Wetland ecological function greatly depends on the wetland hydrology. As a result, correctly estimating the wetland water budget, is essential to the success of created wetlands. A wetland water budget model, Wetbud, was developed by collaborators from Virginia Tech, Old Dominion University, and the Technical University of Crete for estimating wetland water budgets to assist wetland design in the Virginia Piedmont. The Wetbud model has basic and advanced modules. The basic module uses level pool routing to compute average monthly water levels. Based on the groundwater model MODFLOW, the advanced module estimates groundwater interactions and vegetative resistance to surface flows on a daily timestep. The overall goal of this research was to assess Wetbud as an uncalibrated design model for mitigation wetland water budget estimation in the Virginia Piedmont. Specific objectives were to compare predictions using the basic and advanced modules and to compare the Thornthwaite and the FAO-56 Penman-Monteith potential evapotranspiration estimation methods for the design of created wetlands. The Wetbud model was tested using data from two existing mitigation wetlands. Both modules produced reasonable results; however, the basic module did not accurately predict drawdown occurring during dry periods. Results showed that the Wetbud advanced module produced more accurate and detailed results when compared to the basic module: Nash-Sutcliffe model efficiency ratings for the advanced module ranged from to 0.44 to 0.63. Potential evapotranspiration estimates by the FAO-56 Penman Monteith method were more accurate than those from the Thornthwaite method in nearly every model scenario / Master of Science

The composition of seed banks of areas on the drained Kissimmee River floodplain (Florida, USA) that are currently pasture and formerly had been wet prairie, broadleaf marsh, and wetland shrub communities was compared to that of seed banks of areas that have extant stands of these communities. The species composition of the seed banks of existing wet prairie and former wet prairie sites were the most similar, with a Jaccard index of similarity of 55. Existing and former broadleaf marsh and wetland shrub communities had Jaccard indices of 38 and 19, respectively. Although existing and former wet prairie seed banks had nearly the same species richness, species richness at former broadleaf marsh and wetland shrub sites was higher than at existing sites. Mean total seed densities were similar in existing and former wet prairies (700 to 800 seeds m2). However, seed densities in former broadleaf marsh and wetland shrub sites were significantly greater than in comparable existing communities (>4,900 seeds m2 at former sites versus 200 to 300 in existing communities). The higher seed densities in former broadleaf marsh and wetland shrub sites was due to over 4,000 seeds m2 of Juncus effusus in their seed banks. Half of the species that characterize wet prairies were found in the seed banks at former and existing wet prairie sites. At existing broadleaf marsh and wetland shrub sites, most of the characteristic species were found in their seed banks. However, only one characteristic broadleaf species was found in the seed banks of the former broadleaf marsh sites, and no characteristic wetland shrub species were found in the seed banks of the former wetland shrub sites. The seeds of only two non-indigenous species were found in the seed banks of former wetland communities at very low densities. For all three vegetation types, but particularly for the broadleaf marsh and wetland shrub sites, re-establishment of the former vegetation on the restored floodplain will require propagule dispersal from off-site sources.

A dynamic, compartmental, continuously stirred tank reactor, simulation model (SET-WET) was developed for design and evaluation of constructed wetlands in order to optimize non-point source (NPS) pollution control measures. The model simulates the hydrologic, nitrogen, carbon, dissolved oxygen, bacteria, vegetative, phosphorous and sediment cycles of a wetland system. Written in Fortran 77, SET-WET models both free water surface (FWS) and sub-surface flow (SSF) wetlands and is designed in a modular manner which gives the user the flexibility to decide which cycles and processes to model. SET-WET differs from many existing wetland models in that it uses a system's approach, and limits the assumptions made concerning the interactions of the various nutrient cycles in a wetland system. It accounts for carbon and nitrogen interactions, as well as effect of oxygen levels upon microbial growth. It also directly links microbial growth and death to the consumption and transformations of nutrients in the wetland system. Many previous models have accounted for these interactions with zero and first order rate equations that assume rates are dependent only on initial concentrations. The SET-WET model is intended to be utilized with an existing NPS hydrologic simulation model, such as ANSWERS or BASINS, but may also be used in situations where measured input data to the wetland are available. The model was calibrated and validated using limited data collected at Benton, Kentucky. A non-parametric statistical analysis of the model's output indicated eight out of nine examined outflow predictions were not statistically different from the measured observations. Linear regression analysis showed that six out of nine examined parameters were statistically similar, and that within the expected operating range, all of the examined outflow parameters (9) were within the 95% confidence intervals of the regression lines. A sensitivity analysis showed the most significant input parameters to the model were those which directly affect bacterial growth and oxygen uptake and movement. The model was applied to a subwatershed in the Nomini Creek watershed located in Virginia. Two year simulations were completed for five separate wetland designs, with reductions in percentage of BOD5 (4%-45%), TSS (85%-100%), total nitrogen (42%-56%), and total phosphorous (38%-57%) comparable to levels reported by previous research. / Master of Science

To meet the requirements of the Clean Water Act (1972), natural resource managers need to be able to detect biological degradation in wetland ecosystems. Biological indices are commonly used by managers to assess wetland biological condition. The accuracy and precision of wetland condition assessments are directly related to the performance of these indices, and biological index performance is thought to be related to how well an index controls for the effects of environmental attributes on biological assemblages. Many plant-based biological indices control for environmental and biological variation through the use of classification schemes that are based on geographic location and dominant vegetation type. However, the use of classification schemes tends to produce indices with limited applicability and may not adequately control for natural variation. The goal of my research was to use modeling techniques, as an alternative to classification, to account for biological variation associated with natural environmental gradients and to improve the performance of previously developed indices. I developed two types of model-based biological indices to quantify the biological condition of Ohio wetlands: a vegetation-based index of biological integrity (MVIBI) based on several attributes of wetland plant assemblages, and several indices of plant assemblage taxonomic completeness. I evaluated the accuracy and precision of the MVIBI relative to previously developed indices, and determined that the use of modeling techniques can significantly improve the performance of plant-based indices of biological integrity. Due to increases in accuracy and precision, use of the MVIBI should improve manager’s confidence in wetland biological condition assessments. The indices of taxonomic completeness exhibited poor performance relative to similar indices developed for other types of biological assemblages (i.e. aquatic insects, fish). I attribute poor index performance to my inability to accurately predict individual species occurrence, which is likely a result of plant communities being heavily structured by random disturbance events and biotic interactions that are difficult to account for. My results should help inform index developers of ways to potentially improve wetland condition assessment indices.

A major goal in restoration is to reestablish native plant communities. There are several ways to reestablish species, but for large areas the most logistically feasible approach is to sow seed of desirable species. However, most wetland seeds are buoyant and are extremely difficult to establish in designated areas before floating away. In upland areas, tackifiers have been used to stabilize hill slopes from erosion and to keep seeds in place. The tackifier works as an adhesive that binds the seeds to the soil. However, the use of a tackifier has not been widely employed in wetland restorations, and prior to its broad implementation into wetland restoration practice, it is important to determine if tackifiers will hold up in wetland conditions. In greenhouse studies, we tested the effectiveness of different tackifier types and concentrations on Bolboschoenus maritimus seedling emergence, the influence of soil moisture and flooding on the duration of tackifier effectiveness, the effect of a mulch addition on tackifier effectiveness (Bolboschoenus maritimus, Schoenoplectus acutus and S. americanus), the effectiveness of pre-germination in enhancing Bolboschoenus maritimus seedling emergence using a tackifier, and the effectiveness of tackifier over time. We concluded that the use of a tackifier was effective at keeping seeds from washing away for at least 15 days, a mulch addition did not enhance tackifier effectiveness, and pre-germination did not benefit B. maritimus seedling emergence. The results from this study provide strong evidence that the use of a tackifier could be an effective solution to establish bulrush species in designated areas in wetland restorations.

Studies have shown wetlands act as filters for nutrient rich waters, in part due to macrophyte properties. Differences have been found in nitrogen removal rates among plant species in studies of monocultures grown in mesocosms mimicking wastewater treatment constructed wetlands, but little research has been done on assemblages in natural or restored wetlands. This study aims to identify differences in water quality among plant assemblages in natural and restored wetlands. Thirty natural and restored wetlands in the Mississippi portion of the Mississippi Alluvial Valley were sampled four times. Water quality was measured and plant assemblages identified. Significant differences in pH, conductivity, and turbidity were found among four different plant growth forms, but nutrient concentrations were not significantly different among growth forms. Because nutrient concentrations were low, data collected may not have adequately captured potential differences in nutrient concentrations among plant assemblages.

No description available.

Projekt "Växa mot Våtmarken" handlar om att skapa en byggnad som tar människan till naturen, och inte minst våtmarken. Nynäsvägen och järnvägen till Norviks hamn skapar idag barriärer för Nynäshamnsborna att ta sig till Alhagens våtmark, ett vackert naturområde med stora värden för naturen och människan. Med denna nya byggnad tillkommer ett våtmarksområde närmare bostadsområdena samtidigt som byggnaden visar vägen till Alhagen genom dess placering intill bron som leder dit. Byggnadens program ska främst fokusera på våtmarken och dess funktioner. Här finns en utställning, ett labb och interaktivt rum där förskolebarn kan leka, skolklasser kan undervisas och forskare kan studera våtmarken. Här kan även mindre rum och en öppen studie- och arbetsyta utnyttjas för de som vill studera eller arbeta nära naturen. Serveringen med utsikt över både den befintliga och nya våtmarken blir en attraktiv del i huset.  Materialen ska vara lokala och naturliga så att känslan av huset knyter samman med dess funktion. Vid bygget av dammar i den nya våtmarken kan den överblivna jorden bidra till att bygga upp bärande väggar mad stampad jord-teknik vilka kompletteras med KL-träpelare och täcks med ett biotoptak som fungerar likt en trädgård för allmänheten och som på samma sätt som våtmarken bidrar till biologisk mångfald och ett omhändertagande av vatten vid stora nederbörder. / Project "Towards the Wetland" is about creating a building that brings people to nature, and more specifically to the wetland. Road 73 and the railway to Norvik harbour currently create barriers for Nynäshamn residents to get to Alhagen's wetland, a beautiful area with great values for nature and people. With this new building, a wetland area is added closer to the residential areas, while the building shows the way to Alhagen through its location next to the bridge that leads there. The building's programme will focus primarily on the wetland and its functions. It includes an exhibition, lab and interactive space where preschoolers can play, school classes can be taught and researchers can study the wetland. Smaller rooms and an open study and work area can also be utilised for those who want to study or work close to nature. The cafeteria overlooking both the existing and new wetland will be an attractive part of the building.  Materials should be local and natural so that the feel of the building is linked to its function. In the construction of ponds in the new wetland, the leftover soil can contribute to the construction of load-bearing walls using rammed earth technology, which are supplemented with CLT columns and covered with a biotope roof that functions like a garden for the public and which, in the same way as the wetland, contributes to biodiversity and water management during heavy rainfall.

Indiana University-Purdue University Indianapolis (IUPUI) / Wetland habitats are characterized by periodic inundation and saturation by water creating anaerobic conditions that generate hydric soils and support hydrophytic vegetation. Wetland habitats provide important ecological functions including breeding grounds for fish, other wildlife, water purification, reduction in flooding, species diversity, recreation, food production, aesthetic value, and transformation of nutrients (Tiner, 1999). The multiple benefits of wetlands make them an important resource to monitor. A literature review suggests a combination of geospatial variables and methods should be tested for appropriateness in wetland delineation within local settings. Advancements in geospatial data technology and ease of accessing new, higher resolution geospatial data make study at local levels easier and more feasible (Barrette et al, 2000). The purpose of the current study is to evaluate new sources of geospatial data as potential variables to improve wetland identification and delineation. High resolution multispectral digital imagery, topographic data, and soils information are used to derive and evaluate independent variables. Regression analysis was used to analyze the data.

Arbuscular mycorrhizal fungi, colonizing over 80% of all plants, were long thought absent in wetlands; however, recent studies have shown many wetland plants harbor arbuscular mycorrhizae (AM) and dark septate endophytes (DSE). Wetland services such as biodiversity, shoreline stabilization, water purification, flood control, etc. have been estimated to have a global value of $14.9 trillion. Recognition of these vital services is accompanied by growing concern for their vulnerability and continued loss, which has resulted in an increased need to understand wetland plant communities and mycorrhizal symbiosis. Factors regulating AM and DSE colonization need to be better understood to predict plant community response and ultimately wetland functioning when confronting natural and human induced stressors. This study focused on the effects of water quality, hydrology, sedimentation, and hurricanes on AM and DSE colonization in three wetland species (Taxodium distichum, Panicum hemitomon, and Typhal domingensis) and plant communities of coastal wetlands in Southeast Louisiana and effects of an antimicrobial biocide, triclosan (TCS), on AM (Glomus intraradices) spore germination, hyphal growth, hyphal branching, and colonization in fresh water wetland plants (Eclipta prostrata, Hibiscus laevis, and Sesbania herbacea) from bottom land hardwood forest in north central Texas. The former, mesocosm studies simulating coastal marsh vegetation ran for five years. In the latter studies, AM spores and wetland plants were exposed to 0 g/L, 0.4 g/L, and 4.0 g/L TCS concentrations in static renewal and flow through exposures for 21 and 30 days, respectively. AM and DSE colonization was significantly affected by individual and interactions of four independent variables in mesocosm experiments. Similarly, spore germination, hyphal growth, hyphal branching, and AM colonization in selected wetland plants were significantly lowered by exposure to the TCS at environmentally relevant concentrations. However, levels of effects were plant species and fungal propagules specific. My results showed that natural and human induced alterations in environmental factors and chemical contaminants can significantly impact levels of mycorrhizal spore germination, colonization, and spore density in coastal and freshwater wetland plants. The resulting impacts on plant community structure and ecosystem function require further study.