Marsh Wetland Research Articles

New DGGE strategies for the analyses of methanotrophic microbial communities using different combinations of existing 16S rRNA-based primers

Methane-oxidising microbial communities are studied intensively because of their importance for global methane cycling. A suite of molecular microbial techniques has been applied to the study of these communities. Denaturing gradient gel electrophoresis (DGGE) is a diversity screening tool combining high sample throughput with phylogenetic information of high resolution. The existing 16S rRNA-based DGGE assays available for methane-oxidising bacteria suffer from low-specificity, low phylogentic information due to the length of the amplified fragments and/or from lack of resolving power. In the present study we developed new combinations of existing primers and applied these on methane-oxidising microbial communities in a freshwater wetland marsh. The designed strategies comprised nested as well as direct amplification of environmental DNA. Successful application of direct amplification using combinations of universal and specific primers circumvents the nested designs currently used. All developed assays resulted in identical community profiles in wetland soil cores with Methylobacter sp. and Methylocystis sp.-related sequences. Changes in the occurrence of Methylobacter-related sequences with depth in the soil profile may be related to the decrease in methane-oxidizing activity.

Responses of Emergent Marsh Wetlands in Upstate New York to Variations in Urban Typology

Kleppel, G., S. A. Madewell and S. E. Hazzard 2004. Responses of Emergent Marsh Wetlands in Upstate New York to Variations in Urban Typology. Ecology and Society 9(5):1. https://doi.org/10.5751/ES-00686-090501

Malaria in Britain: past, present, and future.

There has been much recent speculation that global warming may allow the reestablishment of malaria transmission in previously endemic areas such as Europe and the United States. In this report we analyze temporal trends in malaria in Britain between 1840 and 1910, to assess the potential for reemergence of the disease. Our results demonstrate that at least 20% of the drop-off in malaria was due to increasing cattle population and decreasing acreage of marsh wetlands. Although both rainfall and average temperature were associated with year-to-year variability in death rates, there was no evidence for any association with the long-term malaria trend. Model simulations for future scenarios in Britain suggest that the change in temperature projected to occur by 2050 is likely to cause a proportional increase in local malaria transmission of 8-14%. The current risk is negligible, as >52,000 imported cases since 1953 have not led to any secondary cases. The projected increase in proportional risk is clearly insufficient to lead to the reestablishment of endemicity.

Sedimentation Characterization and Reconstruction of Time-scale of Typical Profile in Xianghai Marsh Wetlands, Jilin Province

Cumulated sediments during marsh wetlands development really recorded the region environment change and marsh processes. Here we reported a case study on the Xianghai marsh wetlands at downstream of an anourous river-Huolin River, Jilin Province. By analysis of sediment layer structure, sediment bulk density, and sedimentation rate in the typical sedimentation profiles, the following results are revealed: The layer relationship among marsh sediments could reveal the marsh formation and its environment change; The riverine marsh might receive much more mineral sediments; the mark of river shifting near 1880-1885AD in the research field was discovered; That the sedimentation rates of Xianghai marsh wetlands were similar to typical estuarine deltas indicated the property of trailing end of estuarine; The cause of suddenly accelerating of the sedimentation rates in Xianghai marsh wetlands in recent 50 years, might related with the human activities strengthen , the plants destroy, and top soil strictly lose after liberation. Furthermore, on time scale, the suddenly accelerating of the sedimentation rates had much better coupling with the mining period of time of large open-cast coal located on upstream of the Huolin River catchments.

Darwin's Naturalization Hypothesis Revisited

In The Origin of Species, Darwin (1859) drew attention to observations by Alphonse de Candolle (1855) that floras gain by naturalization far more species belonging to new genera than species belonging to native genera. Darwin (1859, p. 86) goes on to give a specific example: “In the last edition of Dr. Asa Gray’s ‘Manual of the Flora of the United States’ ... out of the 162 naturalised genera, no less than 100 genera are not there indigenous.” Darwin used these data to support his theory of intense competition between congeners, described only a few pages earlier: “As the species of the same genus usually have, though by no means invariably, much similarity in habits and constitution, and always in structure, the struggle will generally be more severe between them” (1859, p. 60). Darwin’s intriguing observations have recently attracted renewed interest, as comprehensive lists of naturalized plants have become available for various regions of the world. Two studies (Mack 1996; Rejmanek 1996, 1998) have concluded that naturalized floras provide some support for Darwin’s hypothesis, but only one of these studies used statistical tests. Analyses of additional floras are needed to test the generality of Darwin’s naturalization hypothesis. Mack (1996) tabulated data from six regional floras within the United States and noted that naturalized species more often belong to alien genera than native genera, with the curious exception of one region (New York). In addition to the possibility of strong competition between native and introduced congeners, Mack (1996) proposed that specialist native herbivores, or pathogens, may be

Hydrochemical characteristics of salt marsh wetlands in western Songnen Plain

In western Songnen Plain of China, the saline-alkaline degree of water bodies is high in salt marsh wetlands. Generally, pH is above 8.0, and the hydrochemical types belong to HCO3 2−-Na+. Through analysis on the basic saline variables such as CO3 2−, HCO3 2−, Cl−, Ca2+, Mg2+, SO4 2−, Na+, and the derivative variables such as SAR, SDR, RSC, SSP, the relationships between different variables are found, and the discriminant equations are established to identify different saline-alkaline water bodies by using principal component analysis.

Spatial patterning of net primary production in wetlands of continental western Canada

Net primary production in wetlands of continental western Canada (Alberta, Saskatchewan, Manitoba) is mapped and summarized by wetland type and ecoregion. The region contains 405 300 km2 of wetlands, with peatlands representing 90.1% of all wetlands. Based on a regional synthesis of published values of net primary production, shrubby swamp and marsh wetlands produce more biomass annually through the process of net primary production than peatlands. Different peatland types appear to sequester similar amounts of plant biomass on an annual basis, with the exception of permafrost bogs that sequester less. Wetland net primary production for the region is calculated as 2.1 ¥ 1014 g yr-1 of plant biomass, with 73.5% sequestered in peatlands. This is equivalent to 9.95 ¥ 1013 g yr-1 of carbon. Provincially this carbon is partitioned into 50% for Manitoba, 30% for Alberta, and 20% for Saskatchewan. Over the last 1000 years, an average of only 5% of this biomass (and carbon) accumulate as peat, with most lost through the process of decomposition. When the annual amount of carbon that accumulates as peat is compared to the amount emitted provincially as anthropogenic greenhouse gases, wetlands present in each of the provinces accumulate 4% (Alberta), 8% (Saskatchewan), and 62% (Manitoba) of the emitted carbon annually. Wetlands in continental western Canada are a significant, active biosphere carbon sink following accumulation patterns of the last one thousand years. Future changes, particularly in fire frequency or intensity, may alter this accumulation pattern.

ISOTOPE HYDROLOGY DYNAMICS OF RIVERINE WETLANDS IN THE KANKAKEE WATERSHED, INDIANA1

ABSTRACT: Wetland restoration activities may disturb shallow ground‐water flow dynamics. There may be unintentional sources of water flowing into a constructed wetland that could compromise the long‐term viability of a wetland function. Measurement of naturally‐occurring isotopes in the hydrosphere can provide an indication of provenance, flow paths or components, and residence times or ages of wetland ground‐water flow systems. Hydraulic head measurements may not provide sufficient detail of shallow flow disturbances and can be complemented by analyzing isotopes in waters flowing through the wetland. Two north‐central Indiana wetlands in the Kankakee watershed are being studied to determine the adequacy of wetland restoration activities. The native LaSalle wetland and the restored Hog Marsh wetland have contrasting ground‐water flow regimes. The conservative water isotopes 18O, 2H, and 3H, and selected solute isotopes 13C, 14C, 15N, 34S, 87Sr, and 206–208Pb, demonstrate the complexity of ground‐water flow in Hog Marsh compared to the established flow regime at the LaSalle wetland.

A test of the Canadian land surface scheme (class) for a variety of wetland types

The validation of the Canadian Land Surface Scheme (CLASS) for several wetland types: fen, marsh and bog was undertaken. Incorporating organic soil parameters resulted in a significant improvement in turbulent flux estimates for the vascular dominated fen and marsh wetlands, yet non‐vascular bog‐type wetlands are relatively poorly modelled. Bog surfaces were treated as bare soil surfaces in this testing procedure since the non‐vascular nature is not readily incorporated within the current CLASS model vegetation categories. CLASS does not contain a method for moisture transfer from vegetation other than transpiration by the vascular pathway of root, stem and leaf while evaporation of water from moss and lichen dominated surfaces found in bogs is presently not included. With improved parametrization of the water table already introduced, and an additional non‐vascular vegetation category, it should be possible to model accurately the range of wetland types with CLASS.

Hydraulic Resistance Determination in Marsh Wetlands

Restoration of degraded and creation of constructed wetlands require proper hydraulic design. Of particular importance is the accurate determination of flow resistancefactors and the proper use of resistance equations, somethingessential for computing basic hydraulic parameters, such as depth and velocity, and for modeling the hydrodynamics of the system. In this study, selected previous theoretical, laboratoryand field studies on wetlands and vegetated-channel hydraulics are reviewed, and existing data from these studies are extractedand compiled in a common database. Resistance determining parameters are discussed, and results are summarized and presented, aiming at obtaining laws governing the flow, and deriving values for frictional factors under various flow scenarios. Graphs of Darcy-Weisbach f or Manning's n versus appropriate hydraulic parameters are presented.A modified n-VR graph is also presented, appropriate for marsh preliminary hydraulic analyses and design. These graphs also indicate missing information and can guide in future research.

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

A 9.9-ha combined habitat and wastewater treatment demonstration wetland was constructed and planted in the summer of 1994, at Eastern Municipal Water District’s (EMWD) Hemet/San Jacinto Regional Water Reclamation Facility (RWRF) in southern California. From January 1996 through September 1997, the marsh–pond–marsh wetland system was operated to polish an average of 3785 m 3 d −1 (1×10 6 gal day −1) of secondary-treated effluent from the RWRF. Nitrogen removal was a major objective of this wetland treatment. Weekly inflow/outflow water quality monitoring of the wetland was supplemented with biannual, 45-station synoptic surveys within the system to determine internal distribution patterns of the nitrogen species (total ammonia, nitrite, nitrate, and organic nitrogen), total organic carbon (TOC), and ultraviolet absorbance at 254 nm (UV 254). Synoptic surveys were carried out during May 22 and September 17, 1996, and May 6 and September 25, 1997 and the results were mapped using the ARC/INFO processing package and inverse distance weighted mathematical techniques. Distribution patterns of the various nitrogen species, TOC, and UV 254 within the wetland indicate that the nitrogen dynamics of the system are influenced both by variations in treatment plant loading, and, increasingly, by the degree of coverage and maturity of the emergent vegetation.

Estimating phosphorus removal in lakes using marsh wetlands

The objective of this study was to develop a modified simplest seasonal model that predicts phosphorus removal efficiency for lakes using marsh wetland system using lake waters. The proposed model calculates the wetland removal efficiency and total outflow phosphorus (TPout) concentration as a function of the soluble and nonsoluble reactive phosphorus (SRP and NSRP respectively) while considering the accumulation mechanisms. The observed and predicted TPoutconcentrations compared reasonably which suggest that empirical models can be adapted to estimate the phosphorus removal efficiency of the marsh wetlands. The results also indicate that TPout concentrations decreased exponentially with time through the wetland and decreasing the surface hydraulic loading rate of the system would increase the removal efficiency of phosphorus. It was observed that about 78% of the total phosphorus and 77% of the soluble phosphorus content within the water column was removed with about 19% of the total phosphorus removed within the first 5 days (13% of the system detention time).

Characterisation of the hydrology of an estuarine wetland

The intertidal zone of estuarine wetlands is characterised by a transition from a saline marine environment to a freshwater environment with increasing distance from tidal streams. An experimental site has been established in an area of mangrove and salt marsh wetland in the Hunter River estuary, Australia, to characterise and provide data for a model of intertidal zone hydrology. The experimental site is designed to monitor water fluxes at a small scale (36m). A weather station and groundwater monitoring wells have been installed and hydraulic head and tidal levels are monitored over a 10-week period along a short one-dimensional transect covering the transition between the tidal and freshwater systems. Soil properties have been determined in the laboratory and the field. A two-dimensional finite element model of the site was developed using SEEP/W to analyse saturated and unsaturated pore water movement. Modification of the water retention function to model crab hole macropores was found necessary to reproduce the observed aquifer response. Groundwater response to tidal fluctuations was observed to be almost uniform beyond the intertidal zone, due to the presence of highly permeable subsurface sediments below the less permeable surface sediments. Over the 36m transect, tidal forcing was found to generate incoming fluxes in the order of 0.22m3/day per metre width of creek bank during dry periods, partially balanced by evaporative fluxes of about 0.13m3/day per metre width. During heavy rainfall periods, rainfall fluxes were about 0.61m3/day per metre width, dominating the water balance. Evapotranspiration rates were greater for the salt marsh dominated intertidal zone than the non-tidal zone. Hypersalinity and salt encrustation observed show that evapotranspiration fluxes are very important during non-rainfall periods and are believed to significantly influence salt concentration both in the surface soil matrix and the underlying aquifer.

A spectrofluorimetric study of the binding of carbofuran, carbaryl, and aldicarb with dissolved organic matter

This study examined the binding of carbamate pesticides with dissolved organic matter (DOM) using fluorescence quenching and synchronous scan fluorescence spectroscopy (SSFS). Fluorescence spectra of the three pesticides were characterized as follows: carbofuran and carbaryl fluoresce at 305 and 330 nm, respectively, upon excitation at 276–279 nm, whereas, aldicarb shows broad emission at 350–380 nm upon excitation at 326 nm. A fluorescence quenching technique was used to obtain conditional binding constants for the carbamate pesticides with Aldrich humic acid under fixed conditions of 22°C and pH 6. The binding constant of carbofuran with humic acid is greater than the binding constants of both carbaryl and aldicarb. Estimates were also obtained for the binding of carbofuran with DOM samples from a coniferous forest soil O horizon, a deciduous forest soil O horizon, a sedge marsh wetland, and a stream in the drainage sequence and their molecular weight (MW) fractions. Those conditional binding constants were used to predict the potential transport of carbofuran in the drainage sequence. When binding constants and DOM concentrations were both taken into account, it was found that DOM from the coniferous forest O horizon had the largest capacity to bind and to transport carbofuran in the drainage sequence. SSFS was used to probe the binding mechanisms of DOM with carbofuran. Overall, the potential mobility of carbofuran in the upland–wetland–stream drainage sequence was significantly enhanced via binding with DOM.

Comparison of mercury accumulation in Lake Eden and the Savannas Marsh wetland, Florida, USA

Comparison of mercury accumulation in Lake Eden and the Savannas Marsh wetland, Florida, USA

Beltway 8 Wetland Water Quality Project: Constructed Wetlands for Storm Water Polishing and Wetland Mitigation Banking

The Harris County Flood Control District is implementing a wetland mitigation bank project that includes highway runoff as a significant water source. Part of this project is being implemented in cooperation with the Texas Department of Transportation through funding from the Intermodal Surface Transportation Efficiency Act for water quality improvement. This collaborative effort includes treatment and final polishing of storm water runoff from a portion of Beltway 8, northeast of Houston, Texas. The project includes approximately 89 ha (220 acres) of storm water-polishing wetlands and associated wildlife habitat. The overall train of natural treatment processes includes a tie-in to the existing beltway storm sewer, a surge basin for initial collection and storage of storm water, a pump station and force mail allowing flexible water delivery to the rest of the system, a series of polishing ponds and polishing wetland marshes, and an interconnected array of habitat wetlands and swales including ponds, littoral marshes, and transitional wetland forest areas. Design of the polishing and treatment wetlands balances the multiple goals of water quality improvement, flood-flow retention, and creation of valuable wildlife habitat.

Pollen Evidence of Late Holocene Mangrove Development in Bermuda

Bermuda is the northern latitudinal limit for mangroves, but communities are diverse and productive. Two pollen diagrams from the largest mangrove area show vegetation changes over the last 5000 years. From 5000 to 2100 years ago this was a marsh wetland, and pollen evidence is also shown of the dryland endemic forest before colonisation of Bermuda. Establishment of mangroves has only occurred in the last 3000 years, when sea-level rise slowed from 26 to 7 cm/100 years. Flotation experiments indicate that propagules could readily colonize from the Caribbean, and evidence both of cooler climate during the glacial and that none of Bermuda's many endemics utilize a mangrove habitat suggests that mangroves have had discontinuous presence in Bermuda through the Late Pleistocene. This study shows that mangrove ranges may be more plastic than was previously thought, subject to availability of habitats rather than dispersal capability.

Mercury accumulation trends in Florida Everglades and Savannas Marsh flooded soils

Global and regional increases in atmospheric mercury (Hg) concentrations have previously been identified as the cause of increased mercury accumulation rates in north temperate lakes in Sweden, Wisconsin, and Minnesota. Atmospheric deposition can often account for elevated Hg concentrations in fish from these systems. Mercury levels in sportfish collected from some areas of the Florida Everglades and Savannas Marsh exceed limits that are acceptable for human consumption. Forty five soil cores and soil grab samples were retrieved from the Everglades and Savannas Marsh wetlands. Eighteen sediment cores were dated radiochemically with 210Pb and 137Cs using γ-ray spectroscopy to determine modem and historic mercury accumulation rates for these subtropical wetland systems. Recent (“post-1985”) Hg accumulation rates averaged 53 μg m−2 y−1 (23 to 141, n=18) corresponding to an average rate increase of 4.9 times (1.6 to 19.1) over those observed around the turn of the century. This accumulation seems to result more from either global or regional atmospheric deposition rather than from lateral transport via overlying surface water. The trends for mercury accumulation match those reported for lakes in Sweden and the northern United States, even though these systems are distinctly different in their climate, vegetational composition, and location. We provide the first data on accumulation of mercury in subtropical wetland systems, and demonstrate the feasibility of radiochemical dating of wetland sediment.

Changes in wetlands on nonfederal rural land of the conterminous United States from 1982 to 1987

Recent wetland area trends were estimated from the National Resources Inventory (NRI) for nonfederal rural lands for the period 1982–1987. NRI-based estimates of wetland area for states comprising the conterminous United States were highly correlated with estimates made by the US Fish and Wildlife Service and with estimates of coastal salt marsh wetlands made by the National Oceanic and Atmospheric Administration. Net wetland area declined by 1.1% (≈363,200 ha) during the five-year study period. Conversion to open water, primarily caused by natural flooding in western inland basins, was responsible for altering extensive wetland areas (≈171,400 ha). Of the human-induced wetland conversions, urban and built-up land was responsible for 48% of the wetland loss, while agricultural development was indicated in 37% of the converted wetland area. A decrease in rural land, and increases in both population, and urban and built-up land were associated with wetland loss among states. Potential reasons for wetland loss were different in 20 coastal states than in 28 inland states. Proportionately, wetland loss due to development was three times greater in coastal states than inland states, while agriculturally induced wetland losses were similar in both groups. The proportionate declines of forested vs nonforested wetlands were not significantly different among states.

Geologic and human factors in the decline of the tidal salt marsh lithosome: the Delaware estuary and Atlantic coastal zone

Two to three thousand years ago, the fringing tidal salt marsh wetlands (including brackish and freshwater marsh) of the Delaware coastal zone were three to four times wider than at present. Observed variations in rates of marsh surface aggradation suggest that some areas are undergoing inundation whereas many other areas are undergoing aggradation at rates greater than sea-level rise as measured by a local tidal gauge (average 33 cm/ century based on a 70-year record) and may be undergoing floral succession. Accompanying these sedimentary processes are coastal erosion rates up to 6.9 m/yr along the Delaware estuary, up to 2.8 m/yr along the Delaware Atlantic coast, and ranging from 0.1 m/yr to 0.6 m/yr along the Delaware Atlantic coastal lagoons. Human development has destroyed nearly 9% of Delaware's fringing salt marshes between 1938 and 1975. The rapidly growing trend toward hardening the edge of the adjacent landward uplands leads us to the conclusion that much of the fringing salt marsh of Delaware will disappear over the next two to three centuries with only small remnants declining to extinction ca. 1500–1700 years into the future. Impacts on the State of Delaware, comprised of 13% fringing salt marshes 1/4 century ago, will be profound in terms of destruction of a large segment of the Atlantic coastal or eastern North American migratory bird flyway, and an eventual forced accommodation of the inhabitants of Delaware to these naturally ongoing geological processes.