Student: Tara Bortoluzzi (Masters degree student), Department of Botany, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2; tbortoluzzi@hotmail.com

Proposal Title:  The Hydrological Influence of Lake Manitoba on the Nutrient Status of an Adjoining Coastal Freshwater Wetland, Delta Marsh, Manitoba

Abstract:  Understanding the ecological processes in that occur in coastal freshwater wetlands has been a growing area of research over the last decade, however recent endeavors to better understand coastal wetland functions have been primarily focused on processes that occur within wetlands, and little had been done to determine the influence of adjoining water bodies on coastal freshwater wetlands. In addition, interactions between coastal wetlands and offshore waters have received significantly more attention in marine environments, than those in freshwater environments. This lack of information on the impact of lakes on the biological and chemical properties of coastal freshwater wetlands limits our ability to consider the impact of human activities on wetland functions and values. The purpose of this research is to study the impacts of lake hydrology and chemistry on the nutrient dynamics of adjoining coastal wetlands, as indicated by the growth potential of a major contributor to wetland food webs, benthic algae. Specifically, this project will use nutrient-diffusing substrata (NDS) that act as point sources of inorganic nitrogen and phosphorus, deployed at several sites throughout Delta Marsh, a coastal freshwater wetland in south-central Manitoba. I will identify spatial and temporal patterns in algal growth as an indicator of the degree of anthropogenic nutrient enrichment in Delta Marsh. This research should lead to a better understanding of coastal wetland nutrient dynamics and its relationship to hydrological processes of adjacent water bodies, and to more informed management of Delta Marsh and other coastal freshwater wetlands in North American.

Student: Jason Demers (M.S./Ph.D. student), Department of Natural Resources, 8 Fernow Hall, Cornell University, Ithaca, New York 14853; jdd24@cornell.edu

Proposal Title:  Mercury Retention and Potential Long-term Methylation and Export from Wetlands of the Adirondack Region, New York

Abstract: Anthropogenic emissions of mercury into the atmosphere during the past century have increased atmospheric mercury deposition, increased mercury contamination of surface waters, and have led to toxic rates of mercury bioaccumulation in associated biota.  Research in the Adirondacks Region has indicated that wetlands are important controls of methyl mercury flux to surface waters, but this has mainly been supported through the circumstantial evidence of whole watershed mass-balance studies.  This study proposes to directly measure the retention and transformation of mercury in Adirondack wetlands at an individual wetland scale.  At this scale, the potential of individual wetlands to contribute mercury contamination to surface waters may be assessed.  While watershed studies characterize current rates of mercury deposition, transformation, and transport to surface waters, understanding wetland mercury retention and associated delayed mercury transport to downstream waters may allow us to better predict the future potential for mercury contamination of surface waters.

Student: Philip Garone, Department of History (Ph.D) and Graduate Group in Ecology (M.S.), University of California, One Shields Avenue, Davis, California 95616; pfgarone@ucdavis.edu

Proposal Title: The History and Ecology of the Wetlands of California's Great Central Valley: 1850 to the Present

Abstract: The scientific community, the federal government, and governments throughout the world have demonstrated a strong interest in wetlands for at least three decades, yet wetlands have remained largely terra incognita to environmental historians and their public. This project is an interdisciplinary study of the wetlands of California’s Central Valley that bridges the gap between ecology and history. The Central Valley consists of three distinct physiographic regions: The Sacramento Valley, the Sacramento-San Joaquin Delta, and the San Joaquin Valley. Each has been dramatically altered by human action. The common thread that links their physical transformation has been the draining and destruction of over 90% of their permanent and seasonal wetlands, and the simplification and homogenization of their biota. Yet, each region has followed a unique historical trajectory. In reconstructing the ecological histories of these regions from archival collections and scientific literature, I specifically address the following questions: What role did private, state, and federal irrigation projects play in the restructuring of the landscape and the destruction of wetlands? To what extent have the population dynamics of waterfowl, and of other wetland-dependent organisms, been affected by contamination from pesticides, salts, and leached elements such as selenium? Which wetlands have been subject to these threats, and to what degree? How, why, and to what extent have traditional economic incentives to drain wetlands recently been overshadowed by environmental incentives to preserve and restore them? The ecological history of the Central Valley, understood in the light of these questions, reveals the ways in which nineteenth- and twentieth-century Americans valued wetlands, and how these value systems began to change—and continue to change—in the face of ecological limits. This work will serve both the needs of wetland ecologists, environmental scientists, and policy makers seeking a longer-term historical perspective within which to situate their work, and of historians seeking a more scientific understanding of wetlands. At the same time, precisely because this ecological history is intended to reach a broad audience, it may well provide an increase in public interest in wetlands and their protection.

Student: Hem Nalini Morzaria-Luna (doctoral student), University of Wisconsin-Madison, 341 Birge Hall, 430 Lincoln Drive, Madison, Wisconsin 53706; morzarialuna@students.wisc.edu

Proposal Title: Factors Influencing Plant Community Structure during Plant Reintroduction and Salt Marsh Restoration

Abstract: The establishment of native vegetation is essential for the restoration of wetland areas. Native plants of appropriate composition aid canopy development, slow the spread of exotic plants, and promote germination and establishment of native plants. As part of my dissertation research I ask: what is the role of interactions between species in the establishment of a plant community in a restored marsh? This summer I want to test the hypothesis that seedling germination and survival of Salicornia bigelovii (Annual pickleweed), a fast-growing plant rarely found in regional wetlands, is aided by Triglochin concinna (Arrow grass). T. concinna is very efficient in sequestering nitrogen and accumulating it in its tap-root. This plant grows and flowers in the spring and dies-back at the beginning of summer. I hypothesize that T. concinna releases nitrogen as it dies back, and this nitrogen can be used by S. bigelovii at the time of year it grows the most. I will conduct greenhouse and field experiments to demonstrate T. concinna and S. bigelovii share nitrogen pools throughout their life cycle. I will mark T. concinna tissue with an above-normal concentration of the nitrogen-15 isotope label and I will follow whether the labeled nitrogen is preferentially used by S. bigelovii at the end of the growing season. Although the use of nitrogen accumulated or fixed by one plant species and then used by another species has been documented for agricultural uses (i.e. alfalfa and corn), this type of mechanism has not been documented in salt marshes nor has it been used in restoration techniques to promote vegetation establishment. My research will test existing theories on how restoration sites develop; the information I obtain can be used to improve techniques for marsh restoration. My results will also contribute to the adaptive management of the Tijuana Estuary Reserve.

Student: John Navaratnam (Masters degree student), Department of Biology, Villanova University, 800 Lancaster Ave., Villanova, Pennsylvania 19085; John.Navaratnam@Villanova.edu

Proposal Title: Profiling Microbial Communities in a Boreal, Continental, Western Canadian Peatland Using Molecular Ecological Techniques

Abstract: Boreal and subarctic peatlands (covering 450 million ha globally) are found in Russia, the Baltic Republics, Fennoscandia, Alaska, and Canada. Approximately 170 million ha of Canada’s landmass is covered by peatlands, which are subdivided into bogs, permafrost mounds, and internal lawn features. Although these features coexist within a heterogeneous landscape, differences in plant populations, nutrient concentrations, organic matter quality, water table fluctuations (aerobic/anaerobic profile) and chemistry affect microbial decomposition rates, which is a critical factor in carbon balance responses of peatlands to climate warming. With global change and the predicted 4-5 °C mean annual temperature increases over the next 30 yr, net primary production and microbial respiration/decomposition may accelerate, increasing greenhouse gas emission and providing a positive feedback for global warming. Given the complexity and uncertainty concerning predictions of peatland carbon balance responses to global warming, linking investigations of microbial diversity to microbial function regarding carbon processing is vital. I propose to investigate the archaea bacterial, eubacterial and fungal species diversity of all three features, as well as changes in distribution at 0-5 cm and 30-35 cm within each feature, using total DNA extractions, PCR amplification, plasmid cloning and sequence analysis. To correlate diversity with population densities, I will also determine the bacterial/fungal biomass between features and along a depth profile within each feature. Preliminary sequence results of a total of 1093 eubacterial and fungal clones show that the diversity (H, Shannon-Wiener index which combines components of diversity, species richness and evenness), and evenness (E) values for eubacterial species isolated from 0-5 cm subsection of peat was highest in permafrost peat (H=3.56, E=0.91), and lowest in internal lawn peat (H=1.98, E=0.77). At 30-35 cm the eubacterial diversity and evenness values remain the lowest in internal lawn peat (H=1.31, E=0.50), but are highest in bog peat (H=3.40, E=0.90). The fungal community diversity and evenness in the 0-5 cm subsection was greatest in bog peat (H=1.88, E=0.71), and lowest in permafrost peat (H=1.66, E=0.63). Whereas, the fungal isolates at 30-35 cm show diversity and evenness values that are highest in permafrost peat (H=2.85, E=0.86), and lowest in internal lawn peat (H=1.73, E=0.68).

Student: Catherine Peacock (doctoral student), Institute of Water and Environment, Cranfield University, Silsoe, Bedfordshire, MK45 4DT, United Kingdom; c.peacock.s99@cranfield.ac.uk

Proposal Title: Estimating Evapotranspiration from a UK Reedbed for Creation of a Water Balance

Abstract: Increase in demand for water for agricultural and domestic use, combined with new European water resource legislation, have led to an increased need for accurate calculations of hydrological fluxes through wetlands. Research is being carried out on Stodmarsh National Nature Reserve in Kent, UK, a National Nature Reserve containing the largest reedbeds in southern England. The water balance of the site is being computed in order to quantify water gain and loss on the site to allow more effective management of water levels and maintenance of maximum conservation potential for birdlife. Evapotranspiration is one of the most important but least well understood fluxes in wetland hydrology and therefore particular emphasis is given to its measurement. The Bowen ratio energy balance approach is being employed, which is thought to be one of the most accurate ways of measuring evapotranspiration but has been rarely used in humid climates or on reedbeds. We are therefore testing the feasibility of this approach in the climate and environment of Stodmarsh and its ability to create data to calibrate evapotranspiration models. The output from these will then be fed into the overall water balance model for the site. In addition, estimates of evapotranspiration will be created by the parameterisation of the Penman Monteith equation in order to increase understanding of the evaporative processes involved. The data will be combined with historical meteorological data to create a model that will enable water levels on the site to be predicted for particular climatic conditions to assist management and ensure ideal hydrological conditions are maintained for species of conservation interest.

Student: Oliver Pierson (M.S./Ph.D. student), Department of Natural Resources, 8 Fernow Hall, Cornell University, Ithaca, New York 14853; ope2@cornell.edu

Proposal Title: Spatial And Temporal Influences on Phosphorus Dynamics in a Large Cattail Wetland

Abstract: Freshwater wetlands can improve water quality by retaining nutrients and sediments transported in surface water. Phosphorus, a key element affecting ecosystem productivity, can reach undesirably high concentrations in stormwater, agricultural, or industrial runoff, leading to eutrophication and pollution of water bodies receiving this runoff. Natural wetlands have been shown to be effective long-term phosphorus sinks, although they vary in their ability to remove and store this nutrient. Recent research has stressed the dynamic hydrologic regime of all wetland and aquatic systems and additional research is necessary to determine how these natural dynamics in the hydrologic regimes of wetlands are linked to biogeochemical processes. In particular, variations in wetland hydroperiods can significantly alter the biogeochemical processes responsible for phosphorus retention and therefore have the potential to affect a wetland’s retention capacity, as well as the rate at which phosphorus saturation occurs. In the proposed study, I will use a mass balance approach to determine spatial and temporal influences on phosphorus dynamics in a large, natural wetland. I will investigate the potential impacts of the wetland’s varying annual hydrologic regime on biogeochemical phosphorus retention processes. I will determine if the phosphorus removal processes are still functioning, if there is uniform phosphorus removal throughout the wetland over space and time, and to determine the effects of varying groundwater and surface water inputs on these processes. This study will be conducted in the Ellison Park Wetland, a 171 ha cattail marsh that receives drainage from a 300 km² watershed near Rochester, NY. The site is dominated by productive cattail stands, and was shown to be a net sink for total phosphorus between 1990 and 1996. Loads of total phosphorus entering this wetland have increased by over 50 percent from 1980 to 1996. Recent research indicates that surface water-groundwater dynamics within this wetland vary temporally and spatially among four distinct phases, and it is expected that phosphorus retention processes will also vary. Improved knowledge about the mechanisms enabling natural wetlands to retain phosphorus will be an important tool for wetland management.

Student: Andrew Ray (doctoral student), Center for Ecological Research and Education, Box 8007, Department of Biological Sciences, Idaho State University, Pocatello, Idaho 83209; rayandr@isu.edu

Proposal Title: The Effect of Arbuscular Mycorrhizae on the Productivity and Chemistry of Typha latifolia in Experimental Mesocosms

Abstract: Wetlands are recognized for their physiochemical complexity, dynamic biological processes, and complex foodwebs. Biogeochemical processes in wetlands are responsible for the immobilization of CO₂ and phosphorus (P), and for the transformation and removal of nitrogen (N). The ability of wetlands to function as nutrient sinks is supported by well-established plant and microbial communities. The interactions between microorganisms and vascular plants are known to influence nutrient dynamics in wetlands and attempts to examine these relationships in the field have focused primarily on the presence of the symbiosis rather than its function. There is ample evidence to suggest that mycorrhizae, the relationship between fungi and plant roots, are common in wetlands and that mycorrhizal plants exhibit greater P assimilation than non-mycorrhizal plants. However, improved P assimilation is not achieved without some cost to the plant. Photosynthetically derived carbon is supplied to the mycorrhizae in exchange for P. As a result, the C drain imposed by the mycorrhizae is thought to stimulate photosynthetic capacity. To understand how mycorrhizae influence ecosystem processes, we must first describe the effect of this symbiosis on plant growth, physiology, and nutrition. I will use Typha latifolia plants to test the following hypotheses: 1) mycorrhizal plants will have higher photosynthetic rates than non-mycorrhizal plants; 2) mycorrhizal plants will have less belowground biomass than non-mycorrhizal plants; and 3) mycorrhizal plants will have greater concentrations of P and N in tissues than non-mycorrhizal plants. To test these hypotheses, I will introduce plants and viable soil inoculum into ten 400 L mesocosms. Five of these mesocosms will be treated with a fungicide and will serve as non-mycorrhizal controls. I will examine growth patterns, concentrations of C, N, and P in above and belowground tissues, and C assimilation rates for mycorrhizal and control plants. This research is fundamental to understanding the effect of mycorrhizae on the biogeochemistry of wetlands and, to my knowledge, will be the most comprehensive look at plant-microbe associations outside of the greenhouse.

Student: Heather Ray (Masters Degree student), Department of Biological Sciences, Stream Ecology Center, Box 8007, Idaho State University, Pocatello, Idaho 83209; heateray@isu.edu

Proposal Title: Macroinvertebrate Colonization of Cattail and Bulrush Litter in a Newly Constructed Wetland

Abstract: Aquatic macroinvertebrates (insects) are important for their contribution to plant litter decomposition and food web support in aquatic systems and consequently, researchers are focusing on macroinvertebrate fauna to better understand the functions of wetlands.  The goals of this research are to determine if there are changes in macroinvertebrate compositions due to seasonal patterns in plant litter decomposition, differences in species of plant litter (because of their tissue chemistry), or differences between newly constructed and established wetlands.  Litter bags will be filled with Typha (Cattail) and Schoenoplectus (Bulrush) litter and placed in groups on the wetland surface at five locations within the constructed and established wetlands and removed at three sampling dates over the irrigation season.  The macroinvertebrates colonizing the litter will be identified, counted, and weighed.  The elemental percentage carbon, nitrogen, and phosphorus will be determined for the litter of each plant species to detect differences in tissue chemistry at the onset of the experiment and throughout the project duration.  The decomposition rate will be determined for the litter throughout the experiment. This study will provide baseline data on the macroinvertebrates colonizing litter in a newly constructed wetland used for the treatment of agricultural wastewater and, when compared with the established wetland, will reveal how litter decomposition and tissue chemistry influence early macroinvertebrate colonization in these wetlands.  Wetlands such as this one, created for wastewater treatment and water quality important in arid communities, can also function indirectly for water conservation and wildlife habitat.

Student: Michael Rubbo (doctoral student), Department of Biology, 208 Mueller Lab, The Pennsylvania State University, University Park, Pennsylvania 16802; mjr297@psu.edu

Proposal Title: Linking Process and Pattern: The Influence of Urbanization on the Functioning and Structure of Wetlands

Abstract: The widespread loss of wetland habitat throughout the world has played a major role in the disappearance of many species both on a local and regional scale.  In contrast to the obvious direct effects of wetland habitat loss we know relatively little about how organisms may respond to less dramatic disturbance (e.g., nutrient addition). In particular, we know little about how the community composition of a particular wetland may change in response to changes in wetland function resulting from the subtle effects of human development. The process of urbanization is well known for its role in the loss of wetland habitat; however urbanization has also been shown to influence wetlands through indirect pathways.  Urbanization commonly influences wetland ecosystems by increasing the input rates of nutrients.  Elevated nutrient levels typically lead to an increase in rates of primary production; a factor that may alter the food webs of wetlands by providing varying quantities and/or qualities of food to primary consumers and decomposers.  Such alterations in the base of the food web can de-stabilize species interactions such as competition or predation, potentially leading to the exclusion of vulnerable species.   In order to describe the effects of increased nutrient input on community structure (i.e., species richness and diversity of all major trophic groups), I will be conducting an experimental manipulation of the nutrient levels in 9 small, temporary wetlands.  The functioning of these sites (e.g., primary production, decomposition, net ecosystem production) and community structure of all major trophic groups will then be monitored for the entire period during which these sites hold water.  Additionally, I shall conduct a rigorous evaluation of wetland functioning and community structure along a gradient of urbanization.  This monitoring will take place in 10 rural (49-69 people/mi.²), 10 suburban (130-267 people/mi.²), and 10 urban (1165 people/mi.²) wetlands.  These sites have been subject to preliminary monitoring, and nutrient levels have been found to increase with increasing urban influence.  These data will allow me to assess the impact(s) of urbanization on ecosystem functioning and to determine how such alterations in function influence organisms inhabiting these wetlands.

Student: Virginia Shervette (doctoral student), Department of Fisheries and Wildlife, Texas A&M University, College Station, Texas 77843; shervette@neo.tamu.edu

Proposal Title: Assessment of Fish Diversity in Ecuadorian Mangroves: Tools for Management and Conservation

Abstract: Mangrove wetlands provide important habitat for fishes.  Anthropogenic destruction of these habitats necessitates an increase in ecological understanding so that better management practice can alleviate problems with mangrove deforestation. Tremendous losses of mangrove wetlands in Ecuador have primarily been due to shrimp aquaculture. Such large scale alterations can impair the integrity of these wetlands and reduce their capacity to function as centers of biological diversity.   Because fish production is likely mangrove-dependent, and subsistence fishing is a widespread method of provisioning families, loss of these forests also risks loss of a major source of livelihood and cultural tradition for these people.  Through quantitative drop sampling in undisturbed and disturbed mangrove wetlands, my research will focus on evaluating the functional roles of mangroves in the life history of Ecuadorian estuarine fishes so that effective fisheries and land-use management plans can be developed.    I will assess community structure, densities, and biomass of fishes among mangrove prop roots along a tidal gradient in both areas.  In addition, I will analyze the diets of fishes collected and measure indices of habitat structure.  Results will determine the following: 1) If shrimp farming and the subsequent deforestation of mangrove habitat in Ecuador has affected the fish assemblage structure of that habitat; and 2) How mangroves function in the juvenile life stages of a commercially important group of fishes (Cynoscion species).   Data gathered from this study will also indicate particular species groups on which to focus subsequent work.

Student: Peter Weishampel (doctoral student), Department of Natural Resources, Fernow Hall, Cornell University, Ithaca, New York 14850; paw22@cornell.edu

Proposal Title: Investigating the Influence of Nutrients and Hydrology on the Interactions of Plants and Arbuscular Mycorrhizal Fungi in Calcareous Fens using a DNA Fingerprinting Approach

Abstract: Plant communities are influenced by the presence of mycorrhizal fungi, soil organisms that colonize the roots of most plant species.  These organisms generally are considered to be mutualists, providing plants with increased access to nutrients and other benefits in exchange for plant-derived carbohydrates.  Although mycorrhizal fungi are aerobic organisms, many recent studies report mycorrhizal colonization of wetland plant roots despite saturated soil conditions.  The species composition of the mycorrhizal community has been found to influence the species composition and productivity of plant communities, but this research has been limited to upland ecosystems. I propose to investigate the species composition of mycorrhizal fungi in calcareous fens, groundwater-fed peatlands that frequently harbor diverse plant communities. Although wetland plants have often been generalized as non-mycorrhizal, my own research shows that some fen plant species are often highly colonized by mycorrhizal fungi.  No information exists that describes the composition of mycorrhizal fungal communities in these ecosystems.  I will use a DNA fingerprinting method to identify species of mycorrhizas in plant tissues, enabling me to test whether different plant species are preferentially colonized by different fungal species.  Additionally, I will test whether different species of mycorrhizal fungi are preferentially tolerant of saturated conditions by culturing them from continuously and intermittently saturated soil.  Finally, I will test the effects of nitrogen and phosphorus fertilization on the species richness of mycorrhizal fungi.  My research seeks to understand functional differences among species of mycorrhizal fungi.  Plant responses to these differences may help structure the diverse plant communities of calcareous fens.  My research will also show whether mycorrhizal fungal diversity is threatened by nutrient enrichment, a realistic threat to these ecosystems.