overexposed infrared black and white photography from a flight in September 1971. Several vegetation types and species groups were recognizable with the aid of color, color infrared, and black and white infrared photography. Proper timing of flights, use of multispectral photography, and knowledge of the ecology of the area are considered essential for wetland mapping by remote sensing.

  19. Coevolution of hydraulic, soil and vegetation processes in estuarine wetlands

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    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.

  20. Reestablishment of wetland vegetation on gas pipeline rights-of-way in six different wetland ecosystems

    SciTech Connect

    Zimmerman, R.E. Shem, L.; Wilkey, P.L.; Van Dyke, G.D.; Hackney, C.; Gowdy, M.

    1992-05-01

    Vegetational surveys were carried out to compare reestablished vegetation on pipeline rights-of-way (ROWS) with that in adjacent natural ecosystems undisturbed by pipeline installation. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the ROW approximated or exceeded those in the adjacent natural area. In four ecosystems, the vegetation on the ROW was limited to a herbaceous layer by ROW maintenance; thus, the ROWs often involved a complex of species quite different from that found in the adjacent ecosystems.

  1. Vegetation of wetlands of the prairie pothole region

    USGS Publications Warehouse

    Kantrud, H.A.; Millar, J.B.; Van Der Valk, A.G.; van der Valk, A.

    1989-01-01

    Five themes dominate the literature dealing with the vegetation of palustrine and lacustrine wetlands of the prairie pothole region: environmental conditions (water or moisture regime, salinity), agricultural disturbances (draining, grazing, burning, sedimentation, etc.), vegetation dynamics, zonation patterns, and classification of the wetlands.The flora of a prairie wetland is a function of its water regime, salinity, and disturbance by man. Within a pothole, water depth and duration determines distribution of species. In potholes deep enough to have standing water even during droughts, the central zone will be dominated by submersed species (open water). In wetlands that go dry during periods of drought or annually, the central zone will be dominated by either tall emergent species (deep marsh) or midheight emergents (shallow marsh), respectively. Potholes that are only flooded briefly in the spring are dominated by grasses, sedges, and forbs (wet meadow). Within a pothole, the depth of standing water in the deepest, usually central, part of the basin determines how many zones will be present. Lists of species associated with different water regimes and salinity levels are presented.Disturbances due to agricultural activities have impacted wetlands throughout the region. Drainage has eliminated many potholes, particularly in the southern and eastern parts of the region. Grazing, mowing, and burning have altered the composition of pothole vegetation. The composition of different vegetation types impacted by grazing, haying, and cultivation is presented in a series of tables. Indirect impacts of agriculture (increased sediment, nutrient, and pesticide inputs) are widespread over the region, but their impacts on the vegetation have never been studied.Because of the periodic droughts and wet periods, many palustrine and lacustrine wetlands undergo vegetation cycles associated with water-level changes produced by these wet-dry cycles. Periods of above normal

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

    USGS Publications Warehouse

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

    2011-01-01

    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

  3. Early vegetational changes on a forested wetland constructed for mitigation

    USGS Publications Warehouse

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

    1997-01-01

    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.

  4. Classification of wetlands vegetation using small scale color infrared imagery

    NASA Technical Reports Server (NTRS)

    Williamson, F. S. L.

    1975-01-01

    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.

  5. Boron in Pariette Wetland Sediments, Aquatic Vegetation & Benthic Organisms

    NASA Astrophysics Data System (ADS)

    Vasudeva, P.; Jones, C. P.; Powelson, D.; Jacobson, A. R.

    2015-12-01

    The Pariette Wetlands are comprised of 20 ponds located in Utah's Uintah Basin. Boron concentration in the Pariette Wetlands have been observed to exceed the total maximum daily limit of 750 µg L-1. Considering water flow in and out of the wetlands, boron is accumulating within the wetlands where it is sorbed to sediments and bioconcentrated by wetland plant and macro invertebrates. Since boron is an avian teratogen, an estimate of boron ingestion exposure is warranted. Samples from 3 of the 23 Pariette Wetland ponds with one pond near the inlet, one near the outlet, and one in the middle were collected. Five sampling points were designated along a 100 m transect of each pond. At each sampling point duplicate (or triplicate) samples of water, sediments, benthic organisms and wetland vegetation were collected. The sediments were collected with a KB-corer and divided at depths of 0-2 cm, 2-7 cm, and 7+ cm from the sediment surface. Sample splits were sent to the USU Bug lab for identification of invertebrate species. Whenever this transect was not intercepting vegetation, 2-3 additional sample sites were identified at the pond within stands of representative vegetation where bird nests are located. The plant parts used for boron analyses will include seeds, shoot and roots of vascular plants, as well as algae or duckweeds skimmed from the surface. Samples were processed within 2 days of collection. Water samples filtered through a 0.45 μ membrane filter were analyzed for DOC, pH and ECe. The dried and washed vegetation samples were ground and stored. The benthic organisms and macro invertebrates were netted at the water surface. The dried samples were weighed, ground and stored. Samples were weighed, oven dried and reweighed. For plant and macro-invertebrate samples, a nitric and hydrogen peroxide digestion procedure is used to dissolve environmentally available elements. The Hot Water extraction and DTPA-Sorbitol extraction were compared to estimate wetland plant

  6. Vegetation community composition in wetlands created following oil sand mining in Alberta, Canada.

    PubMed

    Roy, Marie-Claude; Foote, Lee; Ciborowski, Jan J H

    2016-05-01

    Reclaiming wetlands following open pit mining for industrial oil sand extraction is challenging due to the physical and chemical conditions of the post-mined landscape. The aim of our study was to examine and compare the influence of oil sands process water (OSPW) and material (fine fluid tails or FFT) on the plant community composition of created wetlands. Compared to created-unamended and natural wetlands, the created wetlands amended with OSPW and/or FFT (created-tailings wetlands) had significantly higher water salinity, conductivity, dissolved oxygen concentration and lower oxidative-reductive potential. Water chemistry parameters of created-unamended did not differ significantly from those of natural wetlands. The sediment of created wetlands had significantly less moisture, total nitrogen, and organic content than the natural wetlands. The application of OSPW/FFT in created wetlands will likely lead to initial vegetation composition atypical of natural regional wetlands. For the objective of reclaiming vegetation composition to the status of natural regional wetlands, unamended wetlands were the best reclamation option, based on the physical and chemical parameters measured. Despite being the favored reclamation option, created-unamended wetlands' physical and chemical characteristics remain atypical of natural wetlands. Most significantly, the basin morphometry of created wetlands was significantly different from that of naturally-formed wetlands in the region, and this appears to partly explain difference in vegetation composition. We also demonstrate that species richness alone is not a useful measure in wetland monitoring. Instead, plant community composition is a better indicator of wetland conditions.

  7. Vegetation establishment in convectively accelerated streams

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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

  8. Environmental dispersion in a tidal wetland with sorption by vegetation

    NASA Astrophysics Data System (ADS)

    Wang, Ping; Chen, G. Q.

    2015-05-01

    Understanding of the solute transport mechanism under the effect of sorption by vegetation in tidal wetland gains its significance for environmental and ecological management. Presented in this paper is a theoretical analysis of effective environmental dispersion in a depth-dominated tidal wetland. Based on the transport in porous media, a linear sorption isotherm model is adopted to account for the sorption by vegetation, and two models for momentum and concentration transport in wetlands are given, respectively. The velocity of flow forced by oscillating pressure is derived, and the effect of dimensionless parameters on velocity pulsation is analyzed. The velocity direction may reverse in the case of pulsation amplitude larger than the mean velocity. Using Aris's method of concentration moments, we investigate the effective environmental dispersivity and concentration distribution. The effective environmental dispersivity increases over time at the initial stage to attain a steady oscillating status, the growth rate of which depends on the distribution coefficient KD . The variations of concentration distribution with typical dimensionless parameters are determined, which turn out to be consistent with those of dispersivity. The sorption by vegetation leads to lowered concentration and delayed contaminant cloud, contributing to the dispersion.

  9. The role of hydrochory in structuring riparian and wetland vegetation.

    PubMed

    Nilsson, Christer; Brown, Rebecca L; Jansson, Roland; Merritt, David M

    2010-11-01

    Hydrochory, or the passive dispersal of organisms by water, is an important means of propagule transport, especially for plants. During recent years, knowledge about hydrochory and its ecological consequences has increased considerably and a substantial body of literature has been produced. Here, we review this literature and define the state of the art of the discipline. A substantial proportion of species growing in or near water have propagules (fruits, seeds or vegetative units) able to disperse by water, either floating, submerged in flowing water, or with the help of floating vessels. Hydrochory can enable plants to colonize sites out of reach with other dispersal vectors, but the timing of dispersal and mechanisms of establishment are important for successful establishment. At the population level, hydrochory may increase the effective size and longevity of populations, and control their spatial configuration. Hydrochory is also an important source of species colonizing recruitment-limited riparian and wetland communities, contributing to maintenance of community species richness. Dispersal by water may even influence community composition in different landscape elements, resulting in landscape-level patterns. Genetically, hydrochory may reduce spatial aggregation of genetically related individuals, lead to high gene flow among populations, and increase genetic diversity in populations receiving many propagules. Humans have impacted hydrochory in many ways. For example, dams affect hydrochory by reducing peak flows and hence dispersal capacity, altering the timing of dispersal, and by presenting physical barriers to dispersal, with consequences for riverine plant communities. Hydrochory has been inferred to be an important vector for the spread of many invasive species, but there is also the potential for enhancing ecosystem restoration by improving or restoring water dispersal pathways. Climate change may alter the role of hydrochory by modifying the

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

    USGS Publications Warehouse

    Miller, R.L.; Fujii, R.

    2010-01-01

    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.

  11. Texture classification of vegetation cover in high altitude wetlands zone

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

  12. Coupled Simulation of Wetland Hydrology, Nutrient and Vegetation Dynamics

    NASA Astrophysics Data System (ADS)

    Yang, L.; Campbell, K. L.; Graham, W. D.; Kiker, G. A.

    2004-12-01

    Ecohydrological variations such as altered hydrologic regime, invasion of exotic flora, and nutrient enrichment in the Kissimmee-Okeechobee-Everglades aquatic ecosystem in south Florida have been observed. It is important to study the dynamics of wetland hydrology, nutrient and vegetation communities and their interactions over multiple spatial and temporal scales so that wetland restoration, ecological protection, and best management policy decision-making can be effectively accomplished. Hydrologic models are important tools in these decision-making processes. Hydrological components capable of multi-directional overland flow and lateral groundwater flow simulation within the Java-based, object-oriented framework of the ACRU2000 model were developed to make the existing hydrologic model in ACRU2000 more applicable in the Lake Okeechobee Basin where flat topography, high-water-table and sandy soils define the very unique hydrology. In addition nutrient components capable of multi-directional transport and transformation of nitrogen and phosphorus were modified to make the current nutrient model in ACRU2000 more applicable in the Lake Okeechobee Basin. Observed data in the Lake Okeechobee Basin were used to validate the coupled hydrologic and nutrient cycling model's predictions of the spatial and temporal distribution of flow and nutrient concentrations. The simulated results indicate that the coupled model is capable of simulating nutrient, overland, and lateral groundwater flows over a watershed that incorporates wetlands. Future work will focus on the development of a new wetland vegetation model to be integrated into this coupled hydrological and nutrient model. The new model will then be applied in the Lake Okeechobee Basin to simulate the ecohydrological variations due to the implementation of alternative water and land management practices. (More information regarding ACRU2000 and its modification for use in the Southeastern Coastal Plain can be found at

  13. Coevolution of hydrodynamics, vegetation and channel evolution in wetlands of a semi-arid floodplain

    NASA Astrophysics Data System (ADS)

    Seoane, Manuel; Rodriguez, Jose Fernando; Rojas, Steven Sandi; Saco, Patricia Mabel; Riccardi, Gerardo; Saintilan, Neil; Wen, Li

    2015-04-01

    The Macquarie Marshes are located in the semi-arid region in north western NSW, Australia, and constitute part of the northern Murray-Darling Basin. The Marshes are comprised of a system of permanent and semi-permanent marshes, swamps and lagoons interconnected by braided channels. The wetland complex serves as nesting place and habitat for many species of water birds, fish, frogs and crustaceans, and portions of the Marshes was listed as internationally important under the Ramsar Convention. Some of the wetlands have undergone degradation over the last four decades, which has been attributed to changes in flow management upstream of the marshes. Among the many characteristics that make this wetland system unique is the occurrence of channel breakdown and channel avulsion, which are associated with decline of river flow in the downstream direction typical of dryland streams. Decrease in river flow can lead to sediment deposition, decrease in channel capacity, vegetative invasion of the channel, overbank flows, and ultimately result in channel breakdown and changes in marsh formation. A similar process on established marshes may also lead to channel avulsion and marsh abandonment, with the subsequent invasion of terrestrial vegetation. All the previous geomorphological evolution processes have an effect on the established ecosystem, which will produce feedbacks on the hydrodynamics of the system and affect the geomorphology in return. In order to simulate the complex dynamics of the marshes we have developed an ecogeomorphological modelling framework that combines hydrodynamic, vegetation and channel evolution modules and in this presentation we provide an update on the status of the model. The hydrodynamic simulation provides spatially distributed values of inundation extent, duration, depth and recurrence to drive a vegetation model based on species preference to hydraulic conditions. It also provides velocities and shear stresses to assess geomorphological

  14. Vegetation of natural and artificial shorelines in Upper Klamath Basin’s fringe wetlands

    USGS Publications Warehouse

    Ray, Andrew M.; Irvine, Kathryn M.; Hamilton, Andy S.

    2013-01-01

    The Upper Klamath Basin (UKB) in northern California and southern Oregon supports large hypereutrophic lakes surrounded by natural and artificial shorelines. Lake shorelines contain fringe wetlands that provide key ecological services to the people of this region. These wetlands also provide a context for drawing inferences about how differing wetland types and wave exposure contribute to the vegetative assemblages in lake-fringe wetlands. Here, we summarize how elevation profiles and vegetation richness vary as a function of wave exposure and wetland type. Our results show that levee wetland shorelines are 4X steeper and support fewer species than other wetland types. We also summarize the occurrence probability of the five common wetland plant species that represent the overwhelming majority of the diversity of these wetlands. In brief, the occurrence probability of the culturally significant Nuphar lutea spp. polysepala and the invasive Phalaris arundinacea in wave exposed and sheltered sites varies based on wetland type. The occurrence probability for P. arundinacea was greatest in exposed portions of deltaic shorelines, but these trends were reversed on levees where the occurrence probability was greater in sheltered sites. The widespread Schoenoplectus acutus var. acutus occurred throughout all wetland and exposure type combinations but had a higher probability of occurrence in wave exposed sites. Results from this work will add to our current understanding of how wetland shoreline profiles interact with wave exposure to influence the occurrence probability of the dominant vegetative species in UKB’s shoreline wetlands.

  15. The effects of water-level fluctuations on vegetation in a Lake Huron wetland

    USGS Publications Warehouse

    Wilcox, D.A.; Nichols, S.J.

    2008-01-01

    The diversity and resultant habitat value of wetland plant communities in the Laurentian Great Lake's are dependent on water-level fluctuations of varying frequency and amplitude. Conceptual models have described the response of vegetation to alternating high and low lake levels, but few quantitative studies have documented the changes that occur. In response to recent concerns over shoreline management activities during an ongoing period of low lake levels in lakes Superior, Michigan, and Huron that began in 1999, we analyzed a quantitative data set from Saginaw Bay of Lake Huron collected from 1988 to 1993 during a previous lake-level decline to provide the needed information on vegetation responses. Transects were established that followed topographic contours with water-level histories that differed across a six-year period, ranging from barely flooded to dewatered for varying numbers of years to never dewatered. Percent cover data from randomly placed quadrats along those transects were analyzed to assess floristic changes over time, document development of distinct plant assemblages, and relate the results to lake-level changes. Ordinations showed that plant assemblages sorted out by transects that reflect differing water-level histories. Distinction of assemblages was maintained for at least three years, although the composition and positioning of those assemblages changed as lake levels changed. We present a model that uses orthogonal axes to plot transects by years out of water against distance above water and sorted those transects in a manner that matched ordination results. The model suggests that vegetation response following dewatering is dependent on both position along the water level/soil moisture gradient and length of time since dewatering. This study provided quantitative evidence that lake-level fluctuations drive vegetative change in Great Lakes wetlands, and it may assist in making decisions regarding shoreline management in areas that

  16. Vegetative ecological characteristics of restored reed (Phragmites australis) wetlands in the Yellow River Delta, China.

    PubMed

    Wang, Xuehong; Yu, Junbao; Zhou, Di; Dong, Hongfang; Li, Yunzhao; Lin, Qianxin; Guan, Bo; Wang, Yongli

    2012-02-01

    In this study, we compared ecological characteristics of wetland vegetation in a series of restoration projects that were carried out in the wetlands of Yellow River Delta. The investigated characteristics include plant composition structure, species diversity and community similarity in three kinds of Phragmites australis wetlands, i.e. restored P. australis wetlands (R1, R2, R3 and R4: restored in 2002, 2005, 2007 and 2009, respectively), natural P. australis wetland (N) and degraded P. australis wetland (D) to assess the process of wetlands restoration. The coverage of the R1 was 99%, which was similar to natural wetland. Among all studied wetlands, the highest and lowest stem density was observed in R1 and R2, respectively, Plant height and stem diameter show the same trend as N > R2 > R1 > R3 > D > R4. Species diversity of restored P. australis wetlands became closed to natural wetland. Both species richness and Shannon-Wiener index had similar tendency: increased first and then decreased with restored time. The highest species richness and species diversity were observed in R2, while the lowest values of those parameters were found in natural P. australis wetland. Similarity indexes between restored wetlands and natural wetland increased with the restoration time, but they were still less than 50%. The results indicate that the vegetation of P. australis wetlands has experienced a great improvement after several years' restoration, and it is feasible to restored degraded P. australis wetlands by pouring fresh water into those wetlands in the Yellow River Delta. However, it is notable that costal degraded P. australis wetland in this region may take years to decades to reach the status of natural wetland.

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

    SciTech Connect

    Sharitz, Rebecca, A.; Mulhouse, John, M.

    2004-05-01

    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 selected for restoration, and an additional four were initially chosen to serve as non-restored controls. Restoration treatments included plugging the existing ditches to increase water volume retention and wetland hydroperiod and clear-cutting removal of woody vegetation in the interiors. Planned endpoints of the restoration were herbaceous meadow and forested savanna bay interiors, and pine savanna and pine/hardwood forested bay margins (Barton and Singer 2001). To promote forested savanna interiors, saplings of bald cypress and swamp tupelo were planted following removal of the woody species.

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

    USGS Publications Warehouse

    Miller, Robin L.

    2011-01-01

    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.

  19. Wetland Vegetation Monitoring within Barataria Basin, Louisiana Following Exposure to Oil

    NASA Astrophysics Data System (ADS)

    Steyer, G.; Piazza, S.; Kokaly, R. F.; Patton, B.; Heckman, D.

    2011-12-01

    Following the Deepwater Horizon explosion and subsequent oil spill in April 2010 coastal wetlands in Louisiana were directly oiled, exposing vegetation and marsh soils to petroleum hydrocarbons. Oiling was observed at the marsh/water interface as well as within coastal marshes. The physical and chemical effects of oil spills can have both short and long term effects on wetland vegetation. These effects can include reductions in primary productivity and direct plant mortality. Even in the absence of this oiling event, the coastal landscape of Louisiana experiences high rates of land loss resulting from natural and anthropogenic causes. This additional stress has the potential to further reduce the extent and health of coastal marshes in this fragile ecosystem. We conducted a field study to document the impact of oiling on above and belowground vegetation biomass, plant species composition, and vegetation cover at sites within Barataria Basin, Louisiana. Six sampling sites were established, three within obviously oiled marshes and three where oiling was not readily apparent. Four sampling events occurred between October 2010 and October 2011. The preliminary results of the field study will be presented along with how these data helped validate remotely sensed data observations (AVIRIS) and calibrate ground reflectance in oiled and non-oiled marshes.

  20. [Factors affecting the vegetation restoration after fires in cold temperate wetlands: A review].

    PubMed

    Zhao, Feng-Jun; Wang, Li-Zhong; Shu, Li-Fu; Chen, Peng-Yu; Chen, Li-guang

    2013-03-01

    Cold temperate wetland plays an important role in maintaining regional ecological balance. Fire is an important disturbance factor in wetland ecosystem. Severe burning can induce the marked degradation of the ecological functions of wetland ecosystem. The vegetation restoration, especially the early vegetation restoration, after fires, is the premise and basis for the recovery of the ecological functions of the ecosystem. This paper reviewed the research progress on the factors affecting the vegetation restoration after fires in wetlands. The vegetation restoration after fires in cold temperate wetlands was controlled by the fire intensity, fire size, vegetation types before fires, regeneration characteristics of plant species, and site conditions. It was considered that the long-term monitoring on the post-fire vegetation restoration in cold temperate wetland, the key factors affecting the vegetation restoration, the roles of frozen soil layer on the post-fire vegetation restoration, and the theories and technologies on the vegetation restoration would be the main research directions in the future.

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

    USGS Publications Warehouse

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

    2007-01-01

    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.

  2. Microbial and vegetative changes associated with development of a constructed wetland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wetlands may be constructed to provide several ecosystem functions. A constructed wetland receiving agricultural runoff water was observed prior to, and for more than two years after, establishment. The excavated portion of this wetland was compared to an undisturbed, upland area and to an adjacent...

  3. Tidal wetland vegetation and ecotone profiles: The Rush Ranch Open Space Preserve

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Rush Ranch Open Space Preserve (Rush Ranch) is a component site of the San Francisco Bay National Estuarine Research Reserve (SF Bay NERR) that includes one of the largest undiked tidal wetlands in the San Francisco Estuary. The brackish tidal wetlands grade into transitional vegetation and unde...

  4. Tidal saline wetland regeneration of sentinel vegetation types in the Northern Gulf of Mexico: An overview

    USGS Publications Warehouse

    Jones, Scott F; Stagg, Camille L.; Krauss, Ken W.; Hester, Mark W.

    2016-01-01

    Tidal saline wetlands in the Northern Gulf of Mexico (NGoM) are dynamic and frequently disturbed systems that provide myriad ecosystem services. For these services to be sustained, dominant macrophytes must continuously recolonize and establish after disturbance. Macrophytes accomplish this regeneration through combinations of vegetative propagation and sexual reproduction, the relative importance of which varies by species. Concurrently, tidal saline wetland systems experience both anthropogenic and natural hydrologic alterations, such as levee construction, sea-level rise, storm impacts, and restoration activities. These hydrologic alterations can affect the success of plant regeneration, leading to large-scale, variable changes in ecosystem structure and function. This review describes the specific regeneration requirements of four dominant coastal wetland macrophytes along the NGoM (Spartina alterniflora, Avicennia germinans, Juncus roemerianus, and Batis maritima) and compares them with current hydrologic alterations to provide insights into potential future changes in dominant ecosystem structure and function and to highlight knowledge gaps in the current literature that need to be addressed.

  5. Tidal saline wetland regeneration of sentinel vegetation types in the Northern Gulf of Mexico: An overview

    NASA Astrophysics Data System (ADS)

    Jones, Scott F.; Stagg, Camille L.; Krauss, Ken W.; Hester, Mark W.

    2016-06-01

    Tidal saline wetlands in the Northern Gulf of Mexico (NGoM) are dynamic and frequently disturbed systems that provide myriad ecosystem services. For these services to be sustained, dominant macrophytes must continuously recolonize and establish after disturbance. Macrophytes accomplish this regeneration through combinations of vegetative propagation and sexual reproduction, the relative importance of which varies by species. Concurrently, tidal saline wetland systems experience both anthropogenic and natural hydrologic alterations, such as levee construction, sea-level rise, storm impacts, and restoration activities. These hydrologic alterations can affect the success of plant regeneration, leading to large-scale, variable changes in ecosystem structure and function. This review describes the specific regeneration requirements of four dominant coastal wetland macrophytes along the NGoM (Spartina alterniflora, Avicennia germinans, Juncus roemerianus, and Batis maritima) and compares them with current hydrologic alterations to provide insights into potential future changes in dominant ecosystem structure and function and to highlight knowledge gaps in the current literature that need to be addressed.

  6. Effects of salinity and flooding on post-hurricane regeneration potential in coastal wetland vegetation

    USGS Publications Warehouse

    Middleton, Beth A.

    2016-01-01

    CONCLUSIONS: Seed germination and subsequent seedling growth in coastal wetlands may in some cases be affected by salinity intrusion events even at low salinity levels (1 and 5 ppt). These results indicate that the potential is great for hurricanes to shift vegetation type in sensitive wetland types (e.g., maritime forest) if post-hurricane environments do not support the regeneration of extent vegetation.

  7. 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)

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

    2012-07-01

    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.

  8. Impact of Multiple Environmental Stresses on Wetland Vegetation Dynamics

    NASA Astrophysics Data System (ADS)

    Muneepeerakul, C. P.; Tamea, S.; Muneepeerakul, R.; Miralles-Wilhelm, F. R.; Rinaldo, A.; Rodriguez-Iturbe, I.

    2009-12-01

    This research quantifies the impacts of climate change on the dynamics of wetland vegetation under the effect of multiple stresses, such as drought, water-logging, shade and nutrients. The effects of these stresses are investigated through a mechanistic model that captures the co-evolving nature between marsh emergent plant species and their resources (water, nitrogen, light, and oxygen). The model explicitly considers the feedback mechanisms between vegetation, light and nitrogen dynamics as well as the specific dynamics of plant leaves, rhizomes, and roots. Each plant species is characterized by three independent traits, namely leaf nitrogen (N) content, specific leaf area, and allometric carbon (C) allocation to rhizome storage, which govern the ability to gain and maintain resources as well as to survive in a particular multi-stressed environment. The modeling of plant growth incorporates C and N into the construction of leaves and roots, whose amount of new biomass is determined by the dynamic plant allocation scheme. Nitrogen is internally recycled between pools of plants, litter, humus, microbes, and mineral N. The N dynamics are modeled using a parallel scheme, with the major modifications being the calculation of the aerobic and anoxic periods and the incorporation of the anaerobic processes. A simple hydrologic model with stochastic rainfall is used to describe the water level dynamics and the soil moisture profile. Soil water balance is evaluated at the daily time scale and includes rainfall, evapotranspiration and lateral flow to/from an external water body, with evapotranspiration loss equal to the potential value, governed by the daily average condition of atmospheric water demand. The resulting feedback dynamics arising from the coupled system of plant-soil-microbe are studied in details and species’ fitnesses in the 3-D trait space are compared across various rainfall patterns with different mean and fluctuations. The model results are then

  9. Forested floristic quality index: An assessment tool for forested wetland habitats using the quality and quantity of woody vegetation at Coastwide Reference Monitoring System (CRMS) vegetation monitoring stations

    USGS Publications Warehouse

    Wood, William B.; Shaffer, Gary P.; Visser, Jenneke M.; Krauss, Ken W.; Piazza, Sarai C.; Sharp, Leigh Anne; Cretini, Kari F.

    2017-02-08

    overstory and health of the herbaceous community beneath it because of resource competition (for example, light) and differing environmental preferences between the two communities. The herbaceous layer vegetation responds rapidly to basic environmental factors such as flooding, salinity, and nutrients and can offer insight into the sustainability of swamps on a temporal scale shorter than tha of the slowly growing woody vegetation.The FFQI will be available via the CRMS spatial viewer (http://lacoast.gov/crms2/home.aspx), and a new score will be calculated annually for each CRMS forested wetland site as data are collected to establish trends, to compare among sites, and to evaluate specific restoration projects when applicable. The FFQI will identify forested wetland areas in need of restoration and conservation and will help define targets and trajectories for restoration planning.

  10. Statistical classification of vegetation and water depths in montane wetlands

    USGS Publications Warehouse

    Sharp, Julia L.; Sodja, Richard S.; Greenwood, Mark; Rosenberry, Donald O.; Warren, Jeffrey M.

    2013-01-01

    Relationships between water depths and density of submergent vegetation were studied in montane wetlands using statistical techniques based on clustering and an extension of regression trees. Sago pondweed (Stuckenia pectinata) was associated with lower average water depths than water milfoil (Myriophyllum sibiricum). We detected a nonlinear relationship when average water depths were used to predict percent cover in S. pectinata, with depths of 30–40 cm, producing the highest predicted average percent cover of S. pectinata; higher and lower depths resulted in lower percent cover predictions. For M. sibiricum, higher water depths were monotonically associated with higher average percent cover. To foster more S. pectinata and less M. sibiricum, managers might employ water control structures to reduce water depths below 1 m, using both temporary drawdowns and average depths of 30–40 cm. Other species responded less markedly to water depth variation. Should decreased water depths become more common, these results suggest an increase in S. pectinata and a decrease in M. sibiricum.

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

    USGS Publications Warehouse

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

    2009-01-01

    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.

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

    PubMed

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

    2013-11-01

    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.

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

    USGS Publications Warehouse

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

    2010-01-01

    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.

  14. Effects of vegetation management in constructed wetland treatment cells on water quality and mosquito production

    USGS Publications Warehouse

    Thullen, J.S.; Sartoris, J.J.; Walton, W.E.

    2002-01-01

    The impact of three vegetation management strategies on wetland treatment function and mosquito production was assessed in eight free water surface wetland test cells in southern California during 1998-1999. The effectiveness of the strategies to limit bulrush Schoenoplectus californicus culm density within the cells was also investigated. Removing accumulated emergent biomass and physically limiting the area in which vegetation could reestablish, significantly improved the ammonia - nitrogen removal efficiency of the wetland cells, which received an ammonia-dominated municipal wastewater effluent (average loading rate = 9.88 kg/ha per day NH4-N). We determined that interspersing open water with emergent vegetation is critical for maintaining the wetland's treatment capability, particularly for systems high in NH4-N. Burning aboveground plant parts and thinning rhizomes only temporarily curtailed vegetation proliferation in shallow zones, whereas creating hummocks surrounded by deeper water successfully restricted the emergent vegetation to the shallower hummock areas. Since the hummock configuration kept open water areas interspersed throughout the stands of emergent vegetation, the strategy was also effective in reducing mosquito production. Decreasing vegetation biomass reduced mosquito refuge areas while increasing mosquito predator habitat. Therefore, the combined goals of water quality improvement and mosquito management were achieved by managing the spatial pattern of emergent vegetation to mimic an early successional growth stage, i.e. actively growing plants interspersed with open water. ?? 2002 Elsevier Science B.V. All rights reserved.

  15. Role of vegetation in a constructed wetland on nutrient-pesticide mixture toxicity of Hyalella azteca

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The toxicity of a nutrient-pesticide mixture in non-vegetated and vegetated sections of a constructed wetland (60 X 30 X 0.3 m) was assessed using Hyalella azteca 48 h aqueous whole effluent toxicity bioassays. Both sections were amended with a mixture of sodium nitrate, triple super phosphate, dia...

  16. Effects of vegetation in mitigating the toxicity of pesticide mixtures in sediments of a wetland mesocosm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study assessed effects of a mixture of two pesticides, diazinon and permethrin, on 48-h sediment toxicity to Hyalella azteca in a constructed wetland mesocosm containing non-vegetated and vegetated sections. Sediment samples were collected at inflow, middle, and back points within each sectio...

  17. Aircraft MSS data registration and vegetation classification of wetland change detection

    USGS Publications Warehouse

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

    1988-01-01

    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.

  18. Use of a wetland index to evaluate changes in riparian vegetation after livestock exclusion

    USGS Publications Warehouse

    Coles-Ritchie, M. C.; Roberts, D.W.; Kershner, J.L.; Henderson, R.C.

    2007-01-01

    A method was developed to characterize ecological integrity of riparian sites based on the abundance of hydric species. This wetland index can be calculated with species data, or with community type data as performed here. Classified riparian community types were used to describe vegetation at 14 livestock exclosures and adjacent grazed areas. Community type wetland index values were generated and used to calculate site wetland index values. It was hypothesized that removal of livestock would result in higher wetland index values because of release from herbivory and decreased physical disturbance of vegetation, streambanks, and soil. The wetland index for exclosures was about 12% higher than grazed sites; differences were statistically significant (p < 0.01) based on paired t-tests. The increase in hydric vegetation after livestock exclusion may have contributed to the greater bank stability (p = 0.002) and smaller width-to-depth ratio (p = 0.005) in exclosures. Challenges were encountered in using community types to describe and compare site vegetation, which could be avoided with species data collection. The wetland index can be a tool to monitor sites over time, compare sites with similar environments, or compare sites for which environmental differences can be accounted.

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

    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

  20. Unmanned Aerial Vehicles Produce High-Resolution Seasonally-Relevant Imagery for Classifying Wetland Vegetation

    NASA Astrophysics Data System (ADS)

    Marcaccio, J. V.; Markle, C. E.; Chow-Fraser, P.

    2015-08-01

    With recent advances in technology, personal aerial imagery acquired with unmanned aerial vehicles (UAVs) has transformed the way ecologists can map seasonal changes in wetland habitat. Here, we use a multi-rotor (consumer quad-copter, the DJI Phantom 2 Vision+) UAV to acquire a high-resolution (< 8 cm) composite photo of a coastal wetland in summer 2014. Using validation data collected in the field, we determine if a UAV image and SWOOP (Southwestern Ontario Orthoimagery Project) image (collected in spring 2010) differ in their classification of type of dominant vegetation type and percent cover of three plant classes: submerged aquatic vegetation, floating aquatic vegetation, and emergent vegetation. The UAV imagery was more accurate than available SWOOP imagery for mapping percent cover of submergent and floating vegetation categories, but both were able to accurately determine the dominant vegetation type and percent cover of emergent vegetation. Our results underscore the value and potential for affordable UAVs (complete quad-copter system < 3,000 CAD) to revolutionize the way ecologists obtain imagery and conduct field research. In Canada, new UAV regulations make this an easy and affordable way to obtain multiple high-resolution images of small (< 1.0 km2) wetlands, or portions of larger wetlands throughout a year.

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

    DTIC Science & Technology

    2010-07-01

    bryophytes , can be effectively sampled using much smaller plots (Bonham 1989). The most appropriate size for a sample plot depends on the type of...and, when abundant, provide strong indicators of hydrophytic vegetation (Seppelt et al. 2008; Lichvar et al. 2009). Sampling bryophytes presents...of wetland specialist bryophytes (USACE 2007). In some wetland types, bryophytes may contribute significant floristic diversity and canopy coverage

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

    USGS Publications Warehouse

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

    2013-01-01

    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.

  3. Poyang Lake wetland vegetation biomass inversion using polarimetric RADARSAT-2 synthetic aperture radar data

    NASA Astrophysics Data System (ADS)

    Shen, Guozhuang; Liao, Jingjuan; Guo, Huadong; Liu, Ju

    2015-01-01

    Poyang Lake is the largest freshwater lake in China and one of the most important wetlands in the world. Vegetation, an important component of wetland ecosystems, is one of the main sources of the carbon in the atmosphere. Biomass can quantify the contribution of wetland vegetation to carbon sinks and carbon sources. Synthetic aperture radar (SAR), which can operate in all day and weather conditions and penetrate vegetation to some extent, can be used to retrieve information about vegetation structure and the aboveground biomass. In this study, RADARSAT-2 polarimetric SAR data were used to retrieve aboveground vegetation biomass in the Poyang Lake wetland. Based on the canopy backscatter model, the vegetation backscatter characteristics in the C-band were studied, and a good relation between simulated backscatter and backscatter in the RADARSAT-2 imagery was achieved. Using the backscatter model, pairs of training data were built and used to train the back propagation artificial neural network. The biomass was retrieved using this ANN and compared with the field survey results. The root-mean-square error in the biomass estimation was 45.57 g/m2. This shows that the combination of the model and polarimetric decomposition components can efficiently improve the inversion precision.

  4. Fractional Vegetation Cover of East African Wetlands Observed on Ground and from Space

    NASA Astrophysics Data System (ADS)

    Schmidt, M.; Amler, E.; Guerschmann, J. P.; Scarth, P.; Behn, K.; Thonfeld, F.

    2016-08-01

    Wetlands are important ecosystems providing numerous ecosystem services. They are of particular importance to communities in East Africa where agriculture is the most important economic sector and where food availability to households critical. During an intensive field campaign in the dry season of 2013 were Fractional Vegetation Cover (FVC) measurements, botanical vegetation cover and vegetation structure estimates acquired in three wetland test sites within the East African region. FVC cover data were collated in three strata: ground layer, midstorey and overstorey (woody vegetation greater than 2 m). Fractional cover estimates for the green and no-green vegetative fraction were calculated for Landsat MODIS imagery. These FVC data products were evaluated a) with FVC field data and b) relative to each other for their usability in the East African region. First results show some promise for further studies.

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

    PubMed

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

    2013-01-01

    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.

  6. Comparison between microwave coherent and incoherent scattering models for wetland vegetation in Poyang Lake area

    NASA Astrophysics Data System (ADS)

    Xu, Tao; Liao, Jingjuan

    2014-11-01

    In order to reveal more deeply the scattering characteristics of wetland vegetation and determine the microwave scattering model suitable for the inversion of wetland vegetation parameters, the comparison and analysis between microwave coherent and incoherent scattering models for wetland vegetation in Poyang Lake area were performed in this paper. In the research, we proposed a coherent scattering model exclusive for wetland vegetation, in which, Generalized Rayleigh-Gans (GRG) approach and infinite-length dielectric cylinder were used to calculate single-scattering matrices of wetland vegetation leaves and stalks. In addition, coherent components produced from interaction among the scattering mechanisms and different scatterers were also considered and this coherent model was compared with Michigan Microwave Canopy Scattering (MIMICS) model. The measured data collected in 2011 in Poyang Lake wetland were used as the input parameters of the coherent and incoherent models. We simulated backscattering coefficients of VV, VH and HH polarization at C band and made a comparison between the simulation results and C-band data from the Radarsat-2 satellite. For both coherent and incoherent scattering model, simulation results for HH and VV polarization were better than the simulation results for HV polarization. In addition, comparisons between coherent and incoherent scattering models proved that the coherence triggered by the scattering mechanism and different scatterers can't be ignored. In the research, we analyzed differences between coherent and incoherent scattering models with change of incident angle. In most instances, the difference between coherent and incoherent scattering models is of the order of several dB.

  7. Analysis on vegetation changes of Maqu alpine wetlands in the Yellow River source region

    NASA Astrophysics Data System (ADS)

    Chu, Lin; Huang, Chong; Liu, Gaohuan; Liu, Qingsheng; Zhao, Jun

    2014-11-01

    The Maqu alpine wetlands have irreplaceable function in maintaining ecological balance and conserving biodiversity to the upriver regions of the Yellow River. In last 30 years, Global warming causes significant changes in vegetation. However, the Maqu alpine wetland is undergoing a degradation caused by warming and drying climate. Aim of this study is to investigate the vegetation changes for a better understanding the consequence of climate variations to the wetland degradation. Based on the Landsat TM images of 2000 and 2010, the landscape pattern changes were analyzed by classification statistics, dynamic transfer matrix and landscape pattern indices. Based on the MOD11A2 and MOD13A2 data from 2000 to 2010, NDVI and land surface temperature (LST) dataset were extracted. NDVI time-series data processed with S-G filtering method was used to find temporal and spatial variation characteristics, and linear trend was analyzed by ordinary least squares regression method. NDVI and LST were used to construct Ts-NDVI feature space, and then TVDI was obtained to explore changes of soil moisture. Relationship between climate variations and wetland degradation were found by ordinary least squares regression method. Results indicated that both wetland area and landscape heterogeneity decreased. Annual NDVI presented fluctuated decreasing trend and there was strong spatial heterogeneity in patterns of NDVI change. Annual TVDI proved to have an increasing trend which showed the drought gradually intensified. "Warming and drought" climate appear to be critical factors contributing to wetland degradation. Precipitation has a stronger correlation rather than temperature.

  8. A comparison of Aedes vigilax larval population densities and associated vegetation categories in a coastal wetland, Northern Territory, Australia.

    PubMed

    Jacups, S P; Kurucz, N; Whelan, P I; Carter, J M

    2009-12-01

    Darwin's northern suburbs border an extensive coastal reed and upper mangrove wetland recognized as an important larval habitat for Aedes vigilax (Skuse), the northern salt marsh mosquito, an established vector for Ross River and Barmah Forest viruses and an appreciable pest species. We sought to identify the most important vegetation categories associated with Ae. vigilax breeding to maximize the efficiency of mosquito control efforts. Using a generalized linear model with negative binominal distribution and log link, this study compares larval densities, determined by focused dipping, between 13 discernable vegetation categories. The incidence rate ratios (RR) generated can be used to compare the magnitude of larval densities for each vegetation category, compared with the reference category. Aedes vigilax larval densities were almost ten times greater in artificial drainage areas (RR=9.82), followed by tide-affected reticulate (Sporobolus/Xerochloa) areas (RR=8.15), then Schoenoplectus/mangroves (RR=2.29), compared with the reference vegetation category "lower mangroves." Furthermore, larval densities were highest in May, due to tidal inundation, for drainage areas and tide-affected reticulates (RR=12.2, 11.7, respectively) compared with March, the reference month. Thus, to maximize the efficiency of aerial salt marsh mosquito control operations in this wetland, larval control is best accomplished by concentrating on drains, Schoenoplectus/mangroves, and tide-affected reticulate areas, commencing early after the wet season. These results should apply to other areas of salt marsh mosquito breeding across northern Australia.

  9. Mapping swamp timothy (Cripsis schenoides) seed productivity using spectral values and vegetation indices in managed wetlands

    SciTech Connect

    Rahilly, P.J.A.; Li, D.; Guo, Q.; Zhu, J.; Ortega, R.; Quinn, N.W.T.; Harmon, T.C.

    2010-01-15

    This work examines the potential to predict the seed productivity of a key wetland plant species using spectral reflectance values and spectral vegetation indices. Specifically, the seed productivity of swamp timothy (Cripsis schenoides) was investigated in two wetland ponds, managed for waterfowl habitat, in California's San Joaquin Valley. Spectral reflectance values were obtained and associated spectral vegetation indices (SVI) calculated from two sets of high resolution aerial images (May 11, 2006 and June 9, 2006) and were compared to the collected vegetation data. Vegetation data were collected and analyzed from 156 plots for total aboveground biomass, total aboveground swamp timothy biomass, and total swamp timothy seed biomass. The SVI investigated included the Simple Ratio (SR), Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), Transformed Soil Adjusted Vegetation Index (TSAVI), Modified Soil Adjusted Vegetation Index (MSAVI), and Global Environment Monitoring Index (GEMI). We evaluated the correlation of the various SVI with in situ vegetation measurements for linear, quadratic, exponential and power functions. In all cases, the June image provided better predictive capacity relative to May, a result that underscores the importance of timing imagery to coincide with more favorable vegetation maturity. The north pond with the June image using SR and the exponential function (R{sup 2}=0.603) proved to be the best predictor of swamp timothy seed productivity. The June image for the south pond was less predictive, with TSAVI and the exponential function providing the best correlation (R{sup 2}=0.448). This result was attributed to insufficient vegetal cover in the south pond (or a higher percentage of bare soil) due to poor drainage conditions which resulted in a delay in swamp timothy germination. The results of this work suggest that spectral reflectance can be used to estimate seed productivity in managed seasonal

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

    USGS Publications Warehouse

    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

    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.

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

    USGS Publications Warehouse

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

    2009-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2010-08-01

    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.

  14. The effect of floating vegetation on denitrification and greenhouse gas production in wetland mesocosms

    NASA Astrophysics Data System (ADS)

    Jacobs, A. E.; Harrison, J. A.

    2012-12-01

    Anthropogenic intensification of nitrogen (N) loading to aquatic ecosystems is widespread and can lead to the degradation of these systems. Wetlands are important sites for N removal via denitrification, the microbially mediated reduction of reactive nitrate to inert N2 gas, but they can also produce high levels of greenhouse gases. Floating plants play an important role in encouraging denitrification, since they create low oxygen conditions that may favor denitrification. We investigated whether wetland sediments with floating plant cover had higher denitrification and greenhouse gas production rates than wetland sediments without floating plants. Replicate flow-through mesocosms with wetland sediment and water were constructed in a growth chamber to mimic the wetland where the sediment and water were collected. Mesocosm treatments were covered with floating vegetation (duckweed), an opaque tarp, or no cover to determine how cover type affects denitrification and greenhouse gas production and whether biotic or abiotic factors are likely responsible for observed differences. Denitrification and greenhouse gas production rates were calculated by measuring excess N2 gas, methane, and nitrous oxide concentrations in the water column and measuring the gas exchange rates between the water column and the atmosphere. Gas exchange rates were measured using an inert volatile tracer added to the water column and accumulation of gas in the mesocosm headspace. Additional mesocosm experiments were performed to determine how duckweed-dominated wetland systems respond to nitrogen loading and which mechanism for lowering dissolved oxygen concentrations is important in affecting denitrification under floating vegetation. Mesocosms with floating vegetation had lower dissolved oxygen than no cover or tarp-covered mesocosms, which is consistent with field and literature observations. Water flowing out of the mesocosms had statistically lower total nitrogen and nitrate concentrations

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

    USGS Publications Warehouse

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

    2008-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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

  17. Soil-vegetation correlations in selected wetlands and uplands of North-Central Florida

    USGS Publications Warehouse

    Best, G. Ronnie; Wolfe, Charlotte; Segal, Debra S.

    1990-01-01

    Vegetation on four hydric and two nonhydric soils series in north-central Florida was sampled as part of a national study examining the correspondence between wetland vegetation and soils. The wetland character of the vegetation was estimated by weighted average calculations using published wetland indicator values for individual plant species. The weighted averages produced an ordering of plant communities in general agreement with the hydric character of the soils. However, the two nonhydric soils has weighted average scores slightly below 3, normally considered the lowest end of the range of nonhydric vegetation. There was no clear or consistent effect of fire management on the weighted average scores. Vegetation strata (herbaceous, low shrub, tall shrub, and trees) were generally similar in weighted average values, with the wettest of the hydric soils tending to be low in all strata and the nonhydric soils tending to be high in all strata. However, strata differed considerably in the specific values for a single soil and in the specific rank ordering of soils in different strata.

  18. Estimating canopy water content of wetland vegetation using hyperspectral and multispectral remote sensing data

    NASA Astrophysics Data System (ADS)

    Sun, Yonghua; Wang, Yihan; Huang, Jin

    2015-10-01

    The canopy water content of wetland vegetation is an important measuring index of the health status of wetland ecosystem. This article takes the Honghe national wetland nature reserve as study area. We focus on innovative approaches for retrieving canopy water content from optical remote sensing data-multispectral and hyperspectral data. Spectral features, such as narrow band spectral indices, hyperspectral vegetation indices in early literatures, absorption features and vegetation indices extracted from TM image were used to estimate the canopy water content. For narrow band spectral indices, Normalized difference vegetation index comprised of 970 nm and at 900 nm had a highest correlation with canopy water content. For general hyperspectral vegetation indices in early literatures, WI had a highest correlation with canopy water content. For absorption features, the absorption deepness at 1200nm had a highest correlation with canopy water content. In addition, NDII (band5) extracted from TM images could be used for estimating canopy water content. Finally, a distribution map of canopy water content in HNNR was generated.

  19. Role of vegetation in a constructed wetland on nutrient-pesticide mixture toxicity to Hyalella azteca.

    PubMed

    Lizotte, Richard E; Moore, Matthew T; Locke, Martin A; Kröger, Robert

    2011-02-01

    The toxicity of a nutrient-pesticide mixture in nonvegetated and vegetated sections of a constructed wetland (882 m² each) was assessed using Hyalella azteca 48-h aqueous whole-effluent toxicity bioassays. Both sections were amended with a mixture of sodium nitrate, triple superphosphate, diazinon, and permethrin simulating storm-event agricultural runoff. Aqueous samples were collected at inflow, middle, and outflow points within each section 5 h, 24 h, 72 h, 7 days, 14 days, and 21 days postamendment. Nutrients and pesticides were detected throughout both wetland sections with concentrations longitudinally decreasing more in vegetated than nonvegetated section within 24 h. Survival effluent dilution point estimates-NOECs, LOECs, and LC₅₀s-indicated greatest differences in toxicity between nonvegetated and vegetated sections at 5 h. Associations of nutrient and pesticide concentrations with NOECs indicated that earlier toxicity (5-72 h) was from permethrin and diazinon, whereas later toxicity (7-21 days) was primarily from diazinon. Nutrient-pesticide mixture concentration-response assessment using toxic unit models indicated that H. azteca toxicity was due primarily to the pesticides diazinon and permethrin. Results show that the effects of vegetation versus no vegetation on nutrient-pesticide mixture toxicity are not evident after 5 h and a 21-day retention time is necessary to improve H. azteca survival to ≥90% in constructed wetlands of this size.

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

    USGS Publications Warehouse

    Kantrud, H.A.

    1986-01-01

    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.

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

    USGS Publications Warehouse

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

    2004-01-01

    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

  2. Vegetation survey of Four Mile Creek wetlands. [Savannah River Plant

    SciTech Connect

    Loehle, C.

    1990-11-01

    A survey of forested wetlands along upper Four Mile Creek was conducted. The region from Road 3 to the creek headwaters was sampled to evaluate the composition of woody and herbaceons plant communities. All sites were found to fall into either the Nyssa sylvatica (Black Gum) -- Persea borbonia (Red Bay) or Nyssa sylvatica -- Acer rubrum (Red Maple) types. These community types are generally species-rich and diverse. Previous studies (Greenwood et al., 1990; Mackey, 1988) demonstrated contaminant stress in areas downslope from the F- and H-Area seepage basins. In the present study there were some indications of contaminant stress. In the wetland near H-Area, shrub basal area, ground cover stratum species richness, and diversity were low. In the area surrounding the F-Area tree kill zone, ground cover stratum cover and shrub basal area were low and ground cover stratum species richness was low. The moderately stressed site at F-Area also showed reduced overstory richness and diversity and reduced ground cover stratum richness. These results could, however, be due to the very high basal area of overstory trees in both stressed F-Area sites that would reduce light availability to understory plants. No threatened or endangered plant species were found in the areas sampled. 40 refs., 4 figs., 8 tabs.

  3. An evaluation of rapid methods for monitoring vegetation characteristics of wetland bird habitat

    USGS Publications Warehouse

    Tavernia, Brian G; Lyons, James E.; Loges, Brian W; Wilson, Andrew; Collazo, Jaime; Runge, Michael C.

    2016-01-01

    Wetland managers benefit from monitoring data of sufficient precision and accuracy to assess wildlife habitat conditions and to evaluate and learn from past management decisions. For large-scale monitoring programs focused on waterbirds (waterfowl, wading birds, secretive marsh birds, and shorebirds), precision and accuracy of habitat measurements must be balanced with fiscal and logistic constraints. We evaluated a set of protocols for rapid, visual estimates of key waterbird habitat characteristics made from the wetland perimeter against estimates from (1) plots sampled within wetlands, and (2) cover maps made from aerial photographs. Estimated percent cover of annuals and perennials using a perimeter-based protocol fell within 10 percent of plot-based estimates, and percent cover estimates for seven vegetation height classes were within 20 % of plot-based estimates. Perimeter-based estimates of total emergent vegetation cover did not differ significantly from cover map estimates. Post-hoc analyses revealed evidence for observer effects in estimates of annual and perennial covers and vegetation height. Median time required to complete perimeter-based methods was less than 7 percent of the time needed for intensive plot-based methods. Our results show that rapid, perimeter-based assessments, which increase sample size and efficiency, provide vegetation estimates comparable to more intensive methods.

  4. Surface elevation change and vegetation distribution dynamics in a subtropical coastal wetland: Implications for coastal wetland response to climate change

    NASA Astrophysics Data System (ADS)

    Rogers, Kerrylee; Saintilan, Neil; Woodroffe, Colin D.

    2014-08-01

    The response of coastal wetlands to sea-level rise is receiving global attention and observed changes in the distribution of mangrove and salt marsh are increasingly associated with global climate change, particularly sea-level and temperature rise, and potentially elevated carbon dioxide. Processes operating over smaller-spatial scales, such as rainfall variability and nutrient enrichment are also proposed as possible short-term drivers of changes in the distribution of mangrove and salt marsh. We consider the response of mangrove and salt marsh in a subtropical estuary to changes in environmental variables over a 12 year period by comparing rates of surface elevation change and vegetation distribution dynamics to hydrological and climatic variables, specifically water level and rainfall. This period of analysis captured inter-annual variability in sea level and rainfall associated with different phases of the El Niño Southern Oscillation (ENSO). We found that the mangrove and salt marsh trend of increasing elevation was primarily controlled by position within the tidal prism, in this case defined by inundation depth and distance to the tidal channel. Rainfall was not a primary driver of elevation trends in mangrove and salt marsh, but rainfall and water level variability did influence variability in elevation over the study period, though cross-correlation of these factors confounds identification of a single process driving this variability. These results highlight the scale-dependence of coastal wetland vegetation distribution dynamics; the longer-term trend of surface elevation increase and mangrove encroachment of salt marsh correlated with global sea-level trends, while short-term variability in surface elevation was related to local variability in water level and rainfall. Rates of surface elevation increase were found to lag behind rates of water level change within the Tweed River, which may facilitate further expansion of mangrove into salt marsh. This

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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

  6. Hydrodynamics, vegetation transition and geomorphology coevolution in a semi-arid floodplain wetland.

    NASA Astrophysics Data System (ADS)

    Sandi, Steven; Rodriguez, Jose F.; Saco, Patricia M.; Riccardi, Gerardo; Wen, Li; Saintilan, Neil

    2016-04-01

    The Macquarie Marshes is a complex system of marshes, swamps and lagoons interconnected by a network of streams in the semi-arid region in north western NSW, Australia. The low-gradient topography of the site leads to channel breakdown processes where the river network becomes practically non-existent. As a result, the flow extends over large areas of wetland that later re-join and reform channels exiting the system. Vegetation in semiarid wetlands are often water dependent and flood tolerant species that rely on periodical floods in order to maintain healthy conditions. The detrimental state of vegetation in the Macquarie Marshes over the past few decades has been linked to decreasing inundation frequencies. Spatial distribution of flood tolerant overstory species such as River Red Gum and Black Box has not greatly changed since early 1990's, however; the condition of the vegetation patches shows a clear deterioration evidenced by terrestrial species encroachment on the wetland understory. On the other hand, areas of flood dependent species such as Water Couch and Common Reed have undergone complete succession to terrestrial species and dryland. In order to simulate the complex dynamics of the marshes we have developed an ecogeomorphological modelling framework that combines hydrodynamic, vegetation and channel evolution modules and in this presentation we provide an update on the status of the model. The hydrodynamic simulation provides spatially distributed values of inundation extent, duration, depth and recurrence to drive a vegetation model based on species preference to hydraulic conditions. It also provides velocities and shear stresses to assess geomorphological changes. Regular updates of stream network, floodplain surface elevations and vegetation coverage provide feedbacks to the hydrodynamic model. We presents also the development and assessment of transitional rules to determine if the water conditions have been met for different vegetation

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

    PubMed

    Tang, Ming-Yan; Yang, Yong-Xing

    2014-05-01

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

  8. Wetland vegetation responses to liming an Adirondack watershed

    SciTech Connect

    Mackun, I.R.

    1993-01-01

    Watershed liming as a long-term mitigation strategy to neutralize lake acidity, from increasing acid deposition, was initiated in North America at Woods Lake in the west central Adirondack region of New York. In October 1989, a dose of 10 MT lime (83.5% CaCO[sub 3]) ha[sup [minus]1] was aerially applied to 48% of the watershed. The wetlands adjacent to Woods Lake showed two distinct community types: one dominated by Chamaedaphne calyculata, and one dominated by graminoids and other herbaceous species. Within two years, liming did not alter the structure of either community type, and changed the cover or frequency of only 6 of 64 individual taxa. Most of these changes occurred in the herbaceous community type. The only strong positive response to liming was a nearly threefold increase in cover of the rhizomatous sedge Cladium mariscoides. The cover of Carex interior and Sphagnum spp. benefited from lime addition, while cover of Drosera intermedia and Muhlenbergia uniflora, and frequency of Hypericum canadense responded negatively to lime. Liming influenced the competitive release of only three taxa, all forbs with small growth forms. The tissue chemistry of foliage and twigs of Myrica gale, Chamaedaphne calyculata, and Carex stricta in the Chamaedaphne calyculata community type clearly illustrated species-specific patterns of nutrient accumulation and allocation both before and after liming. Concentrations of 17 of 20 elements responded to liming, although the responses varied among species and plant parts. Carex foliage was least responsive to liming, and Chamaedaphne twigs were most responsive. Elemental changes in plant tissues will be reflected in litter and many influence long-term nutrient dynamics in the wetland community.

  9. The design of vegetative constructed wetlands for the treatment of highway runoff.

    PubMed

    Shutes, R B; Revitt, D M; Lagerberg, I M; Barraud, V C

    1999-09-01

    The Environment Agency for England and Wales are responsible for assessing the effects of highway runoff and for monitoring the treatment systems/procedures which have been introduced for the reduction of deleterious effects. The Agency is looking into the improvement of surface water management in terms of best management practices and plans to work in partnership with the Highways Agency to achieve this aim. Among the treatment options being considered are constructed wetlands. Draft Guidelines have been developed to provide information on their design. This paper describes procedures for carrying out an Environmental Sensitivity Analysis to determine whether treatment by a constructed wetland is appropriate. Information on water quality and quantity is required as well as the sensitivity of the receiving environment. The legislative position, particularly in relation to the discharge quality of the water and the conservation status of the receiving environment, needs also to be considered. The factors that will determine the most appropriate wetland design criteria include traffic loadings, road drainage area, land availability, cost and the size/extent and type of the receiving water body. The following structures are recommended for incorporation in the overall design; oil separator and silt trap, spillage containment, settlement pond, vegetative wetland and final settlement tank. The operation and maintenance procedures and the monitoring requirements for a functioning wetland are described.

  10. Energy and water balance response of a vegetated wetland to herbicide treatment of invasive Phragmites australis

    NASA Astrophysics Data System (ADS)

    Mykleby, Phillip M.; Lenters, John D.; Cutrell, Gregory J.; Herrman, Kyle S.; Istanbulluoglu, Erkan; Scott, Durelle T.; Twine, Tracy E.; Kucharik, Christopher J.; Awada, Tala; Soylu, Mehmet E.; Dong, Bo

    2016-08-01

    The energy and water balance of a Phragmites australis dominated wetland in south central Nebraska was analyzed to assess consumptive water use and the potential for "water savings" as a result of vegetation eradication via herbicide treatment. Energy balance measurements were made at the field site for two growing seasons (treated and untreated), including observations of net radiation, heat storage, and sensible heat flux, which was measured using a large-aperture scintillometer. Latent heat flux was calculated as a residual of the energy balance, and comparisons were made between the two growing seasons and with model simulations to examine the relative impacts of vegetation removal and climate variability. Observed ET rates dropped by roughly 32% between the two growing seasons, from a mean of 4.4 ± 0.7 mm day-1 in 2009 (with live vegetation) to 3.0 ± 0.8 mm day-1 in 2010 (with dead P. australis). These results are corroborated by the Agro-IBIS model simulations, and the reduction in ET implies a total "water savings" of 245 mm over the course of the growing season. The significant decreases in ET were accompanied by a more-than-doubling of sensible heat flux, as well as a ∼60% increase in heat storage due to decreased LAI. Removal of P. australis was also found to cause measurable changes in the local micrometeorology at the wetland. Consistent with the observed increase in sensible heat flux during 2010, warmer, drier, windier conditions were observed in the dead, P. australis section of the wetland, compared to an undisturbed section of live, native vegetation. Modeling results suggest that the elimination of transpiration in 2010 was partially offset by an increase in surface evaporation, thereby reducing the subsequent water savings by roughly 60%. Thus, the impact of vegetation removal depends on the local climate, depth to groundwater, and management decisions related to regrowth of vegetation.

  11. Vegetation-induced spatial variability of soil redox properties in wetlands

    NASA Astrophysics Data System (ADS)

    Szalai, Zoltán; Jakab, Gergely; Kiss, Klaudia; Ringer, Marianna; Balázs, Réka; Zacháry, Dóra; Horváth Szabó, Kata; Perényi, Katalin

    2016-04-01

    Vegetation induced land patches may result spatial pattern of on soil Eh and pH. These spatial pattern are mainly emerged by differences of aeration and exudation of assimilates. Present paper focuses on vertical extent and temporal dynamics of these patterns in wetlands. Two study sites were selected: 1. a plain wetland on calcareous sandy parent material (Ceglédbercel, Danube-Tisza Interfluve, Hungary); 2. headwater wetland with calcareous loamy parent material (Bátaapáti, Hungary). Two vegetation patches were studied in site 1: sedgy (dominated by Carex riparia) and reedy (dominated by Phragmites australis). Three patches were studied in site2: sedgy1 (dominated by C vulpina), sedgy 2 (C. riparia); nettle-horsetail (Urtica dioica and Equisetum arvense). Boundaries between patches were studied separately. Soil redox, pH and temperature studied by automated remote controlled instruments. Three digital sensors (Ponsell) were installed in each locations: 20cm and 40cm sensors represent the solum and 100 cm sensor monitors the subsoil). Groundwater wells were installed near to triplets for soil water sampling. Soil Eh, pH and temperature values were recorded in each 10 minutes. Soil water sampling for iron and DOC were carried out during saturated periods. Spatial pattern of soil Eh is clearly caused by vegetation. We measured significant differences between Eh values of the studied patches in the solum. We did not find this kinds horizontal differences in the subsoil. Boundaries of the patches usually had more reductive soil environment than the core areas. We have found temporal dynamics of the spatial redox pattern. Differences were not so well expressed during wintertime. These spatial patterns had influence on the DOC and iron content of porewater, as well. Highest temporal dynamics of soil redox properties and porewater iron could be found in the boundaries. These observations refer to importance patchiness of vegetation on soil chemical properties in

  12. Vegetation survey of Pen Branch and Four Mile Creek wetlands

    SciTech Connect

    Not Available

    1992-10-01

    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.

  13. Vegetation survey of Pen Branch and Four Mile Creek wetlands

    SciTech Connect

    Not Available

    1992-01-01

    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.

  14. [Secondary succession characteristics of vegetations on reclaimed land inside Chongming wetland seawall].

    PubMed

    Ge, Zhenming; Wang, Tianhou; Shi, Wenyu; Zhao, Ping

    2005-09-01

    National reserve Chongming Dongtan wetland was designated as an important international wetland (ramsar site) in 2002. The area outside 98 seawalls is the core area of the reserve, while their inside is the experimental area. A wetland restoration project was started in June 2003, and a large pond behind the seawall was unwatered, which changed the soil condition and appeared drought and salinization. The vegetations presented typical secondary succession, and Aeluropus littoralis and Suaeda glauca invaded the area originally dominated by reed. From July 2003 to April 2004, the soil moisture content and salinity of 15 samples were determined, with the biomass, height, density, and coverage of each kind of vegetations measured. The results showed that the vegetation layout had become an obviously zonary distribution of Aeluropus littoralis-Aeluropus littoralis/Suaeda glauca-Suaeda glauca/Phragmites communis-Phragmites communis community. Suaeda glauca gradually extended to the reed area, and became the dominant species of the area, with an average biomass of 2003 415.4 g x m(-2) in autumn, and of 2004 391.53 g x m(-2) in spring. The biomass and height of Suaeda glauca increased, and its density was getting stable, suggesting that the plant had strong growth ability in drought area.

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

    USGS Publications Warehouse

    Larsen, Laurel G.; Harvey, Judson W.

    2010-01-01

    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.

  16. [Characteristics of soil nematode communities in coastal wetlands with different vegetation types].

    PubMed

    Liu, Bei-Bei; Ye, Cheng-Long; Yu, Li; Jiao, Jia-Guo; Liu, Man-Qiang; Hu, Feng; Li, Hui-Xin

    2012-11-01

    An investigation was conducted on the characteristics of soil nematode communities in different vegetation belts (Spartina alterniflora belt, Sa; Suaeda glauca belt, Sg; bare land, B1; Phragmites australis belt, Pa; and wheat land, Wl) of Yancheng Wetland Reserve, Jiangsu Province of East China. A total of 39 genera and 20 families of soil nematodes were identified, and the individuals of dominant genera and common genera occupied more than 90% of the total. The total number of the nematodes differed remarkably with vegetation belts, ranged from 79 to 449 individuals per 100 grams of dry soil. Wheat land had the highest number of soil nematodes, while bare land had the lowest one. The nematode ecological indices responded differently to the vegetation belts. The Shannon index (H) and evenness index (J) decreased in the order of Pa > Sg > Wl > Sa > Bl, and the dominance index (lambda) was in the order of Bl > Sa > Wl > Sg > Pa, suggesting that the diversity and stability of the nematode community in bare land were lower than those in the other vegetation belts, and the nematode community in the bare land tended to be simplified. The maturity index (MI) was higher in uncultivated vegetation belts than in wheat land, suggesting that the wheat land was disturbed obviously. The nematode community structure differed significantly with vegetation belts, and the main contributing species in different vegetation belts also differed. There existed significant correlations between the soil physical and chemical characteristics and the nematode numbers, trophic groups, and ecological indices. Our results demonstrated that the changes of soil nematode community structure could be used as an indicator well reflecting the diversity of vegetation belt habitat, and an important bio-indicator of coastal wetland ecosystem.

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

    PubMed

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

    2014-01-01

    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.

  18. Developing an algorithm for enhancement of a digital terrain model for a densely vegetated floodplain wetland

    NASA Astrophysics Data System (ADS)

    Mirosław-Świątek, Dorota; Szporak-Wasilewska, Sylwia; Michałowski, Robert; Kardel, Ignacy; Grygoruk, Mateusz

    2016-07-01

    Airborne laser scanning survey data were conducted with a scanning density of 4 points/m2 to accurately map the surface of a unique central European complex of wetlands: the lower Biebrza River valley (Poland). A method to correct a degrading effect of vegetation (so-called "vegetation effect") on digital terrain models (DTMs) was applied utilizing remotely sensed images, real-time kinematic global positioning system elevation measurements, topographical surveys, and vegetation height measurements. Geographic object-based image analysis (GEOBIA) was performed to map vegetation within the study area that was used as categories from which vegetation height information was derived for the DTM correction. The final DTM was compared with a model obtained, where additional correction of the "vegetation effect" was neglected. A comparison between corrected and uncorrected DTMs demonstrated the importance of accurate topography through a simple presentation of the discrepancies arising in features of the flood using various DTM products. An overall map classification accuracy of 80% was attained with the use of GEOBIA. Correction factors developed for various types of the vegetation reached values from 0.08 up to 0.92 m and were dependent on the vegetation type.

  19. Denitrification potential and organic matter as affected by vegetation community, wetland age, and plant introduction in created wetlands.

    PubMed

    Hernandez, Maria E; Mitsch, William J

    2007-01-01

    Denitrification potential (DP) and organic matter (OM) in soils were compared in three different vegetation communities-emergent macrophyte, open water, and forested edge-in two 10-yr-old created riverine wetlands. Organic matter, cold water-extractable organic matter (CWEOM), anaerobic mineralizable carbon (AnMC), and DP varied significantly (P<0.05) among vegetation communities. The surface (0 to 9 cm) soils in the emergent macrophyte community (EMC) showed highest DP (0.07+/-0.01 mg N h-1 kg-1), OM (84.90+/-5.60 g kg-1), CWEOM (1.12+/-0.20 g kg-1), and AnMC (1.50+/-0.10 mg C h-1 kg-1). In the deeper layer (9 to 18 cm), DP and CWEOM (0.04+/-0.01 mg N h-1 kg-1 and 1.13+/-0.20 g kg-1, respectively) were significantly higher in the open water community (OWC) than in the emergent macrophyte and forested edge communities. Plant introduction did not affect DP or OM content and characteristics. After 10 yr of wetland development, mean DP increased 25-fold in the surface layer (from 0.002 to 0.053 mg N h-1 kg-1); OM content more than doubled to 90.80+/-19.22 g kg-1, and CWEOM and HWEOM increased 2.5 and 2.7 times respectively from 1993 (prewetland conditions) to 2004. Humic acids were the most abundant form of OM in 2004 and 1993 samples. Significant (P<0.05) positive relationships between DP and OM, CWEOM, and AnMC were found in the surface layer; in the 9- to 18-cm layer, significant positive relationships were found between DP and CWEOM and AnMC.

  20. Vegetation establishment on soil-amended weathered fly ash

    SciTech Connect

    Semalulu, O.; Barnhisel, R.I.; Witt, S.

    1998-12-31

    A field study was conducted with the following objectives in mind: (1) to study the effect of soil addition to weathered fly ash on the establishment and survival of different grasses and legumes, (2) to identify suitable grasses and/or legume species for vegetation of fly ash, (3) to study the fertilizer N and P requirements for successful vegetation establishment on fly ash and ash-soil mixtures, (4) to examine the nutrient composition of the plant species tested, and (5) to study the plant availability of P from fly ash and ash-soil mixtures. Three rooting media were used: weathered fly ash, and 33% or 50% soil blended with the ash. Four experiments were established on each of these media to evaluate warm season grasses in pure stands, warm season grasses inter-seeded with legumes, cool season grasses, and cool season grasses inter-seeded with legumes. Soil used in this study was more acidic than the fly ash. Only the results from characterization of the rooting media, ground cover, and yield will be presented here.

  1. Microbial Transformations of Nitrogen, Sulfur, and Iron Dictate Vegetation Composition in Wetlands: A Review

    PubMed Central

    Lamers, Leon P. M.; van Diggelen, Josepha M. H.; Op den Camp, Huub J. M.; Visser, Eric J. W.; Lucassen, Esther C. H. E. T.; Vile, Melanie A.; Jetten, Mike S. M.; Smolders, Alfons J. P.; Roelofs, Jan G. M.

    2012-01-01

    The majority of studies on rhizospheric interactions focus on pathogens, mycorrhizal symbiosis, or carbon transformations. Although the biogeochemical transformations of N, S, and Fe have profound effects on vegetation, these effects have received far less attention. This review, meant for microbiologists, biogeochemists, and plant scientists includes a call for interdisciplinary research by providing a number of challenging topics for future ecosystem research. Firstly, all three elements are plant nutrients, and microbial activity significantly changes their availability. Secondly, microbial oxidation with oxygen supplied by radial oxygen loss from roots in wetlands causes acidification, while reduction using alternative electron acceptors leads to generation of alkalinity, affecting pH in the rhizosphere, and hence plant composition. Thirdly, reduced species of all three elements may become phytotoxic. In addition, Fe cycling is tightly linked to that of S and P. As water level fluctuations are very common in wetlands, rapid changes in the availability of oxygen and alternative terminal electron acceptors will result in strong changes in the prevalent microbial redox reactions, with significant effects on plant growth. Depending on geological and hydrological settings, these interacting microbial transformations change the conditions and resource availability for plants, which are both strong drivers of vegetation development and composition by changing relative competitive strengths. Conversely, microbial composition is strongly driven by vegetation composition. Therefore, the combination of microbiological and plant ecological knowledge is essential to understand the biogeochemical and biological key factors driving heterogeneity and total (i.e., microorganisms and vegetation) community composition at different spatial and temporal scales. PMID:22539932

  2. Effectiveness of vegetation buffers surrounding playa wetlands at contaminant and sediment amelioration

    USGS Publications Warehouse

    Haukos, David A.; Johnson, Lacrecia A.; Smith, Loren M.; McMurry, Scott T.

    2016-01-01

    Playa wetlands, the dominant hydrological feature of the semi-arid U.S. High Plains providing critical ecosystem services, are being lost and degraded due to anthropogenic alterations of the short-grass prairie landscape. The primary process contributing to the loss of playas is filling of the wetland through accumulation of soil eroded and transported by precipitation from surrounding cultivated watersheds. We evaluated effectiveness of vegetative buffers surrounding playas in removing metals, nutrients, and dissolved/suspended sediments from precipitation runoff. Storm water runoff was collected at 10-m intervals in three buffer types (native grass, fallow cropland, and Conservation Reserve Program). Buffer type differed in plant composition, but not in maximum percent removal of contaminants. Within the initial 60 m from a cultivated field, vegetation buffers of all types removed >50% of all measured contaminants, including 83% of total suspended solids (TSS) and 58% of total dissolved solids (TDS). Buffers removed an average of 70% of P and 78% of N to reduce nutrients entering the playa. Mean maximum percent removal for metals ranged from 56% of Na to 87% of Cr. Maximum removal was typically at 50 m of buffer width. Measures of TSS were correlated with all measures of metals and nutrients except for N, which was correlated with TDS. Any buffer type with >80% vegetation cover and 30–60 m in width would maximize contaminant removal from precipitation runoff while ensuring that playas would continue to function hydrologically to provide ecosystem services. Watershed management to minimize erosion and creations of vegetation buffers could be economical and effective conservation tools for playa wetlands.

  3. Effectiveness of vegetation buffers surrounding playa wetlands at contaminant and sediment amelioration.

    PubMed

    Haukos, David A; Johnson, Lacrecia A; Smith, Loren M; McMurry, Scott T

    2016-10-01

    Playa wetlands, the dominant hydrological feature of the semi-arid U.S. High Plains providing critical ecosystem services, are being lost and degraded due to anthropogenic alterations of the short-grass prairie landscape. The primary process contributing to the loss of playas is filling of the wetland through accumulation of soil eroded and transported by precipitation from surrounding cultivated watersheds. We evaluated effectiveness of vegetative buffers surrounding playas in removing metals, nutrients, and dissolved/suspended sediments from precipitation runoff. Storm water runoff was collected at 10-m intervals in three buffer types (native grass, fallow cropland, and Conservation Reserve Program). Buffer type differed in plant composition, but not in maximum percent removal of contaminants. Within the initial 60 m from a cultivated field, vegetation buffers of all types removed >50% of all measured contaminants, including 83% of total suspended solids (TSS) and 58% of total dissolved solids (TDS). Buffers removed an average of 70% of P and 78% of N to reduce nutrients entering the playa. Mean maximum percent removal for metals ranged from 56% of Na to 87% of Cr. Maximum removal was typically at 50 m of buffer width. Measures of TSS were correlated with all measures of metals and nutrients except for N, which was correlated with TDS. Any buffer type with >80% vegetation cover and 30-60 m in width would maximize contaminant removal from precipitation runoff while ensuring that playas would continue to function hydrologically to provide ecosystem services. Watershed management to minimize erosion and creations of vegetation buffers could be economical and effective conservation tools for playa wetlands.

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

    NASA Astrophysics Data System (ADS)

    Jarosław, J.; Szporak, S.; Verbeiren, B.; Batelaan, O.

    2012-04-01

    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

  5. Water temperature differences by plant community and location in re-established wetlands in the Sacramento-San Joaquin Delta, California, July 2005 to February 2008

    USGS Publications Warehouse

    Crepeau, Kathryn L.; Miller, Robin L.

    2014-01-01

    Rates of carbon storage in wetlands are determined by the balance of its inputs and losses, both of which are affected by environmental factors such as water temperature and depth. In the autumn of 1997, the U.S. Geological Survey re-established two wetlands with different shallow water depths—about 25 and 55 centimeters deep—to investigate the potential to reverse subsidence of delta islands by preserving and accumulating organic substrates derived from plant biomass inputs over time. Because cooler water temperatures can slow decomposition rates and increase accretion of plant biomass, water temperature was recorded from July 2005 to February 2008 in the deeper of the two wetlands, where areas of emergent and submerged vegetation persisted throughout the study, to assess differences in water temperature between the two vegetation types. Water temperature was compared at three depths in the water column between areas of emergent and submerged vegetation and between areas near the water inflow and in the wetland interior in both vegetation types. The latter comparison was a way of evaluating the effect of the length of time water had resided in the wetland on water temperatures. There were statistically significant differences in water temperature at all depths between the two vegetation types. Overall, in areas of emergent marsh vegetation, the mean water temperature at the surface was 1.4 degrees Celsius (°C) less than it was in areas of submerged vegetation; however, when analyses accounted for the changes in temperature due to seasonal and diurnal cycles, differences in the mean water temperature between the vegetation types were even greater than this. For example, in the spring, the mean temperatures in areas of emergent marsh vegetation at the surface, mid-point, and near the sediment in the water column were 2.0, 2.3, and 2.1 °C less, respectively, than water temperatures in areas of submerged vegetation. When diurnal changes in temperature were

  6. Short-term responses of wetland vegetation after liming of an Adirondack watershed

    SciTech Connect

    Mackun, I.R.; Leopold, D.J.; Raynal, D.J. )

    1994-08-01

    Watershed liming has been suggested as a long-term mitigation strategy for lake acidity, particularly in areas subject to high levels of acidic deposition. However, virtually no information has been available on the impacts of liming on wetland vegetation. In 1989, 1100 Mg of limestone (83.5% CaCO[sub 3]) were aerially applied to 48% (100 ha) of the Woods Lake watershed in the west-central Adirondack region of New York as part of the first comprehensive watershed liming study in North America. We inventoried wetland vegetation in 1.0-m[sup 2] plots before liming and during the subsequent 2 yr. Within this period liming influenced the cover, frequency, or importance values of only 6 of 64 wetland taxa. The cover of Sphagnum spp. and of the cespitose sedge Carex interior decreased in control relative to limed plots, and cover of the rhizomatous sedge Cladium mariscoides increased nearly threefold in limed areas. These two sedges, which are relatively tall, are characteristic of more calcareous habitats. Cover of the grass Muhlenbergia uniflora, cover and importance were adversely affected or inhibited by lime. It is unclear whether liming directly inhibited the growth of these three small-statured species, or whether the adverse effects of lime were mediated through shifts in competitive interactions with other species. The limited responses that we observed to liming, along with changes that occurred in control plots over the study period, may indicate that in the short term watershed liming was no more of a perturbation than the environmental factors responsible for natural annual variation in wetland communities.

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  8. Particle removal by vegetation: comparison in a forest and a wetland.

    PubMed

    Liu, Jiakai; Zhai, Jiexiu; Zhu, Lijuan; Yang, Yilian; Liu, Jiatong; Zhang, Zhenming

    2017-01-01

    Vegetation collection is one of the most effective scavenging methods but relevant studies are limited. It can be described by some abstract parameters such as collection rates and deposition fluxes within the canopy. In order to estimate the dry deposition within the canopy of particular matters (PMs) in Beijing, a highly particle-polluted city, and reveal the PM pollution-removal abilities of plants in wetlands and forests, concentration and meteorological data were collected during the daytime in an artificial forest and a wetland in the Olympic Park in Beijing. The dry depositions within the canopy and vegetation collection rates were calculated by a well-developed model and validated by measured deposition fluxes in 11 random experiment days. The experiment year was divided into three plant growth stages based on canopy density, and the day was divided into four different times. Two heights, 10 and 1.5 m, were defined in the forest while in the wetland, 0.5 and 1.5 m were defined. The results showed that in Beijing, the most severe pollution by PMs occurs in the non-leaf stage (NS), and the full-leaf stage (FS) is the cleanest stage. In NS, namely winter, more fossil fuel was used for worms in Beijing and peripheral areas and this might be the reason for the serious pollution condition. Within the canopy, PM deposition fluxes in the wetland are more than those in the forest, but the vegetation collection rates of the forest are higher. The lower temperature conditions led to more dry deposition, and the larger canopy contributed to the higher collection rates. During the daytime, over the year, the deposition of PM10 in three plant growth stages is NS ≥ half-leaf stages (HS) ≥ FS, whereas the deposition of PM2.5 is NS ≥ FS ≥ HS, and during the daytime, the maximum deposition fluxes occur in 6:00-9:00 in the wetland while the minimum deposition values occur in 15:00-18:00. This phenomenon was related to the temporal variation of particle

  9. Vegetation composition and soil microbial community structural changes along a wetland hydrological gradient

    NASA Astrophysics Data System (ADS)

    Balasooriya, W. K.; Denef, K.; Peters, J.; Verhoest, N. E. C.; Boeckx, P.

    2007-10-01

    Fluctuations in wetland hydrology create an interplay between aerobic and anaerobic conditions, controlling vegetation composition and microbial community structure and activity in wetland soils. In this study, we investigated the vegetation composition and microbial community structural and functional changes along a wetland hydrological gradient. Two different vegetation communities were distinguished along the hydrological gradient; textit{Caricetum gracilis} at the wet depression and textit{Arrhenatherum elatioris} at the drier upper site. Microbial community structural changes were studied by a combined in situ 13CO2 pulse labeling and phospholipid fatty acid (PLFA) based stable isotope probing approach, which identifies the microbial groups actively involved in assimilation of newly photosynthesized, root-derived C in the rhizosphere soils. Gram negative bacterial communities were relatively more abundant in the surface soils of the drier upper site than in the surface soils of the wetter lower site, while the lower site and the deeper soil layers were relatively more inhabited by gram positive bacterial communities. Despite their large abundance, the metabolically active proportion of gram positive bacterial and actinomycetes communities was much smaller at both sites, compared to that of the gram negative bacterial and fungal communities. This suggests much slower assimilation of root-derived C by gram positive and actinomycetes communities than by gram negative bacteria and fungi at both sites. Ground water depth showed a significant effect on the relative abundance of several microbial communities. Relative abundance of gram negative bacteria was significantly decreased with increasing ground water depth while the relative abundance of gram positive bacteria and actinomycetes at the surface layer increased with increasing ground water depth.

  10. Vegetation composition and soil microbial community structural changes along a wetland hydrological gradient

    NASA Astrophysics Data System (ADS)

    Balasooriya, W. K.; Denef, K.; Peters, J.; Verhoest, N. E. C.; Boeckx, P.

    2008-02-01

    Fluctuations in wetland hydrology create an interplay between aerobic and anaerobic conditions, controlling vegetation composition and microbial community structure and activity in wetland soils. In this study, we investigated the vegetation composition and microbial community structural and functional changes along a wetland hydrological gradient. Two different vegetation communities were distinguished along the hydrological gradient; Caricetum gracilis at the wet depression and Arrhenatheretum elatioris at the drier upper site. Microbial community structural changes were studied by a combined in situ 13CO2 pulse labeling and phospholipid fatty acid (PLFA) based stable isotope probing approach, which identifies the microbial groups actively involved in assimilation of newly photosynthesized, root-derived C in the rhizosphere soils. Gram negative bacterial communities were relatively more abundant in the surface soils of the drier upper site than in the surface soils of the wetter lower site, while the lower site and the deeper soil layers were relatively more inhabited by gram positive bacterial communities. Despite their large abundance, the metabolically active proportion of gram positive bacterial and actinomycetes communities was much smaller at both sites, compared to that of the gram negative bacterial and fungal communities. This suggests much slower assimilation of root-derived C by gram positive and actinomycetes communities than by gram negative bacteria and fungi at both sites. Ground water depth showed a significant effect on the relative abundance of several microbial communities. Relative abundance of gram negative bacteria significantly decreased with increasing ground water depth while the relative abundance of gram positive bacteria and actinomycetes at the surface layer increased with increasing ground water depth.

  11. Importance of vegetation classes in modeling CH4 emissions from boreal and subarctic wetlands in Finland.

    PubMed

    Li, Tingting; Raivonen, Maarit; Alekseychik, Pavel; Aurela, Mika; Lohila, Annalea; Zheng, Xunhua; Zhang, Qing; Wang, Guocheng; Mammarella, Ivan; Rinne, Janne; Yu, Lijun; Xie, Baohua; Vesala, Timo; Zhang, Wen

    2016-12-01

    Boreal/arctic wetlands are dominated by diverse plant species, which vary in their contribution to CH4 production, oxidation and transport processes. Earlier studies have often lumped the processes all together, which may induce large uncertainties into the results. We present a novel model, which includes three vegetation classes and can be used to simulate CH4 emissions from boreal and arctic treeless wetlands. The model is based on an earlier biogeophysical model, CH4MODwetland. We grouped the vegetation as graminoids, shrubs and Sphagnum and recalibrated the vegetation parameters according to their different CH4 production, oxidation and transport capacities. Then, we used eddy-covariance-based CH4 flux observations from a boreal (Siikaneva) and a subarctic fen (Lompolojänkkä) in Finland to validate the model. The results showed that the recalibrated model could generally simulate the seasonal patterns of the Finnish wetlands with different plant communities. The comparison between the simulated and measured daily CH4 fluxes resulted in a correlation coefficient (R(2)) of 0.82 with a slope of 1.0 and an intercept of -0.1mgm(-2)h(-1) for the Siikaneva site (n=2249, p<0.001) and an R(2) of 0.82 with a slope of 1.0 and an intercept of 0.0mgm(-2)h(-1) for the Lompolojänkkä site (n=1826, p<0.001). Compared with the original model, the recalibrated model in this study significantly improved the model efficiency (EF), from -5.5 to 0.8 at the Siikaneva site and from -0.4 to 0.8 at the Lompolojänkkä site. The simulated annual CH4 emissions ranged from 7 to 24gm(-2)yr(-1), which was consistent with the observations (7-22gm(-2)yr(-1)). However, there are some discrepancies between the simulated and observed daily CH4 fluxes for the Siikaneva site (RMSE=50.0%) and the Lompolojänkkä site (RMSE=47.9%). Model sensitivity analysis showed that increasing the proportion of the graminoids would significantly increase the CH4 emission levels. Our study demonstrated that

  12. Establishment of vegetation on mined sites by management of mycorrhizae

    SciTech Connect

    Marrs, L.F.; Marx, D.H.; Cordell, C.E.

    1999-07-01

    Plant ecosystems, including those in the tropical, temperate, boreal, and desert zones, began evolving more than 400 million years ago. Trees and other land plants in these environments were faced with many natural stresses including extreme temperature changes, fluctuating levels of available water, soil infertility, catastrophic fires and storms, poor soil physical conditions and competition. Basically, these plants evolved by genetic selection and developed many physical, chemical, and biological requirements necessary to survive these periodically stressed environments. Survivors were those that could form extensive lateral root systems to occupy soil volumes sufficiently large for them to obtain enough essential mineral elements and water to support their above and below ground growth needs. The most competitive plants in these stressed ecosystems were those with the largest root systems. One major biological requirement that evolved was the association of plants with mycorrhizal fungi. This is still true today for land that has been disturbed by mining, construction, and other activities. Successful vegetation establishment on these lands has been achieved by using the biological tools; native tree seedlings, shrubs, forbs, and grasses inoculated with specific, beneficial mycorrhizal fungi. Trees and shrubs are custom grown in nurseries with selected mycorrhizal fungi, such as Pisolithus tinctorius (Pt) and other fungi, provide significant benefits to the plants through increased water and mineral adsorption, decreased toxin absorption and overall reduction of plant stress. This has resulted in significant increases in plant growth and survival rates, density and sustainable vegetation.

  13. Distribution of Culex species in vegetation bands of a constructed wetland undergoing integrated mosquito management.

    PubMed

    Walton, William E; Popko, David A; Van Dam, Alex R; Merrill, Andrea

    2013-03-01

    The distribution and abundance of emerging Culex spp. were assessed within narrow (width: 3 m) and wide (width: 20 m) bands of California bulrush (Schoenoplectus californicus) and in the open water adjacent to emergent vegetation in 2 marshes of an ammonia-dominated wastewater treatment wetland in southern California. Emerging mosquitoes were collected along transects perpendicular to the path of water flow at 3 distances (1.5, 5, and 10 m) from the vegetation-open water interface in the wide bands of emergent vegetation, at the center of narrow bands of emergent vegetation, and at 1.5 m from the edge of emergent vegetation in the open water. The width of vegetation bands (3 vs. 20 m) influenced the effectiveness of integrated mosquito management practices, especially the application of mosquito control agents. Mosquito production from the 2 marshes also differed up to 14-fold, suggesting that the distance between the shorelines (62 vs. 74 m) of each marsh also influenced the efficacy of mosquito control agents applied from the shore and boats. Hot spots of mosquito production (75424 female Culex/m2/day) were found within the wide bands of bulrush. During summer, the relative abundance of Culex stigmatosoma among emerging mosquitoes increased from the periphery to the center of wide bands of emergent vegetation. Culex erythrothorax emergence rates were comparatively similar among the transects in the wide bands of emergent vegetation. Culex tarsalis adults increased in number from the periphery to the center of wide bands of bulrush and, in May, were > 95% of emerged mosquitoes.

  14. Using two classification schemes to develop vegetation indices of biological integrity for wetlands in West Virginia, USA.

    PubMed

    Veselka, Walter; Rentch, James S; Grafton, William N; Kordek, Walter S; Anderson, James T

    2010-11-01

    Bioassessment methods for wetlands, and other bodies of water, have been developed worldwide to measure and quantify changes in "biological integrity." These assessments are based on a classification system, meant to ensure appropriate comparisons between wetland types. Using a local site-specific disturbance gradient, we built vegetation indices of biological integrity (Veg-IBIs) based on two commonly used wetland classification systems in the USA: One based on vegetative structure and the other based on a wetland's position in a landscape and sources of water. The resulting class-specific Veg-IBIs were comprised of 1-5 metrics that varied in their sensitivity to the disturbance gradient (R2=0.14-0.65). Moreover, the sensitivity to the disturbance gradient increased as metrics from each of the two classification schemes were combined (added). Using this information to monitor natural and created wetlands will help natural resource managers track changes in biological integrity of wetlands in response to anthropogenic disturbance and allows the use of vegetative communities to set ecological performance standards for mitigation banks.

  15. A computer model to forecast wetland vegetation changes resulting from restoration and protection in coastal Louisiana

    USGS Publications Warehouse

    Visser, Jenneke M.; Duke-Sylvester, Scott M.; Carter, Jacoby; Broussard, Whitney P.

    2013-01-01

    The coastal wetlands of Louisiana are a unique ecosystem that supports a diversity of wildlife as well as a diverse community of commercial interests of both local and national importance. The state of Louisiana has established a 5-year cycle of scientific investigation to provide up-to-date information to guide future legislation and regulation aimed at preserving this critical ecosystem. Here we report on a model that projects changes in plant community distribution and composition in response to environmental conditions. This model is linked to a suite of other models and requires input from those that simulate the hydrology and morphology of coastal Louisiana. Collectively, these models are used to assess how alternative management plans may affect the wetland ecosystem through explicit spatial modeling of the physical and biological processes affected by proposed modifications to the ecosystem. We have also taken the opportunity to advance the state-of-the-art in wetland plant community modeling by using a model that is more species-based in its description of plant communities instead of one based on aggregated community types such as brackish marsh and saline marsh. The resulting model provides an increased level of ecological detail about how wetland communities are expected to respond. In addition, the output from this model provides critical inputs for estimating the effects of management on higher trophic level species though a more complete description of the shifts in habitat.

  16. Fire-Vegetation-Microclimate Feedbacks under Simulated Global Change in Savanna - Wetland Ecotones

    NASA Astrophysics Data System (ADS)

    Just, M.; Hohmann, M. G.; Hoffmann, W. A.

    2015-12-01

    Boundaries between pyrogenic and adjacent pyrophobic vegetation communities are created and maintained by positive feedbacks between fire, vegetation, and microclimate. These feedbacks either promote or hinder fire and the boundary is situated at the transition from flammable to non-flammable. Consequently, vegetation is only directly influenced by fire if it is burned. Therefore, revealing where fire stops between communities is important for understanding their capacity to withstand change. We identified vegetation structure and microclimate components as predictors of fire spread along a (pyrogenic) savanna - (pyrophobic) wetland ecotonal gradient in North Carolina, USA. The ability of the fire feedback to maintain the transition from flammable to non-flammable conditions under potential global change is not known. We built a cellular automaton which employed Markov transition probabilities and associated fire spread probabilities to simulate the conditions of the ecotonal gradient under differing fire frequencies. Changes to the gradient boundaries were estimated from the location of the flammable to non-flammable transition. Our simulations produced movement of the boundary under certain fire return intervals. In general, more frequent fires resulted in fire failure deeper into wetland, and less frequent fires resulted in fire failure nearer savanna. Our simulations indicate that fire feedbacks are capable of controlling boundary locations up to a perturbation threshold, but that this control is not absolute. The transition from flammable to non-flammable within these pyrogenic-pyrophobic ecotones is essential to distinct communities. The management and conservation of these systems is fire-focused and, therefore, improving predictions about where fire stops under global change is important for those objectives.

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

    PubMed

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

    2011-09-01

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

  18. Effects of landscape gradients on wetland vegetation communities: information for large-scale restoration

    USGS Publications Warehouse

    Zweig, Christa L.; Kitchens, Wiley M.

    2008-01-01

    Projects of the scope of the restoration of the Florida Everglades require substantial information regarding ecological mechanisms, and these are often poorly understood. We provide critical base knowledge for Everglades restoration by characterizing the existing vegetation communities of an Everglades remnant, describing how present and historic hydrology affect wetland vegetation community composition, and documenting change from communities described in previous studies. Vegetation biomass samples were collected along transects across Water Conservation Area 3A South (3AS). Ten community types were present between November 2002 and 2005. Separate analyses for key a priori groups (slough, wet prairie, and sawgrass) provided detailed conclusions about effects of historic hydrology on the vegetation of 3AS. Communities were affected by hydrologic variables LIP to four years previous to the sample. We identified wet prairie/slough species such as Eleocharis spp. and Nymphaea odorata as short-term sentinel species of community change. Sawgrass and N. odorata should be monitored for long-term change. Comparisons to preceding studies indicated that many of the communities of previous times, when conditions were drier, no longer exist in our study area and have been replaced by deeper water community types.

  19. The influence of vegetation on sedimentation and resuspension of soil particles in small constructed wetlands.

    PubMed

    Braskerud, B C

    2001-01-01

    When initiatives to mitigate soil erosion are insufficient or fail, constructed surface flow wetlands (CWs) could be a final buffer to reduce pollution before reaching recipients. The objective of this study was to determine the influence of CW vegetation on the retention of soil particles from arable land. Retention was measured with water flow-proportional sampling systems in the inlet and outlet, sedimentation traps, and sedimentation plates in four small CWs over a period of 5 yr. The surface area of the CWs was 265 to 900 m2, and the average hydraulic loads were 1.2 to 3.4 m d(-1). Watershed areas were 0.5 to 1.5 km2. Annual soil particle retention was 30 to 80% or 14 to 121 kg m(-2). Results show that macrophytes stimulate sediment retention by mitigating resuspension of CW sediment. Five years after construction, resuspension had decreased approximately 40% and was negligible. As vegetation cover increases, the influence of macrophytes on soil particle retention reaches a level where other factors, such as hydraulic load and sediment load, were more important. Macrophytes increased the hydraulic efficiency by reducing short-circuit or preferential flow. However, vegetation did not have any influence on the clay concentration in the sediment. Hence, a possible stimulation of particle flocculation was not detected. Vegetation makes it possible to use the positive effect of a short particle settling distance in shallow ponds by hindering resuspension.

  20. Combined influence of sedimentation and vegetation on the soil carbon stocks of a coastal wetland in the Changjiang estuary

    NASA Astrophysics Data System (ADS)

    Zhang, Tianyu; Chen, Huaipu; Cao, Haobing; Ge, Zhenming; Zhang, Liquan

    2016-08-01

    Coastal wetlands play an important role in the global carbon cycle. Large quantities of sediment deposited in the Changjiang (Yangtze) estuary by the Changjiang River promote the propagation of coastal wetlands, the expansion of saltmarsh vegetation, and carbon sequestration. In this study, using the Chongming Dongtan Wetland in the Changjiang estuary as the study area, the spatial and temporal distribution of soil organic carbon (SOC) stocks and the influences of sedimentation and vegetation on the SOC stocks of the coastal wetland were examined in 2013. There was sediment accretion in the northern and middle areas of the wetland and in the Phragmites australis marsh in the southern area, and sediment erosion in the Scirpus mariqueter marsh and the bare mudflat in the southern area. More SOC accumulated in sediments of the vegetated marsh than in the bare mudflat. The total organic carbon (TOC) stocks increased in the above-ground biomass from spring to autumn and decreased in winter; in the below-ground biomass, they gradually increased from spring to winter. The TOC stocks were higher in the below-ground biomass than in the above-ground biomass in the P. australis and Spartina alterniflora marshes, but were lower in the below-ground biomass in S. mariqueter marsh. Stocks of SOC showed temporal variation and increased gradually in all transects from spring to winter. The SOC stocks tended to decrease from the high marsh down to the bare mudflat along the three transects in the order: P. australis marsh > S. alterniflora marsh > S. mariqueter marsh > bare mudflat. The SOC stocks of the same vegetation type were higher in the northern and middle transects than in the southern transect. These results suggest that interactions between sedimentation and vegetation regulate the SOC stocks in the coastal wetland in the Changjiang estuary.

  1. Accounting for non-photosynthetic vegetation in remote-sensing-based estimates of carbon flux in wetlands

    USGS Publications Warehouse

    Schile, Lisa M.; Byrd, Kristin B.; Windham-Myers, Lisamarie; Kelly, Maggi

    2013-01-01

    Monitoring productivity in coastal wetlands is important due to their high carbon sequestration rates and potential role in climate change mitigation. We tested agricultural- and forest-based methods for estimating the fraction of absorbed photosynthetically active radiation (f APAR), a key parameter for modelling gross primary productivity (GPP), in a restored, managed wetland with a dense litter layer of non-photosynthetic vegetation, and we compared the difference in canopy light transmission between a tidally influenced wetland and the managed wetland. The presence of litter reduced correlations between spectral vegetation indices and f APAR. In the managed wetland, a two-band vegetation index incorporating simulated World View-2 or Hyperion green and near-infrared bands, collected with a field spectroradiometer, significantly correlated with f APAR only when measured above the litter layer, not at the ground where measurements typically occur. Measures of GPP in these systems are difficult to capture via remote sensing, and require an investment of sampling effort, practical methods for measuring green leaf area and accounting for background effects of litter and water.

  2. Wetlands.

    ERIC Educational Resources Information Center

    Nelson, Patricia L.

    1986-01-01

    Suggests studying New York's wetlands, both in the classroom and in the field, to illustrate ecological concepts of diversity, succession, and adaptation and to learn about their importance in controlling flooding, erosion, and pollution. (NEC)

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

    PubMed

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

    2013-10-15

    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.

  4. Flora and ecological profile of native and exotic estuarine wetland vegetation by hydrogeomorphic setting at Rush Ranch, Suisun Marsh

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The manuscript includes a profile of the ecology and distribution of estuarine wetland vegetation at the Rush Ranch reserve site in the brackish Suisun Marsh reach of San Francisco Estuary The data and analyses will serve as a baseline for future scientific research and conservation management. A ...

  5. Vegetative changes in a wetland in the vicinity of a well field, Dade County, Florida

    USGS Publications Warehouse

    Hofstetter, R.H.; Sonenshein, R.S.

    1990-01-01

    Plant communities present in 1978 and 1986 were analyzed at 250 random points on stereoscopic pairs of aerial photographs for four study sites in the vicinity of the Northwest Well Field in Dade County, Florida. Sites NW and NE lie northwest of the well field beyond the cone of depression. Site SW lies in the outer part of the cone, and site SE lies within the cone of depression. Relative frequency values for several plant types including herbs, shrubs-small trees, and trees were analyzed by the Heterogeneity G-test to determine heterogeneity among sites in 1978 and 1986. In 1978, all four sites were dominated by plant communities having herbs, shrubs, or a mixture thereof. The communities at sites NW and NE were similar, and those at SE and SW were somewhat similar. In 1986, sites NW, NE, and SE were dominated by a mixture of shrubs and trees. Only at site SW was the relative frequency of occurrence of herbaceous plants still high. At each site, there was a decrease in herbaceous vegetation and an increase in woody vegetation during this period, with the increase in trees being greatest at site SE. Time between the start of the well-field operation in May 1983 and the January 1986 photographs was insufficient to allow determination of any direct effects of the well field on the vegetation. Ground-level observations in 1987 and 1988 indicate a trend toward continued increase in dominance of woody plants and a decrease in herbaceous wetland vegetation. Development of a forest of the exotic pest tree melaleuca is occurring at all four sites, but especially at site SE. Vegetative changes between 1978 and 1986 are attributed to an invasion of the exotic species melaleuca, a shortened hydroperiod, and natural succession within the plant communities.

  6. Halophytes as vertical-flow constructed wetland vegetation for domestic wastewater treatment.

    PubMed

    Fountoulakis, M S; Sabathianakis, G; Kritsotakis, I; Kabourakis, E M; Manios, T

    2017-04-01

    Recent findings show that halophytes have the ability to accumulate salts in their tissues, making them a very interesting group of plants for domestic wastewater treatment in constructed wetlands (CWs). In that case, it might be possible to reduce the salinity of the final effluent, which is a crucial parameter for wastewater reuse in agriculture. During this study three halophytes, Atriplex halimus, Juncus acutus and Sarcocornia perennis, were tested for phyto-desalination of domestic wastewater in a vertical flow constructed wetland (VFCW) and compared with common reeds (Phragmites australis). In addition, the effect of this alternative vegetation on the overall performance of the system regarding organic matter, nutrients, boron and pathogen removal was monitored. The organic loading rate (OLR) was about 21gCOD/m(2)/d and the hydraulic loading rate (HLR) was 95mm/d in both cases. Promising results were obtained for A. halimus, which shows high biomass productivity and significant capability to accumulate salts, mainly Na, in its tissues. A positive effect on pathogen removal efficiency was also recorded. However, nitrogen concentration in the effluent of the VFCW planted with halophytes was found to be higher than in the effluent of the VFCW planted with reeds. Finally, no significant effect on organic matter and phosphorus removal efficiency was observed from the use of halophytes in place of reeds.

  7. [Effects of soil factors on vegetation community structure in an abandoned subtropical paddy wetland].

    PubMed

    Peng, Yi; Li, Yu-Yuan; Li, Zhong-Wu; Ye, Fang-Yi; Pan, Chun-Xiang; Xie, Xiao-Li

    2009-07-01

    Based on the investigation data from a subtropical wetland having been abandoned from paddy agriculture for one year, a redundancy analysis was conducted on the relationships between vegetation community and soil factors in the wetland. It was found that soil moisture regime, available K and P, and pH were the main factors affecting the distribution of plant species. The common plant species could be classified into three groups, i. e., Ludwigia prostrata - Murdannia triquetra group (G1), Hemarthria altissima - Rotala rotundifolia - Lapsana apogonoides group (G2), and Conyza canadensis - Polygonum hydropiper - Paspalum pasaloides group (G3). G1 mainly distributed on the soils with higher available K, G2 mainly distributed in periodically flooded area, while G3 mainly distributed in drainage area and was positively correlated to soil available P and pH. Species diversity and above-ground biomass had significant positive correlations with soil pH and total K, respectively, while evenness index was significantly negatively correlated with soil available N. No significant correlations were observed among other indices.

  8. Evaluating the effect of rainfall variability on vegetation establishment in a semidesert grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Of the operations required for reclamation in arid and semi-arid regions, establishing vegetation entails the most uncertainty due to reliance on unpredictable rainfall for seed germination and seedling establishment. The frequency of successful vegetation establishment was estimated based on a land...

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

    USGS Publications Warehouse

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

    1996-01-01

    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.

  10. Derivation of Ground Surface and Vegetation in a Coastal Florida Wetland with Airborne Laser Technology

    USGS Publications Warehouse

    Raabe, Ellen A.; Harris, Melanie S.; Shrestha, Ramesh L.; Carter, William E.

    2008-01-01

    The geomorphology and vegetation of marsh-dominated coastal lowlands were mapped from airborne laser data points collected on the Gulf Coast of Florida near Cedar Key. Surface models were developed using low- and high-point filters to separate ground-surface and vegetation-canopy intercepts. In a non-automated process, the landscape was partitioned into functional landscape units to manage the modeling of key landscape features in discrete processing steps. The final digital ground surface-elevation model offers a faithful representation of topographic relief beneath canopies of tidal marsh and coastal forest. Bare-earth models approximate field-surveyed heights by + 0.17 m in the open marsh and + 0.22 m under thick marsh or forest canopy. The laser-derived digital surface models effectively delineate surface features of relatively inaccessible coastal habitats with a geographic coverage and vertical detail previously unavailable. Coastal topographic details include tidal-creek tributaries, levees, modest topographic undulations in the intertidal zone, karst features, silviculture, and relict sand dunes under coastal-forest canopy. A combination of laser-derived ground-surface and canopy-height models and intensity values provided additional mapping capabilities to differentiate between tidal-marsh zones and forest types such as mesic flatwood, hydric hammock, and oak scrub. Additional derived products include fine-scale shoreline and topographic profiles. The derived products demonstrate the capability to identify areas of concern to resource managers and unique components of the coastal system from laser altimetry. Because the very nature of a wetland system presents difficulties for access and data collection, airborne coverage from remote sensors has become an accepted alternative for monitoring wetland regions. Data acquisition with airborne laser represents a viable option for mapping coastal topography and for evaluating habitats and coastal change on marsh

  11. Regeneration of vegetation on wetland crossings for gas pipeline rights-of-way one year after construction

    SciTech Connect

    Shem, L.M.; Zimmerman, R.E.; Zellmer, S.D.; Van Dyke, G.D.; Rastorfer, J.R.

    1993-10-01

    Four wetland crossings of gas pipeline rights-of-way (ROWs), located in Florida, Michigan, New Jersey, and New York, were surveyed for generation of vegetation roughly one year after pipeline construction was completed. Conventional trench-and-fill construction techniques were employed for all four sites. Estimated areal coverage of each species by vegetative strata within transect plots was recorded for plots on the ROW and in immediately adjacent wetlands undisturbed by construction activities. Relative success of regeneration was measured by percent exposed soil, species diversity, presence of native and introduced species, and hydric characteristics of the vegetation. Variable site factors included separation and replacement of topsoil, final grading of the soil, application of seed and fertilizer, and human disturbance unrelated to construction. Successful regeneration exhibited greater dependency on the first three factors listed.

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

    NASA Astrophysics Data System (ADS)

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

    2010-03-01

    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 simulations. Emissions are computed from the dominant controls of water table depth, soil temperature, and plant productivity, and we analyze the relative role of each factor in the glacial decline. It is found that latitudinal changes in soil moisture, in combination with ice sheet expansion, cause boreal wetlands to shift southward in all simulations. This southward migration is instrumental in maintaining the boreal wetland source at a significant level. The mean emission temperature over boreal wetlands drops by only a few degrees, despite the strong overall cooling. The temperature effect on the glacial decline in the methane flux is therefore moderate, while reduced plant productivity contributes equally to the total reduction. Model results indicate a relatively small boreal and large tropical source during the LGM, with wetlands on the exposed continental shelves mainly contributing to the tropical source. This distribution in emissions is consistent with the low interpolar difference in glacial methane concentrations derived from ice core data.

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

    NASA Astrophysics Data System (ADS)

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

    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 violaceus, Phragmites mauritianus and Colocasia C. esculenta), of Nakivubo and Kirinya wetlands at the shores of Lake Victoria in Uganda, was studied through the determination of phytomass production and nutrient concentration in the plant parts at different stages of growth. The above ground phytomass production increased rapidly during the exponential growth for C. papyrus and P. mauritianus. In all the dominant plants, nitrogen concentration was highest in juvenile plants and decreased with increasing age. The most pronounced nitrogen level occurred in the young umbels of C. papyrus during the first month of growth with total nitrogen content of 1.95% DW which dropped to 0.62% DW after the fifth month in Nakivubo wetland. Corms (tubers) of yams had the highest nitrogen content in Kirinya and Nakivubo wetlands exhibiting respective values of 4.8% DW and 3.7% DW. There is a close relationship between nutrient content and increase in phytomass. In Nakivubo and Kirinya wetlands, the rapid increase in phytomass during the third and fourth month corresponded with high nutrient levels. Since plants store significant amounts of nitrogen during their growth, periodic harvesting of above ground plant parts can remove significant amounts of nutrients (during the first five months of growth) from the wastewater flowing into the two wetlands. Wetland plant species with high phytomass productivity and well developed root systems and ability to withstand flooding are the best in nutrient removal.

  14. A High Density Storm Surge Monitoring Network: Evaluating the Ability of Wetland Vegetation to Reduce Storm Surge

    NASA Astrophysics Data System (ADS)

    Lawler, S.; Denton, M.; Ferreira, C.

    2013-12-01

    Recent tropical storm activity in the Chesapeake Bay and a potential increase in the predicted frequency and magnitude of weather systems have drawn increased attention to the need for improved tools for monitoring, modeling and predicting the magnitude of storm surge, coastal flooding and the respective damage to infrastructure and wetland ecosystems. Among other forms of flood protection, it is believed that coastal wetlands and vegetation can act as a natural barrier that slows hurricane flooding, helping to reduce the impact of storm surge. However, quantifying the relationship between the physical process of storm surge and its attenuation by wetland vegetation is an active area of research and the deployment of in-situ measuring devices is crucial to data collection efforts in this field. The United States Geological Survey (USGS) mobile storm-surge network has already successfully provided a framework for evaluating hurricane induced storm surge water levels on a regional scale through the use of in-situ devices installed in areas affected by storm surge during extreme events. Based on the success of the USGS efforts, in this study we adapted the monitoring network to cover relatively small areas of wetlands and coastal vegetation with an increased density of sensors. Groups of 6 to 10 water level sensors were installed in sites strategically selected in three locations on the Virginia coast of the lower Chesapeake Bay area to monitor different types of vegetation and the resulting hydrodynamic patterns (open coast and inland waters). Each group of sensors recorded time series data of water levels for both astronomical tide circulation and meteorological induced surge. Field campaigns were carried out to survey characteristics of vegetation contributing to flow resistance (i.e. height, diameter and stem density) and mapped using high precision GPS. A geodatabase containing data from field campaigns will support the development and calibration of

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

    NASA Technical Reports Server (NTRS)

    Butera, M. K. (Principal Investigator)

    1978-01-01

    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%.

  16. Treatment and utilization of septic tank effluent using vertical-flow constructed wetlands and vegetable hydroponics.

    PubMed

    Cui, Li-Hua; Luo, Shi-Ming; Zhu, Xi-Zhen; Liu, Ying-Hu

    2003-01-01

    Vertical flow constructed wetlands is a typical ecological sanitation system for sewage treatment. The removal rates for COD, BOD5, SS, TN, and TP were 60%, 80%, 74%, 49% and 79%, respectively, when septic tank effluent was treated by vertical flow filter. So the concentration of COD and BOD5 in the treated effluent could meet the quality standard for irrigation water. After that the treated effluent was used for hydroponic cultivation of water spinach and romaine lettuce, the removal efficiencies of the whole system for COD, BOD5, SS, TN and TP were 71.4%, 97.5%, 96.9%, 86.3%, and 87.4%, respectively. And it could meet the integrated wastewater discharge standard for secondary biological treatment plant. It was found that using treated effluent for hydroponic cultivation of vegetables could reduce the nitrate content in vegetables. The removal rates for total bacteria and coliform index by using vertical flow bed system with cinder substrate were 80%-90% and 85%-96%, respectively.

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

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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.

  18. A numerical study of vegetation impact on reducing storm surge by wetlands in a semi-enclosed estuary

    USGS Publications Warehouse

    Kelin, Hu; Qin, Chen; Wang, Hongqing

    2014-01-01

    Coastal wetlands play a unique role in extreme hurricane events. The impact of wetlands on storm surge depends on multiple factors including vegetation, landscape, and storm characteristics. The Delft3D model, in which vegetation effects on flow and turbulence are explicitly incorporated, was applied to the semi-enclosed Breton Sound (BS) estuary in coastal Louisiana to investigate the wetland impact. Guided by extensive field observations, a series of numerical experiments were conducted based on variations of actual vegetation properties and storm parameters from Hurricane Isaac in 2012. Both the vegetation-induced maximum surge reduction (MSR) and maximum surge reduction rate (MSRR) increased with stem height and stem density, and were more sensitive to stem height. The MSR and MSRR decreased significantly with increasing wind intensity. The MSRR was the highest with a fast-moving weak storm. It was also found that the MSRR varied proportionally to the expression involving the maximum bulk velocity and surge over the area of interest, and was more dependent on the maximum bulk surge. Both MSR and MSRR appeared to increase when the area of interest decreased from the whole BS estuary to the upper estuary. Within the range of the numerical experiments, the maximum simulated MSR and MSRR over the upper estuary were 0.7 m and 37%, respectively.

  19. Vegetation effects on floating treatment wetland nutrient removal and harvesting strategies in urban stormwater ponds.

    PubMed

    Wang, Chih-Yu; Sample, David J; Bell, Cameron

    2014-11-15

    Floating treatment wetlands (FTWs) consist of emergent macrophytes that are placed on a floating mat in a pond for water treatment and aesthetic purposes. FTWs may have unique advantages with respect to treating urban runoff within existing retention ponds for excess nutrients. However, research is lacking in providing guidance on performance of specific species for treating urban runoff, and on timing of harvest. Harvesting is needed to remove nutrients permanently from the retention pond. We investigated vegetation effects on FTWs on nitrogen (N) and phosphorus (P) removal performance and storage in above-ground FTW macrophyte tissues. The study evaluated pickerelweed (PW, Pontederia cordata L.) and softstem bulrush (SB, Schoenoplectus tabernaemontani) over time in microcosms flushed with water obtained from a nearby urban retention pond in northern Virginia near Washington, DC. While the literature exhibits a wide range of experimental sizes, using the term mesocosm, we have chosen the term microcosm to reflect the small size of our vessel; and do not include effects of sediment. The experiment demonstrated PW outperformed SB for P and N removal. Based upon analysis of the accumulated nutrient removal over time, a harvest of the whole PW and SB plants in September or October is recommended. However, when harvesting only the aerial parts, we recommend harvesting above-ground PW tissues in July or August to maximize nutrient removal. This is because PW translocates most of its nutrients to below-ground storage organs in the fall, resulting in less nutrient mass in the above-ground tissue compared to the case in the summer (vegetative stage). Further research is suggested to investigate whether vegetation can be overly damaged from multiple harvests on an annual basis in temperate regions.

  20. Prototype Application of NASA Missions to Identify Patterns of Wetland Vegetation Development within the South San Francisco Bay Salt Ponds

    NASA Astrophysics Data System (ADS)

    Hsu, W.; Newcomer, M. E.; Justice, E.; Guild, L. S.; Skiles, J. W.

    2010-12-01

    The South Bay Salt Pond Restoration Project is the largest tidal wetland restoration on the west coast of the United States. Monitoring vegetation development in these emergent habitats with remote sensing can provide restoration managers with an indication of ecological health and progress of development. Remotely sensed imagery was used to monitor vegetation development and to map vegetation patterns and biota changes historically, during, and after salt pond construction for ponds A19, A20, and A21. Percent vegetative cover was mapped using the Normalized Difference Vegetation Index (NDVI) from MODIS, Tasseled Cap Greenness (TCG) and NDVI from Landsat TM, and the Ratio Vegetation Index (RVI) from ASTER. Field parameters included in-situ measurements and geographic locations for percent vegetative cover, and site specific species information. Field data were incorporated into GIS, and vegetation was analyzed using spatial statistics methods and a qualitative post-classification comparison technique. NDVI values obtained from the Landsat scenes indicated a net gain of 3.35 acres of vegetation cover from February 2006 (before pond breaching) to August 2009 for pond A21 and 1.33 acres and 3.14 acres for ponds A20 and A19, respectively. Increases in vegetation indicate the marsh has built up to a steady-state condition to provide appropriate habitat for endangered plant and animal species and also indicates the success of restoration practices.

  1. The Influence of Vegetation on Methane Ebullition in a Temperate Wetland

    NASA Astrophysics Data System (ADS)

    Roddy, S.; Varner, R. K.; Palace, M. W.

    2014-12-01

    Methane (CH4) is a potent greenhouse gas, with wetlands being the main natural source of CH4 to the atmosphere. Ebullition, or bubbling, is one pathway of CH4 emission to the atmosphere from wetland ecosystems. Rates of ebullition vary spatially and temporally and can be impacted by vegetation type, peat density, temperature and pressure. We present three years of ebullition measurements from Sallie's Fen, a temperate peatland located in Barrington, NH. We observed the continuous and episodic nature of ebullition and how it varied with species composition, specifically sedge dominated and shrub dominated areas, using six acoustic and manual sensors. These sensors recorded continuously from June through October in each year (2011-2013). From these sensors, manual collections of accumulated gas were sampled to measure both the volume of gas and concentration of CH4. To identify differences in ebullition rates due to varying species composition, we installed six additional sensors in June 2013. Measured ebullitive fluxes ranged from 0 to 345 mg/m2/day. Manual measurements in sedge dominated sites had an average flux of 40.8 mg/m2/day for the three year data set compared to an average flux rate of 31.7 mg/m2/day for the shrub dominated sites. Acoustic data shows relationships between water table height and changes in other environmental variables. A subsample of the manual bubble collections at each sensor was also analyzed for 13C-CH4 in order to understand the dominant methanogenic pathway and how this varies with species composition and season.

  2. Comparison of carbon balance in Mediterranean pilot constructed wetlands vegetated with different C4 plant species.

    PubMed

    Barbera, Antonio C; Borin, Maurizio; Cirelli, Giuseppe L; Toscano, Attilio; Maucieri, Carmelo

    2015-02-01

    This study investigates carbon dioxide (CO2) and methane (CH4) emissions and carbon (C) budgets in a horizontal subsurface flow pilot-plant constructed wetland (CW) with beds vegetated with Cyperus papyrus L., Chrysopogon zizanioides (L.) Roberty, and Mischantus × giganteus Greef et Deu in the Mediterranean basin (Sicily) during the 1st year of plant growing season. At the end of the vegetative season, M. giganteus showed the higher biomass accumulation (7.4 kg m(-2)) followed by C. zizanioides (5.3 kg m(-2)) and C. papyrus (1.8 kg m(-2)). Significantly higher emissions of CO2 were detected in the summer, while CH4 emissions were maximum during spring. Cumulative CO2 emissions by C. papyrus and C. zizanioides during the monitoring period showed similar trends with final values of about 775 and 1,074 g m(-2), respectively, whereas M. giganteus emitted 3,395 g m(-2). Cumulative CH4 bed emission showed different trends for the three C4 plant species in which total gas release during the study period was for C. papyrus 12.0 g m(-2) and ten times higher for M. giganteus, while C. zizanioides bed showed the greatest CH4 cumulative emission with 240.3 g m(-2). The wastewater organic carbon abatement determined different C flux in the atmosphere. Gas fluxes were influenced both by plant species and monitored months with an average C-emitted-to-C-removed ratio for C. zizanioides, C. papyrus, and M. giganteus of 0.3, 0.5, and 0.9, respectively. The growing season C balances were positive for all vegetated beds with the highest C sequestered in the bed with M. giganteus (4.26 kg m(-2)) followed by C. zizanioides (3.78 kg m(-2)) and C. papyrus (1.89 kg m(-2)). To our knowledge, this is the first paper that presents preliminary results on CO2 and CH4 emissions from CWs vegetated with C4 plant species in Mediterranean basin during vegetative growth.

  3. Mangrove and Freshwater Wetland Conservation Through Carbon Offsets: A Cost-Benefit Analysis for Establishing Environmental Policies

    NASA Astrophysics Data System (ADS)

    Vázquez-González, César; Moreno-Casasola, Patricia; Hernández, María Elizabeth; Campos, Adolfo; Espejel, Ileana; Fermán-Almada, José Luis

    2017-02-01

    Mexico has extensive coastal wetlands (4,243,137 ha), and one of its most important sites is the Alvarado Lagoon System, located in the Papaloapan River Basin on the Gulf of Mexico. The land cover dedicated to livestock and sugarcane has increased: by 25 % in 2005 and 50 % in 2010, with a loss of wetland vegetation and the carbon that it stores. We found that the Net Present Value of mangrove carbon offsets profit is equal to 5822.71, that of broad-leaved marshes is 7958.86, cattail marshes 5250.33, and forested wetlands 8369.41 per hectare, during a 30-year-carbonoffset contract. However, the opportunity cost from conserving wetland instead of growing sugarcane is positive according to REDD+ methodology, e.g., broad-leaved marsh conservation ranged from 6.73 to 20 USD/t CO2e, that of cattail marshes from 12.20 to 32.65 USD/t CO2e, and forested wetlands from 7.15 to 20.60 USD/t CO2e, whereas the opportunity cost between conservation and livestock was negative, it means that conservation is more profitable. The cost-benefit analysis for assessing investment projects from a governmental perspective is useful to determine the viability of conserving coastal wetlands through carbon offset credits. It also shows why in some areas it is not possible to conserve ecosystems due to the opportunity cost of changing from one economic activity (livestock and sugarcane) to carbon offsets for protecting wetlands. Furthermore, it allows for a comparison of carbon markets and assessment in terms of REDD+ and its methods for determining the social cost per ton of carbon avoided.

  4. Mangrove and Freshwater Wetland Conservation Through Carbon Offsets: A Cost-Benefit Analysis for Establishing Environmental Policies.

    PubMed

    Vázquez-González, César; Moreno-Casasola, Patricia; Hernández, María Elizabeth; Campos, Adolfo; Espejel, Ileana; Fermán-Almada, José Luis

    2017-02-01

    Mexico has extensive coastal wetlands (4,243,137 ha), and one of its most important sites is the Alvarado Lagoon System, located in the Papaloapan River Basin on the Gulf of Mexico. The land cover dedicated to livestock and sugarcane has increased: by 25 % in 2005 and 50 % in 2010, with a loss of wetland vegetation and the carbon that it stores. We found that the Net Present Value of mangrove carbon offsets profit is equal to $5822.71, that of broad-leaved marshes is $7958.86, cattail marshes $5250.33, and forested wetlands $8369.41 per hectare, during a 30-year-carbonoffset contract. However, the opportunity cost from conserving wetland instead of growing sugarcane is positive according to REDD+ methodology, e.g., broad-leaved marsh conservation ranged from $6.73 to $20 USD/t CO2e, that of cattail marshes from $12.20 to $32.65 USD/t CO2e, and forested wetlands from $7.15 to $20.60 USD/t CO2e, whereas the opportunity cost between conservation and livestock was negative, it means that conservation is more profitable. The cost-benefit analysis for assessing investment projects from a governmental perspective is useful to determine the viability of conserving coastal wetlands through carbon offset credits. It also shows why in some areas it is not possible to conserve ecosystems due to the opportunity cost of changing from one economic activity (livestock and sugarcane) to carbon offsets for protecting wetlands. Furthermore, it allows for a comparison of carbon markets and assessment in terms of REDD+ and its methods for determining the social cost per ton of carbon avoided.

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

    USGS Publications Warehouse

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

    2012-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Butera, M. K.

    1979-01-01

    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.

  7. After the deluge: Establishing rates of geographically isolated wetland loss within the prairie pothole region

    NASA Astrophysics Data System (ADS)

    Serran, J.; Creed, I. F.

    2014-12-01

    Geographically isolated wetlands (GIWs) from the prairie pothole region of North America are particularly vulnerable to loss and increasing urban, agricultural, and natural resource development pressures continue to place these wetlands at risk. Although small in area and low in surface hydrologic connectivity, GIWs provide important functions such as flood control and water purification and their loss has been recognized as a contributing factor to the eutrophication of Lake Winnipeg. Within Canada, GIW loss can be attributed to the lack of high-resolution wetland inventories and the lack of information about historic wetland loss rates. In this study, we tested an approach to estimate GIW loss by improving their detection and delineation. To initialize our work, a high-resolution wetland inventory was created using a novel approach that fuses LiDAR data (probability of wetland) with aerial photographs (to distinguish open water and wet meadow) for the Beaverhill watershed, a major tributary of the North Saskatchewan watershed. Our wetland mapping results validated our ability to detect wetlands on the landscape. Secondly, we applied a power law area-frequency function to an aerial photograph time series spanning the watershed's natural climate variation range (1960 to present) to estimate historic wetland loss, with historic wetland loss determined via a break in slope in the power law function. Our analysis revealed ongoing loss of small GIWs in the watershed, despite the implementation of wetland policy measures to mitigate this loss. This ongoing GIW loss is particularly detrimental as it is concomitant with a loss in the important associated ecosystem functions of these GIWs, which has serious repercussions for downstream waters. Overall, our findings support a shift in wetland policies from area to function assessments that provide governments with tools to manage the potential consequences of wetland loss in terms of increased flooding and pollution of

  8. 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)

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

    2014-05-01

    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 (λ 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

  9. Remediation of sewage and industrial effluent using bacterially assisted floating treatment wetlands vegetated with Typha domingensis.

    PubMed

    Ijaz, Amna; Iqbal, Zafar; Afzal, Muhammad

    2016-11-01

    This investigation reports the quantitative assessment of endophyte-assisted floating treatment wetlands (FTWs) for the remediation of sewage and industrial wastewater. Typha domingensis was used to vegetate FTWs that were subsequently inoculated with a consortium of pollutant-degrading and plant growth-promoting endophytic bacteria. T. domingensis, being an aquatic species, holds excellent potential to remediate polluted water. Nonetheless, investigation conducted on Madhuana drain carrying industrial and sewage water from Faisalabad City revealed the percentage reduction in chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) to be 87% and 87.5%, respectively, within 96 h on coupling the plant species with a consortium of bacterial endophytes. With the endophytes surviving in plant tissue, maximal reduction was obtained in not only the aforementioned pollution parameters but for other major environmental quality parameters including nutrients (N and P), ions (Na(+) and K(+)), Cl(-), and SO4(2-) as well, which showed percentage reductions up to 90%, 39%, 77%, 91.8%, 40%, and 60%, respectively. This significant improvement in polluted wastewater quality treated with the proposed method render it safe to be discharged freely in larger water bodies as per the National Environmental Quality Standards (NEQS) of Pakistan or to be reused safely for irrigation purposes; thus, FTWs provide a sustainable and affordable approach for in situ remediation of sewage and industrial wastewater.

  10. Vegetation Types Alter Soil Respiration and Its Temperature Sensitivity at the Field Scale in an Estuary Wetland

    PubMed Central

    Han, Guangxuan; Xing, Qinghui; Luo, Yiqi; Rafique, Rashad; Yu, Junbao; Mikle, Nate

    2014-01-01

    Vegetation type plays an important role in regulating the temporal and spatial variation of soil respiration. Therefore, vegetation patchiness may cause high uncertainties in the estimates of soil respiration for scaling field measurements to ecosystem level. Few studies provide insights regarding the influence of vegetation types on soil respiration and its temperature sensitivity in an estuary wetland. In order to enhance the understanding of this issue, we focused on the growing season and investigated how the soil respiration and its temperature sensitivity are affected by the different vegetation (Phragmites australis, Suaeda salsa and bare soil) in the Yellow River Estuary. During the growing season, there were significant linear relationships between soil respiration rates and shoot and root biomass, respectively. On the diurnal timescale, daytime soil respiration was more dependent on net photosynthesis. A positive correlation between soil respiration and net photosynthesis at the Phragmites australis site was found. There were exponential correlations between soil respiration and soil temperature, and the fitted Q10 values varied among different vegetation types (1.81, 2.15 and 3.43 for Phragmites australis, Suaeda salsa and bare soil sites, respectively). During the growing season, the mean soil respiration was consistently higher at the Phragmites australis site (1.11 µmol CO2 m−2 s−1), followed by the Suaeda salsa site (0.77 µmol CO2 m−2 s−1) and the bare soil site (0.41 µmol CO2 m−2 s−1). The mean monthly soil respiration was positively correlated with shoot and root biomass, total C, and total N among the three vegetation patches. Our results suggest that vegetation patchiness at a field scale might have a large impact on ecosystem-scale soil respiration. Therefore, it is necessary to consider the differences in vegetation types when using models to evaluate soil respiration in an estuary wetland. PMID:24608636

  11. Vegetation types alter soil respiration and its temperature sensitivity at the field scale in an estuary wetland.

    PubMed

    Han, Guangxuan; Xing, Qinghui; Luo, Yiqi; Rafique, Rashad; Yu, Junbao; Mikle, Nate

    2014-01-01

    Vegetation type plays an important role in regulating the temporal and spatial variation of soil respiration. Therefore, vegetation patchiness may cause high uncertainties in the estimates of soil respiration for scaling field measurements to ecosystem level. Few studies provide insights regarding the influence of vegetation types on soil respiration and its temperature sensitivity in an estuary wetland. In order to enhance the understanding of this issue, we focused on the growing season and investigated how the soil respiration and its temperature sensitivity are affected by the different vegetation (Phragmites australis, Suaeda salsa and bare soil) in the Yellow River Estuary. During the growing season, there were significant linear relationships between soil respiration rates and shoot and root biomass, respectively. On the diurnal timescale, daytime soil respiration was more dependent on net photosynthesis. A positive correlation between soil respiration and net photosynthesis at the Phragmites australis site was found. There were exponential correlations between soil respiration and soil temperature, and the fitted Q10 values varied among different vegetation types (1.81, 2.15 and 3.43 for Phragmites australis, Suaeda salsa and bare soil sites, respectively). During the growing season, the mean soil respiration was consistently higher at the Phragmites australis site (1.11 µmol CO2 m(-2) s(-1)), followed by the Suaeda salsa site (0.77 µmol CO2 m(-2) s(-1)) and the bare soil site (0.41 µmol CO2 m(-2) s(-1)). The mean monthly soil respiration was positively correlated with shoot and root biomass, total C, and total N among the three vegetation patches. Our results suggest that vegetation patchiness at a field scale might have a large impact on ecosystem-scale soil respiration. Therefore, it is necessary to consider the differences in vegetation types when using models to evaluate soil respiration in an estuary wetland.

  12. Wetland vegetation in Manzala lagoon, Nile Delta coast, Egypt: Rapid responses of pollen to altered nile hydrology and land use

    USGS Publications Warehouse

    Bernhardt, C.E.; Stanley, J.-D.; Horton, B.P.

    2011-01-01

    The pollen record in a sediment core from Manzala lagoon on the Nile delta coastal margin of Egypt, deposited from ca. AD 1860 to 1990, indicates rapid coastal wetland vegetation responses to two primary periods of human activity. These are associated with artificially altered Nile hydrologic regimes in proximal areas and distal sectors located to ???1200 km south of Manzala. Freshwater wetland plants that were dominant, such as Typha and Phragmites, decreased rapidly, whereas in the early 1900s, brackish water wetland species (e.g., Amaranthaceae) increased. This change occurred after closure of the Aswan Low Dam in 1902. The second major modification in the pollen record occurred in the early 1970s, after Aswan High Dam closure from 1965 to 1970, when Typha pollen abundance increased rapidly. Massive population growth occurred along the Nile during the 130 years represented by the core section. During this time, the total volume of lagoon water decreased because of conversion of wetland areas to agricultural land, and input of organic-rich sediment, sewage (municipal, agricultural, industrial), and fertilizer in Manzala lagoon increased markedly. Although the wetland plant community has continued to respond to increasingly intensified and varied human-induced pressures in proximal sectors, the two most marked changes in Manzala pollen best correlate with distal events (i.e., closure of the two dams at Aswan). The study also shows that the two major vegetation changes in Manzala lagoon each occurred less than 10 years after closure upriver of the Low and High dams that markedly altered the Nile regime from Upper Egypt to the coast. ?? 2011, the Coastal Education & Research Foundation (CERF).

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

    USGS Publications Warehouse

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

    1993-01-01

    A study of hydrologic conditions, vegetation, and soils was made in wetland forests of four north Florida streams from 1987 to 1990. The study was conducted by the U.S. Geological Survey in cooperation with the Florida Department of Environmental Regulation to support State and Federal efforts to improve wetland delineation methodology in flood plains. Plant communities and soils were described and related to topographic position and long-term hydrologic conditions at 10 study plots located on 4 streams. Detailed appendixes give average duration, frequency, and depth of flooding; canopy, subcanopy, and ground-cover vegetation; and taxonomic classification, series, and profile descriptions of soils for each plot. Topographic relief, range in stage, and depth of flooding were greatest on the alluvial flood plain of the Ochlockonee River, the largest of the four streams. Soils were silty in the lower elevations of the flood plain, and tree communities were distinctly different in each topographic zone. The Aucilla River flood plain was dominated by levees and terraces with very few depressions or low backwater areas. Oaks dominated the canopy of both lower and upper terraces of the Aucilla flood plain. Telogia Creek is a blackwater stream that is a major tributary of the Ochlockonee River. Its low, wet flood plain was dominated by Wyssa ogeche (Ogeechee tupelo) trees, had soils with mucky horizons, and was inundated by frequent floods of very short duration. The St. Marks River, a spring-fed stream with high base flow, had the least topographic relief and lowest range in stage of the four streams. St. Marks soils had a higher clay content than the other streams, and limestone bedrock was relatively close to the surface. Wetland determinations of the study plots based on State and Federal regulatory criteria were evaluated. Most State and Federal wetland determinations are based primarily on vegetation and soil characteristics because hydrologic records are usually not

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    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

  15. 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)

    Poindexter, C.; Variano, E. A.

    2012-12-01

    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

  16. Land Surface Temperature Retrieval in Wetlands Using Normalized Difference Vegetation Index-Emissivity Estimation and ASTER Emissivity Product

    NASA Astrophysics Data System (ADS)

    Muro, Javier; Heinmann, Sascha; Strauch, Adrian; Menz, Gunter

    2016-08-01

    Land Surface Temperature (LST) has the potential to act as a continuous indicator of the ecological status of wetlands. Accurate emissivity values are required in order to calculate precise LST. We test two emissivity retrieval methods and their influence on LST calculated from a Landsat 7 image of a highly dynamic wetland in Southern Spain. LST calculated using NDVI (Normalized Difference Vegetation Index) threshold estimations and the ASTER emissivity product are compared. The results show differences of around 0-1 K for most land covers, and up to 3 K for areas of bare soil when Landsat and ASTER images have the same acquisition date. Tests using Landsat and ASTER images from different seasons do not show greater differences between both LSTs. This has important implications for automated LST retrieval methods, such as the one planed by the USGS using Landsat and ASTER emissivity products.

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

    USGS Publications Warehouse

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

    2009-01-01

    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

  18. Response of Plant Height, Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands, Northeast China.

    PubMed

    Lou, Yanjing; Pan, Yanwen; Gao, Chuanyu; Jiang, Ming; Lu, Xianguo; Xu, Y Jun

    2016-01-01

    Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region.

  19. Response of Plant Height, Species Richness and Aboveground Biomass to Flooding Gradient along Vegetation Zones in Floodplain Wetlands, Northeast China

    PubMed Central

    Lou, Yanjing; Pan, Yanwen; Gao, Chuanyu; Jiang, Ming; Lu, Xianguo; Xu, Y. Jun

    2016-01-01

    Flooding regime changes resulting from natural and human activity have been projected to affect wetland plant community structures and functions. It is therefore important to conduct investigations across a range of flooding gradients to assess the impact of flooding depth on wetland vegetation. We conducted this study to identify the pattern of plant height, species richness and aboveground biomass variation along the flooding gradient in floodplain wetlands located in Northeast China. We found that the response of dominant species height to the flooding gradient depends on specific species, i.e., a quadratic response for Carex lasiocarpa, a negative correlation for Calamagrostis angustifolia, and no response for Carex appendiculata. Species richness showed an intermediate effect along the vegetation zone from marsh to wet meadow while aboveground biomass increased. When the communities were analysed separately, only the water table depth had significant impact on species richness for two Carex communities and no variable for C. angustifolia community, while height of dominant species influenced aboveground biomass. When the three above-mentioned communities were grouped together, variations in species richness were mainly determined by community type, water table depth and community mean height, while variations in aboveground biomass were driven by community type and the height of dominant species. These findings indicate that if habitat drying of these herbaceous wetlands in this region continues, then two Carex marshes would be replaced gradually by C. angustifolia wet meadow in the near future. This will lead to a reduction in biodiversity and an increase in productivity and carbon budget. Meanwhile, functional traits must be considered, and should be a focus of attention in future studies on the species diversity and ecosystem function in this region. PMID:27097325

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

    USGS Publications Warehouse

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

    2013-01-01

    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

  1. 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

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

    2006-01-01

    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

  2. Bottom-up control of carabid beetle communities in early successional wetlands: mediated by vegetation structure or plant diversity?

    PubMed

    Brose, U

    2003-05-01

    Two hypotheses of bottom-up control that predict that the species richness of Carabidae will depend either on the taxonomic diversity of plants ("taxonomic diversity hypothesis") or on the structural heterogeneity of the vegetation ("structural heterogeneity hypothesis") were tested. Plant species were classified into nine plant structural groups through cluster analysis of morphological traits (e.g. total height) at 30 early successional temporary wetlands in the east-German agricultural landscape. In a linear regression analysis, the heterogeneity of vegetation structures explained 55% of the variation in carabid beetle diversity. According to a partial correlation analysis, plant taxonomic diversity did not have a significant effect, consistent with the "structural heterogeneity hypothesis," and contradicting previous studies which concluded that plant taxonomic diversity would be the most important factor in early successional habitats. An experimental study was used to test hypotheses on the processes underlying this bottom-up control by vegetation structure: the "hunting efficiency hypothesis," the "enemy-free space hypothesis," and the "microhabitat specialization hypothesis." The composition of plant structural groups in 15 vegetation plots (1 m(2)) was manipulated, creating a gradient from dense vegetation to open plots. Subsequent pitfall catches revealed significant differences in the activity-abundances of the carabid species. Large species preferred dense vegetation plots, consistent with the enemy-free space hypothesis that large species are more vulnerable to predation on the open plots and prefer dense vegetation to escape from natural enemies. The results indicate that bottom-up control is not mediated only by plant taxonomic or functional group diversity and that vegetation structures may be more important than previously suggested.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

    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

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

    NASA Astrophysics Data System (ADS)

    Poindexter, Cristina M.; Variano, Evan A.

    2013-07-01

    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.

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

    USGS Publications Warehouse

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

    2012-01-01

    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.

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

    USGS Publications Warehouse

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

    2014-01-01

    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

  7. The backscattering characteristics of wetland vegetation and water-level changes detection using multi-mode SAR: A case study

    NASA Astrophysics Data System (ADS)

    Zhang, Meimei; Li, Zhen; Tian, Bangsen; Zhou, Jianmin; Tang, Panpan

    2016-03-01

    A full understanding of the backscattering characteristics of wetlands is necessary for the analysis of the hydrological conditions. In this study, a temporal set of synthetic aperture radar (SAR) imagery, acquired at different frequencies, polarizations and incidence angles over the coastal wetlands of the Liaohe River Delta, China, were used to characterize seasonal variations in radar backscattering coefficient for reed marshes and rice fields. The combination of SAR backscattering intensity and an optical-based normalized difference vegetation index (NDVI) for long time series can provide additional insight into vegetation structural and its hydrological states. After identifying the factors that induce the backscattering and scattering mechanism changes, detailed analysis of L-band ALOS PALSAR interferometric SAR (InSAR) imagery was conducted to study water-level changes under different environmental conditions. In addition, ENVISAT altimetry was used to validate the accuracy of the water-level changes estimated using the InSAR technique-this is an effective tool instead of sparsely distributed gauge stations for the validation. Our study demonstrates that L-band SAR data with horizontal polarization is particularly suitable for the extraction of water-level changes in the study area; however, vertically-polarized C-band data may also be useful where the density of herbaceous vegetation is low at the initial stage. It is also shown that integrated analysis of the backscattering mechanism and interferometric characteristics using multi-mode SAR can considerably enhance the reliability of the water-level retrieval scheme and better capture the spatial distribution of hydrological patterns.

  8. Developing a National Vegetation Multimetric Metric Index of Wetland Condition for the Conterminous United States

    EPA Science Inventory

    This product is an abstract for the 2015 Ecological Society Meeting in Baltimore, Maryland in August. The U.S. Environmental Protection Agency (USEPA), with states, tribes, and other partners, conducted the first-ever National Wetland Condition Assessment (NWCA) in 2011, using a...

  9. Vegetation dynamics of restored and remnant Willamette Valley, OR wet prairie wetlands

    EPA Science Inventory

    Wet prairie wetlands are now one of the rarest habitat types in the Willamette Valley of Oregon, USA. Less than two percent of their historic extent remains, with most having been converted into agricultural fields (Christy and Alverson 2011, ONHP 1983). This habitat is the obl...

  10. Planting richness affects the recovery of vegetation and soil processes in constructed wetlands following disturbance.

    PubMed

    Means, Mary M; Ahn, Changwoo; Noe, Gregory B

    2017-02-01

    The resilience of constructed wetland ecosystems to severe disturbance, such as a mass herbivory eat-out or soil disturbance, remains poorly understood. In this study, we use a controlled mesocosm experiment to examine how original planting diversity affects the ability of constructed freshwater wetlands to recover structurally and functionally after a disturbance (i.e., aboveground harvesting and soil coring). We assessed if the planting richness of macrophyte species influences recovery of constructed wetlands one year after a disturbance. Mesocosms were planted in richness groups with various combinations of either 1, 2, 3, or 4 species (RG 1-4) to create a gradient of richness. Structural wetland traits measured include morphological regrowth of macrophytes, soil bulk density, soil moisture, soil %C, and soil %N. Functional wetland traits measured include above ground biomass production, soil potential denitrification, and soil potential microbial respiration. Total mesocosm cover increased along the gradient of plant richness (43.5% in RG 1 to 84.5% in RG 4) in the growing season after the disturbance, although not all planted individuals recovered. This was largely attributed to the dominance of the obligate annual species. The morphology of each species was affected negatively by the disturbance, producing shorter, and fewer stems than in the years prior to the disturbance, suggesting that the communities had not fully recovered one year after the disturbance. Soil characteristics were almost uniform across the planting richness gradient, but for a few exceptions (%C, C:N, and non-growing season soil moisture were higher slightly in RG 2). Denitrification potential (DEA) increased with increasing planting richness and was influenced by the abundance and quality of soil C. Increased open space in unplanted mesocosms and mesocosms with lower species richness increased labile C, leading to higher C mineralization rates.

  11. Diagnosing the roles of vegetation, surface albedo, and presence of lakes and wetlands on dust emission and feedbacks during the mid-Holocene

    NASA Astrophysics Data System (ADS)

    Murphy, L.; Clement, A. C.

    2015-12-01

    During the early to mid-Holocene North Africa was much wetter and the Saharan desert was replaced with savannah vegetation with numerous lakes and wetlands. Correspondingly dust fluxes in the eastern North Atlantic were much lower compared to modern. This period is considered an analogue for dust free conditions. It is uncertain whether dust acts as a positive or negative feedback on the hydrological cycle, and the underlying surface albedo has a strong impact on the shortwave dust radiative effect. Here we examine the roles of vegetation, surface albedo, and lake/wetland coverage on dust emissions and the resulting dust-climate feedbacks using a fully coupled climate model with an interactive dust model. Preliminary results show that the addition of lakes and wetlands reduces dust emissions over North Africa, and enhances evaporation and precipitation by more than 50%.

  12. Responses of Hyalella azteca to a Pesticide-Nutrient Mixture in Vegetated and Non-vegetated Wetland Mesocosms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquatic vegetation has been shown to improve water quality by trapping and processing contaminants such as pesticides, nutrients and sediments. Currently there is little information regarding effects of pesticide and nutrient mixtures on aquatic biota in these systems and the influence aquatic vege...

  13. Comparison of phosphorus fractions and phosphatase activities in coastal wetland soils along vegetation zones of Yancheng National Nature Reserve, China

    NASA Astrophysics Data System (ADS)

    Huang, Lidong; Zhang, Yaohong; Shi, Yiming; Liu, Yibo; Wang, Lin; Yan, Ning

    2015-05-01

    Phosphorus (P) fractions and phosphatase activities were measured in 22 coastal wetland soils with typical vegetation successions in Yancheng National Nature Reserve, China. P forms and phosphatase activities varied greatly from site to site even under the same vegetation cover. NH4Cl-P, bicarbonate/dithionite extracted P and NaOH-P were remarkably higher (p < 0.05) in soils with exotic invasive plants, Spartina alterniflora, than in soils with the native species Suaeda salsa, Scirpus mariquete and Phragmites australis. HCl-P and refractory P showed little variation. No significant differences were detected for either alkaline phosphatase (ALAP) or acid phosphatase (ACAP) among the soils. All of the above properties were much higher in soils with plant growth compared to bare flat soils. Regression analysis demonstrated that organic matter (OM), Al, Ca, Fe and total P (TP) were able to explain more than 70% of the variations in the P fractions (except 29% of NH4Cl-P), and OM was the most important contributing factor. ALAP and ACAP were irrelevant to P but were significantly related to TOC, suggesting that carbon was a limiting factor for P mineralization in this area. Owing to its huge biomass and densities, Spartina alterniflora displayed great potential for carbon input, thus facilitating P mineralization and cycling. The results enhance our understanding of P availability differences in this area covered by invasive and native vegetation.

  14. Trace element-induced stress in freshwater wetland vegetation: Preliminary results

    NASA Technical Reports Server (NTRS)

    Wood, B. L.; Beck, L. H.

    1986-01-01

    Airborne Imaging Spectrometer (AIS) data were acquired over an area of freshwater wetlands in Central California on September 23, 1985. Plant samples were subsequently collected along the flight line with the goal of relating plant tissue chemistry to spectral reflectance in the near-infrared region. It was determined that a consistent relationship existed between spectral response and plant tissue chemistry. This was especially evident in the 1500 to 1700 nm region.

  15. Nitrogen and phosphorus removal from plant nursery runoff in vegetated and unvegetated subsurface flow wetlands.

    PubMed

    Huett, D O; Morris, S G; Smith, G; Hunt, N

    2005-09-01

    Subsurface horizontal flow reed beds are being evaluated for Nitrogen (N) and Phosphorus (P) removal from plant nursery runoff water in New South Wales Australia. The need to include plants (Phragmites australis), the effect of reaction time (3.5 v 7.0 d) and dissolved organic carbon (DOC) on N and P removal in batch fed gravel wetland tubs (55 L) was studied over 19 months. Simulated nursery runoff water containing N (10.1 mg L(-1), 74% as NO3) and P (0.58 mg L(-1), 88% as PO4) and DOC (2-5 mg L(-1)) was used. The planted wetland tubs removed >96% TN and TP over most of the 19-month study period while unplanted tubs were inefficient (<16% N and <45% P removal) and occasionally discharged nutrients. Doubling the reaction time to 7.0 days had no effect on nutrient removal. Plant nutrient uptake accounted for most of the N (76%) and P (86%) removed while roots and rhizomes were the dominant sink (N 58%, P 67%). The addition of methanol (C:N-3:1) to unplanted tubs achieved 81-98% N removal. In Carbon limited low nutrient nursery runoff, plants were essential to a gravel-based wetland to achieve efficient nutrient removal with effluent TN and TP concentrations of <1 mg L(-1) and 0.05 mg L(-1), respectively with a 3.5 day reaction time.

  16. Bark mulch promotes establishment of vegetation on minesoils with south and west exposures

    SciTech Connect

    Dyer, K.L.; Sencindiver, J.C.

    1985-12-01

    In early July 1976, a non-topsoiled head-of-hollow fill in Breathitt County, Kentucky, was seeded to grasses and legumes. From July 12 to July 16, a hardwood bark mulch was applied in a band around this fill. After late August 1976, the mulched areas were nearly fully sodded, regardless of aspect. South- and west-facing unmulched slopes were nearly void of vegetation. At this time, the north-facing slope had the best vegetative cover even though no mulch had been applied. By the end of the second growing season, nearly the entire head-of-hollow fill was well vegetated, regardless of aspect or whether mulch had been applied. The mulch protected the exposed minesoil from erosion during the first year and speeded the establishment of vegetative cover on the south- and west-facing slopes. On a nearby mountain top removal tract, hardwood bark and black locust chips were compared on gentle north- and south-facing slopes. After to growing seasons, vegetative cover was much heavier on the north-facing than on the south-facing slopes. In April 1985, almost 9 years after these tracts had been seeded, it was apparent that the south- and west-facing slopes had a much heavier vegetative cover than the north-facing slopes. The initial slow growth of vegetation on the south-facing slopes apparently had been more than overcome by (1) greater growth potential due to more available sunlight and warmer temperatures, and (2) greater fertility due to the better survival of legumes. 8 references, 2 figures, 3 tables.

  17. The importance of hydrology in restoration of bottomland hardwood wetland functions

    USGS Publications Warehouse

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

    2008-01-01

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

  18. Coastal vegetation invasion increases greenhouse gas emission from wetland soils but also increases soil carbon accumulation.

    PubMed

    Chen, Yaping; Chen, Guangcheng; Ye, Yong

    2015-09-01

    Soil properties and soil-atmosphere fluxes of CO2, CH4 and N2O from four coastal wetlands were studied throughout the year, namely, native Kandelia obovata mangrove forest vs. exotic Sonneratia apetala mangrove forest, and native Cyperus malaccensis salt marsh vs. exotic Spartina alterniflora salt marsh. Soils of the four wetlands were all net sources of greenhouse gases while Sonneratia forest contributed the most with a total soil-atmosphere CO2-equivalent flux of 137.27 mg CO2 m(-2) h(-1), which is 69.23%, 99.75% and 44.56% higher than that of Kandelia, Cyperus and Spartina, respectively. The high underground biomass and distinctive root structure of Sonneratia might be responsible for its high greenhouse gas emission from the soil. Soils in Spartina marsh emitted the second largest amount of total greenhouse gases but it ranked first in emitting trace greenhouse gases. Annual average CH4 and N2O fluxes from Spartina soil were 13.77 and 1.14 μmol m(-2) h(-1), respectively, which are 2.08 and 1.46 times that of Kandelia, 1.03 and 1.15 times of Sonneratia, and 1.74 and 1.02 times of Cyperus, respectively. Spartina has longer growing season and higher productivity than native marshes which might increase greenhouse gas emission in cold seasons. Exotic wetland soils had higher carbon stock as compared to their respective native counterparts but their carbon stocks were offset by a larger proportion because of their higher greenhouse gas emissions. Annual total soil-atmosphere fluxes of greenhouse gases reduced soil carbon burial benefits by 8.1%, 9.5%, 6.4% and 7.2% for Kandelia, Sonneratia, Cyperus and Spartina, respectively, which narrowed down the gaps in net soil carbon stock between native and exotic wetlands. The results indicated that the invasion of exotic wetland plants might convert local coastal soils into a considerable atmospheric source of greenhouse gases although they at the same time increase soil carbon accumulation.

  19. Gradient Analysis and Classification of Carolina Bay Vegetation: A Framework for Bay Wetlands Conservation and Restoration

    SciTech Connect

    Diane De Steven,Ph.D.; Maureen Tone,PhD.

    1997-10-01

    This report address four project objectives: (1) Gradient model of Carolina bay vegetation on the SRS--The authors use ordination analyses to identify environmental and landscape factors that are correlated with vegetation composition. Significant factors can provide a framework for site-based conservation of existing diversity, and they may also be useful site predictors for potential vegetation in bay restorations. (2) Regional analysis of Carolina bay vegetation diversity--They expand the ordination analyses to assess the degree to which SRS bays encompass the range of vegetation diversity found in the regional landscape of South Carolina's western Upper Coastal Plain. Such comparisons can indicate floristic status relative to regional potentials and identify missing species or community elements that might be re-introduced or restored. (3) Classification of vegetation communities in Upper Coastal Plain bays--They use cluster analysis to identify plant community-types at the regional scale, and explore how this classification may be functional with respect to significant environmental and landscape factors. An environmentally-based classification at the whole-bay level can provide a system of templates for managing bays as individual units and for restoring bays to desired plant communities. (4) Qualitative model for bay vegetation dynamics--They analyze present-day vegetation in relation to historic land uses and disturbances. The distinctive history of SRS bays provides the possibility of assessing pathways of post-disturbance succession. They attempt to develop a coarse-scale model of vegetation shifts in response to changing site factors; such qualitative models can provide a basis for suggesting management interventions that may be needed to maintain desired vegetation in protected or restored bays.

  20. 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)

    Mita, Dath Kakole

    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

  1. Evaluating Hyperspectral Imaging of Wetland Vegetation as a Tool for Detecting Estuarine Nutrient Enrichment

    DTIC Science & Technology

    2008-05-01

    exchanges. Collectively, these studies suggest that estuarine vegetation has considerable potential as a practical bioindicator of temporal nutrient... bioindicators of potential eutrophication in the field and at landscape scales. Most previous work on spectral responses to nutrient enrichment has been

  2. Integrated Field Lysimetry and Porewater Sampling for Evaluation of Chemical Mobility in Soils and Established Vegetation

    PubMed Central

    Gannon, Travis W.; Polizzotto, Matthew L.

    2014-01-01

    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

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

    PubMed

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

    2014-07-04

    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.

  4. Submerged macrophyte seed bank in a Mediterranean temporary marsh: abundance and relationship with established vegetation.

    PubMed

    Grillas, P; Garcia-Murillo, P; Geertz-Hansen, O; Marbá, N; Montes, C; Duarte, C M; Tan Ham, L; Grossmann, A

    1993-05-01

    The abundance and composition of the submerged macrophyte seed bank in the Doñana marsh (southwestern Spain) was evaluated to assess its relationship with the overlying vegetation. The results obtained demonstrate the existence of a dense seed-bank, both in terms of the number of seeds and their biomass, which represented about 10% (5% for angiosperms and >20% for Charophyta) of the total plant biomass, which ensures the maintenance of the annual submerged macrophyte populations of the seasonally inundated Donñana marsh. Seed bank and established vegetation were coupled, as reflected in the existence of significant correlations between their structure and abundance. This coupling was lacking for Charophyta, whose oospores are widespread and abundant across the marsh, even at locations where they are absent, or rare, in the established vegetation. These differences between the seed bank of annual angiosperms and Charophyta appear to reflect, in part, structural differences between angiosperm seeds and Charophyta oospores, with important ecological consequences. An important aspect of these differences is the allocation of Charophyta reproductive effort to many small propagules lacking embryo storage, compared to those of angiosperms, which ensures their efficient dispersal and numerical abundance in the seed bank.

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

    USGS Publications Warehouse

    Shafroth, P.B.; Auble, G.T.; Stromberg, J.C.; Patten, D.T.

    1998-01-01

    Previous studies have revealed the close coupling of components of annual streamflow hydrographs and the germination and establishment of Populus species. Key hydrograph components include the timing and magnitude of flood peaks, the rate of decline of the recession limb, and the magnitude of base flows. In this paper, we retrospectively examine establishment of four woody riparian species along the Bill Williams River, Arizona, USA, in the context of annual patterns of streamflow for the years 1993-1995. The four species examined were the native Populus fremontii, Salix gooddingii, and Baccharis salicifolia and the exotic Tamarix ramosissima. We modeled locations suitable for germination of each species along eight study transects by combining historic discharge data, calculated stage-discharge relationships, and seed-dispersal timing observations. This germination model was a highly significant predictor of seedling establishment. Where germination was predicted to occur, we compared values of several environmental variables in quadrats where we observed successful establishment with quadrats where establishment was unsuccessful. The basal area of mature woody vegetation, the maximum annual depth to ground water, and the maximum rate of water-table decline were the variables that best discriminated between quadrats with and without seedlings. The results of this study suggest that the basic components of models that relate establishment of Populus spp. to annual patterns of streamflow may also be applicable to other woody riparian species. Reach-to-reach variation in stage-discharge relationships can influence model parameters, however, and should be considered if results such as ours are to be used in efforts to prescribe reservoir releases to promote establishment of native riparian vegetation.

  6. Greenhouse gas emissions from constructed wetlands treating dairy wastewater

    NASA Astrophysics Data System (ADS)

    Glass, Vimy M.

    In Nova Scotia, constructed wetland systems are widely considered as effective treatment systems for agricultural wastewater. Although research has examined the water quality treatment attributes, there has been limited focus on the air quality effects of these systems. Six operational pilot-scale constructed wetlands were built with flow-through chambers for quantifying greenhouse gas (GHG) emissions in Truro, NS. Utilized within this facility were three gas analyzers to monitor GHG emissions (CO2, N 2O, CH4) and the gaseous fluxes could then be determined using the mass balance micrometeorological technique. Prior to data collection, the site underwent testing to ensure valid conclusions and replicated responses from the wetland systems. Those wetlands receiving wastewater at a typical HLR (10.6 mm d-1) and with ample vegetation displayed the best concentration reductions. During the growing season (GS), average CO 2 consumption was large (approximately -44 g CO2m -2 d-1) for wetlands with dense vegetation (approximately 100% cover) at the typical loading rate. For those wetlands at higher loading rates, CO2 emissions were observed to be as high as +9.2 g CO 2m-2 d-1. Wetlands with typical loading rates and healthy aquatic vegetation produced average CH4 fluxes of approximately 43 g CO2 eq. m-2d-1, while higher loaded systems with little vegetation approached 90 g CO 2 eq. m-2d-1. During the non-growing season (NGS), all vegetated wetlands exhibited higher CH4 emissions than the non-vegetated systems (˜15 to 20% higher). Vegetation maturity played a strong role in the GHG balance. The average CO2consumption for wetlands with established vegetation was ˜ -36 g CO2 m -2 d-1 during the GS. Wetland 4, which had been newly transplanted in 2004, had the highest single day CO2 consumption of -152 g CO2m-2 d-1 . Methane emissions from wetlands with two-year-old vegetation followed the same pattern but were approximately half of the emissions recorded from 2003. The

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

    USGS Publications Warehouse

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

    2002-01-01

    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

  8. Examining Discrepancies Among Three Methods Used to Make Hydrophytic Vegetation Determinations for Wetland Delineation Purposes

    DTIC Science & Technology

    2014-03-01

    determinations in plots where hydrophyte cover was 50% or less, and a nonhydrophytic bias in plots dominated by even numbers of plant species. These... Plant List ........................................... 1 2 Chi-Square test and Fisher’s Exact test results comparing the percentage of hydrophytic...whether vegetation is predominantly hydrophytic or nonhydrophytic, plant species have traditionally been assessed using wet- land indicator status

  9. Interactions among vegetation, climate, and herbivory control greenhouse gas fluxes in a subarctic coastal wetland

    USGS Publications Warehouse

    Kelsey, K.C.; Leffler, A.J.; Beard, K.H.; Schmutz, Joel A.; Choi, R.T.; Welker, J.M.

    2016-01-01

    High-latitude ecosystems are experiencing the most rapid climate changes globally, and in many areas these changes are concurrent with shifts in patterns of herbivory. Individually, climate and herbivory are known to influence biosphere-atmosphere greenhouse gas (GHG) exchange; however, the interactive effects of climate and herbivory in driving GHG fluxes have been poorly quantified, especially in coastal systems that support large populations of migratory waterfowl. We investigated the magnitude and the climatic and physical controls of GHG exchange within the Yukon-Kuskokwim Delta in western Alaska across four distinct vegetation communities formed by herbivory and local microtopography. Net CO2 flux was greatest in the ungrazed Carex meadow community (3.97 ± 0.58 [SE] µmol CO2 m−2 s−1), but CH4 flux was greatest in the grazed community (14.00 ± 6.56 nmol CH4 m−2 s−1). The grazed community is also the only vegetation type where CH4 was a larger contributor than CO2 to overall GHG forcing. We found that vegetation community was an important predictor of CO2 and CH4 exchange, demonstrating that variation in regional gas exchange is best explained when the effect of grazing, determined by the difference between grazed and ungrazed communities, is included. Further, we identified an interaction between temperature and vegetation community, indicating that grazed regions could experience the greatest increases in CH4 emissions with warming. These results suggest that future GHG fluxes could be influenced by both climate and by changes in herbivore population dynamics that expand or contract the vegetation community most responsive to future temperature change.

  10. Interactions among vegetation, climate, and herbivory control greenhouse gas fluxes in a subarctic coastal wetland

    NASA Astrophysics Data System (ADS)

    Kelsey, K. C.; Leffler, A. J.; Beard, K. H.; Schmutz, J. A.; Choi, R. T.; Welker, J. M.

    2016-12-01

    High-latitude ecosystems are experiencing the most rapid climate changes globally, and in many areas these changes are concurrent with shifts in patterns of herbivory. Individually, climate and herbivory are known to influence biosphere-atmosphere greenhouse gas (GHG) exchange; however, the interactive effects of climate and herbivory in driving GHG fluxes have been poorly quantified, especially in coastal systems that support large populations of migratory waterfowl. We investigated the magnitude and the climatic and physical controls of GHG exchange within the Yukon-Kuskokwim Delta in western Alaska across four distinct vegetation communities formed by herbivory and local microtopography. Net CO2 flux was greatest in the ungrazed Carex meadow community (3.97 ± 0.58 [SE] µmol CO2 m-2 s-1), but CH4 flux was greatest in the grazed community (14.00 ± 6.56 nmol CH4 m-2 s-1). The grazed community is also the only vegetation type where CH4 was a larger contributor than CO2 to overall GHG forcing. We found that vegetation community was an important predictor of CO2 and CH4 exchange, demonstrating that variation in regional gas exchange is best explained when the effect of grazing, determined by the difference between grazed and ungrazed communities, is included. Further, we identified an interaction between temperature and vegetation community, indicating that grazed regions could experience the greatest increases in CH4 emissions with warming. These results suggest that future GHG fluxes could be influenced by both climate and by changes in herbivore population dynamics that expand or contract the vegetation community most responsive to future temperature change.

  11. Importance of Nitrate Attenuation In A Small Wetland Following Forest Harvest: 18O/16O, 15N/14N in nitrate and 15N/14N) in vegetation

    NASA Astrophysics Data System (ADS)

    Spoelstra, J.; Schiff, S. L.; Semkin, R. G.; Jeffries, D. S.; Elgood, R. J.

    2004-05-01

    Forest harvest can result in elevated nitrate concentrations in streams and groundwater affecting forest regeneration and downstream aquatic ecosystems. Turkey Lakes Watershed, located near Sault Ste Marie, Ontario (TLW), exhibits relatively high nitrate export due to naturally high rates of nitrification. During a forest harvest experiment at the TLW, stable isotope techniques were used to investigate nitrate attenuation in an intermediate position natural wetland receiving high concentrations of nitrate following forest clear-cutting. Isotopic analysis of nitrate (18O/16O, 15N/14N) and vegetation (15N/14N) demonstrated that denitrification and plant uptake of nitrate resulted in significantly lower nitrate concentrations in wetland outflow compared to incoming stream water and groundwater. The 0.2-hectare forested swamp, too small to show up on standard topographic maps, retained 65 to 100 percent of upgradient nitrate inputs, elevated due to increased nitrification in soils. The 15N/14N enrichment factor associated with nitrate attenuation in wetland surface water was lower than observed during denitrification in groundwaters, suggesting that denitrification proceeded to completion in some areas of the wetland. Even small, shallow, carbon rich pockets of organic matter in topographic depressions can significantly affect biogeochemical fluxes of C, N, S and Ca. Future forest management practices designed to recognize and preserve small wetlands could significantly reduce the potentially detrimental effects of forest harvest on aquatic systems.

  12. Hydrogeology of wetlands

    USGS Publications Warehouse

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

    1993-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  14. Estimating wetland vegetation abundance from Landsat-8 operational land imager imagery: a comparison between linear spectral mixture analysis and multinomial logit modeling methods

    NASA Astrophysics Data System (ADS)

    Zhang, Min; Gong, Zhaoning; Zhao, Wenji; Pu, Ruiliang; Liu, Ke

    2016-01-01

    Mapping vegetation abundance by using remote sensing data is an efficient means for detecting changes of an eco-environment. With Landsat-8 operational land imager (OLI) imagery acquired on July 31, 2013, both linear spectral mixture analysis (LSMA) and multinomial logit model (MNLM) methods were applied to estimate and assess the vegetation abundance in the Wild Duck Lake Wetland in Beijing, China. To improve mapping vegetation abundance and increase the number of endmembers in spectral mixture analysis, normalized difference vegetation index was extracted from OLI imagery along with the seven reflective bands of OLI data for estimating the vegetation abundance. Five endmembers were selected, which include terrestrial plants, aquatic plants, bare soil, high albedo, and low albedo. The vegetation abundance mapping results from Landsat OLI data were finally evaluated by utilizing a WorldView-2 multispectral imagery. Similar spatial patterns of vegetation abundance produced by both fully constrained LSMA algorithm and MNLM methods were observed: higher vegetation abundance levels were distributed in agricultural and riparian areas while lower levels in urban/built-up areas. The experimental results also indicate that the MNLM model outperformed the LSMA algorithm with smaller root mean square error (0.0152 versus 0.0252) and higher coefficient of determination (0.7856 versus 0.7214) as the MNLM model could handle the nonlinear reflection phenomenon better than the LSMA with mixed pixels.

  15. Community structure and quality after 10 years in two central Ohio mitigation bank wetlands.

    PubMed

    Spieles, Douglas J; Coneybeer, Meagan; Horn, Jonathan

    2006-11-01

    We evaluate two 10-year-old mitigation bank wetlands in central Ohio, one created and one with restored and enhanced components, by analysis of vegetation characteristics and by comparison of the year-10 vegetation and macroinvertebrate communities with reference wetlands. To assess different measures of wetland development, we compare the prevalence of native hydrophytes with an index of floristic quality and we evaluate the predictability of these parameters in year 10, given 5 years of data. Results show that the mitigation wetlands in this study meet vegetation performance criteria of native hydrophyte establishment by year 5 and maintain these characteristics through year 10. Species richness and floristic quality, as well as vegetative similarity with reference wetlands, differ among mitigation wetlands in year 1 and also in their rate of change during the first 10 years. The prevalence of native hydrophytes is reasonably predictable by year 10, but 5 years of monitoring is not sufficient to predict future trends of floristic quality in either the created or restored wetland. By year 10, macroinvertebrate taxa richness does not statistically differ among these wetlands, but mitigation wetlands differ from reference sites by tolerance index and by trophic guild dominance. The created wetland herbivore biomass is significantly smaller than its reference, whereas detritivore biomass is significantly greater in the created wetland and smaller in the restored wetland as compared with respective reference wetlands. These analyses illustrate differences in measures of wetland performance and contrast the monitoring duration necessary for legal compliance with the duration required for development of more complex indicators of ecosystem integrity.

  16. Community Structure and Quality After 10 Years in Two Central Ohio Mitigation Bank Wetlands

    NASA Astrophysics Data System (ADS)

    Spieles, Douglas J.; Coneybeer, Meagan; Horn, Jonathan

    2006-11-01

    We evaluate two 10-year-old mitigation bank wetlands in central Ohio, one created and one with restored and enhanced components, by analysis of vegetation characteristics and by comparison of the year-10 vegetation and macroinvertebrate communities with reference wetlands. To assess different measures of wetland development, we compare the prevalence of native hydrophytes with an index of floristic quality and we evaluate the predictability of these parameters in year 10, given 5 years of data. Results show that the mitigation wetlands in this study meet vegetation performance criteria of native hydrophyte establishment by year 5 and maintain these characteristics through year 10. Species richness and floristic quality, as well as vegetative similarity with reference wetlands, differ among mitigation wetlands in year 1 and also in their rate of change during the first 10 years. The prevalence of native hydrophytes is reasonably predictable by year 10, but 5 years of monitoring is not sufficient to predict future trends of floristic quality in either the created or restored wetland. By year 10, macroinvertebrate taxa richness does not statistically differ among these wetlands, but mitigation wetlands differ from reference sites by tolerance index and by trophic guild dominance. The created wetland herbivore biomass is significantly smaller than its reference, whereas detritivore biomass is significantly greater in the created wetland and smaller in the restored wetland as compared with respective reference wetlands. These analyses illustrate differences in measures of wetland performance and contrast the monitoring duration necessary for legal compliance with the duration required for development of more complex indicators of ecosystem integrity.

  17. Microbiological quality of fresh, minimally-processed fruit and vegetables, and sprouts from retail establishments.

    PubMed

    Abadias, M; Usall, J; Anguera, M; Solsona, C; Viñas, I

    2008-03-31

    A survey of fresh and minimally-processed fruit and vegetables, and sprouts was conducted in several retail establishments in the Lleida area (Catalonia, Spain) during 2005-2006 to determine whether microbial contamination, and in particular potentially pathogenic bacteria, was present under these commodities. A total of 300 samples--including 21 ready-to-eat fruits, 28 whole fresh vegetables, 15 sprout samples and 237 ready-to-eat salads containing from one to six vegetables--were purchased from 4 supermarkets. They were tested for mesophilic and psychrotrophic aerobic counts, yeasts and moulds, lactic acid bacteria, Enterobacteriaceae, presumptive E. coli and Listeria monocytogenes counts as well as for the presence of Salmonella, E. coli O157:H7, Yersinia enterocolitica and thermotolerant Campylobacter. Results for the fresh-cut vegetables that we analyzed showed that, in general, the highest microorganism counts were associated with grated carrot, arugula and spinach (7.8, 7.5 and 7.4 log cfu g(-1) of aerobic mesophilic microorganisms; 6.1, 5.8 and 5.2 log cfu g(-1) of yeast and moulds; 5.9, 4.0 and 5.1 log cfu g(-1) lactic acid bacteria and 6.2, 5.3 and 6.0 log cfu g(-1) of Enterobacteriaceae). The lowest counts were generally associated with fresh-cut endive and lettuce (6.2 and 6.3 log cfu g(-1) of aerobic mesophilic microorganisms; 4.4 and 4.6 log cfu g(-1) of yeast and moulds; 2.7 and 3.8 log cfu g(-1) lactic acid bacteria and 4.8 and 4.4 log cfu g(-1) of Enterobacteriaceae). Counts of psychrotrophic microorganisms were as high as those of mesophilic microorganisms. Microbiological counts for fresh-cut fruit were very low. Sprouts were highly contaminated with mesophilic (7.9 log cfu g(-1)), psychrotrophic microorganisms (7.3 log cfu g(-1)) and Enterobacteriaceae (7.2 log cfu g(-1)) and showed a high incidence of E. coli (40% of samples). Of the samples analyzed, four (1.3%) were Salmonella positive and two (0.7%) harboured L. monocytogenes. None of the

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

    SciTech Connect

    Lindberg, Steven Eric; Dong, Weijin; Meyers, Tilden

    2002-07-01

    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.

  19. Wetlands Research Program. Evaluation of Methods for Sampling Vegetation and Delineating Wetlands Transition Zones in Coastal West-Central Florida, January 1979-May 1981.

    DTIC Science & Technology

    1984-04-01

    inundate Nymphoides aquatic a C=- ---= Bacopa carolinians Hypericum fasciculatum ______"___..... Lachnanthes carolinians , Eriocaulon decangulare...30 40 50 Typha domingensis Polygonum hydropiperoides - Spirodela polyrrhiza Ludwigia peruviana Cephalanthus occidentalis _ Bacopa .caroliniana...peruviana 24.5 Mikania scandens, Bacopa caroLinana WETLAND TRANSITION BOUNDARY -17.5 Polygonum hydropiperoides 15 14.0 Spirodela polyrrhlza 15- 7.5 Typha

  20. 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)

    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

    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

  1. Important considerations for establishing a secondary ozone standard to protect vegetation

    SciTech Connect

    Lefohn, A.S. ); Runeckles, V.C. ); Krupa, S.V. ); Shadwick, D.S. )

    1989-08-01

    Based on recent evidence published in the literature, as well as retrospective studies using data from the National Crop Loss Assessment Network (NCLAN), cumulative indices can be used to describe exposures of ozone for predicting agricultural crop effects. However, the mathematical form of the standard that may be proposed to protect crops does not necessarily have to be of the same form as that used in the statistical or process oriented mathematical models that relate ambient ozone exposures with vegetation effects. This paper discusses the limitations associated with applying a simple statistic that may take the place of a more biologically meaningful exposure parameter. While the NCLAN data have been helpful in identifying identifying indices that may be appropriate for establishing exposure-response relationships, the limitations associated with the NCLAN protocol need to be considered when attempting to apply these relationships in the establishment of a secondary national ambient air quality standard. The Weibull model derived from NCLAN experiments must demonstrate its generality and universal applicability. Furthermore, its predictive power must be tested using independent sets of field data.

  2. Wetlands Research Program. Evaluation of Methods for Sampling Vegetation and Delineating Wetlands Transition Zones in Southern Louisiana, January 1979-May 1981.

    DTIC Science & Technology

    1983-10-01

    Laboratory, 1978), grass- sedge bogs (Garren, 1943), and pitcher-plant lands (Pessin, 1933). Dominant species include panic grasses (Panicum spp... sedges (Carex spp.), spikerushes, smartweeds (Polygonum spp.), and arrowheads (Sagittaria spp.). Wet prairies typically have mineral soils and are usually...carpet weed (Mollugo verticillata), and sedge (Cyperus virens). 113. Shrubs were dominant in wetland Site C as compared to Site A, with an

  3. AmeriFlux US-Tw4 Twitchell East End Wetland

    DOE Data Explorer

    Baldocchi, Dennis [University of California, Berkeley

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-Tw4 Twitchell East End Wetland. Site Description - The Twitchell East End Wetland is a newly constructed restored wetland on Twitchell Island, CA. This site and the surrounding region are part of the San Joaquin - Sacramento River Delta drained beginning in the 1850's and subsequently used for agriculture. The site was previously a corn field. The wetland was designed to have a mix of vegetated and open water channels and ponds (due to surface elevation differences). Flooding of the wetland was done gradually beginning in January, 2014. Berms wind throughout the wetland to allow vehicle access. Tule and Cattail plant material from a nearby wetland were spread along the berms immediately prior to flooding to facilitate plant establishment and stabilization of the berms from wind/water erosion. The tower was installed on November 25, 2013.

  4. Transplanting native dominant plants to facilitate community development in restored coastal plain wetlands.

    SciTech Connect

    De Steven, Diane; Sharitz, Rebecca R.

    2007-12-01

    Abstract: Drained depressional wetlands are typically restored by plugging ditches or breaking drainage tiles to allow recovery of natural ponding regimes, while relying on passive recolonization from seed banks and dispersal to establish emergent vegetation. However, in restored depressions of the southeastern United States Coastal Plain, certain characteristic rhizomatous graminoid species may not recolonize because they are dispersal-limited and uncommon or absent in the seed banks of disturbed sites. We tested whether selectively planting such wetland dominants could facilitate restoration by accelerating vegetative cover development and suppressing non-wetland species. In an operational-scale project in a South Carolina forested landscape, drained depressional wetlands were restored in early 2001 by completely removing woody vegetation and plugging surface ditches. After forest removal, tillers of two rhizomatous wetland grasses (Panicum hemitomon, Leersia hexandra) were transplanted into singlespecies blocks in 12 restored depressions that otherwise were revegetating passively. Presence and cover of all plant species appearing in planted plots and unplanted control plots were recorded annually. We analyzed vegetation composition after two and four years, during a severe drought (2002) and after hydrologic recovery (2004). Most grass plantings established successfully, attaining 15%–85% cover in two years. Planted plots had fewer total species and fewer wetland species compared to control plots, but differences were small. Planted plots achieved greater total vegetative cover during the drought and greater combined cover of wetland species in both years. By 2004, planted grasses appeared to reduce cover of non-wetland species in some cases, but wetter hydrologic conditions contributed more strongly to suppression of non-wetland species. Because these two grasses typically form a dominant cover matrix in herbaceous depressions, our results indicated that

  5. The effect of wetland vegetation on the survival of Escherichia coli, Salmonella typhimurium, bacteriophage MS-2 and polio virus.

    PubMed

    Karim, Mohammad R; Glenn, Edward P; Gerba, Charles P

    2008-06-01

    A study was conducted to examine the role of aquatic plants used in constructed wetlands on the survival of enteric bacteria and viruses. Four small-scale wetland systems, receiving fresh water and two other wetland systems, receiving secondary unchlorinated sewage were used in this study. Fresh water and secondary sewage without the presence of any aquatic plants were used as controls. Escherichia coli, Salmonella typhimurium, bacteriophage MS-2 and poliovirus were added to the waters collected from the wetlands and controls. The presence of aquatic plants significantly increased the die-off of both bacteria in fresh water and secondary sewage. No significant difference in the die-off of E. coli and S. typhimurium was observed in water from wetlands with different types of plants in freshwater. However, there was a significant difference in the die-off of E. coli in water with aquatic plants when sewage was used. The presence of the plants significantly increased the inactivation of MS-2 and poliovirus. Additional work on the survival of E. coli indicated that the plausible mechanism of bacterial die-off in constructed wetlands is through increased microbial competition or predation.

  6. Pipeline Corridors through wetlands -- Impacts on plant communities: Mill Creek Tributary Crossing, Jefferson County, New York, 1992 Survey

    SciTech Connect

    Van Dyke, G.D.; Shem, L.M.; Zimmerman, R.E.

    1994-12-01

    The goal of the Gas Research Institute Wetland Corridors Program is to identify representative 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 the survey July 1992, at the Mills Creek tributary crossing, Jefferson County, New York. Data were collected from three wetland communities along the 1991 pipeline and compared with predisturbance data obtained in a June 1991 survey. Within one year after pipeline installation, 50% of the soil surface of the ROW in the scrub-shrub community was covered by emergent vegetation. Average wetland values for the ROW in 1992 were lower than in 1991, indicating that the removal of woody plants resulted in a community composed of species with greater fidelity to wetlands. In the emergent marsh community after one year, the average percentage of surface covered by standing water was greater in the ROW than in the adjacent natural areas. The ROW in the forested wetland community also contained standing water, although none was found in the natural forest areas. The entire study site remains a wetland, with the majority of plant species in all sites being either obligate or facultative wetland species. Weighted and unweighted average wetland indices for each community, using all species, indicated wetland vegetation within the newly established ROW.

  7. Establishing a design for passive vertical flow constructed wetlands treating small sewage discharges to meet British Standard EN 12566.

    PubMed

    Weedon, Christopher Michael; Murphy, Clodagh; Sweaney, Geoff

    2017-01-01

    Owing to legislation change (which made General Binding Rules effective from 1 January 2015) unless discharge is to specified environmentally sensitive sites, small sewage discharges (SSDs) in England - that is, <2 m(3) d(-1) to ground; <5 m(3) d(-1) to surface waters - no longer require an Environmental Permit (EP) and need not be registered for exemption, provided discharge to surface waters is preceded by treatment using equipment complying with BS EN 12566. This effectively excludes the use of treatment wetlands, unless covered by an EP, because the cost of certification to EN 12566 for bespoke designs is prohibitive. EPs take up to four months to obtain. Therefore, the new legislation has created a commercial disadvantage for constructed wetlands treating SSDs, compared with mass-produced sewage treatment plants. However, the UK statutory pollution regulators have maintained a dialogue with the Constructed Wetland Association (CWA), with a view to assessing whether treatment of SSD using constructed wetlands might be allowable, without requiring EPs. This paper presents treatment performance data obtained over 15 years, from a variety of full-scale operational treatment wetlands, as supporting evidence for design guidelines, proposed by the CWA to the UK regulators, for the implementation of constructed wetlands continuously passively treating SSD to 20:30:20 mg l(-1) BOD/SS/NH4-N under a wide range of loading rates. Relevant experience of UK designers, installers and operators since the early 1990s is included, resulting in recommended physical design criteria and loading rates for compact vertical flow reed beds, presented here as key elements of the draft guidelines.

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

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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

  9. Reducing sedimentation of depressional wetlands in agricultural landscapes

    USGS Publications Warehouse

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

    2008-01-01

    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

  10. Seasonal Dynamics of Soil Labile Organic Carbon and Enzyme Activities in Relation to Vegetation Types in Hangzhou Bay Tidal Flat Wetland.

    PubMed

    Shao, Xuexin; Yang, Wenying; Wu, Ming

    2015-01-01

    Soil labile organic carbon and soil enzymes play important roles in the carbon cycle of coastal wetlands that have high organic carbon accumulation rates. Soils under three vegetations (Phragmites australis, Spartina alterniflora, and Scirpusm mariqueter) as well as bare mudflat in Hangzhou Bay wetland of China were collected seasonally. Seasonal dynamics and correlations of soil labile organic carbon fractions and soil enzyme activities were analyzed. The results showed that there were significant differences among vegetation types in the contents of soil organic carbon (SOC) and dissolved organic carbon (DOC), excepting for that of microbial biomass carbon (MBC). The P. australis soil was with the highest content of both SOC (7.86 g kg-1) and DOC (306 mg kg-1), while the S. mariqueter soil was with the lowest content of SOC (6.83 g kg-1), and the bare mudflat was with the lowest content of DOC (270 mg kg-1). Soil enzyme activities were significantly different among vegetation types except for urease. The P. australis had the highest annual average activity of alkaline phosphomonoesterase (21.4 mg kg-1 h-1), and the S. alterniflora had the highest annual average activities of β-glycosidase (4.10 mg kg-1 h-1) and invertase (9.81 mg g-1 24h-1); however, the bare mudflat had the lowest activities of alkaline phosphomonoesterase (16.2 mg kg-1 h-1), β-glycosidase (2.87 mg kg-1 h-1), and invertase (8.02 mg g-1 24h-1). Analysis also showed that the soil labile organic carbon fractions and soil enzyme activities had distinct seasonal dynamics. In addition, the soil MBC content was significantly correlated with the activities of urease and β-glucosidase. The DOC content was significantly correlated with the activities of urease, alkaline phosphomonoesterase, and invertase. The results indicated that vegetation type is an important factor influencing the spatial-temporal variation of soil enzyme activities and labile organic carbon in coastal wetlands.

  11. Seasonal Dynamics of Soil Labile Organic Carbon and Enzyme Activities in Relation to Vegetation Types in Hangzhou Bay Tidal Flat Wetland

    PubMed Central

    Shao, Xuexin; Yang, Wenying; Wu, Ming

    2015-01-01

    Soil labile organic carbon and soil enzymes play important roles in the carbon cycle of coastal wetlands that have high organic carbon accumulation rates. Soils under three vegetations (Phragmites australis, Spartina alterniflora, and Scirpusm mariqueter) as well as bare mudflat in Hangzhou Bay wetland of China were collected seasonally. Seasonal dynamics and correlations of soil labile organic carbon fractions and soil enzyme activities were analyzed. The results showed that there were significant differences among vegetation types in the contents of soil organic carbon (SOC) and dissolved organic carbon (DOC), excepting for that of microbial biomass carbon (MBC). The P. australis soil was with the highest content of both SOC (7.86 g kg-1) and DOC (306 mg kg-1), while the S. mariqueter soil was with the lowest content of SOC (6.83 g kg-1), and the bare mudflat was with the lowest content of DOC (270 mg kg-1). Soil enzyme activities were significantly different among vegetation types except for urease. The P. australis had the highest annual average activity of alkaline phosphomonoesterase (21.4 mg kg-1 h-1), and the S. alterniflora had the highest annual average activities of β-glycosidase (4.10 mg kg-1 h-1) and invertase (9.81mg g-1 24h-1); however, the bare mudflat had the lowest activities of alkaline phosphomonoesterase (16.2 mg kg-1 h-1), β-glycosidase (2.87 mg kg-1 h-1), and invertase (8.02 mg g-1 24h-1). Analysis also showed that the soil labile organic carbon fractions and soil enzyme activities had distinct seasonal dynamics. In addition, the soil MBC content was significantly correlated with the activities of urease and β-glucosidase. The DOC content was significantly correlated with the activities of urease, alkaline phosphomonoesterase, and invertase. The results indicated that vegetation type is an important factor influencing the spatial-temporal variation of soil enzyme activities and labile organic carbon in coastal wetlands. PMID:26560310

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

    USGS Publications Warehouse

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

    1992-01-01

    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.

  13. Effects of a long-term disturbance on arthropods and vegetation in subalpine wetlands: manifestations of pack stock grazing in early versus mid-season.

    PubMed

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

    2013-01-01

    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.

  14. 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

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

    2013-01-01

    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. PMID:23308297

  15. Seasonal variability of turbulent fluxes over a vegetated subtropical coastal wetland measured by large aperture scintillometry and eddy covariance

    NASA Astrophysics Data System (ADS)

    Guyot, Adrien; Gray, Michael; Riesenkamp, Michiel; Lockington, David; McGowan, Hamish

    2016-04-01

    Subtropical coastal wetlands are particularly susceptible to the impacts of climate variability: their recharge rates strongly depend on rainfall, and the occurrence of prolonged droughts or wet periods have direct consequences for wetland health and bio-diversity. There is therefore a need to close the water budget of these ecosystems and this requires the quantification of rates of evaporation/evapotranspiration. However, few studies have documented land-atmosphere exchanges over wetlands for which water level varies considerably during a typical annual cycle. Here, we present a year of turbulent flux observations over a wetland on the subtropical coast of eastern Australia. Large Aperture Scintillometry and Eddy Covariance are used to derive sensible heat fluxes. Latent heat fluxes are also derived through an energy balance for both instruments' observations and also directly through Eddy Covariance. Careful sensitivity analysis of the instrumental footprints, seasonal variations of land surface parameters such as roughness length and displacement height are examined and subsequent uncertainties in the derived turbulent fluxes are discussed. Finally we show how these observations can also help better understand hydrological processes at the catchment scale.

  16. The impact of pumped water from a de-watered Magnesian limestone quarry on an adjacent wetland: Thrislington, County Durham, UK.

    PubMed

    Mayes, W M; Large, A R G; Younger, P L

    2005-12-01

    Although quarrying is often cited as a potential threat to wetland systems, there is a lack of relevant, quantitative case studies in the literature. The impact of pumped groundwater discharged from a quarry into a wetland area was assessed relative to reference conditions in an adjacent fen wetland that receives only natural runoff. Analysis of vegetation patterns at the quarry wetland site, using Detrended Correspondence Analysis and the species indicator values of Ellenberg, revealed a clear disparity between community transitions in the quarry wetland and the reference site. Limited establishment of moisture-sensitive taxa, the preferential proliferation of robust wetland species and an overall shift towards lower species diversity in the quarry wetland were explicable primarily by the physico-chemical environment created by quarry dewatering. This encompassed high pH (up to 12.8), sediment-rich effluent creating a nutrient-poor substrate with poor moisture retention in the quarry wetland, and large fluctuations in water levels.

  17. The contribution of leaching to the rapid release of nutrients and carbon in the early decay of wetland vegetation

    USGS Publications Warehouse

    Davis, S. E.; Childers, D.L.; Noe, G.B.

    2006-01-01

    Our goal was to quantify the coupled process of litter turnover and leaching as a source of nutrients and fixed carbon in oligotrophic, nutrient-limited wetlands. We conducted poisoned and non-poisoned incubations of leaf material from four different perennial wetland plants (Eleocharis spp., Cladium jamaicense, Rhizophora mangle and Spartina alterniflora) collected from different oligotrophic freshwater and estuarine wetland settings. Total phosphorus (TP) release from the P-limited Everglades plant species (Eleocharis spp., C. jamaicense and R. mangle) was much lower than TP release by the salt marsh plant S. alterniflora from N-limited North Inlet (SC). For most species and sampling times, total organic carbon (TOC) and TP leaching losses were much greater in poisoned than non-poisoned treatments, likely as a result of epiphytic microbial activity. Therefore, a substantial portion of the C and P leached from these wetland plant species was bio-available to microbial communities. Even the microbes associated with S. alterniflora from N-limited North Inlet showed indications of P-limitation early in the leaching process, as P was removed from the water column. Leaves of R. mangle released much more TOC per gram of litter than the other species, likely contributing to the greater waterborne [DOC] observed by others in the mangrove ecotone of Everglades National Park. Between the two freshwater Everglades plants, C. jamaicense leached nearly twice as much P than Eleocharis spp. In scaling this to the landscape level, our observed leaching losses combined with higher litter production of C. jamaicense compared to Eleocharis spp. resulted in a substantially greater P leaching from plant litter to the water column and epiphytic microbes. In conclusion, leaching of fresh plant litter can be an important autochthonous source of nutrients in freshwater and estuarine wetland ecosystems. ?? Springer 2006.

  18. Future vegetation patterns and primary production in the coastal wetlands of East China under sea level rise, sediment reduction, and saltwater intrusion

    NASA Astrophysics Data System (ADS)

    Ge, Zhen-Ming; Cao, Hao-Bin; Cui, Li-Fang; Zhao, Bin; Zhang, Li-Quan

    2015-10-01

    To explore the effects of sea level rise (SLR), sediment reduction (SR), and saltwater intrusion (SWI) on the vegetation patterns and primary production of one exotic (Spartina alterniflora) and two native dominant (Scirpus mariqueter and Phragmites australis) species in the coastal wetlands of East China, range expansion monitoring and stress experiments were conducted, followed by model prediction. After a rapid invasion period, the expansion rate of S. alterniflora slowed down due to the decreasing availability of suitable habitat under prolonged inundation. SLR was shown to decrease the colonization of S. alterniflora and the native P. australis up to 2100. In contrast, the native S. mariqueter that has a high tolerance of inundation increased in area following SLR, due to a reduction in competition from S. alterniflora in low-lying habitats and even recolonized areas previously invaded by the exotic species. The combination of SLR and SR resulted in further degradation of S. alterniflora and P. australis, while the area of S. mariqueter was not reduced significantly. The decrease in the area of vegetation would reduce the gross primary production under SLR and SR. SWI exacerbates the impacts, especially for P. australis, because S. alterniflora and S. mariqueter have a higher tolerance of salinity. Thus, the coastal vegetation pattern was predicted to be modified due to species-specific adaption to changed geophysical features. This study indicated that the native species better adapted to prolonged inundation and increased salinity might once again become key contributors to primary production on the muddy coasts of East China.

  19. The impact of aridification and vegetation type on changes in the community structure of methane-cycling microorganisms in Japanese wetland soils.

    PubMed

    Narihiro, Takashi; Hori, Tomoyuki; Nagata, Osamu; Hoshino, Tamotsu; Yumoto, Isao; Kamagata, Yoichi

    2011-01-01

    Over the years, the wetlands covered by Sphagnum in Bibai, Japan have been turning into areas of aridity, resulting in an invasion of Sasa into the bogs. Yet little is known about the methane-cycling microorganisms in such environments. In this study, the methanotrophic, methanogenic, and archaeal community structures within these two types of wetland vegetation were studied by phylogenetic analysis targeting particulate methane monooxygenase (pmoA), methyl coenzyme M reductase (mcrA), and the archaeal 16S rRNA gene. The pmoA library indicated that Methylomonas and Methylocystis predominated in the Sphagnum-covered and Sasa-invaded areas, respectively. The mcrA and 16S rRNA libraries indicated that Methanoregula were abundant methanogens in the Sphagnum-covered area. In the Sasa-invaded area, by contrast, mcrA genes were not detected, and no 16S rRNA clones were affiliated with previously known methanogens. Because the Sasa-invaded area still produced methane, of the various uncultured populations detected, novel euryarchaeotal lineages are candidate methane producers.

  20. Use of Vegetation in Delineating Wetland Borders in Upper Missouri River Basin; North-Central United States.

    DTIC Science & Technology

    1982-08-01

    and graphics wore performed by Thomas Pinn (VPI). The report was typed by . - 6 - e - .I - -_7, , , ~ 1...production areas), in which case the uplands are sometimes protected from disturbance. Wetlands include a wide variety of meadows, marshes, small ponds...methods %0’-..a identical in 11 of 34 cases , while in the remaining 23 cases the distances were estimated to be shorter with the line-intercept

  1. Pipeline corridors through wetlands

    SciTech Connect

    Zimmerman, R.E.; Wilkey, P.L.; Isaacson, H.R.

    1992-12-01

    This paper presents preliminary findings from six vegetational surveys of gas pipeline rights-of-way (ROW) through wetlands and quantifies the impacts of a 20-year-old pipeline ROW through a boreal forest wetland. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the Row approximated or exceeded those in the adjacent natural area. The boreal forest study showed that (1) adjacent natural wetland areas were not altered in type; (2) water sheet flow restriction had been reversed by nature; (3) no nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity.

  2. Pipeline corridors through wetlands

    SciTech Connect

    Zimmerman, R.E.; Wilkey, P.L. ); Isaacson, H.R. )

    1992-01-01

    This paper presents preliminary findings from six vegetational surveys of gas pipeline rights-of-way (ROW) through wetlands and quantifies the impacts of a 20-year-old pipeline ROW through a boreal forest wetland. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the Row approximated or exceeded those in the adjacent natural area. The boreal forest study showed that (1) adjacent natural wetland areas were not altered in type; (2) water sheet flow restriction had been reversed by nature; (3) no nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity.

  3. Differences in flooding tolerance between species from two wetland habitats with contrasting hydrology: implications for vegetation development in future floodwater retention areas

    PubMed Central

    Banach, Katarzyna; Banach, Artur M.; Lamers, Leon P. M.; De Kroon, Hans; Bennicelli, Riccardo P.; Smits, Antoine J. M.; Visser, Eric J. W.

    2009-01-01

    Background and Aims Plants need different survival strategies in habitats differing in hydrological regimes. This probably has consequences for vegetation development when former floodplain areas that are currently confronted with soil flooding only, will be reconnected to the highly dynamical river bed. Such changes in river management are increasingly important, especially at locations where increased water retention can prevent flooding events in developed areas. It is therefore crucial to determine the responses of plant species from relatively low-dynamic wetlands to complete submergence, and to compare these with those of species from river forelands, in order to find out what the effects of such landscape-scale changes on vegetation would be. Methods To compare the species' tolerance to complete submergence and their acclimation patterns, a greenhouse experiment was designed with a selection of 19 species from two contrasting sites: permanently wet meadows in a former river foreland, and frequently submerged grasslands in a current river foreland. The plants were treated with short (3 weeks) and long (6 weeks) periods of complete submergence, to evaluate if survival, morphological responses, and changes in biomass differed between species of the two habitats. Key Results All tested species inhabiting river forelands were classified as tolerant to complete submergence, whereas species from wet meadows showed either relatively intolerant, intermediate or tolerant responses. Species from floodplains showed in all treatments stronger shoot elongation, as well as higher production of biomass of leaves, stems, fine roots and taproots, compared with meadow species. Conclusions There is a strong need for the creation of temporary water retention basins during high levels of river discharge. However, based on the data presented, it is concluded that such reconnection of former wetlands (currently serving as meadows) to the main river bed will strongly influence plant

  4. The Carolina Bay Restoration Project: Implementation and Management of a Wetland Mitigation Bank.

    SciTech Connect

    Barton, Christopher; DeSteven, Diane; Sharitz, Rebecca; Kilgo, John; Imm, Donald; Kolka, Randy; Blake, John, I.

    2003-01-01

    A wetlands Mitigation Bank was established at the Savannah River Site (SRS) in 1997 as a compensatory alternative for unavoidable wetland losses associated with future authorized construction and environmental restoration projects in SRS wetlands. The Bank was intended not only to hasten mitigation efforts with respect to regulatory requirements and implementation, but also to provide onsite and fully functional compensation of impacted wetland acreage prior to any impact. Restoration and enhancement of small isolated wetlands, as well as major bottomland wetland systems scattered throughout the nonindustrialized area of SRS were designated for inclusion in the Bank. Based on information and techniques gained from previous research efforts involving Carolina bay wetlands (DOE 1997), a project to restore degraded Carolina bays on SRS has been undertaken to serve as the initial ''deposit'' in The Bank. There are over 300 Carolina bays or bay-like depression wetlands on the SRS, of which an estimated two-thirds were ditched or disturbed prior to federal occupation of the Site (Kirkman et al., 1996). These isolated wetlands range from small ephemeral depressions to large permanent ponds of 10-50 hectares in size. They provide habitat to support a wide range of rare plant species, and many vertebrates (birds, amphibians, bats). Historical impacts to the Carolina bays at SRS were primarily associated with agricultural activities. Bays were often drained tilled and planted to crops. The consequence was a loss in the wetland hydrologic cycle, the native wetland vegetation, and associated wildlife. The purpose of this mitigation and research project is to restore the functions and vegetation typical of intact depression wetlands and, in doing so, to enhance habitat for wetland dependent wildlife on SRS.

  5. Microbial community structure and denitrification in a wetland mitigation bank.

    PubMed

    Peralta, Ariane L; Matthews, Jeffrey W; Kent, Angela D

    2010-07-01

    Wetland mitigation is implemented to replace ecosystem functions provided by wetlands; however, restoration efforts frequently fail to establish equivalent levels of ecosystem services. Delivery of microbially mediated ecosystem functions, such as denitrification, is influenced by both the structure and activity of the microbial community. The objective of this study was to compare the relationship between soil and vegetation factors and microbial community structure and function in restored and reference wetlands within a mitigation bank. Microbial community composition was assessed using terminal restriction fragment length polymorphism targeting the 16S rRNA gene (total bacteria) and the nosZ gene (denitrifiers). Comparisons of microbial function were based on potential denitrification rates. Bacterial community structures differed significantly between restored and reference wetlands; denitrifier community assemblages were similar among reference sites but highly variable among restored sites throughout the mitigation bank. Potential denitrification was highest in the reference wetland sites. These data demonstrate that wetland restoration efforts in this mitigation bank have not successfully restored denitrification and that differences in potential denitrification rates may be due to distinct microbial assemblages observed in restored and reference (natural) wetlands. Further, we have identified gradients in soil moisture and soil fertility that were associated with differences in microbial community structure. Microbial function was influenced by bacterial community composition and soil fertility. Identifying soil factors that are primary ecological drivers of soil bacterial communities, especially denitrifying populations, can potentially aid the development of predictive models for restoration of biogeochemical transformations and enhance the success of wetland restoration efforts.

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

    USGS Publications Warehouse

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

    2009-01-01

    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.

  7. Long-Term Effects of Dredging Operations Program. Long-Term Evaluation of Plants and Animals Colonizing Contaminated Estuarine Dredged Material Placed in Both Upland and Wetland Environments

    DTIC Science & Technology

    1991-09-01

    into the surface of the dredged material, enhancing plant growth and establishment. The lime and lime + manure plots showed 51 and 28 percent cover...have greatly improved plant growth and vegetative cover. Vegetative cover plays a significant role in improving surface runoff water quality (Skogerboe...large portion of tie wetland (Figure 9f, left side). As the wetland extended across the marsh creation site, the most robust plant growth was observed

  8. Wetland restoration and compliance issues on the Savannah River site

    SciTech Connect

    Wein, G.R.; McLeod, K.W.; Sharitz, R.R. )

    1993-01-01

    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.

  9. 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

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

    2013-05-01

    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.

  10. Bacterial communities and enzymatic activities in the vegetation-activated sludge process (V-ASP) and related advantages by comparison with conventional constructed wetland.

    PubMed

    Yuan, Jiajia; Dong, Wenyi; Sun, Feiyun; Zhao, Ke; Du, Changhang; Shao, Yunxian

    2016-11-01

    A new-developed vegetation-activated sludge process (V-ASP) was implemented for decentralized domestic wastewater treatment, and studied in lab-scale and full-scale. The main purpose of this work was the investigation of biomass activities and microbial communities in V-ASP by comparison with conventional constructed wetland (CW), to unveil the causations of its consistently higher pollutants removal efficiencies. Compared with CWs, V-ASP has greater vegetation nitrogen and phosphorus uptake rates, higher biomass and enzymatic activities, and more bacteria community diversity. The microbial community structure was comprehensively analyzed by using high-throughput sequencing. It was observed that Proteobacteria was dominated in both CWs and V-ASPs, while their subdivisions distribution was rather different. V-ASPs contained a higher nitrite-oxidizing bacteria (Nitrospira) abundances that resulted in a consistently better nitrogen removal efficiency. Hence, a long-term experiment of full-scale V-ASP displayed stably excellent capability in resistance of influent loading shocks and seasonal temperature effect.

  11. Influence of wetland size on aquatic communities within wetland reservoir subirrigation systems in northwestern Ohio.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Establishment of a water management system known as the wetland-reservoir subirrigation system (WRSIS) results in the creation of wetlands adjacent to agricultural fields. Specifically, each WRSIS consists of one wetland designed to process agricultural chemicals (WRSIS wetlands) and one wetland to ...

  12. The potential use of storm water and effluent from a constructed wetland for re-vegetating a degraded pyrite trail in Queen Elizabeth National Park, Uganda

    NASA Astrophysics Data System (ADS)

    Osaliya, R.; Kansiime, F.; Oryem-Origa, H.; Kateyo, E.

    During the operation of the Kilembe Mines (copper mining) a cobaltiferous stockpile was constructed, which began to erode after the closure of the mines in the early 1970s. The erosion of the pyrite stockpile resulted in a large acid trail all the way to Lake George (a Ramsar site). The acid trail contaminated a large area of Queen Elizabeth National Park (QENP) resulting in the death of most of the shallow-rooted vegetation. Processes and conditions created by storm water and effluent from a constructed wetland were assessed for vegetation regeneration in the degraded QENP pyrite trail. Cynodon dactylon, Imperata cylindrica and Hyparrhenia filipendula dominated the regeneration zone (RZ) where storm water and effluent from a constructed wetland was flowing; and the adjacent unpolluted area (UP) with importance value indices of 186.4 and 83.3 respectively. Typha latifolia and C. dactylon formed two distinct vegetation sub-zones within the RZ with the former inhabiting areas with a higher water table. Soil pH was significantly higher in the RZ, followed by UP and bare pyrite trail (BPT) at both 0-15 cm and 16-30 cm depths. Soil electrical conductivity was not significantly different in the RZ and BPT but significantly higher than that in UP for both depths. For 0-15 cm depth, RZ had significantly higher concentrations of copper than BPT and UP which had similar concentrations. Still at this depth (0-15 cm), the unpolluted area had significantly higher concentrations of total phosphorus and total nitrogen than the regeneration zone and the bare pyrite trail which had similar concentrations. The RZ dominated by Typha had significantly higher concentrations of TP and TN compared to the RZ dominated by Cynodon. The concentrations of NH 4-N were significantly lower in Typha regeneration zone than in CRZ at 0-15 cm depth but similar at 16-30 cm depth. At 16-30 cm depth, concentrations of copper were significantly higher in the regeneration zone followed by the bare pyrite

  13. Impacts of vegetation and temperature on the treatment of domestic sewage in constructed wetlands incorporated with Ferric-Carbon Micro-Electrolysis material.

    PubMed

    Zhou, Qingwei; Zhu, Hui; Bañuelos, Gary; Yan, Baixing; Liang, Yinxiu; Yu, Jing; Li, Huai

    2017-03-20

    Ferric-Carbon Micro-Electrolysis (Fe/C-M/E) material had been widely used for the pretreatment of wastewater. Therefore, we hypothesized that Fe/C-M/E material could enhance the treatment of domestic sewage when integrated into CWs. In this study, constructed wetlands (CWs) integrated with Fe/C-M/E material were developed. During the experiment of vegetation influence, percentages of NH4(+)-N, NO3(-)-N, TN, and COD removed in polyculture (W1) were up to 91.8%, 97.0%, 92.3%, and 85.4%, respectively, which were much higher than those in Lythrum salicaria monoculture (W2) and Canna indica monoculture (W3). In the experiment of temperature influences, temperature substantially influenced the performance of CWs. For example, NO3(-)-N removal percentages of W1, W2 and W3 at high temperature (25.5°C and 19.8°C) were relatively stable and greater than 85.4%. At 8.9°C, however, a sharp decline of NO3(-)-N removal percentage was observed in all CWs. Temperature also influenced the COD removal and soil microbial activity and biomass. Overall, the polyculture showed the best performance during most of the operating time, average temperature ≥ 19.8°C, due to the functional complementarity between vegetation. All the CWs consistently achieved high removal efficiency (above 96%) for TP in all experiments, irrespective of vegetation types, phosphorous loadings and temperatures. In conclusion, polyculture was an attractive solution for the treatment of domestic sewage during most of the operating time, average temperature ≥ 19.8°C). Furthermore, CWs with Fe/C-M/E material were ideally suitable for domestic sewage treatment, especially for TP removal.

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

    PubMed

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

    2012-06-01

    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 μM 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.

  15. Forested wetland habitat

    USGS Publications Warehouse

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

    2015-01-01

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

  16. FGD liner experiments with wetlands

    SciTech Connect

    Mitsch, W.J.; Ahn, C.; Wolfe, W.E.

    1999-07-01

    The construction of artificial wetlands for wastewater treatment often requires impermeable liners not only to protect groundwater resources but also to ensure that there is adequate water in the wetland to support appropriate aquatic life, particularly wetland vegetation. Liners or relatively impervious site soils are very important to the success of constructed treatment wetlands in areas where ground water levels are typically close to the ground surface. This study, carried out at the Olentangy River Wetland Research Park, investigated the use of FGD material from sulfur scrubbers as a possible liner material for constructed wetlands. While several studies have investigated the use of FGD material to line ponds, no studies have investigated the use of this material as a liner for constructed wetlands. They used experimental mesocosms to see the effect of FGD liner materials in constructed wetlands on water quality and on wetland plant growth. This paper presents the results of nutrient analyses and physicochemical investigation of leachate and surface outflow water samples collected from the mesocosms. Plant growth and biomass of wetland vegetation are also included in this paper. First two year results are reported by Ahn et al. (1998, 1999). The overall goal of this study is the identification of advantages and disadvantages of using FGD by-product as an artificial liner in constructed wetlands.

  17. Wetlands for Wastewater Treatment.

    PubMed

    Martinez-Guerra, Edith; Jiang, Yi; Lee, Gordon; Kokabian, Bahareh; Fast, Sara; Truax, Dennis D; Martin, James L; Magbanua, Benjamin S; Gude, Veera Gnaneswar

    2015-10-01

    This paper provides a review of the treatment technologies, which utilize natural processes or passive components in wastewater treatment. In particular, this paper primarily focuses on wetland systems and their applications in wastewater treatment (as an advanced treatment unit or decentralized system), nutrient and pollutant removal (single and multiple pollutants, and metals), and emerging pollutant removal (pharmaceuticals). A summary of studies involving the plant (vegetation) effects, wetland design and modeling, hybrid and innovative systems, storm water treatment and pathogen removal is also included.

  18. Selective coal mine overburden treatment with topsoil and compost to optimise pasture or native vegetation establishment.

    PubMed

    Spargo, A; Doley, D

    2016-11-01

    Overburden at a coal mine in the Hunter Valley, New South Wales, was stored in a flat-topped artificial mound with 14-degree side slopes. Topsoil was scarce, dispersive and readily eroded. A split-plot factorial experiment applied an enhanced municipal solid waste compost at 0, 60 or 100 t ha(-1) to untreated overburden or to overburden covered with 0.1 m of topsoil. Two seeding treatments, of trees and shrubs or of pasture species, were applied to two 0.5-ha replicates of each surface treatment. Substrate physical and chemical properties and vegetation attributes were assessed 2.5 years later. Compost application to both topsoil and overburden significantly increased total N, P, Cu and Zn, soluble K, Ca and Mg, and significantly reduced soluble Na and pH. Mean tree density, size and total canopy cover were significantly greater with compost applied at 60 t ha(-1) to overburden than with all other treatments, especially those on topsoil where tree growth was inhibited by undesired species. Compost application to overburden and topsoil at 100 t ha(-1) significantly increased biomass of desired pasture species and significantly reduced undesired species cover compared with unamended topsoil and the extent of bare ground compared with unamended overburden. Successful development of woody species on overburden and pastures on both overburden and topsoil treated with compost provides opportunities for new combinations of landscape design, surface preparation and plant species introductions to increase the stability of final landforms, the effectiveness of resource use, and the delivery of commercial and biodiversity benefits from mine site rehabilitation.

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

    PubMed

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

    2012-07-01

    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.

  20. Field Testing New Plot Designs and Methods for Determining Hydrophytic Vegetation during Wetland Delineations in the United States

    DTIC Science & Technology

    2014-03-01

    Engineers. Walter Ochs provided the ini- tial idea for evaluating the 80% approach based on differences in the standard deviation. Christy Everett and Jim...Godswire provided assistance in selecting sites to collect the CRREL data. Bruce Allen, Lindsey Lefevbre, Walter Ochs , Corinna Photos, Bill Sipple...vegetation determination (USACE 2010a). The 80.0% value was developed in 2005 (R. Lichvar and W. Ochs , unpublished data) by analyzing a national set of

  1. Carbon sequestration capacity of shifting sand dune after establishing new vegetation in the Tengger Desert, northern China.

    PubMed

    Yang, Haotian; Li, Xinrong; Wang, Zengru; Jia, Rongliang; Liu, Lichao; Chen, Yongle; Wei, Yongping; Gao, Yanhong; Li, Gang

    2014-04-15

    Reconstructing vegetation in arid and semiarid areas has become an increasingly important management strategy to realize habitat recovery, mitigate desertification and global climate change. To assess the carbon sequestration potential in areas where sand-binding vegetation has been established on shifting sand dunes by planting xeric shrubs located near the southeastern edge of the Tengger Desert in northern China, we conducted a field investigation of restored dune regions that were established at different times (20, 30, 47, and 55 years ago) in the same area. We quantified the total organic carbon (TOC) in each ecosystem by summing the individual carbon contributions from the soil (soil organic carbon; SOC), shrubs, and grasses in each system. We found that the TOC, as well as the amount of organic carbon in the soil, shrubs, and grasses, significantly increased over time in the restored areas. The average annual rate of carbon sequestration was highest in the first 20 years after restoration (3.26 × 10(-2)kg·m(-2) ·year(-1)), and reached a stable rate (2.14 × 10(-2) kg·m(-2) ·year(-1)) after 47 years. Organic carbon storage in soil represented the largest carbon pool for both restored systems and a system containing native vegetation, accounting for 67.6%-85.0% of the TOC. Carbon in grass root biomass, aboveground grass biomass, litter, aboveground shrub biomass, and shrub root biomass account for 10.0%-21.0%, 0.2%-0.6%, 0.1%-0.2%, 1.7%-12.1% and 0.9%-6.2% of the TOC, respectively. Furthermore, we found that the 55-year-old restored system has the capacity to accumulate more TOC (1.02 kg·m(-2) more) to reach the TOC level found in the natural vegetation system. These results suggest that restoring desert ecosystems may be a cost-effective and environmentally friendly way to sequester CO2 from the atmosphere and mitigate the effects of global climate change.

  2. Avian utilization of subsidence wetlands

    SciTech Connect

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

    1995-09-01

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

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  4. Classification of vegetable oils according to their botanical origin using n-alkane profiles established by GC-MS.

    PubMed

    Troya, F; Lerma-García, M J; Herrero-Martínez, J M; Simó-Alfonso, E F

    2015-01-15

    n-Alkane profiles established by gas chromatography-mass spectrometry (GC-MS) were used to classify vegetable oils according to their botanical origin. The n-alkanes present in corn, grapeseed, hazelnut, olive, peanut and sunflower oils were isolated by means of alkaline hydrolysis followed by silica gel column chromatography of the unsaponifiable fractions. The n-alkane fraction was constituted mainly of n-alkanes in the range C8-C35, although only those most abundant (15 n-alkanes, from 21 to 35 carbon No.) were used as original variables to construct linear discriminant analysis (LDA) models. Ratios of the peak areas selected by pairs were used as predictors. All the oils were correctly classified according to their botanical origin, with assignment probabilities higher than 95%, using an LDA model.

  5. Establishing the Capability of a 1D SVAT Modelling Scheme in Predicting Key Biophysical Vegetation Characterisation Parameters

    NASA Astrophysics Data System (ADS)

    Ireland, Gareth; Petropoulos, George P.; Carlson, Toby N.; Purdy, Sarah

    2015-04-01

    Sensitivity analysis (SA) consists of an integral and important validatory check of a computer simulation model before it is used to perform any kind of analysis. In the present work, we present the results from a SA performed on the SimSphere Soil Vegetation Atmosphere Transfer (SVAT) model utilising a cutting edge and robust Global Sensitivity Analysis (GSA) approach, based on the use of the Gaussian Emulation Machine for Sensitivity Analysis (GEM-SA) tool. The sensitivity of the following model outputs was evaluated: the ambient CO2 concentration and the rate of CO2 uptake by the plant, the ambient O3 concentration, the flux of O3 from the air to the plant/soil boundary, and the flux of O3 taken up by the plant alone. The most sensitive model inputs for the majority of model outputs were related to the structural properties of vegetation, namely, the Leaf Area Index, Fractional Vegetation Cover, Cuticle Resistance and Vegetation Height. External CO2 in the leaf and the O3 concentration in the air input parameters also exhibited significant influence on model outputs. This work presents a very important step towards an all-inclusive evaluation of SimSphere. Indeed, results from this study contribute decisively towards establishing its capability as a useful teaching and research tool in modelling Earth's land surface interactions. This is of considerable importance in the light of the rapidly expanding use of this model worldwide, which also includes research conducted by various Space Agencies examining its synergistic use with Earth Observation data towards the development of operational products at a global scale. This research was supported by the European Commission Marie Curie Re-Integration Grant "TRANSFORM-EO". SimSphere is currently maintained and freely distributed by the Department of Geography and Earth Sciences at Aberystwyth University (http://www.aber.ac.uk/simsphere). Keywords: CO2 flux, ambient CO2, O3 flux, SimSphere, Gaussian process emulators

  6. Do created wetlands replace the wetlands that are destroyed?

    USGS Publications Warehouse

    Hunt, Randall J.

    1997-01-01

    Wetlands, once perceived as worthless land, are now recognized as a necessary component of a vital landscape. However, due to draining and filling we have lost many of our wetlands. The loss of wetlands can have undesirable effects on the landscape, such as erosion, flooding, habitat loss and deterioration of water quality. While natural wetland systems are being destroyed nationwide, the wetlands restored or created to compensate for these losses are commonly not evaluated or contain large percentages of non-wetland acreage. At the present time we do not have established methodology that can uniformly evaluate a wetland's function, or that is useful for providing guidelines that enhance wetland restoration/creation success.

  7. Constructed Wetlands

    EPA Pesticide Factsheets

    these systems can improve water quality, engineers and scientists construct systems that replicate the functions of natural wetlands. Constructed wetlands are treatment systems that use natural processes

  8. 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)

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

    2013-09-01

    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.

  9. 7 CFR 12.30 - NRCS responsibilities regarding wetlands.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Section 12.30 Agriculture Office of the Secretary of Agriculture HIGHLY ERODIBLE LAND AND WETLAND...-inventoried designation within a certified wetland is subject to change when the soil, hydrology, and vegetation evaluation is completed and identified as to type of wetland or as a non-wetland. This change...

  10. 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 ...

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

    SciTech Connect

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

    2004-12-31

    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

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

    NASA Astrophysics Data System (ADS)

    Pantaleoni, Eva

    Establishing wetland gains and losses, delineating wetland boundaries, and determining their vegetative composition are major challenges that can be improved through remote sensing studies. We used the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) to separate wetlands from uplands in a study of 870 locations on the Virginia Coastal Plain. We used the first five bands from each of two ASTER scenes (6 March 2005 and 16 October 2005), covering the visible to the short-wave infrared region (0.52-2.185mum). We included GIS data layers for soil survey, topography, and presence or absence of water in a logistic regression model that predicted the location of over 78% of the wetlands. While this was slightly less accurate (78% vs. 86%) than current National Wetland Inventory (NWI) aerial photo interpretation procedures of locating wetlands, satellite imagery analysis holds great promise for speeding wetland mapping, lowering costs, and improving update frequency. To estimate wetland vegetation composition classes, we generated a classification and regression tree (CART) model and a multinomial logistic regression (logit) model, and compared their accuracy in separating woody wetlands, emergent wetlands and open water. The overall accuracy of the CART model was 73.3%, while for the logit model was 76.7%. The CART producer's accuracy of the emergent wetlands was higher than the accuracy from the multinomial logit (57.1% vs. 40.7%). However, we obtained the opposite result for the woody wetland category (68.7% vs. 52.6%). A McNemar test between the two models and NWI maps showed that their accuracies were not statistically different. We conducted a subpixel analysis of the ASTER images to estimate canopy cover of forested wetlands. We used top-of-atmosphere reflectance from the visible and near infrared bands, Delta Normalized Difference Vegetation Index, and a tasseled cap brightness, greenness, and wetness in linear regression model with canopy

  13. Neotropical coastal wetlands

    USGS Publications Warehouse

    McKee, Karen L.; Batzer, Darold P.; Baldwin, Andrew H.

    2012-01-01

    The Neotropical region, which includes the tropical Americas, is one of the world's eight biogeographic zones. It contains some of the most diverse and unique wetlands in the world, some of which are still relatively undisturbed by humans. This chapter focuses on the northern segment of the Neotropics (south Florida, the Caribbean islands, Mexico, and Central America), an area that spans a latitudinal gradient from about 7 N to 29 N and 60 W to 112 W. Examples of coastal wetlands in this realm include the Everglades (Florida, USA), Ten Thousand Islands (Florida, USA), Laguna de Terminos (Mexico), Twin Cays (Belize), and Zapata Swamp (Cuba). Coastal wetlands are dominated by mangroves, which will be emphasized here, but also include freshwater swamps and marshes, saline marshes, and seagrass beds. The aim of this chapter is to provide a broad overview of Neotropical coastal wetlands of the North American continent, with an emphasis on mangroves, since this is the dominant vegetation type and because in-depth coverage of all wetland types is impossible here. Instead, the goal is to describe the environmental settings, plant and animal communities, key ecological controls, and some conservation concerns, with specific examples. Because this book deals with wetlands of North America, this chapter excludes coastal wetlands of South America. However, much of the information is applicable to mangrove, marsh, and seagrass communities of other tropicaI regions.

  14. 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

    Knappová, Jana; Knapp, Michal; Münzbergová, Zuzana

    2013-01-01

    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

  15. Wetlands postcard

    USGS Publications Warehouse

    Ball, Lianne C.

    2016-05-25

    Research conducted by scientists at the U.S. Geological Survey provides reliable scientific information for the management of wetlands ranging from small freshwater alpine lakes in the Western United States to coastal wetlands of the Great Lakes and salt marshes along the Southeastern coast. Learn more about USGS wetlands research at: http://www.usgs.gov/ecosystems/environments/wetlands.html.

  16. Establishing quantitative relations between mammalian communities, climate regimes, and vegetation density - A diversity-based reference model and case study

    NASA Astrophysics Data System (ADS)

    Hertler, Christine; Wolf, Dominik; Bruch, Angela; Märker, Michael

    2013-04-01

    A considerable diversity of hominin taxa is described from the Pleistocene of sub-Saharan Africa. Inner-African range expansions of these taxa are primarily addressed by morphological comparisons of the hominin specimens and systematic interpretation of the results. Considering hominin expansion patterns as being at least co-determined by ecology and environment requires an assessment of respective features of paleo-communities as well as features of the environments with which they are associated. Challenges in validation and integration of reconstructions of hominin environments and ecologies can be met with well-organized recent reference models. Modelling the present day situation permits to assess relevant variables and to establish interactions among them on a quantitative basis. In a next step such a model can be applied to classify hominin paleoenvironments, for which not all data sources are available. An example for this approach is introduced here. In order to characterize hominin environments in sub-Saharan Africa, we assessed sets of variables for composition, structure and diversity of the large mammal communities, climate (temperature and precipitation), and vegetation in African national parks. These data are applied to analyse correlations between faunal communities and their environments on a quantitative basis. While information on large mammal communities is frequently available for hominin localities and regional climate features are addressed on the basis of abiotic proxies, information on paleoflora and vegetation is mostly lacking for the Plio-Pleistocene in sub-Saharan Africa. A quantitative reference model therefore offers new options for reconstructions. A recent reference model moreover permits to quantify descriptive terms like 'savanna'. We will introduce a reference model for sub-Saharan Africa and demonstrate its application in the reconstruction of hominin paleoenvironments. The corresponding quantitative characterization of

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

    USGS Publications Warehouse

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

    2007-01-01

    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.

  18. Wetlands stewardship

    SciTech Connect

    Whelan, J.M.

    1992-04-01

    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.

  19. Tidal freshwater wetland herbivory in Anacostia Park

    USGS Publications Warehouse

    Krafft, Cairn; Hatfield, Jeff S.; Hammerschlag, Richard S.

    2010-01-01

    Herbivory has played a major role in dictating vegetation abundance and species composition at Kingman Marsh in Anacostia Park, Washington, D.C., since restoration of this tidal freshwater wetland was initiated in 2000. In June 2009 an herbivory study was established to document the impacts of resident Canada goose (Branta canadensis maxima) herbivory to vegetation at Kingman Marsh. Sixteen modules consisting of paired exclosed plots and unfenced control plots were constructed. Eight of the modules were installed in vegetated portions of the restoration site that had been protected over time by fencing, while the remaining eight modules were placed in portions of the site that had not been protected over time and were basically unvegetated at the start of the experiment. Since the experiment was designed to determine the impacts of herbivory by resident Canada geese as opposed to other herbivores, exclosure fencing was elevated 0.2 m to permit access by herbivores such as fish and turtles while excluding mature Canada geese. Repeated measures analysis of variance (ANOVA) was used to analyze the differences between paired exclosure and control plots for a number of variables including total vegetative cover. Differences in total vegetative cover were not significant for the baseline data collected in June. By contrast, two months after the old protective fencing was removed from the initially-vegetated areas to allow Canada geese access to the control plots, total vegetative cover had declined dramatically in the initially-vegetated control plots, and differences between paired exclosed and control plots were significant (P = 0.0026). No herbivory by Canada geese or other herbivores such as fish or turtles was observed in the exclosures. These results show that Canada goose herbivory has inflicted significant damage to the native wetland vegetation in the portions of Kingman Marsh that had been refenced and replanted. Significant differences in total vegetative

  20. Restoring biodiversity in the Gwydir Wetlands through environmental flows.

    PubMed

    Mawhinney, W A

    2003-01-01

    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.

  1. Chemical Properties of Pore Water and Sediment at Three Wetland Sites Near the F- and H-Area Seepage Basins, Savannah River Site

    SciTech Connect

    Friday, G.P.

    2001-05-15

    In 1980, vegetative stress and arboreal mortality in wetland plant communities down-gradient from the F- and H-Area seepage basins were detected using aerial imagery. By 1988, approximately six acres in H-Area and four acres in F-Area had been adversely impacted. Today, wetland plant communities have become well established at the H-Area tree-kill zone.

  2. [Wetland landscape ecological classification: research progress].

    PubMed

    Cao, Yu; Mo, Li-jiang; Li, Yan; Zhang, Wen-mei

    2009-12-01

    Wetland landscape ecological classification, as a basis for the studies of wetland landscape ecology, directly affects the precision and effectiveness of wetland-related research. Based on the history, current status, and latest progress in the studies on the theories, indicators, and methods of wetland landscape classification, some scientific wetland classification systems, e.g., NWI, Ramsar, and HGM, were introduced and discussed in this paper. It was suggested that a comprehensive classification method based on HGM and on the integral consideration of wetlands spatial structure, ecological function, ecological process, topography, soil, vegetation, hydrology, and human disturbance intensity should be the major future direction in this research field. Furthermore, the integration of 3S technologies, quantitative mathematics, landscape modeling, knowledge engineering, and artificial intelligence to enhance the automatization and precision of wetland landscape ecological classification would be the key issues and difficult topics in the studies of wetland landscape ecological classification.

  3. Wetlands for Wastewater Treatment.

    PubMed

    Jiang, Yi; Martinez-Guerra, Edith; Gnaneswar Gude, Veera; Magbanua, Benjamin; Truax, Dennis D; Martin, James L

    2016-10-01

    An update on the current research and development of the treatment technologies, which utilize natural processes or passive components in wastewater treatment, is provided in this paper. The main focus is on wetland systems and their applications in wastewater treatment (as an advanced treatment unit or decentralized system), nutrient and pollutant removal (metals, industrial and emerging pollutants including pharmaceutical compounds). A summary of studies involving the effects of vegetation, wetland design and modeling, hybrid and innovative systems, storm water treatment and pathogen removal is also included.

  4. Wetland InSAR

    NASA Astrophysics Data System (ADS)

    Wdowinski, S.; Kim, S.; Amelung, F.; Dixon, T.

    2006-12-01

    Wetlands are transition zones where the flow of water, the nutrient cycling, and the sun energy meet to produce a unique and very productive ecosystem. They provide critical habitat for a wide variety of plant and animal species, including the larval stages of many ocean fish. Wetlands also have a valuable economical importance, as they filter nutrients and pollutants from fresh water used by human and provide aquatic habitats for outdoor recreation, tourism, and fishing. Globally, many such regions are under severe environmental stress, mainly from urban development, pollution, and rising sea level. However, there is increasing recognition of the importance of these habitats, and mitigation and restoration activities have begun in a few regions. A key element in wetlands conservation, management, and restoration involves monitoring its hydrologic system, as the entire ecosystem depends on its water supply. Heretofore, hydrologic monitoring of wetlands are conducted by stage (water level) stations, which provide good temporal resolution, but suffer from poor spatial resolution, as stage station are typically distributed several, or even tens of kilometers, from one another. Wetland application of InSAR provides the needed high spatial resolution hydrological observations, complementing the high temporal resolution terrestrial observations. Although conventional wisdom suggests that interferometry does not work in vegetated areas, several studies have shown that both L- and C-band interferograms with short acquisition intervals (1-105 days) can maintain excellent coherence over wetlands. In this study we explore the usage of InSAR for detecting water level changes in various wetland environments around the world, including the Everglades (south Florida), Louisiana Coast (southern US), Chesapeake Bay (eastern US), Pantanal (Brazil), Okavango Delta (Botswana), and Lena Delta (Siberia). Our main study area is the Everglades wetland (south Florida), which is covered by

  5. Management of wetlands for wildlife

    USGS Publications Warehouse

    Matthew J. Gray,; Heath M. Hagy,; J. Andrew Nyman,; Stafford, Joshua D.

    2013-01-01

    Wetlands are highly productive ecosystems that provide habitat for a diversity of wildlife species and afford various ecosystem services. Managing wetlands effectively requires an understanding of basic ecosystem processes, animal and plant life history strategies, and principles of wildlife management. Management techniques that are used differ depending on target species, coastal versus interior wetlands, and available infrastructure, resources, and management objectives. Ideally, wetlands are managed as a complex, with many successional stages and hydroperiods represented in close proximity. Managing wetland wildlife typically involves manipulating water levels and vegetation in the wetland, and providing an upland buffer. Commonly, levees and water control structures are used to manipulate wetland hydrology in combination with other management techniques (e.g., disking, burning, herbicide application) to create desired plant and wildlife responses. In the United States, several conservation programs are available to assist landowners in developing wetland management infrastructure on their property. Managing wetlands to increase habitat quality for wildlife is critical, considering this ecosystem is one of the most imperiled in the world.

  6. A Study on Effect of Water Background on Canopy Spectral of Wetland Aquatic Plant.

    PubMed

    Liu, Guang; Tang, Peng; Cai Zhan-qing; Wang, Tian-tian; Xu, Jun-feng

    2015-10-01

    Aquatic vegetation is the core of the wetland ecosystem, and it's also the main factor influencing the wetland ecosystem functions. In recent years, satellite remote sensing technology has been widely used in the investigation, classification and protection fields of wetland vegetation resources. Because of its unique growth environment, aquatic vegetation, the canopy spectrum of aquatic vegetation will be affected by water background elements including air-water interface, plankton in the water, sediment content, transparency, water depth, sediment, and the other optically active ingredients. When the remote sensing technology for wetland aquatic vegetation canopy spectral studies, should be considered the growth environment differences between aquatic and terrestrial vegetation. However, previous studies did not get the attention it deserves. This paper choose a typical water plant (Iris tentorium Maxim) as the research object, simulate the growth environment of wetland aquatic plants, use the feature spectrometer measurements the spectral reflectance of Iris tentorium Maxim vegetation canopy under different water depth gradient background (400-2 400 nm). Experimental results show that there is a significant negative correlation between background water depth and Iris canopy reflectance. Visible light band absolute correlation coefficient is above 0.9, near infrared band absolute correlation coefficient is above 0.8. In visible light and near infrared band, with water depth increases, the Iris canopy reflectance decreases obviously. Finally based on the highest correlation band of visible light and near infrared region (505, 717, 1 075 and 2 383 nm) established the linear equation between background water depth and the canopy reflectance, obtained the related parameters.

  7. Tropical Wetland Monitoring Using RapidEye and Sentinel 1 Satellite Images in Ifakara (Tanzania)

    NASA Astrophysics Data System (ADS)

    Kirimi, Fridah; Menz, Gunter

    2016-08-01

    Food insecurity has been a topic of concern particularly for the developing countries. Wetlands have a consistent supply of water throughout the year. To determine whether the utilization of the wetland for increased food production is viable, there was need to analyse the land uses in different months of the year to better understand the dynamics of existing vegetation.Support Vector Machine was used to classify the optical to establish the dynamics of changing vegetation. Bare land coverage gives an indication of the potentially available land that can be utilized for crop growth. The optical images are affected by cloud coverage. As a remedial action the use of SAR images in monitoring the wetlands is assessed. A great percentage of land remains bare. Quantification of this from the classified images forms a basis upon which decisions on strategic plans of increasing production sustainably in the region can be implemented.

  8. Reconstruction of Anacostia wetlands: success?

    USGS Publications Warehouse

    Hammerschlag, R.S.; Perry, M.C.

    2002-01-01

    . 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.

  9. [Disturbance assessment of urban wetland ecosystem services: a case study in Pingshan watershed of Shenzhen City].

    PubMed

    Zhang, Wen-juan; Li, Gui-cai; Zeng, Hui

    2010-05-01

    To understand the wetland ecosystem services in urbanizing area is much needed in wetland assessment. Currently, the dominant approach in assessing wetland value is the assessment model using environmental economic analysis. However, this approach can not reflect the impact of human disturbance. This paper introduced the connotation of wetland ecosystem services and the patterns of human disturbance, established an evaluation index system which could characterize the disturbance impact, and determined the weight of each index by using analytic hierarchy process. Moreover, a dual-grade fuzzy comprehensive evaluation model was applied to analyze the spatial heterogeneity of human disturbance. Our case study in Pingshan River Basin, a typical urbanizing area of Shenzhen, showed that geographic condition was the primary factor in determining the intensity of human disturbance on wetland ecosystem services. The main disturbance pattern in the south hilly area was vegetation degeneration, but the disturbance intensity was low. Even so, the vegetation protection and management in this area shouldn't be ignored though. The disturbance pattern in north valley area was diverse, and the disturbance intensity was much higher than that south hilly area. From the upper reach to the lower reach of the main stream, the impact of human disturbance increased first and decreased then, being accorded with the characteristics of land use pattern, but the disturbance pattern didn't have a continuous distribution. Our study showed that fuzzy comprehensive evaluation model had good performance in the disturbance assessment of wetland ecosystem services.

  10. Indicators: Wetland Vegetation (Introduced Species)

    EPA Pesticide Factsheets

    Introduced plants are indicators of the ecological integrity of waters and evidence of increased human-caused disturbance in the watershed. Introduced species that cause economic or environmental harm, or harm to human health, are called invasive species.

  11. Wetland Mitigation Monitoring at the Fernald Preserve - 13200

    SciTech Connect

    Powell, Jane; Bien, Stephanie; Decker, Ashlee; Homer, John; Wulker, Brian

    2013-07-01

    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)

  12. Ecohydraulics and Estuarine Wetland Rehabilitation

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

    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 the hydraulics of wetlands being influenced by plant and animal activity. Understanding these complex interactions is fundamental for the adequate management of estuarine wetlands. Listed as a Wetland of International Importance under the 1971 Ramsar Convention, the Hunter River estuary is regarded as the most significant site for migratory shorebirds in New South Wales, Australia. Over the past 20 years, the number of migratory shorebirds in the estuary has sharply declined from 8,000 to 4,000 approx. Alteration of bird habitat is believed to be one of the reasons for this alarming trend. In 2004 we started a three-year program to investigate the links between hydraulics, sediment, benthic invertebrates, vegetation and migratory shorebird habitat in the estuary. During the first year we have focused on a highly disturbed part of the Hunter estuary wetlands located on Ash Island. The area is one of the major roosting sites in the estuary and is characterized by a complex hydraulic regime due to a restricted tidal interchange with the Hunter River and the presence of infrastructure for the maintenance of power lines (i.e., roads, bridges, culverts). Salt marshes, mudflat and mangroves are the dominant vegetation types. The monitoring program includes measurements of water levels, salinity, discharge, velocity, turbulence, sediment transport and deposition, plant species and density, soil composition and benthic invertebrates coordinated with observations of bird habitat utilization on a number of locations throughout the wetland and for different flow

  13. Influence of wetland type, hydrology, and wetland destruction on aquatic communities within wetland reservoir subirrigation systems in northwestern Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Establishment of an agricultural water recycling system known as the wetland reservoir subirrigation system (WRSIS) results in the creation of two different types of wetlands adjacent to agricultural fields. Each WRSIS consists of one treatment wetland designed to process agricultural contaminants (...

  14. Climate Change and Intertidal Wetlands

    PubMed Central

    Ross, Pauline M.; Adam, Paul

    2013-01-01

    Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause—the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the “squeeze” experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change. PMID:24832670

  15. Climate change and intertidal wetlands.

    PubMed

    Ross, Pauline M; Adam, Paul

    2013-03-19

    Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause-the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the "squeeze" experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change.

  16. Windows of opportunity for salt marsh vegetation establishment on bare tidal flats: The importance of temporal and spatial variability in hydrodynamic forcing

    NASA Astrophysics Data System (ADS)

    Hu, Zhan; Belzen, Jim; Wal, Daphne; Balke, Thorsten; Wang, Zheng Bing; Stive, Marcel; Bouma, Tjeerd J.

    2015-07-01

    Understanding the mechanisms limiting and facilitating salt marsh vegetation initial establishment is of widespread importance due to the many valuable services salt marsh ecosystems offer. Salt marsh dynamics have been investigated by many previous studies, but the mechanisms that enable or disable salt marsh initial establishment are still understudied. Recently, the "windows of opportunity" (WoO) concept has been proposed as a framework providing an explanation for the initial establishment of biogeomorphic ecosystems and the role of physical disturbance herein. A WoO is a sufficiently long disturbance-free period following seedling dispersal, which enables successful establishment. By quantifying the occurrence of WoO, vegetation establishment pattern can be predicted. For simplicity sake and as prove of concept, the original WoO framework considers tidal inundation as the only physical disturbance to salt marsh establishment, whereas the known disturbance from tidal currents and wind waves is ignored. In this study, we incorporate hydrodynamic forcing in the WoO framework. Its spatial and temporal variability is considered explicitly in a salt marsh establishment model. We used this model to explain the observed episodic salt marsh recruitment in the Westerschelde Estuary, Netherlands. Our results reveal that this model can significantly increase the spatial prediction accuracy of salt marsh establishment compared to a model that excludes the hydrodynamic disturbance. Using the better performing model, we further illustrate how tidal flat morphology determines salt marsh establishing elevation and width via hydrodynamic force distribution. Our model thus offers a valuable tool to understand and predict bottlenecks of salt marsh restoration and consequences of changing environmental conditions due to climate change.

  17. Control of hardwood regeneration in restored carolina bay depression wetlands.

    SciTech Connect

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

    2012-06-01

    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.

  18. Wetlands: Tidal

    USGS Publications Warehouse

    Conner, William H.; Krauss, Ken W.; Baldwin, Andrew H.; Hutchinson, Stephen

    2014-01-01

    Tidal wetlands are some of the most dynamic areas of the Earth and are found at the interface between the land and sea. Salinity, regular tidal flooding, and infrequent catastrophic flooding due to storm events result in complex interactions among biotic and abiotic factors. The complexity of these interactions, along with the uncertainty of where one draws the line between tidal and nontidal, makes characterizing tidal wetlands a difficult task. The three primary types of tidal wetlands are tidal marshes, mangroves, and freshwater forested wetlands. Tidal marshes are dominated by herbaceous plants and are generally found at middle to high latitudes of both hemispheres. Mangrove forests dominate tropical coastlines around the world while tidal freshwater forests are global in distribution. All three wetland types are highly productive ecosystems, supporting abundant and diverse faunal communities. Unfortunately, these wetlands are subject to alteration and loss from both natural and anthropogenic causes.

  19. Methane Fluxes from Subtropical Wetlands

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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

  20. Classification of vegetable oils according to their botanical origin using sterol profiles established by direct infusion mass spectrometry.

    PubMed

    Lerma-García, María J; Ramis-Ramos, Guillermo; Herrero-Martínez, José M; Simó-Alfonso, Ernesto F

    2008-04-01

    A simple and quick method to classify vegetable oils according to their botanical origin, based on direct infusion of sterol extracts into a mass spectrometer, was developed. Using mass spectrometry (MS) with either an electrospray ionization or an atmospheric pressure photoionization source, followed by linear discriminant analysis of the mass spectral data, oil samples corresponding to eight different botanical origins were perfectly classified with an excellent resolution among all the categories. An excellent correlation between the sterol profiles obtained by MS and by the official gas chromatography (with flame ionization detection) method was obtained. Thus, the proposed method is a promising alternative for sterol fingerprinting of vegetable oils, with the advantage that prior chromatographic separation is not required.

  1. Identification and characterization of wetlands in the Bear Creek watershed

    SciTech Connect

    Rosensteel, B.A.; Trettin, C.C.

    1993-10-01

    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.

  2. Macroinvertebrate abundance, water chemistry, and wetland characteristics affect use of wetlands by avian species in Maine

    USGS Publications Warehouse

    Longcore, J.R.; McAuley, D.G.; Pendelton, G.W.; Bennatti, C.R.; Mingo, T.M.; Stromborg, K.L.

    2006-01-01

    Our objective was to determine use by avian species (e.g., piscivores, marsh birds, waterfowl, selected passerines) of 29 wetlands in areas with low (<200 μeq l−1) acid-neutralizing capacity (ANC) in southeastern Maine. We documented bird, pair, and brood use during 1982–1984 and in 1982 we sampled 10 wetlands with a sweep net to collect invertebrates. We related mean numbers of invertebrates per wetland to water chemistry, basin characteristics, and avian use of different wetland types. Shallow, beaver (Castor canadensis)-created wetlands with the highest phosphorus levels and abundant and varied macrophyte assemblages supported greater densities of macroinvertebrates and numbers of duck broods (88.3% of all broods) in contrast to deep, glacial type wetlands with sparse vegetation and lower invertebrate densities that supported fewer broods (11.7%). Low pH may have affected some acid-intolerant invertebrate taxa (i.e., Ephemeroptera), but high mean numbers of Insecta per wetland were recorded from wetlands with a pH of 5.51. Other Classes and Orders of invertebrates were more abundant on wetlands with pH > 5.51. All years combined use of wetlands by broods was greater on wetlands with pH ≤ 5.51 (77.4%) in contract to wetlands with pH > 5.51 that supported 21.8% of the broods. High mean brood density was associated with mean number of Insecta per wetland. For lentic wetlands created by beaver, those habitats contained vegetative structure and nutrients necessary to provide cover to support invertebrate populations that are prey of omnivore and insectivore species. The fishless status of a few wetlands may have affected use by some waterfowl species and obligate piscivores.

  3. Lake Superior Coastal Wetland Fish Assemblages and ...

    EPA Pesticide Factsheets

    The role of the coastal margin and the watershed context in defining the ecology of even very large lakes is increasingly being recognized and examined. Coastal wetlands are both important contributors to the biodiversity and productivity of large lakes and important mediators of the lake-basin connection. We explored wetland-watershed connections and their relationship to wetland function and condition using data collected from 37 Lake Superior wetlands spanning a substantial geographic and geomorphic gradient. While none of these wetlands are particularly disturbed, there were nevertheless clear relationships between watershed landuse and wetland habitat and biota, and these varied consistently across wetland type categories that reflected the strength of connection to the watershed. For example, water clarity and vegetation structure complexity declined with decreasing percent natural land cover, and these effects were strongest in riverine wetlands (having generally large watersheds and tributary-dominated hydrology) and weakest in lagoon wetlands (having generally small watersheds and lake-dominate hydrology). Fish abundance and species richness both increased with decreasing percent natural land cover while species diversity decreased, and again the effect was strongest in riverine wetlands. Lagoonal wetlands, which lack any substantial tributary, consistently harbored the fewest species of fish and a composition different from the more watershed-lin

  4. Uptake of 226Ra by established vegetation and black cutworm larvae, Agrotis ipsilon (class Insecta: order Lepidoptera), on U mill tailings at Elliot Lake, Canada.

    PubMed

    Clulow, F V; Davé, N K; Lim, T P; Cloutier, N R

    1988-07-01

    Radium-226 levels in samples from an inactive U tailings site at Elliot Lake, Ontario, Canada, were: 9,140 +/- 500 mBq g-1 dry weight in the substrate; 62 +/- 1 mBq g-1 dry weight in rye, Secale cereale, and less than 3.7 mBq g-1 dry weight in oats, Avena sativa, the dominant species established by revegetation of the tailings; and 117 +/- 7 mBq g-1 dry weight in washed and unwashed black cutworm larvae. Concentration ratios were: vegetation to tailings 0.001-0.007; black cutworms to vegetation 3.6 and black cutworms to tailings 0.01. The values are considered too low to be considered a hazard to herring gulls, Larus argentatus, which occasionally feed on cutworms.

  5. Exploring Wetlands.

    ERIC Educational Resources Information Center

    Kerr, Elizabeth; Harrison, Gordon

    1996-01-01

    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…

  6. Freshwater Wetlands.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    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)

  7. Wetland Loss.

    ERIC Educational Resources Information Center

    Barrett, Marilyn

    1994-01-01

    Examines what wetland conservation means to different groups of Louisiana's coastal residents. Describes coastal resources, reasons for their deterioration, conservation efforts, and the impact of a public perception that conservation of wetlands is closely tied to conservation of the existing lifestyle. (LZ)

  8. Productivity of wet soils: Biomass of cultivated and natural vegetation

    SciTech Connect

    Johnston, C.A.

    1988-12-01

    Wet soils, soils which have agronomic limitations because of excess water, comprise 105 million acres of non-federal land in the conterminous United States. Wet soils which support hydrophytic plants are ''wetlands'', and are some of the most productive natural ecosystems in the world. When both above- and belowground productivity are considered, cattail (Typha latifolia) is the most productive temperate wetland species (26.4 Mg/ha/year). Both cattail and reed (Phragmites australis) have aboveground productivities of about 13 Mg/ha/year. Although average aboveground yields of reed canarygrass (Phalaris arundinacea) are lower (9.5 Mg/ha/year), techniques for its establishment and cultivation are well-developed. Other herbaceous wetland species which show promise as biomass crops include sedge (Carex spp.), river bulrush (Scirpus fluviatilis) and prairie cordgrass (Spartina pectinata). About 40% of wet soils in the conterminous US are currently cultivated, and they produce one-quarter of the major US crops. Most of this land is artificially drained for crops such as corn, soybeans, and vegetables. US wetlands are drained for agriculture at the rate of 223,000 ha/yr. Paddies flooded with water are used to grow rice, cranberries, and wild rice. Forage and live sphagnum moss are products of undrained wetlands. A number of federal and state regulations apply to the draining or irrigation of wetlands, but most do not seriously restrict their use for agriculture. 320 refs., 36 tabs.

  9. ERTS-1 investigation of wetlands ecology

    NASA Technical Reports Server (NTRS)

    Anderson, R. R. (Principal Investigator); Carter, V.; Mcginness, J.

    1975-01-01

    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.

  10. Remote sensing of coastal wetlands

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  11. 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)

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

    2012-04-01

    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

  12. The National Wetland Condition Assessment

    EPA Science Inventory

    The first National Wetland Condition Assessment (NWCA) was conducted in 2011 by the US Environmental Protection Agency (USEPA). Vegetation, algae, soil, water chemistry,and hydrologic data were collected at each of 1138 sites across the contiguous US. Ecological condition was ass...

  13. Opposing environmental gradients govern vegetation zonation in an intermountain playa

    USGS Publications Warehouse

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

    2008-01-01

    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.

  14. Hydrogeomorphic and Anthropogenic Influences on Water Quality, Habitat, and Fish of Great Lakes Coastal Wetlands

    EPA Science Inventory

    Great Lakes coastal wetlands represent a dynamic interface between coastal watersheds and the open lake. Compared to the adjacent lakes, these wetlands have generally warmer water, reduced wave energy, shallow bathymetry, higher productivity, and structurally complex vegetated h...

  15. Use of evapotranspiration model based on energy balance in the Ebinur Lake Wetland Nature Reserve

    NASA Astrophysics Data System (ADS)

    Shi, Qingsan; Shi, Qingdong; Wang, Zhi; Gao, Wei; Chang, Shunli

    2009-06-01

    An evapotranspiration model based on the energy balance for different vegetation types in arid area was built in the study, and applied to the natural ecological system of Lake Ebinur wetland nature reserve in Xinjiang. The spatial-temporal dynamic change of the vegetation evapotranspiration in the study area was computed, and the evapotranspiration of three typical vegetations was analyzed and compared. The ground meteorological data were used to test the model. The results show that the evapotranspiration of all the natural system is about 10mm/d, and the maximum is over 20mm/d and occurs between May and August. The evapotranspiration of three typical arid vegetations was estimated in sequence of Populus euphratica Oliv. Tamarix chinensis Lour. Haloxylon ammodendron (Meye)Bge. Finally, it is suggested that the ground surface vegetation types and arid characteristics are most important in the establishment of the evapotranspiration model of natural ecological system based on energy balance in arid areas.

  16. 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

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

    1994-02-25

    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.

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

    NASA Technical Reports Server (NTRS)

    Peteet, Dorothy

    2000-01-01

    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.

  18. What Makes a Wetland a Wetland?

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    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)

  19. Spatiotemporal analysis of encroachment on wetlands: a case of Nakivubo wetland in Kampala, Uganda.

    PubMed

    Isunju, John Bosco; Kemp, Jaco

    2016-04-01

    Wetlands provide vital ecosystem services such as water purification, flood control, and climate moderation among others, which enhance environmental quality, promote public health, and contribute to risk reduction. The biggest threat to wetlands is posed by human activities which transform wetlands, often for short-term consumptive benefits. This paper aimed to classify and map recent land cover and provide a multi-temporal analysis of changes from 2002 to 2014 in the Nakivubo wetland through which wastewater from Kampala city drains to Lake Victoria in Uganda. The paper contributes through spatially congruent change maps showing site-specific land cover conversions. In addition, it gives insight into what happened to the wetlands, why it happened, how the changes in the wetlands affect the communities living in them, and how the situation could be better managed or regulated in future. The analysis is based on very high resolution (50-62 cm) aerial photos and satellite imagery, focus group discussions, and key informant interviews. Overall, the analysis of losses and gains showed a 62 % loss of wetland vegetation between 2002 and 2014, mostly attributable to crop cultivation. Cultivation in the wetland buffering the lake shore makes it unstable to anchor. The 2014 data shows large portions of the wetland calved away by receding lake waves. With barely no wetland vegetation buffer around the lake, the heavily polluted wastewater streams will lower the quality of lake water. Furthermore, with increased human activities in the wetland, exposure to flooding and pollution will be likely to have a greater impact on the health and livelihoods of vulnerable communities. This calls for a multi-faceted approach, coordination of the various stakeholders and engagement of wetland-dependent communities as part of the solution, and might require zoning out the wetland and restricting certain activities to specific zones.

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

    USGS Publications Warehouse

    Smith, Thomas J.; Tiling, Ginger; Leasure, Pamela S.

    2007-01-01

    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.

  1. Wetland and water supply

    USGS Publications Warehouse

    Baker, John Augustus

    1960-01-01

    purpose wetlands are land areas that are covered with shallow water or subjected to intermittent flooding and subsequent slow drainage, and which generally are characterized by an accumulation of organic matter hereafter termed swamp deposits.' These wetlands may be classified in a number of different ways depending on the purpose of the classifier. For example, the Fish and Wildlife Service classifies wetlands into 20 different types based on water quality (fresh or salty), drainage, and vegetation. At the risk of some oversimplification we might consider 4 types of wetland from the standpoint of hydrology: (1) fresh-water swamps in which the swamp deposits are underlain by glacial till or bedrock; (2)fresh-water swamps in which the swamp deposits are underlain by marine or lacustrine clay and silt; (3) fresh-water swamps in which the swamp deposits are underlain by glacial outwash or alluvium consisting mostly of sand or sand and gravel; and (4) salt .marshes and salt meadows. The three fresh-water types of wetland are of interest with respect to water supply, and of these, the type in which swamp deposits are underlain by glacial outwash is of particular interest in New England. In the Ipswich River basin above the Geological Survey gaging station at South Middleton, Mass., is an area of 44 square miles which forms the headwaters section of the basin. The relief of the area is low. About half the area consists of hills mostly underlain by bedrock but mantled by a thin layer of glacial till. The other half consists Of lowlands---including swamps, low terraces and plains---underlain by glacial outwash, Swampland, used hereafter as a synonym for wetland, forms about a fourth of the area. Some of the swamps occupy depressions in the till blanket and are situated at somewhat higher levels than the lowlands. The largest swamps, however, border the Ipswich River and its tributaries. Here the swamp deposits, which consist of muck and peat mixed with s

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

    SciTech Connect

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

    2002-01-01

    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.

  3. Macroinvertebrate abundance, water chemistry, and wetland characteristics affect use of wetlands by avian species in Maine

    USGS Publications Warehouse

    Longcore, J.R.; McAuley, D.G.; Pendleton, G.W.; Bennatti, C.R.; Mingo, T.M.; Stromborg, K.L.; Hanson, Alan; Kerekes, Joseph; Paquet, Julie

    2006-01-01

    Our objective was to determine use by avian species (e.g., piscivores, marsh birds, waterfowl, selected passerines) of 29 wetlands in areas with low ( 5.51. All years combined use of wetlands by broods was greater on wetlands with pH 5.51 that supported 21.8% of the broods. High mean brood density was associated with mean number of Insecta per wetland. For lentic wetlands created by beaver, those habitats contained vegetative structure and nutrients necessary to provide cover to support invertebrate populations that are prey of omnivore and insectivore species. The fishless status of a few wetlands may have affected use by some waterfowl species and obligate piscivores.

  4. Nitrate removal and bioenergy production in constructed wetland coupled with microbial fuel cell: Establishment of electrochemically active bacteria community on anode.

    PubMed

    Wang, Junfeng; Song, Xinshan; Wang, Yuhui; Abayneh, Befkadu; Li, Yihao; Yan, Denghua; Bai, Junhong

    2016-12-01

    The constructed wetland coupled with microbial fuel cell (CW-MFC) systems operated at different substrate concentration and pH influents were evaluated for bioelectricity generation, contaminant removal and microbial community structure. Performance of CW-MFC was evaluated at organic loading rate of 75.3gCODm(-3)d(-1) and pH gradients of (5.18±0.14, 7.31±0.13, and 8.75±0.12) using carbon fiber felt as electrodes. Peak power density was observed at slightly neutral influent condition. Compared with the open circuit CW-MFC, average COD and NO3-N removal efficiency in CW-MFC increased by 8.3% and 40.2% respectively under slightly neutral pH of influents. However, the removal efficiency and bioenergy production have been inhibited with acidic influents. The relative abundance of beta-Proteobacteria, nitrobacteria and denitrifying bacteria was significantly promoted in closed-circuit CW-MFC. Using of CW-MFC as a biochemical method for nitrate removal and bioelectricity generation under slightly neutral and alkaline influent conditions was a promising technology.

  5. Strength in Numbers: Describing the Flooded Area of Isolated Wetlands

    USGS Publications Warehouse

    Lee, Terrie M.; Haag, Kim H.

    2006-01-01

    Thousands of isolated, freshwater wetlands are scattered across the karst1 landscape of central Florida. Most are small (less than 15 acres), shallow, marsh and cypress wetlands that flood and dry seasonally. Wetland health is threatened when wetland flooding patterns are altered either by human activities, such as land-use change and ground-water pumping, or by changes in climate. Yet the small sizes and vast numbers of isolated wetlands in Florida challenge our efforts to characterize them collectively as a statewide water resource. In the northern Tampa Bay area of west-central Florida alone, water levels are measured monthly in more than 400 wetlands by the Southwest Florida Water Management Distirct (SWFWMD). Many wetlands have over a decade of measurements. The usefulness of long-term monitoring of wetland water levels would greatly increase if it described not just the depth of water at a point in the wetland, but also the amount of the total wetland area that was flooded. Water levels can be used to estimate the flooded area of a wetland if the elevation contours of the wetland bottom are determined by bathymetric mapping. Despite the recognized importance of the flooded area to wetland vegetation, bathymetric maps are not available to describe the flooded areas of even a representative number of Florida's isolated wetlands. Information on the bathymetry of isolated wetlands is rare because it is labor intensive to collect the land-surface elevation data needed to create the maps. Five marshes and five cypress wetlands were studied by the U.S. Geological Survey (USGS) during 2000 to 2004 as part of a large interdisciplinary study of isolated wetlands in central Florida. The wetlands are located either in municipal well fields or on publicly owned lands (fig. 1). The 10 wetlands share similar geology and climate, but differ in their ground-water settings. All have historical water-level data and multiple vegetation surveys. A comprehensive report by Haag and

  6. Vegetation and soils

    USGS Publications Warehouse

    Burke, M.K.; King, S.L.; Eisenbies, M.H.; Gartner, D.

    2000-01-01

    Intro paragraph: Characterization of bottomland hardwood vegetation in relatively undisturbed forests can provide critical information for developing effective wetland creation and restoration techniques and for assessing the impacts of management and development. Classification is a useful technique in characterizing vegetation because it summarizes complex data sets, assists in hypothesis generation about factors influencing community variation, and helps refine models of community structure. Hierarchical classification of communities is particularly useful for showing relationships among samples (Gauche 1982).

  7. Structural and metabolic responses of microbial community to sewage-borne chlorpyrifos in constructed wetlands.

    PubMed

    Zhang, Dan; Wang, Chuan; Zhang, Liping; Xu, Dong; Liu, Biyun; Zhou, Qiaohong; Wu, Zhenbin

    2016-06-01

    Long-term use of chlorpyrifos poses a potential threat to the environment that cannot be ignored, yet little is known about the succession of substrate microbial communities in constructed wetlands (CWs) under chlorpyrifos stress. Six pilot-scale CW systems receiving artificial wastewater containing 1mg/L chlorpyrifos were established to investigate the effects of chlorpyrifos and wetland vegetation on the microbial metabolism pattern of carbon sources and community structure, using BIOLOG and denaturing gradient gel electrophoresis (DGGE) approaches. Based on our samples, BIOLOG showed that Shannon diversity (H') and richness (S) values distinctly increased after 30days when chlorpyrifos was added. At the same time, differences between the vegetated and the non-vegetated systems disappeared. DGGE profiles indicated that H' and S had no significant differences among four different treatments. The effect of chlorpyrifos on the microbial community was mainly reflected at the physiological level. Principal component analysis (PCA) of both BIOLOG and DGGE showed that added chlorpyrifos made a difference on test results. Meanwhile, there was no difference between the vegetation and no-vegetation treatments after addition of chlorpyrifos at the physiological level. Moreover, the vegetation had no significant effect on the microbial community at the genetic level. Comparisons were made between bacteria in this experiment and other known chlorpyrifos-degrading bacteria. The potential chlorpyrifos-degrading ability of bacteria in situ may be considerable.

  8. Development of an indicator to monitor mediterranean wetlands.

    PubMed

    Sanchez, Antonio; Abdul Malak, Dania; Guelmami, Anis; Perennou, Christian

    2015-01-01

    Wetlands are sensitive ecosystems that are increasingly subjected to threats from anthropogenic factors. In the last decades, coastal Mediterranean wetlands have been suffering considerable pressures from land use change, intensification of urban growth, increasing tourism infrastructure and intensification of agricultural practices. Remote sensing (RS) and Geographic Information Systems (GIS) techniques are efficient tools that can support monitoring Mediterranean coastal wetlands on large scales and over long periods of time. The study aims at developing a wetland indicator to support monitoring Mediterranean coastal wetlands using these techniques. The indicator makes use of multi-temporal Landsat images, land use reference layers, a 50m numerical model of the territory (NMT) and Corine Land Cover (CLC) for the identification and mapping of wetlands. The approach combines supervised image classification techniques making use of vegetation indices and decision tree analysis to identify the surface covered by wetlands at a given date. A validation process is put in place to compare outcomes with existing local wetland inventories to check the results reliability. The indicator´s results demonstrate an improvement in the level of precision of change detection methods achieved by traditional tools providing reliability up to 95% in main wetland areas. The results confirm that the use of RS techniques improves the precision of wetland detection compared to the use of CLC for wetland monitoring and stress the strong relation between the level of wetland detection and the nature of the wetland areas and the monitoring scale considered.

  9. Development of an Indicator to Monitor Mediterranean Wetlands

    PubMed Central

    Sanchez, Antonio; Abdul Malak, Dania; Guelmami, Anis; Perennou, Christian

    2015-01-01

    Wetlands are sensitive ecosystems that are increasingly subjected to threats from anthropogenic factors. In the last decades, coastal Mediterranean wetlands have been suffering considerable pressures from land use change, intensification of urban growth, increasing tourism infrastructure and intensification of agricultural practices. Remote sensing (RS) and Geographic Information Systems (GIS) techniques are efficient tools that can support monitoring Mediterranean coastal wetlands on large scales and over long periods of time. The study aims at developing a wetland indicator to support monitoring Mediterranean coastal wetlands using these techniques. The indicator makes use of multi-temporal Landsat images, land use reference layers, a 50m numerical model of the territory (NMT) and Corine Land Cover (CLC) for the identification and mapping of wetlands. The approach combines supervised image classification techniques making use of vegetation indices and decision tree analysis to identify the surface covered by wetlands at a given date. A validation process is put in place to compare outcomes with existing local wetland inventories to check the results reliability. The indicator´s results demonstrate an improvement in the level of precision of change detection methods achieved by traditional tools providing reliability up to 95% in main wetland areas. The results confirm that the use of RS techniques improves the precision of wetland detection compared to the use of CLC for wetland monitoring and stress the strong relation between the level of wetland detection and the nature of the wetland areas and the monitoring scale considered. PMID:25826210

  10. Impacts of mute swans (Cygnus olor) on submerged aquatic vegetation in Illinois River Valley backwaters

    USGS Publications Warehouse

    Stafford, Joshua D.; Michael W. Eichholz,; Adam C. Phillips,

    2012-01-01

    Wetland loss in North America has been considerable and well documented, and the establishment of exotic species in remaining wetlands can further reduce their ability to support native flora and fauna. In the Chesapeake Bay and Great Lakes ecosystems, exotic mute swans (Cygnus olor) have been found to negatively impact wetlands through degradation of submerged aquatic vegetation (SAV) communities. Mute swan populations have expanded into many areas of mid-continental North America outside the Great Lakes ecosystem, but the environmental impact of these populations is not well known. Mid-continental wetlands in North America differ in physical characteristics (e.g., size, depth, and permanency) and aquatic vegetation species composition compared to wetlands in other areas where mute swans have been studied and, thus, may be more or less susceptible to degradation from swan herbivory. To investigate the impact of mute swan herbivory on SAV communities in mid-continent wetlands, we used exclosures to prevent swans from foraging in 2 wetland complexes in central Illinois. Above-ground biomass of vegetation did not differ between exclosures and controls; however, mean below-ground biomass was greater in exclosures (52.0 g/m2, SE = 6.0) than in controls (34.4 g/m2 SE = 4.0). Thus, although swan densities were lower in our study region compared to that of previous studies, we observed potentially detrimental impacts of swan herbivory on below-ground biomass of SAV. Our results indicate that both above-ground and below-ground impacts of herbivory should be monitored, and below-ground biomass may be most sensitive to swan foraging.

  11. Interactions between river stage and wetland vegetation detected with a Seasonality Index derived from LANDSAT images in the Apalachicola delta, Florida

    NASA Astrophysics Data System (ADS)

    la Cecilia, Daniele; Toffolon, Marco; Woodcock, Curtis E.; Fagherazzi, Sergio

    2016-03-01

    The distribution of swamp floodplain vegetation and its evolution in the lower non-tidal reaches of the Apalachicola River, Florida USA, is mapped using Landsat Thematic Mapper and Enhanced Thematic Mapper Plus (TM/ETM+) images captured over a period of 29 years. A newly developed seasonality index (SI), the ratio of the NDVI in winter months to the summer months, shows that the hardwood swamp, dominated by bald cypress and water tupelo, is slowly replaced by bottomland hardwood forest. This forest shift is driven by lower water levels in the Apalachicola River in the last 30 years, and predominantly occurs in the transitional area between low floodplains and high river banks. A negative correlation between maximum summer NDVI and water levels in winter suggests the growth of more vigorous vegetation in the vicinity of sloughs during years with low river flow. A negative correlation with SI further indicates that these vegetation patches are possibly replaced by species typical of drier floodplain conditions.

  12. Differences in Fish, Amphibian, and Reptile Communities Within Wetlands Created by an Agricultural Water Recycling System in Northwestern Ohio

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Establishment of a water recycling system known as the wetland-reservoir subirrigation system (WRSIS) results in the creation of wetlands adjacent to agricultural fields. Each WRSIS consists of one wetland designed to process agricultural chemicals (WRSIS wetlands) and one wetland to store subirriga...

  13. Reduction of neonicotinoid insecticide residues in Prairie wetlands by common wetland plants.

    PubMed

    Main, Anson R; Fehr, Jessica; Liber, Karsten; Headley, John V; Peru, Kerry M; Morrissey, Christy A

    2017-02-01

    Neonicotinoid insecticides are frequently detected in wetlands during the early to mid-growing period of the Canadian Prairie cropping season. These detections also overlap with the growth of macrophytes that commonly surround agricultural wetlands which we hypothesized may reduce neonicotinoid transport and retention in wetlands. We sampled 20 agricultural wetlands and 11 macrophyte species in central Saskatchewan, Canada, over eight weeks to investigate whether macrophytes were capable of reducing movement of neonicotinoids from cultivated fields and/or reducing concentrations in surface water by accumulating insecticide residues into their tissues. Study wetlands were surrounded by clothianidin-treated canola and selected based on the presence (n=10) or absence (n=10) of a zonal plant community. Neonicotinoids were positively detected in 43% of wetland plants, and quantified in 8% of all plant tissues sampled. Three plant species showed high rates of detection: 78% Equisetum arvense (clothianidin, range: wetlands had higher detection frequency and water concentrations of clothianidin (β±S.E.: -0.77±0.26, P=0.003) and thiamethoxam (β±S.E.: -0.69±0.35, P=0.049) than vegetated wetlands. We assessed the importance of wetland characteristics (e.g. vegetative zone width, emergent plant height, water depth) on neonicotinoid concentrations in Prairie wetlands over time using linear mixed-effects models. Clothianidin concentrations were significantly lower in wetlands surrounded by taller plants (β±S.E.: -0.57±0.12, P≤0.001). The results of this study suggest that macrophytes can play an important role in mitigating water contamination by accumulating neonicotinoids and possibly slowing transport to wetlands during the growing season.

  14. Assessment of wetland/upland vegetation communities and evaluation of soil-plant contamination by polycyclic aromatic hydrocarbons and trace metals in regions near oil sands mining in Alberta.

    PubMed

    Boutin, C; Carpenter, D J

    2017-01-15

    Oil sands mining in Alberta, Canada, has been steadily increasing over the last 50years. The extent to which the surrounding vegetation has been altered/contaminated by pollutants released during bitumen extraction has not been a focus of oil sands environmental monitoring efforts. The objectives of this study were to assess plant species richness and composition in wetlands and uplands in the vicinity of oil sands mining areas and to measure levels of contamination of trace metals and polycyclic aromatic hydrocarbons (PAHs) in soils and plants. Twenty-two sites were selected in three locations: near to (OS, n=7), West (n=7), and East (n=8) of oil sands mining operations. Aboveground plant species were inventoried and soil was collected for a seedbank study. Soils and plants were collected for analyses of 28 metals and 40 parent and alkylated PAHs. Plant species richness and composition differed significantly among locations. More species were found in the OS sites, many of them being non-native, than in East and West sites, which contained almost exclusively native perennials. PAH levels were significantly higher in OS sites, and were mostly comprised of alkylated PAHs. Patterns of PAH distribution indicated contamination from bitumen/petroleum in four sites; other combustion types may have affected five additional sites at different levels. Metals were also elevated in OS sites. Metal levels were significantly correlated with distance to upgrader facilities. Ratios of some metals in soil vs. above- and belowground plant parts were significantly higher in West and East than in OS sites, likely due in part to pH as soil was acidic at the East and West locations but alkaline at OS sites. This study showed that sites located near oil sands mining operations were contaminated with PAHs and metals, and that the vegetation composition at these sites greatly differed from less disturbed areas.

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

    SciTech Connect

    Moser, Lee, Justin

    2009-06-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    Canada is the fourth-largest exporter of agriculture and agri-food products in the world (exports valued at 28B), but instability of agriculture markets can make it difficult for farmers to cope with variability, and new mechanisms are needed for farmers to achieve economic stability. Capitalizing on carbon markets will help farmers achieve environmentally sustainable economic performance. In order to have a viable carbon market, governments and industries need to know what the carbon capital is and what potential there is for growth, and farmers need financial incentives that will not only allow them to conserve existing wetlands but that will also enable them to restore wetlands while making a living. In southern Ontario, farmers' needs to maximize the return on investment on marginal lands have resulted in loss of 70-90% of wetlands, making this region one of the most threatened region in terms of wetland degradation and loss in Canada. Our project establishes the role that mineral wetlands have in the net carbon balance by contributing insight into the potential benefits to carbon management provided by wetland restoration efforts in these highly degraded landscapes. The goal was to establish the magnitude of carbon offsets that could be achieved through wetland conservation (securing existing carbon stocks) and restoration (creating new carbon stocks). The experimental design was to focus on (1) small (0.2-2.0 ha) and (2) isolated (no inflow or outflow) mineral wetlands with the greatest restoration potential that included (3) a range of restoration ages (drained (0 yr), 3 yr, 6 yr, 12 yr, 20 yr, 35 yr, intact marshes) to capture potential changes in rates of carbon sequestration with restoration age of wetland. From each wetland, wetland soil carbon pools samples were collected at four positions: centre of wetland (open-water); emergent vegetation zone; wet meadow zone where flooding often occurs (i.e., high water mark); and upland where flooding rarely

  17. Landsat classification of coastal wetlands in Texas

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  18. Is the interaction between Retama sphaerocarpa and its understorey herbaceous vegetation always reciprocally positive? Competition?facilitation shift during Retama establishment

    NASA Astrophysics Data System (ADS)

    Espigares, Tíscar; López-Pintor, Antonio; Rey Benayas, José M.

    2004-10-01

    Retama sphaerocarpa is a Mediterranean shrub that when adult, facilitates the establishment of herbaceous plants under its canopy. We test the hypothesis that during the establishment of R. sphaerocarpa seedlings, the interaction with the herbaceous plants is negative. We carried out a greenhouse experiment in which seedlings of R. sphaerocarpa were grown under different conditions of competition with herbs, watering and date of emergence. Measurements of seedling mortality, biomass and growth were taken during the first growing season. We found a significant relationship between R. sphaerocarpa seedling mortality and competition in early spring, presumably due to higher water demand of herbaceous plants. Generally, presence of herbaceous species, lower availability of water and late emergence had negative effects on biomass and growth of Retama seedlings. Additional water compensated for the negative effects of competition, except on leaves and cladodes of Retama seedlings, suggesting that other resources, such as light, could be the subject of competition. In contrast, Retama seedlings exerted a positive influence on the herbaceous plants by increasing their survival and biomass, probably as a consequence of the high availability of nutrients provided by the Rhizobia nodules in the roots of Retama seedlings. We concluded that, at the regeneration stage of the shrub, the interaction between the herbaceous vegetation and the shrub is negative for the shrub and positive for the herbs. This suggests a shift from competition to facilitation with age of Retama, as reciprocal positive interactions have been described between herbaceous plants and adult individuals of the shrub.

  19. Fate of viruses in artificial wetlands

    SciTech Connect

    Gersberg, R.M.; Lyon, S.R.; Brenner, R.; Elkins, B.V.

    1987-04-01

    Little is known about the ability of wetlands to remove disease-causing viruses from municipal wastewater. In this study the authors examined the survival of several indicators of viral pollution applied in primary municipal wastewater to artificial wetland ecosystems. Only about 1% of the indigenous F-specific RNA bacteriophages survived flow through the vegetated wetland beds at a 5-cm-day/sup -1/ hydraulic application rate during the period from June through December 1985. The total number of indigenous F-specific bacteriophages was also reduced by about 99% by wetland treatment, with the mean inflow concentration over the period of an entire year reduced from 3129 to 33 PFU ml/sup -1/ in the outflow of an vegetated bed and to 174 PFU ml/sup -1/ in the outflow of an unvegetated bed. Such superior treatment by the vegetated bed demonstrates the significant role of higher aquatic plants in the removal process. Seeded MS2 bacteriophage and seeded poliovirus were removed more efficiently than were the indigenous bacteriophages, with less than 0.2% and MS2 and 0.1% of the poliovirus surviving flow at the same hydraulic application rate. The decay rate (k) of MS2 in a stagnant wetlands was lower than that for flowing systems, reflecting the enhanced capacity for filtration or adsorption of viruses by the root-substrate complex. Artificial wetlands may offer an attractive alternative to conventional land treatment systems for reducing the load disease-causing viruses to the aquatic environment.

  20. Coastal Wetlands.

    ERIC Educational Resources Information Center

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

  1. Saltwater Wetlands.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    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)

  2. Inland Wetlands.

    ERIC Educational Resources Information Center

    Area Cooperative Educational Services, New Haven, CT. Environmental Education 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 material. The material is designed for use with Connecticut schools, but it can be adapted to other localities. The materials emphasize characteristics of inland…

  3. Aquatic herbivores facilitate the emission of methane from wetlands.

    PubMed

    Dingemans, Bas J J; Bakker, Elisabeth S; Bodelier, Paul L E

    2011-05-01

    Wetlands are significant sources of atmospheric methane. Methane produced by microbes enters roots and escapes to the atmosphere through the shoots of emergent wetland plants. Herbivorous birds graze on helophytes, but their effect on methane emission remains unknown. We hypothesized that grazing on shoots of wetland plants can modulate methane emission from wetlands. Diffusive methane emission was monitored inside and outside bird exclosures, using static flux chambers placed over whole vegetation and over single shoots. Both methods showed significantly higher methane release from grazed vegetation. Surface-based diffusive methane emission from grazed plots was up to five times higher compared to exclosures. The absence of an effect on methane-cycling microbial processes indicated that this modulating effect acts on the gas transport by the plants. Modulation of methane emission by animal-plant-microbe interactions deserves further attention considering the increasing bird populations and changes in wetland vegetation as a consequence of changing land use and climate change.

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

    USGS Publications Warehouse

    Brown, R.G.

    1985-01-01

    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)

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

    USGS Publications Warehouse

    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

    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

  6. The Choptank Watershed Wetland Conservation Effects Assessment Project: Monitoring the Delivery of Wetland Ecosystem Services across the Landscape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CEAP-Wetlands (NRCS) and the Choptank Benchmark Watershed CEAP (ARS) have established a partnership to assess and ultimately enhance the effect of conservation practices on ecosystem services provided by wetlands in the Choptank Watershed. The provision of these wetland services (e.g., pollutant red...

  7. A comparative study on the potential of oxygen release by roots of selected wetland plants

    NASA Astrophysics Data System (ADS)

    Yao, Fang; Shen, Gen-xiang; Li, Xue-lian; Li, Huai-zheng; Hu, Hong; Ni, Wu-zhong

    The capacity of root oxygen release by selected wetland plants pre-grown under both nutrient solution and artificial wastewater conditions were determined. The results indicated that the significant differences of root oxygen release by the tested wetland plants existed, and the biochemical process was the main source of root oxygen release as oxygen released by Vetiveria zizanioides L. Nash roots through biochemical process was contributed to 77% and 74% of total root oxygen release under nutrient solution conditions and artificial wastewater conditions, respectively, and that was 72% and 71% of total root oxygen release for Cyperus alternifolius L. It was found that the formation of root plaque with iron oxide was a function of root oxygen release as iron oxide concentration in root plaque was positively correlated to the potential of oxygen released by wetland plant roots with the regression coefficients as 0.874 *( p < 0.05) under nutrient solution conditions and 0.944 **( p < 0.01) under artificial wastewater conditions, which could be regarded as an important mechanism of wetland plants being tolerant to anoxia during wastewater treatment. It was suggested that the potential of root oxygen release could be used as a parameter for selecting wetland plants that can increase oxygen supply to soil or substrate of constructed wetlands and enhance nutrient transformation and removal, and V. zizanioides L. Nash with the highest potential of root oxygen release and higher tolerance to wastewater could be recommended to establish vegetated wetlands for treating nutrient-rich wastewater such as domestic wastewater.

  8. Preliminary monitoring protocol for the tidal freshwater wetland restoration herbivory study in national capital parks--east: Appendix B

    USGS Publications Warehouse

    Krafft, Cairn; Hatfield, Jeffrey S.

    2014-01-01

    Four tidal freshwater wetland restoration projects have been undertaken within Anacostia Park on lands managed by the National Park Service since 1993. Monitoring the impacts of Canada goose (Branta canadensis) herbivory on the wetland vegetation will play a key role in determining the long-term health of these tidal freshwater wetland restorations. This Implementation Plan lays out monitoring for impacts of herbivory on the vegetation in Kingman Area 1 and inferred to the other wetland areas.

  9. Vulnerability of northern prairie wetlands to climate change

    USGS Publications Warehouse

    Johnson, W.C.; Millett, B.V.; Gilmanov, T.; Voldseth, R.A.; Guntenspergen, G.R.; Naugle, D.E.

    2005-01-01

    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.

  10. Utilizing hyperspectral and hyperspatial remote sensing to track invasive species in BARC wetland ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wetland vegetation is a critical component to the function of and ecological services provided by wetland ecosystems. Two non-native invasive species threaten wetland ecosystems in the Mid Atlantic region, Phragmites australis (giant reed) and Lythrum salicaria (purple loosestrife). Hyperspectral ...

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

    PubMed

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

    2014-07-01

    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.

  12. Riparian Wetlands: Mapping

    EPA Science Inventory

    Riparian wetlands are critical systems that perform functions and provide services disproportionate to their extent in the landscape. Mapping wetlands allows for better planning, management, and modeling, but riparian wetlands present several challenges to effective mapping due t...

  13. Our Valuable Wetlands.

    ERIC Educational Resources Information Center

    Texley, Juliana

    1988-01-01

    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)

  14. Classification of land-cover types in muddy tidal flat wetlands using remote sensing data

    NASA Astrophysics Data System (ADS)

    Wang, Cong; Liu, Hong-Yu; Zhang, Ying; Li, Yu-feng

    2013-01-01

    Remote sensing classification of tidal flat wetlands is important for obtaining high-precision information on wetland features. In this study, Thematic Mapper (TM) images of the Yancheng National Reserves, Jiangsu Province, China, for the years of 1996, 2002, 2006, and 2010 were considered. First, the optimum combination of bands was chosen. Second, vegetation and nonvegetation regions of interest were established to investigate the spectral reflectance characteristics of the different ground objects. Then we used the knowledge-based decision tree method on different features, such as the normalized difference vegetation index and the spectral reflectance. In particular, the ancillary information is helpful to distinguish the vegetation classes. The results demonstrate that the classification system has advantages in identifying the types of vegetation in ecotones, and it is 4 percentage points higher than the maximum likelihood method in classification accuracy. This study is useful to discriminate vegetation, and it provides an important reference for the effective extraction of tidal flat land-cover information from TM images.

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

  16. Quality assurance project plan: 1991 EMAP wetlands southeastern pilot study

    SciTech Connect

    Swenson, E.M.; Lee, J.M.; Turner, R.E.

    1992-12-01

    The goal of the Environmental Monitoring and Assessment Program - Wetlands (EMAP-Wetlands) Southeastern Pilot Study is to develop field indicators of salt marsh condition. These indicators are of four general types: (1) vegetation; (2) hydrology; (3) soil parameters; and (4) soil constituents. Field measurements and samples will be collected during late summer/early fall in 1991 and will be analyzed to identify which indicators and measurements best delineate salt marsh in good condition from that in impaired condition. Thus the project will involve field work, laboratory analysis, and data analysis. Results from this project will be used to establish criteria and parameters for long-term monitoring and assessment of salt marshes, particularly those parameters that may serve as indicators of healthy salt marsh and deteriorated salt marsh. Since EMAP-Wetlands-Southeastern is a pilot study, the measurement criteria will be evaluated as one of the project goals. Of concern will be how well the standardized sampling methods performed in actual field conditions, and which of these methods can be used to assess and characterize salt marshes.

  17. Wetland Boundary Determination in the Great Dismal Swamp Using Weighted Averages

    USGS Publications Warehouse

    Carter, Virginia; Garrett, Mary Keith; Gammon, Patricia T.

    1988-01-01

    A weighted average method was used to analyze transition zone vegetation in the Great Dismal Swamp to determine if a more uniform determination of wetland boundaries can be made nationwide. The method was applied to vegetation data collected on four transects and three vertical layers across the wetland-to-upland transition zone of the swamp. Ecological index values based on water tolerance were either taken from the literature or derived from local species tolerances. Wetland index values were calculated for 25-m increments using species cover and rankings based on the ecological indices. Wetland index values were used to designate increments as either wetland, transitional, or upland, and to examine the usefulness of a provisional wetland-upland break-point. The weighted average method did not provide for an objective placement of an absolute wetland boundary, but did serve to focus attention on the transitional boundary zone where supplementary information is necessary to select a wetland-upland breakpoint.

  18. Hydrologic considerations in defining isolated wetlands

    USGS Publications Warehouse

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

    2003-01-01

    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.

  19. Pesticide mass budget in a stormwater wetland.

    PubMed

    Maillard, Elodie; Imfeld, Gwenaël

    2014-01-01

    Wetlands are reactive landscape zones that provide ecosystem services, including the improvement of water quality. Field studies distinguishing pesticide degradation from retention to evaluate the sink and source functions of wetlands are scarce. This study evaluated based on a complete mass budget the partitioning, retention, and degradation of 12 pesticides in water, suspended solids, sediments, and organisms in a wetland receiving contaminated runoff. The mass budget showed the following: (i) dissolved pesticides accounted for 95% of the total load entering the wetland and the pesticide partitioning between the dissolved phase and the suspended solids varied according to the molecules, (ii) pesticides accumulated primarily in the <250 μm bed sediments during spring and late summer, and (iii) the hydrological regime or the incoming pesticide loads did not influence the pesticide dissipation, which varied according to the molecules and the wetland biogeochemical conditions. The vegetation enhanced the pesticide degradation during the vegetative phase and the pesticides were released during plant senescence. The dithiocarbamates were degraded under oxic conditions in spring, whereas glyphosate and aminomethylphosphonic acid (AMPA) degradation occurred under reducing conditions during the summer. The complete pesticide mass budget indicates the versatility of the pesticide sink and source functions of wetland systems.

  20. 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)

    Cowood, Alie; Moore, Leah

    2014-05-01

    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

  1. Primary production control of methane emission from wetlands

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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.

  2. Emissions of sulfur gases from wetlands

    NASA Technical Reports Server (NTRS)

    Hines, Mark E.

    1992-01-01

    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.

  3. Environmental gradients and identification of wetlands in north-central Florida

    USGS Publications Warehouse

    Davis, M.M.; Sprecher, S.W.; Wakeley, J.S.; Best, G.R.

    1996-01-01

    Vegetation composition, soil morphology, and hydrology were characterized along wetland-to-upland gradients at six forested sites in north-central Florida to compare results of Federal wetland delineation methods with 3–5 yr of hydrologic data. Wetland and non-wetland identifications were supported by hydrology data in eight of nine plant communities. Lack of hydric soil indicators and hydrophytic vegetation in two upland communities (scrub and mixed mesic hardwoods) agreed with a deep water table. Six wetland communities (cypress dome, cypress strand, bayhead, cypress/bayhead, red maple/oak swamp, and cedar swamp) with field indicators of wetland hydrology, hydrophytic vegetation, and hydric soils were inundated or had water tables at or near the ground surface at least 5% of the growing season in most years., Flatwoods communities, however, occurred at intermediate positions on the moisture gradient and could not be consistently identified as wetland or upland communities. Identification of flatwoods as wetlands depended on wetland delineation method and was not usually supported by hydrologic measurements. In the flatwoods community, soil properties and vegetation composition were correlated with the mean and standard deviation of water-table depths, as well as the depth continuously exceeded by the water table at least 5% of the growing season in most years. Various hydrologic parameters need to be considered in addition to the 5% exceedence level currently used in Federal wetland delineation guidance when characterizing wetland conditions in low-gradient areas such as flatwoods.

  4. Eco-hydrological feedback mechanisms control ecological services in wetlands

    NASA Astrophysics Data System (ADS)

    Coletti, J.; Hinz, C.; Vogwill, R.; Tareque, H.; Hipsey, M. R.

    2011-12-01

    Wetland ecosystems contain various feedback mechanisms between their abiotc and biotic components. The feedbacks are triggered by climate and propagate into patterns of environment partitioning based on distinct zones of hydrological function that vary in time and space. This partitioning co-evolves with vegetation, defines carbon metabolism and creates niches that govern patterns of flora and fauna abundance and distribution. Using a minimalistic model for wetland eco-hydrology, we explore vegetation adaptation to climate variability and the net metabolism of a wetland ecosystem given a range of climate conditions. We then apply the model to characterize the changes in niche habitat availability for a tortoise population endangered by a drying climate.

  5. Movements and wetland selection by brood-rearing black ducks

    USGS Publications Warehouse

    Ringelman, J.K.; Longcore, J.R.

    1982-01-01

    Movements and wetland selection by brood-rearing black ducks (Anas rubripes) were studied in Maine during 1977-80. Eight radio-marked hens moved their broods an average of 1.2 km from the nest to rearing pond, but only 1 hen initiated secondary brood movements. Half of the 85 broods reared in the study area used only 3 wetlands, and most rearing ponds contained active beaver (Castor canadensis) colonies. Brood-rearing hens preferred Emergent ponds over lakes and Evergreen Scrub-Shrub wetlands, and did not occupy Dead Scrub-Shrub, Unconsolidated Bottom, or Aquatic Bed wetlands. Rearing ponds were large and possessed extensive areas of flooded mountain alder (Alnus incana), willow (Salix spp.), and herbaceous vegetation. Wetlands avoided by brood-rearing hens were those with large areas of open water, submergent aquatics, or ericaceous shrub vegetation.

  6. Exploring Microbial Iron Oxidation in Wetland Soils

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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 α- 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

  7. Physiological Ecology and Ecohydrology of Coastal Forested Wetlands

    USGS Publications Warehouse

    Krauss, Ken W.

    2007-01-01

    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).

  8. Estimating Carbon Stocks Along Depressional Wetlands Using Ground Penetrating Radar (GPR) in the Disney Wilderness Preserve (Orlando, Florida)

    NASA Astrophysics Data System (ADS)

    McClellan, M. D.; Comas, X.; Wright, W. J.; Mount, G. J.

    2014-12-01

    Peat soils store a large fraction of the global carbon (C) in soil. It is estimated that 95% of carbon in peatlands is stored in the peat soil, while less than 5% occurs in the vegetation. The majority of studies related to C stocks in peatlands have taken place in northern latitudes leaving the tropical and subtropical latitudes clearly understudied. In this study we use a combination of indirect non-invasive geophysical methods (mainly ground penetrating radar, GPR) as well as direct measurements (direct coring) to calculate total C stocks within subtropical depressional wetlands in the Disney Wilderness Preserve (DWP, Orlando, FL). A set of three-dimensional (3D) GPR surveys were used to detect variability of the peat layer thickness and the underlying peat-sand mix layer across several depressional wetlands. Direct samples collected at selected locations were used to confirm depth of each interface and to estimate C content in the laboratory. Layer thickness estimated from GPR and direct C content were used to estimate total peat volume and C content for the entire depressional wetland. Through the use of aerial photos a relationship between surface area along the depressional wetlands and total peat thickness (and thus C content) was established for the depressions surveyed and applied throughout the entire preserve. This work shows the importance of depressional wetlands as critical contributors of the C budget at the DWP.

  9. [On the safety threshold of wetlands based on water ecological element--taking wetlands in Sanjiang Plain as an example].

    PubMed

    Liu, Zhenqian; Wang, Jianwu; Luo, Shiming; Lu, Xianguo; Liu, Zhaoli; Liu, Hongyu; Li, Xiujun

    2002-12-01

    The lowest water requirement of the wetlands was demonstrated through different simulations. Based on the relationship between the area of wetlands and its effects on air temperature and humidity, some useful statistical models were established. According to the theory and principles of system dynamics (SD), a dynamic simulation model of the wetlands' retaining water was compiled in DYNAMO language. Finally, the safety threshold of the wetlands was assessed based on its water ecological factors. The feasibility of the method was demonstrated by a case study on the wetlands in Sanjiang Plain of China.

  10. Wetland modeling and information needs at Stillwater National Wildlife Refuge

    USGS Publications Warehouse

    Hamilton, David B.; Auble, Gregor T.

    1993-01-01

    The marshes in and around Stillwater National Wildlife Refuge (the Refuge) are extremely dynamic; expanding and contracting in size both seasonally, due to runoff and subsequent evapotranspiration, and over longer periods, due to climatic variation. The dynamic nature of these marshes results in a diversity of wetland habitats, which support a variety of migratory birds. To maintain this wetland diversity and control the loss of migratory bird habitat in the Lahontan Valley, the Refuge was established and currently manages a complex of marsh units. However, changes in the hydrology, and changes that will occur as a result of the Fallon Paiute-Shoshone and Truckee-Carson-Pyramid Lake Water Rights Settlement Act (Public Law 101-618, 104 Stat. 3389), greatly affect the Refuge's wetland management capability. In light of these changes, and the legal requirements associated with environmental impact assessments, the Refuge convened a workshop to discuss several aspects of wetland management in the Lahontan Valley. The workshop, described in this report, had three primary objectives: 1. discuss the types and relative proportions of primary wetland habitats that should be provided as described in the settlement act; 2. discuss wetland management models that might be developed to help manage these marshes under hydrologic regimes likely in the future; and 3. discuss future information and monitoring needs, including proposals for valley-wide biodiversity surveys, which would be helpful when considering withdrawn Bureau of Reclamation (BR) lands for possible incorporation into the Refuge. Several presentations at the beginning of the workshop provided a common basis for discussing these objectives. Refuge staff provided background on the history and past management. The Nature Conservatory discussed their role in the settlement act, proposals for valley-wide biodiversity surveys, and results of a literature review for Stillwater Marsh and the Lahontan Valley (Nachlinger

  11. Ohio Uses Wetlands Program Development Grants to Protect Wetlands

    EPA Pesticide Factsheets

    The wetland water quality standards require the use of ORAM score to determine wetland quality. OEPA has also used these tools to evaluate wetland mitigation projects, develop performance standards for wetland mitigation banks and In Lieu Fee programs an.

  12. An Inundated Wetlands Earth System Data Record: Global Monitoring of Wetland Extent and Dynamics

    NASA Astrophysics Data System (ADS)

    Podest, E.; McDonald, K.; Chapman, B.; Hess, L.; Moghaddam, M.; Kimball, J. S.; Matthews, E.; Prigent, C.

    2008-12-01

    Wetlands exert major impacts on global biogeochemistry, hydrology, and biological diversity. The extent and seasonal, interannual, and decadal variation of inundated wetlands play key roles in ecosystem dynamics. Despite the importance of these environments in the global cycling of carbon and water and to current and future climate, the extent and dynamics of global wetlands remain poorly characterized and modeled. This is primarily because of the scarcity of suitable regional-to-global remote-sensing data for characterizing wetland distribution and dynamics. As part of a NASA MEaSUREs project, we are constructing a global-scale Earth System Data Record (ESDR) of inundated wetlands to facilitate investigations on their role in climate, biogeochemistry, hydrology, and biodiversity. The ESDR is being generated using legacy algorithms developed from spaceborne remote sensing data sets and is comprised of two complementary components. The first are fine resolution (100 m) maps of wetland extent, vegetation type, and seasonal inundation dynamics, derived from Synthetic Aperture Radar (SAR), for continental-scale areas covering crucial wetland regions. The second are global monthly maps of inundation extent at ~25 km resolution for the period 1992- 2009, derived from multiple satellite observations. We present details of the ESDR construction including remote sensing algorithm applications, cross-product harmonization, and planned data set distribution. The status of current efforts to assemble this ESDR, including data processing, wetland classifications, and open water change mappings derived from L-band data for the state of Alaska and select basins in Eurasia are presented. This ESDR will provide the first accurate, consistent and comprehensive global-scale data set of wetland inundation and vegetation, including continental-scale multitemporal and multi-year monthly inundation dynamics at multiple scales. Portions of this work were carried out at the Jet Propulsion

  13. Effects of flow modification on a cattail wetland at the mouth of Irondequoit Creek near Rochester, New York : water levels, wetland biota, sediment, and water quality

    USGS Publications Warehouse

    Coon, William F.

    2004-01-01

    An 11-year (1990-2001) study of the Ellison Park wetland, a 423-acre, predominantly cattail (Typha glauca) wetland at the mouth of Irondequoit Creek, was conducted to document the effects that flow modifications, including installation of a flow-control structure (FCS) in 1997 and increased diversion of stormflows to the backwater areas of the wetland, would have on the wetlands ability to decrease chemical loads transported by Irondequoit Creek into Irondequoit Bay on Lake Ontario. The FCS was designed to raise the water-surface elevation and thereby increase the dispersal and detention of stormflows in the upstream half of the wetland; this was expected to promote sedimentation and microbial utilization of nutrients, and thereby decrease the loads of certain constituents, primarily phosphorus, that would otherwise be carried into Irondequoit Bay. An ecological monitoring program was established to document changes in the wetlands water levels, biota, sedimentation rates, and chemical quality of water and sediment that might be attributable to the flow modifications. Water-level increases during storms were mostly confined to the wetland area, within about 5,000 ft upstream from the FCS. Backwater at a point of local concern, about 13,000 ft upstream, was due to local debris jams or constriction of flow by bridges and was not attributable to the FCS. Plant surveys documented species richness, concentrations of nutrients and metals in cattail tissues, and cattail productivity. Results indicated that observed differences among survey periods and between the areas upstream and downstream from the FCS were due to seasonal changes in water levels -- either during the current year or at the end of the previous years growing season -- that reflected the water-surface elevation of Lake Ontario, rather than water-level control by the FCS. Results showed no adverse effects from the naturally high water levels that prevail annually during the spring and summer in the wetland

  14. 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

    Ralston, Barbara E.

    2010-01-01

    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

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

    USGS Publications Warehouse

    Hammerschlag, D.; Krafft, C.

    2006-01-01

    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

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

    SciTech Connect

    Shem, L.M.; Van Dyke, G.D.; Zimmerman, R.E.

    1994-12-01

    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.

  17. Options for water-level control in developed wetlands

    USGS Publications Warehouse

    Kelley, J. R.; Laubhan, M. K.; Reid, F. A.; Wortham, J. S.; Fredrickson, L. H.

    1993-01-01

    Wetland habitats in the United States currently are lost at a rate of 260,000 acres/year (105,218 ha/year). Consequently, water birds concentrate in fewer and smaller areas. Such concentrations may deplete food supplies and influence behavior, physiology, and survival. Continued losses increase the importance of sound management of the remaining wetlands because water birds depend on them. Human activities modified the natural hydrology of most remaining wetlands in the conterminous United States, and such hydrologic alterations frequently reduce wetland productivity. The restoration of original wetland functions and productivity often requires the development of water distribution and discharge systems to emulate natural hydrologic regimes. Construction of levees and correct placement of control structures and water-delivery and water-discharge systems are necessary to (1) create soil and water conditions for the germination of desirable plants, (2) control nuisance vegetation, (3) promote the production of invertebrates, and (4) make foods available for wildlife that depends of wetlands (Leaflets 13.2.1 and 13.4.6). This paper provides basic guidelines for the design of wetlands that benefit wildlife. If biological considerations are not incorporated into such designs, the capability of managing wetlands for water birds is reduced and costs often are greater. Although we address the development of palustrine wetlands in migration and wintering areas, many of the discussed principles are applicable to the development of other wetland types and in other locations.

  18. [Waterbird habitat-selection during winter and spring in reclaimed coastal wetlands in Nanhui Dongtan, Shanghai].

    PubMed

    Niu, Jun-Ying; Heng, Nan-Nan; Zhang, Bin; Yuan, Xiao; Wang, Tian-Hou

    2011-12-01

    From December 2009 to May 2010 goose and duck (Anatidae) community censuses in winter and shorebird (Charadriiforms) community censuses in spring were conducted across three types artificial wetlands (urban lake wetland, restorative wetland, abandoned wetland) along the coast of Nanhui, Shanghai. Correlation analyses were undertaken between community indices and habitat factors. The results showed there were significant differences in the density of geese and ducks among the wetlands, but no difference in the number of species. The density of geese and ducks in the restorative wetland was 3.77 times that of abandoned wetland and 6.03 times that of urban lake wetlands. The number of species and density of shorebirds in restorative wetlands was 2.88 and 5.70 times that of abandoned wetlands. We found significant differences in the number and density of shorebird species between restorative and abandoned wetlands. The number of species density of geese and ducks and the Shannon-Wiener (H') index were positively correlated with water area. The number of species and H' were negatively correlated with vegetation area. The number of species, species density and H' and evenness were negatively correlated with vegetation coverage. H' was positively correlated with mean water level. The results showed that the number and density of shorebird species were positively correlated with bare muddy areas. Aquaculture ponds and paddy fields in reclaimed area is efficient sufficient compensation mechanism to maintain more water areas for waterbirds and to control vegetation expansion and maintain shorebird habitat after coastal reclamation.

  19. Wonderful Wetlands: An Environmental Education Curriculum Guide for Wetlands.

    ERIC Educational Resources Information Center

    King County Parks Div., Redmond, WA.

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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

  1. The National Wetland Condition Assessment | Science ...

    EPA Pesticide Factsheets

    The first National Wetland Condition Assessment (NWCA) was conducted in 2011 by the US Environmental Protection Agency (USEPA). Vegetation, algae, soil, water chemistry,and hydrologic data were collected at each of 1138 sites across the contiguous US. Ecological condition was assessed in relation to a disturbance gradient anchored by least (reference) and most disturbed sites identified using chemical, physical, and biological disturbance indices. A vegetation multimetric index (VMMI) indicated condition. Potential stressors to condition were incorporated into indices of hydrologic alteration, physical alteration and soil heavy metals, and a nonnative plant indicator. All 1138 sites sampled were placed along a quantitatively defined disturbance gradient customized by ecoregions used in reporting. The characteristics of the 277 sites identified as least disturbed were considered reference. Least disturbed sites are those with the best available condition given the current status of the landscape in which the site is located. Approximately 48±6% of the national wetland area was in good condition; 32±6% in poor condition as measured by the VMMI. Fair condition is the smallest by percent and total area nationally, in two of four regions, and by wetland type. A possible explanation of this pattern is that, we are doing a good job of protecting the best wetlands, while it’s harder to do the same for wetlands that are degraded to some degree. This results in those

  2. Forms of organic phosphorus in wetland soils

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  3. Conceptual hierarchical modeling to describe wetland plant community organization

    USGS Publications Warehouse

    Little, A.M.; Guntenspergen, G.R.; Allen, T.F.H.

    2010-01-01

    Using multivariate analysis, we created a hierarchical modeling process that describes how differently-scaled environmental factors interact to affect wetland-scale plant community organization in a system of small, isolated wetlands on Mount Desert Island, Maine. We followed the procedure: 1) delineate wetland groups using cluster analysis, 2) identify differently scaled environmental gradients using non-metric multidimensional scaling, 3) order gradient hierarchical levels according to spatiotem-poral scale of fluctuation, and 4) assemble hierarchical model using group relationships with ordination axes and post-hoc tests of environmental differences. Using this process, we determined 1) large wetland size and poor surface water chemistry led to the development of shrub fen wetland vegetation, 2) Sphagnum and water chemistry differences affected fen vs. marsh / sedge meadows status within small wetlands, and 3) small-scale hydrologic differences explained transitions between forested vs. non-forested and marsh vs. sedge meadow vegetation. This hierarchical modeling process can help explain how upper level contextual processes constrain biotic community response to lower-level environmental changes. It creates models with more nuanced spatiotemporal complexity than classification and regression tree procedures. Using this process, wetland scientists will be able to generate more generalizable theories of plant community organization, and useful management models. ?? Society of Wetland Scientists 2009.

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

    USGS Publications Warehouse

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

    2004-01-01

    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.

  5. Systems modeling to improve the hydro-ecological performance of diked wetlands

    NASA Astrophysics Data System (ADS)

    Alminagorta, Omar; Rosenberg, David E.; Kettenring, Karin M.

    2016-09-01

    Water scarcity and invasive vegetation threaten arid-region wetlands and wetland managers seek ways to enhance wetland ecosystem services with limited water, labor, and financial resources. While prior systems modeling efforts have focused on water management to improve flow-based ecosystem and habitat objectives, here we consider water allocation and invasive vegetation management that jointly target the concurrent hydrologic and vegetation habitat needs of priority wetland bird species. We formulate a composite weighted usable area for wetlands (WU) objective function that represents the wetland surface area that provides suitable water level and vegetation cover conditions for priority bird species. Maximizing the WU is subject to constraints such as water balance, hydraulic infrastructure capacity, invasive vegetation growth and control, and a limited financial budget to control vegetation. We apply the model at the Bear River Migratory Bird Refuge on the Great Salt Lake, Utah, compare model-recommended management actions to past Refuge water and vegetation control activities, and find that managers can almost double the area of suitable habitat by more dynamically managing water levels and managing invasive vegetation in August at the beginning of the window for control operations. Scenario and sensitivity analyses show the importance to jointly consider hydrology and vegetation system components rather than only the hydrological component.

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

    SciTech Connect

    Rastorfer, J.R.; Van Dyke, G.D.; Zellmer, S.D.; Wilkey, P.L.

    1995-04-01

    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.

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

    SciTech Connect

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

    1995-12-31

    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.

  8. Why are wetlands important?

    EPA Pesticide Factsheets

    Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs. An immense variety of species of microbes, plants, insects, amphibians, reptiles, birds, fish, and mammals can be part of a wetland ecosystem.

  9. 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...

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    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

  11. Appilications of National Wetland Condition Assessment Data to Wetland Protection and Management

    EPA Science Inventory

    The first National Wetland Condition Assessment (NWCA) was conducted in 2011 by the US Environmental Protection Agency (USEPA) and its federal and state partners, using a survey design allowing extrapolation of results to national and regional scales. Vegetation, algae, soil, wat...

  12. Copper stable isotopes to trace copper behavior in wetland systems.

    PubMed

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

    2014-05-20

    Wetlands are reactive zones of the landscape that can sequester metals released by industrial and agricultural activities. Copper (Cu) stable isotope ratios (δ(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 (Δ(65)Cuinlet-outlet from 0.03‰ to 0.77‰), which reflects Cu adsorption to aluminum minerals and organic matter. The δ(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.

  13. Wetlands: An Interdisciplinary Exploration

    ERIC Educational Resources Information Center

    Czerniak, Charlene M.

    2004-01-01

    The topic of wetlands provides a rich context for curriculum integration. This unit contains seven activities that integrate environmental science with math, technology, social studies, language arts, and other disciplines. In this series, students will identify plants and animals found in wetlands, understand the function of wetlands through the…

  14. Gulf Coast Wetlands

    Atmospheric Science Data Center

    2014-05-15

    article title:  Wetlands of the Gulf Coast     ... web of estuarine channels and extensive coastal wetlands that provide important habitat for fisheries. The city of New Orleans ... or below sea level. The city is protected by levees, but the wetlands which also function as a buffer from storm surges have been ...

  15. Wetlands, Wildlife, and People.

    ERIC Educational Resources Information Center

    Naturescope, 1986

    1986-01-01

    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)

  16. Are isolated wetlands isolated?

    USGS Publications Warehouse

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

    2011-01-01

    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.

  17. Geographically isolated wetlands: Rethinking a misnomer

    USGS Publications Warehouse

    Mushet, David M.; Calhoun, Aram J. K.; Alexander, Laurie C.; Cohen, Matthew J.; DeKeyser, Edward S.; Fowler, Laurie G.; Lane, Charles R.; Lang, Megan W.; Rains, Mark C.; Walls, Susan

    2015-01-01

    We explore the category “geographically isolated wetlands” (GIWs; i.e., wetlands completely surrounded by uplands at the local scale) as used in the wetland sciences. As currently used, the GIW category (1) hampers scientific efforts by obscuring important hydrological and ecological differences among multiple wetland functional types, (2) aggregates wetlands in a manner not reflective of regulatory and management information needs, (3) implies wetlands so described are in some way “isolated,” an often incorrect implication, (4) is inconsistent with more broadly used and accepted concepts of “geographic isolation,” and (5) has injected unnecessary confusion into scientific investigations and discussions. Instead, we suggest other wetland classification systems offer more informative alternatives. For example, hydrogeomorphic (HGM) classes based on well-established scientific definitions account for wetland functional diversity thereby facilitating explorations into questions of connectivity without an a priori designation of “isolation.” Additionally, an HGM-type approach could be used in combination with terms reflective of current regulatory or policymaking needs. For those rare cases in which the condition of being surrounded by uplands is the relevant distinguishing characteristic, use of terminology that does not unnecessarily imply isolation (e.g., “upland embedded wetlands”) would help alleviate much confusion caused by the “geographically isolated wetlands” misnomer.

  18. Fish assemblages, connectivity, and habitat rehabilitation in a diked Great Lakes coastal wetland complex

    USGS Publications Warehouse

    Kowalski, Kurt P.; Wiley, Michael J.; Wilcox, Douglas A.

    2014-01-01

    Fish and plant assemblages in the highly modified Crane Creek coastal wetland complex of Lake Erie were sampled to characterize their spatial and seasonal patterns and to examine the implications of the hydrologic connection of diked wetland units to Lake Erie. Fyke netting captured 52 species and an abundance of fish in the Lake Erie–connected wetlands, but fewer than half of those species and much lower numbers and total masses of fish were captured in diked wetland units. Although all wetland units were immediately adjacent to Lake Erie, there were also pronounced differences in water quality and wetland vegetation between the hydrologically isolated and lake-connected wetlands. Large seasonal variations in fish assemblage composition and biomass were observed in connected wetland units but not in disconnected units. Reestablishment of hydrologic connectivity in diked wetland units would allow coastal Lake Erie fish to use these vegetated habitats seasonally, although connectivity does appear to pose some risks, such as the expansion of invasive plants and localized reductions in water quality. Periodic isolation and drawdown of the diked units could still be used to mimic intermediate levels of disturbance and manage invasive wetland vegetation.

  19. Driving forces behind the construction of an eco-compensation mechanism for wetlands in China

    NASA Astrophysics Data System (ADS)

    Wang, Changhai

    2016-09-01

    This research revealed important driving forces behind the construction of an eco-compensation mechanism for wetlands (DFEMW) in China. Using China's provincial panel data from 1978 to 2008, a fixed-effects model was used to analyze the impacts of agricultural production systems on wetlands. We identified three DFEMW as follows: the change of wetland resources and protection measures in China; declaration and implementation of the provincial Wetland Protection Ordinance; and wetland degradation by agricultural production systems, which necessitated the establishment of a wetland eco-compensation mechanism. In addition to the DFEMW, a significant positive correlation between wetland area and both rural population and gross agricultural production was identified, in addition to a negative correlation with chemical fertilizer usage, reservoir storage capacity, and irrigation area. The underlying reasons for the serious degradation and inadequate protection of wetlands were market failure and government failure; these were the driving forces behind the need to establish a wetland eco-compensation mechanism. From a governmental perspective, it has been difficult to rectify market failures in resource distribution and thus to prevent wetland degradation. Factors include conflicts of interest, lack of investment, effective special laws, a simple means to protect wetlands, and a multidisciplinary management system. Therefore, the key factor is the coordination of interest relationships between those who utilize wetlands and those who seek to minimize wetland degradation and effectively protect wetlands.

  20. Sub-canopy evapotranspiration from floating vegetation and open water in a swamp forest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Among previous studies, there are large discrepancies in the difference between evapotranspiration from wetland vegetation and evaporation from open water. In this study, we investigate evapotranspiration differences between water and vegetation in a scenario that has otherwise not been extensively ...

  1. Negative effects of excessive soil phosphorus on floristic quality in Ohio wetlands.

    PubMed

    Stapanian, Martin A; Schumacher, William; Gara, Brian; Monteith, Steven E

    2016-05-01

    Excessive soil nutrients, often from agricultural runoff, have been shown to negatively impact some aspects of wetland plant communities. We measured plant-available phosphorus (Mehlich-3: MeP) in soil samples, and assessed the vascular plant community and habitat degradation at 27 emergent and 13 forested wetlands in Ohio, USA. We tested two hypotheses: (1) that an index of vegetation biological integrity based on floristic quality was lower in wetlands with higher concentrations of MeP in the soil, and (2) that higher concentrations of MeP occurred in wetlands with more habitat degradation (i.e., lower quality), as estimated by a rapid assessment method. Hypothesis (1) was supported for emergent, but not for forested wetlands. Hypothesis (2) was marginally supported (P=0.09) for emergent, but not supported for forested wetlands. The results indicate that the effect of concentration of phosphorus in wetland soils and the quality of plant species assemblages in wetlands is more complex than shown in site-specific studies and may depend in part on degree of disturbance in the surrounding watershed and dominant wetland vegetation type. Woody plants in forested wetlands are typically longer lived than herbaceous species in the understory and emergent wetlands, and may persist despite high inputs of phosphorus. Further, the forested wetlands were typically surrounded by a wide band of forest vegetation, which may provide a barrier against sedimentation and the associated phosphorus inputs to the wetland interior. Our results indicate that inferences about soil nutrient conditions made from rapid assessment methods for assessing wetland habitat condition may not be reliable.

  2. Negative effects of excessive soil phosphorus on floristic quality in Ohio wetlands

    USGS Publications Warehouse

    Stapanian, Martin A.; Schumacher, William; Gara, Brian; Monteith, Steve

    2016-01-01

    Excessive soil nutrients, often from agricultural runoff, have been shown to negatively impact some aspects of wetland plant communities. We measured plant-available phosphorus (Mehlich-3: MeP) in soil samples, and assessed the vascular plant community and habitat degradation at 27 emergent and 13 forested wetlands in Ohio, USA. We tested two hypotheses: (1) that an index of vegetation biological integrity based on floristic quality was lower in wetlands with higher concentrations of MeP in the soil, and (2) that higher concentrations of MeP occurred in wetlands with more habitat degradation (i.e., lower quality), as estimated by a rapid assessment method. Hypothesis (1) was supported for emergent, but not for forested wetlands. Hypothesis (2) was marginally supported (P = 0.09) for emergent, but not supported for forested wetlands. The results indicate that the effect of concentration of phosphorus in wetland soils and the quality of plant species assemblages in wetlands is more complex than shown in site-specific studies and may depend in part on degree of disturbance in the surrounding watershed and dominant wetland vegetation type. Woody plants in forested wetlands are typically longer lived than herbaceous species in the understory and emergent wetlands, and may persist despite high inputs of phosphorus. Further, the forested wetlands were typically surrounded by a wide band of forest vegetation, which may provide a barrier against sedimentation and the associated phosphorus inputs to the wetland interior. Our results indicate that inferences about soil nutrient conditions made from rapid assessment methods for assessing wetland habitat condition may not be reliable.

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

    SciTech Connect

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

    2010-11-01

    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.

  4. Education and training of future wetland scientists and managers

    USGS Publications Warehouse

    Wilcox, D.A.

    2008-01-01

    Wetland science emerged as a distinct discipline in the 1980s. In response, courses addressing various aspects of wetland science and management were developed by universities, government agencies, and private firms. Professional certification of wetland scientists began in the mid-1990s to provide confirmation of the quality of education and experience of persons involved in regulatory, management, restoration/construction, and research involving wetland resources. The education requirements for certification and the need for persons with specific wetland training to fill an increasing number of wetland-related positions identified a critical need to develop curriculum guidelines for an undergraduate wetland science and management major for potential accreditation by the Society of Wetland Scientists. That proposed major contains options directed toward either wetland science or management. Both options include required basic courses to meet the general education requirements of many universities, required upper-level specialized courses that address critical aspects of physical and biological sciences applicable to wetlands, and a minimum of four additional upper-level specialized courses that can be used to tailor a degree to students' interests. The program would be administered by an independent review board that would develop guidelines and evaluate university applications for accreditation. Students that complete the required coursework will fulfill the education requirements for professional wetland scientist certification and possess qualifications that make them attractive candidates for graduate school or entry-level positions in wetland science or management. Universities that offer this degree program could gain an advantage in recruiting highly qualified students with an interest in natural resources. Alternative means of educating established wetland scientists are likewise important, especially to provide specialized knowledge and experience or

  5. Nature and transformation of dissolved organic matter in treatment wetlands.

    PubMed

    Barber, L B; Leenheer, J A; Noyes, T I; Stiles, E A

    2001-12-15

    This investigation into the occurrence, character, and transformation of dissolved organic matter (DOM) in treatment wetlands in the western United States shows that (i) the nature of DOM in the source water has a major influence on transformations that occur during treatment, (ii) the climate factors have a secondary effect on transformations, (iii) the wetlands receiving treated wastewater can produce a net increase in DOM, and (iv) the hierarchical analytical approach used in this study can measure the subtle DOM transformations that occur. As wastewater treatment plant effluent passes through treatment wetlands, the DOM undergoes transformation to become more aromatic and oxygenated. Autochthonous sources are contributed to the DOM, the nature of which is governed by the developmental stage of the wetland system as well as vegetation patterns. Concentrations of specific wastewater-derived organic contaminants such as linear alkylbenzene sulfonate, caffeine, and ethylenediaminetetraacetic acid were significantly attenuated by wetland treatment and were not contributed by internal loading.

  6. Nature and transformation of dissolved organic matter in treatment wetlands

    USGS Publications Warehouse

    Barber, L.B.; Leenheer, J.A.; Noyes, T.I.; Stiles, E.A.

    2001-01-01

    This investigation into the occurrence, character, and transformation of dissolved organic matter (DOM) in treatment wetlands in the western United States shows that (i) the nature of DOM in the source water has a major influence on transformations that occur during treatment, (ii) the climate factors have a secondary effect on transformations, (iii) the wetlands receiving treated wastewater can produce a net increase in DOM, and (iv) the hierarchical analytical approach used in this study can measure the subtle DOM transformations that occur. As wastewater treatment plant effluent passes through treatment wetlands, the DOM undergoes transformation to become more aromatic and oxygenated. Autochthonous sources are contributed to the DOM, the nature of which is governed by the developmental stage of the wetland system as well as vegetation patterns. Concentrations of specific wastewaterderived organic contaminants such as linear alkylbenzene sulfonate, caffeine, and ethylenediaminetetraacetic acid were significantly attenuated by wetland treatment and were not contributed by internal loading.

  7. Application of LiDAR's multiple attributes for wetland classification

    NASA Astrophysics Data System (ADS)

    Ding, Qiong; Ji, Shengyue; Chen, Wu

    2016-03-01

    Wetlands have received intensive interdisciplinary attention as a unique ecosystem and valuable resources. As a new technology, the airborne LiDAR system has been applied in wetland research these years. However, most of the studies used only one or two LiDAR observations to extract either terrain or vegetation in wetlands. This research aims at integrating LiDAR's multiple attributes (DSM, DTM, off-ground features, Slop map, multiple pulse returns, and normalized intensity) to improve mapping and classification of wetlands based on a multi-level object-oriented classification method. By using this method, we are able to classify the Yellow River Delta wetland into eight classes with overall classification accuracy of 92.5%

  8. Assessment of nutrient retention by Natete wetland Kampala, Uganda

    NASA Astrophysics Data System (ADS)

    Kanyiginya, V.; Kansiime, F.; Kimwaga, R.; Mashauri, D. A.

    Natete wetland which is located in a suburb of Kampala city in Uganda is dominated by C yperus papyrus and covers an area of approximately 1 km 2. The wetland receives wastewater and runoff from Natete town which do not have a wastewater treatment facility. The main objective of this study was to assess nutrient retention of Natete wetland and specifically to: determine the wastewater flow patterns in the wetland; estimate the nutrient loads into and out of the wetland; determine the nutrient retention by soil, plants and water column in the wetland; and assess the above and belowground biomass density of the dominant vegetation. Soil, water and plant samples were taken at 50 m intervals along two transects cut through the wetland; soil and water samples were taken at 10 cm just below the surface. Physico-chemical parameters namely pH, electrical conductivity and temperature were measured in situ. Water samples were analyzed in the laboratory for ammonium-nitrogen, nitrate-nitrogen, total nitrogen, orthophosphate and total phosphorus. Electrical conductivity ranged between 113 μS/cm and 530 μS/cm and the wastewater flow was concentrated on the eastern side of the wetland. pH varied between 6 and 7, temperature ranged from 19 °C to 24 °C. NH 4-N, NO 3-N, and TN concentrations were retained by 21%, 98%, and 35% respectively. Phosphorus concentration was higher at the outlet of the wetland possibly due to release from sediments and leaching. Nutrient loads were higher at the inlet (12,614 ± 394 kgN/day and 778 ± 159 kgP/day) than the outlet (2368 ± 425 kgN/day and 216 ± 56 kgP/day) indicating retention by the wetland. Plants stored most nutrients compared to soil and water. The belowground biomass of papyrus vegetation in the wetland was higher (1288.4 ± 8.3 gDW/m 2) than the aboveground biomass (1019.7 ± 13.8 gDW/m 2). Plant uptake is one of the important routes of nutrient retention in Natete wetland. It is recommended that harvesting papyrus can be an

  9. Experiences with constructed wetland systems in Korea

    NASA Astrophysics Data System (ADS)

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

    2006-10-01

    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.

  10. Exploring Policy Options to Stop the Loss of Wetlands on Prairie Landscapes

    NASA Astrophysics Data System (ADS)

    Serran, J.; Creed, I. F.

    2013-12-01

    Wetlands from the prairie pothole region of North America have been disappearing at rapid rates over the past century. Within Canada, the issue of wetland loss is compounded by the lack of high resolution wetland inventories, the lack of information on rates of wetland loss, and the absence of wetland policies to further protect against loss. In Alberta, the situation is particularly problematic as increasing development pressures continue to place wetlands at risk. The 'no net loss' of wetlands policy established in 1993 has been ineffective, as wetland loss has continued, leaving Albertans searching for alternative policy options. An alternative policy option is to shift focus from wetland area to wetland function. We present a wetland function assessment system founded on ecological and hydrological processes for estimating wetland functions, including biodiversity, flood control, and pollution reduction, for a regional watershed in Alberta. First, we establish wetland loss rates using inventory time series from 1960 to present; wetland loss estimates can be derived from a break in slope in the area-frequency relationship. Second, we create a high-resolution wetland inventory using a novel approach that fuses LiDAR data (probability of wetland) with aerial photographs (to distinguish open water and the surrounding wet meadow zone). Third, using this wetland inventory, we identify indicators of wetland function using GIS and remote sensing data and technologies for application at regional watershed scales. Biodiversity indicators include a wetland's condition, ability to provide habitat, and potential for high ecological diversity. Flood control indicators include a wetland's ability to store water, connect to surface drainage network, and desynchronize flood waves throughout the landscape. Pollution control indicators include a wetland's contributing source area of nutrients, mechanisms that transport nutrients to the wetland, and mechanisms that retain

  11. National Wetlands Inventory products

    USGS Publications Warehouse

    ,

    1998-01-01

    control. These predominantly wet areas, or wetlands as they are commonly called, now represent only about 5 percent of the land surface of the lower 48 States. Out of 221 million acres of wetlands that once existed in the conterminous United States, the U.S. Fish and Wildlife Service (FWS) estimates that only about 103.3 million acres remain. Each year, development, drainage, and agriculture eliminate another 290,000 acres-an area a little less than half the size of Rhode Island. From the 1950's to the 1970's, conversion of wetlands to farmland caused 87 percent of all wetland losses. The FWS has long recognized the importance of America's wetlands because they form breeding and wintering grounds for great numbers of migratory birds. In 1977, the FWS began the National Wetlands Inventory (NWI), a systematic effort to classify and map America's remaining wetlands.

  12. 1997 Monitoring report for the Gunnison, Colorado Wetlands Mitigation Plan

    SciTech Connect

    1997-11-01

    Under the Uranium Mill Tailings Remedial Action (UMTRA) Project, the U.S. Department of Energy (DOE) cleaned up uranium mill tailings and other surface contamination near the town of Gunnison, Colorado. Remedial action resulted in the elimination of 4.3 acres (ac) (1.7 hectares [ha]) of wetlands. This loss is mitigated by the enhancement of six spring-fed areas on Bureau of Land Management (BLM) land (mitigation sites). Approximately 254 ac (1 03.3 ha) were fenced at the six sites to exclude grazing livestock. Of the 254 ac (103.3 ha), 17.8 ac (7.2 ha) are riparian plant communities; the rest are sagebrush communities. Baseline grazed conditions of the riparian plant communities at the mitigation sites were measured prior to fencing. This report discusses results of the fourth year of a monitoring program implemented to document the response of vegetation and wildlife to the exclusion of livestock. Three criteria for determining success of the mitigation were established: plant height, vegetation density (bare ground), and vegetation diversity. By 1996, Prospector Spring, Upper Long`s Gulch, and Camp Kettle met the criteria. The DOE requested transfer of these sites to BLM for long-term oversight. The 1997 evaluation of the three remaining sites, discussed in this report, showed two sites (Houston Gulch and Lower Long`s Gulch) meet the criteria. The DOE will request the transfer of these two sites to the BLM for long-term oversight. The last remaining site, Sage Hen Spring, has met only two of the criteria (percent bare ground and plant height). The third criterion, vegetation diversity, was not met. The vegetation appears to be changing from predominantly wet species to drier upland species, although the reason for this change is uncertain. It may be due to below-normal precipitation in recent years, diversion of water from the spring to the stock tank, or manipulation of the hydrology farther up gradient.

  13. Trends in agricultural impact and recovery of wetlands in prairie Canada.

    PubMed

    Bartzen, Blake A; Dufour, Kevin W; Clark, Robert G; Caswell, F Dale

    2010-03-01

    Despite widespread recognition that they provide valuable ecosystem services and contribute significantly to global biodiversity, over half of the world's wetlands have been lost, primarily to agriculture. Wetland loss is evident in prairie Canada, but comprehensive information about causes of ongoing impact for existing wetlands is lacking. Habitat data collected for approximately 10,500 wetlands during annual waterfowl surveys (1985-2005) were analyzed using multistate models to estimate rates of wetland impact and recovery from agricultural activities in the Canadian prairies. An impact was defined as an agricultural activity that visibly altered a wetland margin (natural vegetation surrounding wetland interiors) or basin (interior depression capable of holding water), whereas recovery was deemed to have occurred if agricultural activities had ceased and effects were no longer visibly apparent. We estimated separate impact and recovery rates for wetland basins and wetland margins and considered covariates such as location, time, wetness indices, land use, and wetland permanence. Results indicate that impact rates for wetland margins have declined over time, likely due to a decreasing percentage of unaffected wetlands on the landscape. Recovery rates for margins were always lower than impact rates, suggesting progressive incidence of impacts to wetlands over time. Unlike margins, impact and recovery rates for basins fluctuated with May pond densities, which we used as a wetness index. Shallow ephemeral wetlands located in agricultural fields had the highest impact and lowest recovery rates relative to wetlands with higher water permanence or situated in areas of lower agricultural intensity. High rates and incidence of wetland impact in conjunction with low recovery rates clearly demonstrate the need for stronger wetland protection in prairie Canada.

  14. Wetland habitat disturbance best predicts metrics of an amphibian index of biotic integrity

    USGS Publications Warehouse

    Stapanian, Martin A.; Micacchion, Mick; Adams, Jean V.

    2015-01-01

    Regression and classification trees were used to identify the best predictors of the five component metrics of the Ohio Amphibian Index of Biotic Integrity (AmphIBI) in 54 wetlands in Ohio, USA. Of the 17 wetland- and surrounding landscape-scale variables considered, the best predictor for all AmphIBI metrics was habitat alteration and development within the wetland. The results were qualitatively similar to the best predictors for a wetland vegetation index of biotic integrity, suggesting that similar management practices (e.g., reducing or eliminating nutrient enrichment from agriculture, mowing, grazing, logging, and removing down woody debris) within the boundaries of the wetland can be applied to effectively increase the quality of wetland vegetation and amphibian communities.

  15. Resilience of coastal wetlands to extreme hydrologic events in Apalachicola Bay

    NASA Astrophysics Data System (ADS)

    Tahsin, Subrina; Medeiros, Stephen C.; Singh, Arvind

    2016-07-01

    Extreme hydrologic events such as hurricanes and droughts continuously threaten wetlands which provide key ecosystem services in coastal areas. The recovery time for vegetation after impact from these extreme events can be highly variable depending on the hazard type and intensity. Apalachicola Bay in Florida is home to a rich variety of saltwater and freshwater wetlands and is subject to a wide range of hydrologic hazards. Using spatiotemporal changes in Landsat-based empirical vegetation indices, we investigate the impact of hurricane and drought on both freshwater and saltwater wetlands from year 2000 to 2015 in Apalachicola Bay. Our results indicate that saltwater wetlands are more resilient than freshwater wetlands and suggest that in response to hurricanes, the coastal wetlands took almost a year to recover, while recovery following a drought period was observed after only a month.

  16. Using Landsat MSS data with soils information to identify wetland habitats

    NASA Technical Reports Server (NTRS)

    Ernst, C. L.; Hoffer, R. M.

    1981-01-01

    A previous study showed that certain fresh water wetland vegetation types can be spectrally separated when a maximum likelihood classification procedure is applied to Landsat spectral data. However, wetland and upland types which have similar vegetative life forms (e.g., upland hardwoods and hardwood swamps) are often confused because of spectral similarity. Therefore, the current investigation attempts to differentiate similar wetland and upland types by combining Landsat multispectral scanner (MSS) data with soils information. The Pigeon River area in northern Indiana used in the earlier study was also employed in this investigation. A layered classification algorithm which combined soils and spectral data was used to generate a wetland classification. The results of the spectral/soils wetland classification are compared to the previous classification that had been based on spectral data alone. The results indicate wetland habitat mapping can be improved by combining soils and other ancillary data with Landsat spectral data.

  17. Anacostia River fringe wetlands restoration project: final report for the five-year monitoring program (2003 through 2007)

    USGS Publications Warehouse

    Krafft, Cairn C.; Hammerschlag, Richard S.; Guntenspergen, Glenn R.

    2009-01-01

    The 6-hectare (ha) freshwater tidal Anacostia River Fringe Wetlands (Fringe Wetlands) were reconstructed along the mainstem of the Anacostia River in Washington, DC (Photograph 1, Figure 1) during the summer of 2003. The Fringe Wetlands consist of two separate planting cells. Fringe A, located adjacent to Lower Kingman Island, on the west bank of the Anacostia River, occupies 1.6 ha; Fringe B, located on the east bank of the Anacostia River, occupies 4.4 ha. This project is the third in a series of freshwater tidal wetland reconstructions on the Anacostia River designed and implemented by the US Army Corps of Engineers (USACE) Baltimore District and District Department of the Environment (DDOE) on lands managed by the National Park Service (NPS). The first was Kenilworth Marsh, reconstructed in 1993 (Syphax and Hammerschlag 2005); the second was Kingman Marsh, reconstructed in 2000 (Hammerschlag et al. 2006). Kenilworth and Kingman were both constructed in low-energy backwaters of the Anacostia. However, the Fringe Wetlands, which were constructed on two pre-existing benches along the high-energy mainstem, required sheet piling to provide protection from erosive impacts of increased flow and volume of water associated with storm events during the establishment phase (Photograph 2). All three projects required the placement of dredged sediment materials to increase elevations enough to support emergent vegetation (Photograph 3). The purpose of all three wetland reconstruction projects was to restore pieces of the once extensive tidal freshwater marsh habitat that bordered the Anacostia River historically, prior to the dredge and fill operations and sea wall installation that took place there in the early to mid-1900's (Photograph 4).

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

    SciTech Connect

    1995-10-01

    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.

  19. Ecosystem attributes related to tidal wetland effects on water quality.

    PubMed

    Findlay, S; Fischer, D

    2013-01-01

    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.

  20. Highlights and overview of the 2011 National Wetland ...

    EPA Pesticide Factsheets

    This presentation is for a webinar sponsored by the Society of Wetland Scientists. It is tailored to a technical audience with research interests in wetland ecology and management. The talk will introduce the National Aquatic Resource Surveys and then transition to a discussion of the methods, results, and applications of the National Wetland Condition Assessment. It is tailored The first National Wetland Condition Assessment (NWCA) was completed in 2011 and the results will be released to the public in 2016. A team of scientists from ORD played a major role in designing the survey, analyzing the data, and reporting on the results of the assessment in cooperation with the Office of Water. The analysis team also developed quantitative national and regional definitions of reference in terms of least disturbed condition. This presentation provides a summary of the major results, examples of their utility to resource management and implications to wetland policy. About 50% of the wetland area nationally was found to be in good biological condition while about 30% was in poor condition. The stressors with the greatest areal extent nationally were vegetation removal, hardening (e.g., roads, paths, extreme soil compaction), and ditching. A relative risk analysis indicated a strong relationship between high levels of nearly all the stressors measured (i.e., vegetation removal, hardening, ditching, damming, filling/erosion, and vegetation replacement) and poor bi

  1. Wetlands in changed landscapes: the influence of habitat transformation on the physico-chemistry of temporary depression wetlands.

    PubMed

    Bird, Matthew S; Day, Jenny A

    2014-01-01

    Temporary wetlands dominate the wet season landscape of temperate, semi-arid and arid regions, yet, other than their direct loss to development and agriculture, little information exists on how remaining wetlands have been altered by anthropogenic conversion of surrounding landscapes. This study investigates relationships between the extent and type of habitat transformation around temporary wetlands and their water column physico-chemical characteristics. A set of 90 isolated depression wetlands (seasonally inundated) occurring on coastal plains of the south-western Cape mediterranean-climate region of South Africa was sampled during the winter/spring wet season of 2007. Wetlands were sampled across habitat transformation gradients according to the areal cover of agriculture, urban development and alien invasive vegetation within 100 and 500 m radii of each wetland edge. We hypothesized that the principal drivers of physico-chemical conditions in these wetlands (e.g. soil properties, basin morphology) are altered by habitat transformation. Multivariate multiple regression analyses (distance-based Redundancy Analysis) indicated significant associations between wetland physico-chemistry and habitat transformation (overall transformation within 100 and 500 m, alien vegetation cover within 100 and 500 m, urban cover within 100 m); although for significant regressions the amount of variation explained was very low (range: ∼2 to ∼5.5%), relative to that explained by purely spatio-temporal factors (range: ∼35.5 to ∼43%). The nature of the relationships between each type of transformation in the landscape and individual physico-chemical variables in wetlands were further explored with univariate multiple regressions. Results suggest that conservation of relatively narrow (∼100 m) buffer strips around temporary wetlands is likely to be effective in the maintenance of natural conditions in terms of physico-chemical water quality.

  2. Wetlands in Changed Landscapes: The Influence of Habitat Transformation on the Physico-Chemistry of Temporary Depression Wetlands

    PubMed Central

    Bird, Matthew S.; Day, Jenny A.

    2014-01-01

    Temporary wetlands dominate the wet season landscape of temperate, semi-arid and arid regions, yet, other than their direct loss to development and agriculture, little information exists on how remaining wetlands have been altered by anthropogenic conversion of surrounding landscapes. This study investigates relationships between the extent and type of habitat transformation around temporary wetlands and their water column physico-chemical characteristics. A set of 90 isolated depression wetlands (seasonally inundated) occurring on coastal plains of the south-western Cape mediterranean-climate region of South Africa was sampled during the winter/spring wet season of 2007. Wetlands were sampled across habitat transformation gradients according to the areal cover of agriculture, urban development and alien invasive vegetation within 100 and 500 m radii of each wetland edge. We hypothesized that the principal drivers of physico-chemical conditions in these wetlands (e.g. soil properties, basin morphology) are altered by habitat transformation. Multivariate multiple regression analyses (distance-based Redundancy Analysis) indicated significant associations between wetland physico-chemistry and habitat transformation (overall transformation within 100 and 500 m, alien vegetation cover within 100 and 500 m, urban cover within 100 m); although for significant regressions the amount of variation explained was very low (range: ∼2 to ∼5.5%), relative to that explained by purely spatio-temporal factors (range: ∼35.5 to ∼43%). The nature of the relationships between each type of transformation in the landscape and individual physico-chemical variables in wetlands were further explored with univariate multiple regressions. Results suggest that conservation of relatively narrow (∼100 m) buffer strips around temporary wetlands is likely to be effective in the maintenance of natural conditions in terms of physico-chemical water quality. PMID:24533161

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  4. Laboratory measurements of wave attenuation through model and live vegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surge and waves generated by hurricanes and tropical storms often cause severe damage and loss of life in coastal areas. It is widely recognized that wetlands along coastal fringes reduce storm surge and waves. Yet, the potential role and primary mechanisms of wave mitigation by wetland vegetation a...

  5. Experimental investigation of wave attenuation through model and live vegetation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hurricanes and tropical storms often cause severe damage and loss of life in coastal areas. It is widely recognized that wetlands along coastal fringes reduce storm surge and waves. Yet, the potential role and primary mechanisms of wave mitigation by wetland vegetation are not fully understood. K...

  6. Freshwater Wetlands: A Citizen's Primer.

    ERIC Educational Resources Information Center

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

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

  7. Removal of metals in constructed wetlands

    SciTech Connect

    Crites, R.W.; Watson, R.C.; Williams, C.R.

    1996-12-31

    Trace metals are difficult to remove from municipal wastewater by conventional wastewater treatment methods. Constructed wetlands have the potential to trap and remove metals from the water column. Long term removal is expected to occur by accumulation and burial in the plant detritus in a manner similar to the removal of phosphorus. Few data are available in the literature on removal of metals by constructed wetlands. A free water surface constructed wetland at Sacramento Regional Wastewater Treatment Plant treating secondary municipal effluent has been operating since the spring of 1994. Removal data for 13 metals are presented for the period from August 1994 to May 1995. About 3,785 m{sup 3}/d (1 mgd) of pure oxygen activated sludge effluent, disinfected using UV light, is further treated through a 8 ha (20 acre) constructed wetlands Ten separate, parallel treatment cells are available to demonstrate the effects of detention time, vegetation management, and application frequency on the removal of metals, organics and ammonia. Detention time can be varied from 3 to 13 days by varying the flow and the water depth. The vegetation, primarily bulrush with some cattails, will be managed by different techniques to minimize mosquito production. Application frequency varies from continuous flow to batch flow (1 to 2 days of loading with 1 day of discharge).

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

    PubMed

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

    2010-05-01

    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.

  9. Interim Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Alaska Region

    DTIC Science & Technology

    2006-02-01

    Sampling wetland cryptogams Background. Cryptogams, defined here as bryophytes (mosses, liverworts, hornworts), lichens, and fungi, form extensive...abundant, constitute a nearly “test positive” indicator of hydrophytic vegetation. Wetland-specialist bryophytes were defined as those having ≥67...percent frequency of occurrence in these wetland types. When one or more of these species comprise >50 percent of the total bryophyte cover, the

  10. Wetlands Assessment for site characterization, Advanced Neutron Source (ANS)

    SciTech Connect

    Wade, M.C.; Socolof, M.L.; Rosensteel, B.; Awl, D.

    1994-10-01

    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.

  11. Assessing avian richness in remnant wetlands: Towards an improved methodology

    USGS Publications Warehouse

    Krzys, Greg; Waite, Thomas A.; Stapanian, Martin; Vucetich, John A.

    2002-01-01

    Because the North American Breeding Bird Survey provides inadequate coverage of wetland habitat, the Wetland Breeding Bird Survey was recently established in Ohio, USA. This program relies on volunteers to conduct 3 counts at each monitored wetland. Currently, all counts are conducted during the morning. Under the premise that volunteer participation could be increased by allowing evening counts, we evaluated the potential for modifying the methodology. We evaluated the sampling efficiency of all 3-count combinations of morning and evening counts using data collected at 14 wetlands. Estimates of overall species richness decreased with increasing numbers of evening counts. However, this pattern did not hold when analyses were restricted to wetland-dependent species or those of conservation concern. Our findings suggest that it would be reasonable to permit evening counts, particularly if the data are to be used to monitor wetland dependent species and those of concern.

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

    NASA Astrophysics Data System (ADS)

    Faubert, Jean-Pascal R.

    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.

  13. Evaluation of surface water dynamics for water-food security in seasonal wetlands, north-central Namibia

    NASA Astrophysics Data System (ADS)

    Hiyama, T.; Suzuki, T.; Hanamura, M.; Mizuochi, H.; Kambatuku, J. R.; Niipele, J. N.; Fujioka, Y.; Ohta, T.; Iijima, M.

    2014-09-01

    Agricultural use of wetlands is important for food security in various regions. However, land-use changes in wetland areas could alter the water cycle and the ecosystem. To conserve the water environments of wetlands, care is needed when introducing new cropping systems. This study is the first attempt to evaluate the water dynamics in the case of the introduction of rice-millet mixed-cropping systems to the Cuvelai system seasonal wetlands (CSSWs) in north-central Namibia. We first investigated seasonal changes in surface water coverage by using satellite remote sensing data. We also assessed the effect of the introduction of rice-millet mixed-cropping systems on evapotranspiration in the CSSWs region. For the former investigation, we used MODIS and AMSR-E satellite remote sensing data. These data showed that at the beginning of the wet season, surface water appears from the southern (lower) part and then expands to the northern (higher) part of the CSSWs. For the latter investigation, we used data obtained by the classical Bowen ratio-energy balance (BREB) method at an experimental field site established in September 2012 on the Ogongo campus, University of Namibia. This analysis showed the importance of water and vegetation conditions when introducing mixed-cropping to the region.

  14. Analyzing surface water budgets for water-food security in seasonal wetlands of north-central Namibia

    NASA Astrophysics Data System (ADS)

    Hiyama, T.; Mizuochi, H.; Kanamori, H.; Fujioka, Y.; Kambatuku, J. R.; Kotani, A.; Ohta, T.; Iijima, M.

    2015-12-01

    This study aims to evaluate the water budgets in case of the introduction of rice-millet mixed-cropping systems (flood- and drought-adaptive cropping systems) to the Cuvelai system seasonal wetlands (CSSWs) in north-central Namibia. To achieve this goal, we at first investigated seasonal changes in surface water coverage by using satellite remote sensing data. For this investigation, we used MODIS and AMSR-E satellite remote sensing data. These data showed that at the beginning of the wet season, surface water appears from the southern (lower) part and then expands to the northern (higher) part of the CSSWs. We also assessed the effect of the introduction of rice-millet mixed-cropping systems on evapotranspiration in the CSSWs region. For this investigation, we used data obtained by the Bowen ratio-energy balance (BREB) method at an experimental field site established in September 2012 on the Ogongo campus, University of Namibia. This analysis showed the importance of water and vegetation conditions when introducing mixed-cropping to the region. Finally, in order to understand water sources of small wetlands in the CSSWs, stable isotopic ratio of water (precipitation, surface-, and subsurface-water) were analyzed. This analysis showed that shallow groundwater of small wetlands is very likely to be recharged from surface-water, source of which was local precipitation and was pooled in lowest part of small wetlands.

  15. Removal processes for arsenic in constructed wetlands.

    PubMed

    Lizama A, Katherine; Fletcher, Tim D; Sun, Guangzhi

    2011-08-01

    Arsenic pollution in aquatic environments is a worldwide concern due to its toxicity and chronic effects on human health. This concern has generated increasing interest in the use of different treatment technologies to remove arsenic from contaminated water. Constructed wetlands are a cost-effective natural system successfully used for removing various pollutants, and they have shown capability for removing arsenic. This paper reviews current understanding of the removal processes for arsenic, discusses implications for treatment wetlands, and identifies critical knowledge gaps and areas worthy of future research. The reactivity of arsenic means that different arsenic species may be found in wetlands, influenced by vegetation, supporting medium and microorganisms. Despite the fact that sorption, precipitation and coprecipitation are the principal processes responsible for the removal of arsenic, bacteria can mediate these processes and can play a significant role under favourable environmental conditions. The most important factors affecting the speciation of arsenic are pH, alkalinity, temperature, dissolved oxygen, the presence of other chemical species--iron, sulphur, phosphate--,a source of carbon, and the wetland substrate. Studies of the microbial communities and the speciation of arsenic in the solid phase using advanced techniques could provide further insights on the removal of arsenic. Limited data and understanding of the interaction of the different processes involved in the removal of arsenic explain the rudimentary guidelines available for the design of wetlands systems.

  16. FUNDAMENTAL INVESTIGATION ON CONSTRUCTED WETLAND DESIGN FOR WASTE WATER PURIFICATION

    NASA Astrophysics Data System (ADS)

    Ishikawa, Tadaharu; Gao, Shuang

    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.

  17. Spread dynamics of perennial pepperweed (Lepidium latifolium) in two seasonal wetland areas

    USGS Publications Warehouse

    Renz, Mark J.; Steinmaus, Scott J.; Gilmer, David S.; DiTomaso, Joseph M.

    2012-01-01

    Perennial pepperweed is an invasive plant that is expanding rapidly in several plant communities in the western United States. In California, perennial pepperweed has aggressively invaded seasonal wetlands, resulting in degradation of habitat quality. We evaluated the rate and dynamics of population spread, assessed the effect of disturbance on spread, and determined the biotic and abiotic factors influencing the likelihood of invasion. The study was conducted at eight sites within two wetland regions of California. Results indicate that in undisturbed sites, spread was almost exclusively through vegetative expansion, and the average rate of spread was 0.85 m yr−1 from the leading edge. Spread in sites that were disked was more than three times greater than in undisturbed sites. While smaller infestations increased at a faster rate compared with larger populations, larger infestations accumulated more newly infested areas than smaller infestations from year to year. Stem density was consistently higher in the center of the infestations, with about 2.4 times more stems per square meter compared with the leading edge at the perimeter of the population. The invasion by perennial pepperweed was positively correlated with increased water availability but was negatively correlated with the cover of perennial and annual species. Thus, high cover of resident vegetation can have a suppressive effect on the rate of invasion, even in wetland ecosystems. On the basis of these results, we recommend that resident plant cover not be disturbed, especially in wet areas adjacent to areas currently infested with perennial pepperweed. For infested areas, management efforts should be prioritized to focus on controlling satellite populations as well as the leading edge of larger infestations first. This strategy could reduce the need for costly active restoration efforts by maximizing the probability of successful re-establishment of resident vegetation from the adjacent seedbank.

  18. Three responses of wetland conditions to climatic extremes in the Prairie Pothole Region

    USGS Publications Warehouse

    Cressey, Ryann L.; Austin, Jane; Stafford, Joshua D.

    2016-01-01

    Wetlands in central North Dakota were revisited after 50 years to assess changes following extreme drought and a prolonged wet period. We compared data collected during 1961–1966 to current (2013–2014) wetland conditions. We revisited 80 wetlands in 2013 and 2014 across three study areas and measured wetland area, ponded-water depth, and specific conductance. Wetlands at the three study areas responded to prolonged wet conditions in one of three ways. Wetlands at Crystal Springs became larger, and had deeper ponds of lower specific conductance in 2013–14 compared to the 1960s. Wetlands at Cottonwood were larger with deeper ponds of slightly higher specific conductance in 2013–2014. Wetlands at Mt. Moriah had only subtle changes in size, pond depth, and specific conductance between periods. Prolonged wet conditions led to merging of most wetlands (defined as the outer edge of wet-meadow vegetation) at Crystal Springs and a few wetlands at Cottonwood. Low topographic relief at Crystal Springs and Cottonwood contributed to storage of excess water in wetlands with associated responses to prolonged wet conditions. In contrast, higher topographic relief and natural outlets into two intermittent streams at Mt. Moriah resulted in wetlands being less impacted by prolonged wet conditions.

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

    USGS Publications Warehouse

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

    2009-01-01

    Comparing altered wetlands to natural wetlands in the same region improves the ability to interpret the gradual and cumulative effects of human development on freshwater wetlands. Hydrologic differences require explicit attention because they affect nearly all wetland functions and are an overriding influence on other comparisons involving wetland water quality and ecology. This study adopts several new approaches to quantify wetland hydrologic characteristics and then describes and compares the hydrology, water quality, and ecology of 10 isolated freshwater marsh and cypress wetlands in the mantled karst landscape of central Florida. Four of the wetlands are natural, and the other six have water levels indirectly lowered by ground-water withdrawals on municipally owned well fields. For several decades, the water levels in four of these altered wetlands have been raised by adding ground water in a mitigation process called augmentation. The two wetlands left unaugmented were impaired because their water levels were lowered. Multifaceted comparisons between the altered and natural wetlands are used to examine differences between marshes and cypress wetlands and to describe the effects of augmentation practices on the wetland ecosystems. In the karstic geologic setting, both natural and altered wetlands predominantly lost water to the surficial aquifer. Water leaking out of the wetlands created water-table mounds below the wetlands. The smallest mounds radiated only slightly beyond the vegetated area of the wetlands. The largest and steepest mounds occurred below two of the augmented wetlands. There, rapid leakage rates regenerated a largely absent surficial aquifer and mounds encompassed areas 7-8 times as large as the wetlands. Wetland leakage rates, estimated using a daily water-budget analysis applied over multiple years and normalized as inches per day, varied thirtyfold from the slowest leaking natural wetland to the fastest leaking augmented wetland. Leakage

  20. Ecological risk assessment of a wetland exposed to boron

    SciTech Connect

    Powell, R.L.; Kimerle, R.A.; Coyle, G.T.; Best, G.R.

    1997-11-01

    A wetland located in the southeastern portion of the United States was the site of an investigation to determine the potential ecological risk of elevated boron concentrations to the flora and fauna living in the wetland. The conceptual model identified the vegetation as the primary receptor of concern, and thus the vegetation is the focus of this article. Samples of surface water, sediments, and selected vegetation were collected from the study wetland and several nearby reference sites and were analyzed for boron. Concentrations of boron in all three media exceeded reference site concentrations. Boron concentrations were highest near the suspected source but decreased almost to reference-site concentrations near the outer perimeter of the wetland. Some plants appeared stressed with yellowing and necrotic leaves; however, a correlation between tissue boron concentrations and the plant`s visual appearance was not apparent for all species studied. Modeling of the fate of boron indicated that the wetland has likely been at a steady state for many years and that boron concentrations were not expected to increase. It was concluded that no observable adverse ecological impacts to the vegetation could be attributed to boron, nor is it likely that the boron poses an unacceptable risk to the surrounding areas.

  1. Use of macroinvertebrates to identify cultivated wetlands in the Prairie Pothole Region

    USGS Publications Warehouse

    Euliss, Ned H.; Mushet, David M.; Johnson, Douglas H.

    2001-01-01

    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.

  2. The ecological value of constructed wetlands for treating urban runoff.

    PubMed

    Pankratz, S; Young, T; Cuevas-Arellano-, H; Kumar, R; Ambrose, R F; Suffet, I H

    2007-01-01

    The Sweetwater Authority's urban runoff diversion system (URDS) comprises constructed wetlands on a hillside between the town of Spring Valley and the Sweetwater Reservoir, California, USA. The URDS were designed to divert dry-weather and first-flush urban runoff flows from the Sweetwater reservoir. However, these constructed wetlands have developed into ecologically valuable habitat. This paper evaluates the following ecological questions related to the URDS: (1) the natural development of the species present and their growth pattern; (2) the biodiversity and pollutant stress on the plants and invertebrates; and (3) the question of habitat provided for endangered species. The URDS wetlands are comprised primarily of rush (Scirpus spp.) and cattails (Typha spp.). This vegetative cover ranged from 39-78% of the area of the individual wetland ponds. Current analyses of plant tissues and wetland sediment indicates the importance of sediment sorption for metals and plant uptake of nutrients. Analyses of URDS water following runoff events show the URDS wetlands do reduce the amount of nutrients and metals in the water column. Invertebrate surveys of the wetland ponds revealed lower habitat quality and environmental stress compared to unpolluted natural habitat. The value of the wetlands as wildlife habitat is constrained by low plant biodiversity and pollution stress from the runoff. Since the primary Sweetwater Authority goal is to maintain good water quality for drinking, any secondary utilization of URDS habitat by species (endangered or otherwise) is deemed an added benefit.

  3. Agricultural Encroachment: Implications for Carbon Sequestration in Tropical African Wetlands

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  4. Classifying and mapping wetlands and peat resources using digital cartography

    USGS Publications Warehouse

    Cameron, Cornelia C.; Emery, David A.

    1992-01-01

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

  5. Current Issues in Alaska Wetland Management

    DTIC Science & Technology

    1994-08-01

    relative to longitude and vary widely in origin, substrate and precipitation, the drainage is impeded by perma- ecosystem properties. They occur in... ecology of tundra ponds has been North Slope (Arctic coastal plain). Vegetation, as "translated" by Hobbie (1984) into a wet- interpieted on color...widespread recognition kan wetlands is generally recognized as related to that Alaskan plant species have broad ecological habitat and food chain

  6. Using aquatic invertebrates to delineate seasonal and temporary wetlands in the Prairie Pothole Region of North America

    USGS Publications Warehouse

    Euliss, Ned H.; Mushet, David M.; Johnson, Douglas H.

    2002-01-01

    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.

  7. EFFECTS OF AGRICULTURAL ACTIVITIES AND BEST MANAGEMENT PRACTICES ON WATER QUALITY OF SEASONAL PRAIRIE POTHOLE WETLANDS

    EPA Science Inventory

    Long-term effectsof within-basin tillage can constrain condition and function of prairie wetlands even after uplands are restored. Runoff was significantly greater to replicate wetlands within tilled basins with or without vegetated buffer strips as compared to ConsrvationReserve...

  8. 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...

  9. Aboveground Net Primary Productivity in a Riparian Wetland Following Restoration of Hydrology.

    PubMed

    Koontz, Melissa; Lundberg, Christopher; Lane, Robert; Day, John; Pezeshki, Reza

    2016-02-04

    This research presents the initial results of the effects of hydrological restoration on forested wetlands in the Mississippi alluvial plain near Memphis, Tennessee. Measurements were carried out in a secondary channel, the Loosahatchie Chute, in which rock dikes were constructed in the 1960s to keep most flow in the main navigation channel. In 2008-2009, the dikes were notched to allow more flow into the secondary channel. Study sites were established based on relative distance downstream of the notched dikes. Additionally, a reference site was established north of the Loosahatchie Chute where the dikes remained unnotched. We compared various components of vegetation composition and productivity at sites in the riparian wetlands for two years. Salix nigra had the highest Importance Value at every site. Species with minor Importance Values were Celtis laevigata, Acer rubrum, and Plantanus occidentalis. Productivity increased more following the introduction of river water in affected sites compared to the reference. Aboveground net primary productivity was highest at the reference site (2926 ± 458.1 g·m(-2)·year(-1)), the intact site; however, there were greater increase at the sites in the Loosahatchie Chute, where measurements ranged from 1197.7 ± 160.0 g m(-2)·year(-1)·to 2874.2 ± 794.0 g·m(-2)·year(-1). The site furthest from the notching was the most affected. Pulsed inputs into these wetlands may enhance forested wetland productivity. Continued monitoring will quantify impacts of restored channel hydrology along the Mississippi River.

  10. Aboveground Net Primary Productivity in a Riparian Wetland Following Restoration of Hydrology

    PubMed Central

    Koontz, Melissa; Lundberg, Christopher; Lane, Robert; Day, John; Pezeshki, Reza

    2016-01-01

    This research presents the initial results of the effects of hydrological restoration on forested wetlands in the Mississippi alluvial plain near Memphis, Tennessee. Measurements were carried out in a secondary channel, the Loosahatchie Chute, in which rock dikes were constructed in the 1960s to keep most flow in the main navigation channel. In 2008–2009, the dikes were notched to allow more flow into the secondary channel. Study sites were established based on relative distance downstream of the notched dikes. Additionally, a reference site was established north of the Loosahatchie Chute where the dikes remained unnotched. We compared various components of vegetation composition and productivity at sites in the riparian wetlands for two years. Salix nigra had the highest Importance Value at every site. Species with minor Importance Values were Celtis laevigata, Acer rubrum, and Plantanus occidentalis. Productivity increased more following the introduction of river water in affected sites compared to the reference. Aboveground net primary productivity was highest at the reference site (2926 ± 458.1 g·m−2·year−1), the intact site; however, there were greater increase at the sites in the Loosahatchie Chute, where measurements ranged from 1197.7 ± 160.0 g m−2·year−1·to 2874.2 ± 794.0 g·m−2·year−1. The site furthest from the notching was the most affected. Pulsed inputs into these wetlands may enhance forested wetland productivity. Continued monitoring will quantify impacts of restored channel hydrology along the Mississippi River. PMID:26861409

  11. Assessment of Water Availability Impact on Wetland Management using Multi-temporal Landsat Images and Bayesian-based Learning Machines

    NASA Astrophysics Data System (ADS)

    Alminagorta, O.; Torres, A. F.

    2013-12-01

    Water availability has a direct impact on the wetland ecosystems. While wetland managers need better information to allocate scarce water to improve wetland services, most monitoring activities of flood areas and vegetation condition on wetlands relies on manual estimation of water depth and use of airboat with GPS devices. This process is costly and time-consuming. Remote sensing techniques have been previously used to characterize vegetation conditions along with hydrological characteristics of the wetlands with excellent results. Nevertheless, limited analysis has been done to relate the resulting wetland characterization with the historical water availability records. The present paper addresses the lack of adequate feedback on wetland conditions upon the available water for the wetland system by making use of multi-temporal Landsat images. These images are processed at wetland unit and system level to extract information about vegetation, soil and water conditions. This information is then correlated with historical water availability records for the wetland system by means of the Relevance Vector Machine, a Bayesian-based algorithm known for its robustness, efficiency, and sparseness. 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-discharge records and coverage vegetation collected at the Refuge has been used to calibrate and evaluate the effects on wetland services to the process of flooding and drought in wetland units during different years. The final product of this research is to provide a methodology that wetland managers can use to make informed decisions about water allocation to improve wetland services while avoiding wasting resources, effort, time and money.

  12. Coastwide Reference Monitoring System (CRMS) Vegetation Volume Index: An assessment tool for marsh habitat focused on the three-dimensional structure at CRMS vegetation monitoring stations

    USGS Publications Warehouse

    Wood, William B.; Visser, Jenneke M.; Piazza, Sarai C.; Sharp, Leigh A.; Hundy, Laura C.; McGinnis, Tommy E.

    2015-12-04

    The VV and VVI will be used to establish trends, to make comparisons, and to evaluate restoration projects. Assessments that rely on the VVI will be included in appropriate Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) project reports and analyses. Implementation of the VVI will give coastal managers a new tool to design, implement, and monitor coastal restoration projects. A yearly trajectory of site, project, basin, and coastwide VVI will be posted on the CRMS Web site as data are collected. The primary purpose of the tool is to assess CWPPRA restoration project effectiveness, but it will also be useful in identifying areas in need of restoration and in coastwide vegetation assessments.

  13. Decline in exotic tree density facilitates increased plant diversity: the experience from Melaleuca quinquenervia invaded wetlands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Australian tree Melaleuca quinquenervia (melaleuca) formed dense monocultural forests several decades after invading Florida and the Caribbean islands. These dominant forests have displaced native vegetation in sensitive wetland systems. We hypothesized that native plant diversity would increa...

  14. Estimation model of soil freeze-thaw erosion in Silingco watershed wetland of Northern Tibet.

    PubMed

    Kong, Bo; Yu, Huan

    2013-01-01

    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.

  15. Estimation Model of Soil Freeze-Thaw Erosion in Silingco Watershed Wetland of Northern Tibet

    PubMed Central

    2013-01-01

    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

  16. Restoration of a forested wetland ecosystem in a thermally impacted stream corridor

    SciTech Connect

    Nelson, E.A.; McKee, W.H. Jr.; Dulohery, C.J.

    1995-09-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Brittingham, K. D.

    2005-05-01

    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 by the U.S. Army Corps of Engineers in 2000. Populations from this 'new' marsh are compared to those of similarly reconstructed Kenilworth Marsh (1993), as well as to the relic Dueling Creek Marsh on the Anacostia and the outside reference Patuxent Marsh in an adjacent watershed. Benthic organisms were collected using selected techniques including the Ekman bottom grab sampler, sediment corer, D-net and Hester-Dendy sampler. Samples were collected seasonally from tidal channels, tidal mudflats, three vegetation zones (low, middle and high marsh), and pools. Data collected from this study can provide valuable information on the extent that benthic macroinvertebrate communities can serve as an indicator of the relative success of freshwater tidal marsh reconstruction.

  18. Effects of Spartina alterniflora Invasion on Soil Quality in Coastal Wetland of Beibu Gulf of South China

    PubMed Central

    Huang, Wei; Liang, Ruwen; Li, Fusheng

    2016-01-01

    Background Since Spartina alterniflora (simplified as Spartina) has strong ecological competitiveness and rapid growth, it has been introduced and living in the coastal wetland regions of China for more than 30 years. Taking coastal wetland in the Beibu Gulf of south China as an example, the effects of Spartina invasion on soil quality were investigated to provide scientific basis for soil management. Methodology The soil quality of six different coastal wetlands, i.e. mangrove (vegetation coverage is above 95%), mangrove- Spartina ecotones (vegetation coverage is above 95%), sparse mangrove (vegetation coverage is 10%-20%), sparse mangrove- Spartina ecotones (vegetation coverage is about 80%), Spartina (vegetation coverage is about 80%) and bare beach (no plants), were analyzed using the following indicators: pH, cation exchange capacity, contents of total nitrogen, total phosphorus and organic carbon, microbial biomass carbon, microbial biomass nitrogen, microbial carbon / organic carbon, and activities of urease, acid phosphatase, invertase, polyphenol oxidase and catalase. Principal Findings The results showed that compared to mangrove wetland, most indicators in the mangrove-Spartina wetland showed a decline tendency except pH value, and the contents of total phosphorus and organic carbon, microbial biomass carbon and soil microbial biomass nitrogen, and the activities of acid phosphatase and invertase were significantly reduced (P<0.05). Compared to sparse mangrove wetland and bare beach, the Spartina invasion wetland (sparse mangrove-Spartina wetland and Spartina wetland) had higher contents of total nitrogen, total phosphorus and organic carbon, microbial biomass carbon, microbial biomass nitrogen, cation exchange capacity and the activities of urease and acid phosphatase, so soil quality in the sparse mangrove wetland and bare beach was significantly improved. Factor Analysis and PCA also showed that: the quality of mangrove wetland soil is better than

  19. System Modeling to Improve the Hydro-Ecological Performance of Diked Wetlands

    NASA Astrophysics Data System (ADS)

    Alminagorta, O.; Rosenberg, D. E.; Kettenring, K.

    2012-12-01

    Managing scarce water resources and invasive vegetation are common problems in wetlands. A systems model was developed to recommend water allocations and vegetation control actions among diked wetland units that will improve wetland habitat for bird species. Model recommendations are subject to constraints such as water availability, spatial connectivity of wetland units, hydraulic infrastructure capacities, vegetation growth and responses to management activities, plus financial and time resources available to manage water and invasive vegetation. Wetland habitat performance is quantified using two performance metrics. The first metric is a habitat suitability index (H) that represents the capacity of a given habitat attribute (such as water depth or vegetation cover) to support selected bird species. Suitability ranges from 0 (poor) to 1 (excellent) habitat quality. We combine the habitat suitability of water depth and vegetation coverage, weight by species and the wetted surface area to create the second metric defined as the weighted usable area for wetlands (WU). The WU represents the available surface area that provides suitable hydrological and ecological conditions for priority bird species. We apply the model at the Bear River Migratory Bird Refuge (the Refuge), which is the largest wetland complex on the Great Salt Lake, Utah. The Refuge provides important habitat for large populations of migratory birds that follow the North American Pacific and Central Flyways. Wetland managers and stakeholders participated throughout this study from identifying the problem, defining performance metrics, collecting data, through interpreting results. We ran the model for a base case representing hydrologic conditions in 2008 and eight scenarios that independently considered changes in water availability, financial budget, vegetation responses, and gate operation. Results of these analysis show that performance of wetland habitat are more affected by changes in

  20. Forecasting the Future of Coastal Wetlands

    NASA Astrophysics Data System (ADS)

    Morris, J. T.

    2012-12-01

    The current distribution of N. American coastal wetlands is 1) the product of progradation that has occurred over 4,000 years of near static sea level and 2) influenced by a legacy of landuse change following European colonization. The rise in sea level that we see today began several centuries ago and is accelerating. Evidence will be presented that some coastal wetlands are not keep up with sea level or cannot keep up with projected rates of sea-level rise (SLR). Vegetated salt marshes survive only at relative elevations that are approximately above mean sea level (MSL) and below the elevation of local mean high water. Salt marsh plants help to stabilize the elevations of salt marshes within this range, even as MSL rises. However, the stable or equilibrium elevation will decrease as the rate of SLR increases, and there is a tipping point beyond which marshes are unable to maintain their relative elevation. The remaining lifetime or survival time of a wetland varies among estuaries depending on a variety of factors, including the concentration of suspended sediment, tide range, and the present relative elevation. The Marsh Equilibrium Model (MEM) predicts that survival time will depend on the actual trajectory of sea level, i.e. its acceleration, and not simply on its ultimate elevation at some future date. For example, marshes can adapt to a linear rise of 1 m in a century, but not to an acceleration to 1 m. The present vulnerability to SLR of a coastal wetland can be quantified as the normalized, modal elevation of vegetated intertidal area. The modal elevation (Em) can be normalized (En) to the dimension of the tidal frame, expressed as -1 to 1 where 0=MSL and 1=MHW, or En = (Em - MSL)/(MHW-MSL). Moreover, the skewness of the distribution will be positive for wetlands near the lower limit of their vertical range and negative near the upper limit, and most stable part of their vertical range.

  1. Forms of organic phosphorus in wetland soils

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  2. [Recreational attraction of urban park wetlands in Beijing].

    PubMed

    Li, Fen; Sun, Ran-Hao; Chen, Li-Ding

    2012-08-01

    Taking the 20 urban park wetlands in Beijing as test objects, a 3-layer evaluation index system including urban park wetland landscape quality, location condition, and accessibility for the recreational attraction of urban bark wetlands was established, and, by using analytic hierarchy process (AHP) and an integrating index evaluation method, the recreational attraction of the urban park wetlands in Beijing was quantitatively assessed, and validated with questionnaire data. In Beijing, the urban park wetlands with high recreational attraction were in the order of the Summer Palace, Olympic Park, Qinglong Lake Park, Beihai Park, Yuanmingyuan Park, Yuyuantan Park, Shidu, Golden Sea Lake scenic area, Taoranting Park, and Yeyahu wetland. The Rice Fragrance Lake wetland and Zhenzhuhu scenic area had the lowest recreational attraction, and the others were fair. The evaluation results were supported by the questionnaire data, which indicated that the index system and evaluation model were useful. According to the recreational services, the 20 park wetlands in Beijing could be clustered into four categories, which could be managed in different ways. Appropriately assessing the recreational services of urban park wetlands could help the decision-making on the urban parks optimal planning and designing, improve human living environment, and optimize the spatial distribution of urban landscape.

  3. Hydroperiod regime controls the organization of plant species in wetlands.

    PubMed

    Foti, Romano; del Jesus, Manuel; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

    2012-11-27

    With urban, agricultural, and industrial needs growing throughout the past decades, wetland ecosystems have experienced profound changes. Most critically, the biodiversity of wetlands is intimately linked to its hydrologic dynamics, which in turn are being drastically altered by ongoing climate changes. Hydroperiod regimes, e.g., percentage of time a site is inundated, exert critical control in the creation of niches for different plant species in wetlands. However, the spatial signatures of the organization of plant species in wetlands and how the different drivers interact to yield such signatures are unknown. Focusing on Everglades National Park (ENP) in Florida, we show here that cluster sizes of each species follow a power law probability distribution and that such clusters have well-defined fractal characteristics. Moreover, we individuate and model those signatures via the interplay between global forcings arising from the hydroperiod regime and local controls exerted by neighboring vegetation. With power law clustering often associated with systems near critical transitions, our findings are highly relevant for the management of wetland ecosystems. In addition, our results show that changes in climate and land management have a quantifiable predictable impact on the type of vegetation and its spatial organization in wetlands.

  4. Redox properties of a constructed wetland: theoretical and practical aspects.

    PubMed

    Síma, Jan; Diáková, Katerina; Pavelcová, Lenka; Havelka, Michal

    2009-03-01

    Constructed wetlands represent a progressive approach to the wastewater treatment. A fundamental prerequisite of the efficient water quality improvement is the presence of redox potential gradients (connected with the aeration of the system) inside the vegetation bed. Redox properties of a constructed wetland were tested in three longitudinal transects crossing the vegetation bed from the inflow zone to the outflow using diverse indicators (e.g., Fe(III)/Fe(II), SO(2-)(4)/S(2-)). Approximately 10-25% of iron was reoxidized in samples taken 10 m from the inflow zone in 2006. Redox processes of iron in artificial (constructed wetland) and natural (peat bog) ecosystems were compared. The peat bog was characterized with higher percentages of Fe(II) (usually ca. 90-100%). Thus, the aeration of the peat land was lower in comparison with the constructed wetland. The constructed wetland efficiently reduced sulfates (average concentrations of 44.7 and 11.2 mg/l at the inflow and the outflow, resp., in 2007). Organics, expressed as COD(Cr) and BOD(5), and NH+(4) were removed with efficiencies of 86.4, 92.2, and 60.4%, respectively. However, total phosphorus (redox processes play a negligible role in this case) was removed only with 39.6% efficiency. Redox properties of the wetland did not significantly depend on the heterogeneity of the treated wastewater flow.

  5. Hydroperiod regime controls the organization of plant species in wetlands

    PubMed Central

    Foti, Romano; del Jesus, Manuel; Rinaldo, Andrea; Rodriguez-Iturbe, Ignacio

    2012-01-01

    With urban, agricultural, and industrial needs growing throughout the past decades, wetland ecosystems have experienced profound changes. Most critically, the biodiversity of wetlands is intimately linked to its hydrologic dynamics, which in turn are being drastically altered by ongoing climate changes. Hydroperiod regimes, e.g., percentage of time a site is inundated, exert critical control in the creation of niches for different plant species in wetlands. However, the spatial signatures of the organization of plant species in wetlands and how the different drivers interact to yield s