The objective of this thesis is to determine the effectiveness of Federal, state and local government interactions in administration of tidal wetland protection measures in Virginia. Federal protection for wetlands is authorized by the Clean Water Act [33 U.S.C.A. 1251 et seq. (1986), as amended (Supp. 1987)] and the Rivers and Harbors Act [33 U.S.C.A. 401 et seq. (1986), as amended (Supp. 1987)]. State and local authority is provided by the Virginia Wetlands Act [Va.Code Ann., sec. 62.1-13.1 et seq. (1987)]. Because of overlapping jurisdictions of the statutes, Federal, state, and local governments must interact while implementing wetland protection programs. Effective interactions between the various levels of government are important for the preservation and protection of tidal wetlands. If the three levels of government are able to efficiently administer a program that provides adequate protection of wetlands, similar programs may be applied in other areas such as non-point source pollution control. A history of the development of the wetlands protection program is presented along with a description of applicable statutes, regulations, and permitting requirements. Included is an analysis of the implementation of the wetland statutes by case studies of program operations, a comparison of decisions on applications made by the three different government agencies, and identification of impacts and future trends of the wetland protection programs. / Master of Science

Disturbances impact abiotic and biotic components within forested ecosystems. This dissertation identifies the impacts of recreational crossing disturbances on water quality, uses dendrochronological techniques to estimate sediment deposition and identify impacts hydrology and climate on radial growth in riparian forested wetlands, and quantifies influences of biotic and abiotic factors on the occurrence of frost-induced cambial damage. In southwestern Virginia, modeled soil erosion rates for multiple-use (hiking, mountain biking, and horseback riding) recreational trail approaches to stream crossings were found to be 13 times greater than rates for undisturbed forests. Downstream changes in macroinvertebrate-based indices indicated water quality was negatively affected downstream from culvert and ford crossings. These findings illustrate recreational stream crossings have the potential to deliver sediment into adjacent streams, particularly where best management practices are not being rigorously implemented, and as a result can negatively impact water quality below stream crossings. Impacts of hydrologic regime were apparent on sediment deposition and on green ash (Fraxinus pennsylvanica Marsh.) and water tupelo (Nyssa aquatica L.) radial growth along the Tensaw River in southwest Alabama. Annual dendrogeomorphic sediment accretion rates were significantly greater for a recent time period (25 years) when compared to longer term rates (131 years) along a natural levee and backswamp. Radial growth in green ash along the natural levee and backswamp was found to be significantly correlated with days flooded and average daily stage level during April while water tupelo further in the backswamp appeared resistant to hydrologic and climatic fluctuations. Results illustrate the importance of riparian wetlands in trapping sediment from adjacent waterways and highlight the role hydrologic regime plays in bottomland succession and productivity. Across northern lower Michigan, late spring frost-induced cambial damage in jack pine (Pinus banksiana Lamb.) occurred more frequently in younger trees and in trees with smaller diameters. Biotic and abiotic factors were found to influence the occurrence of earlywood frost rings. Frequent occurrences of frost-rings can be used to identify frost-prone environments and geographical boundaries for plant species. This dissertation bridged gaps in knowledge of recreational, hydrogeomorphic, and climatic disturbances in forested ecosystems which can be used to develop management strategies. / Ph. D.

Wetlands play a vital role in regional and global biogeochemistry by controlling the movement and cycling of nutrients and carbon. While individual wetlands may provide these ecosystem services, high density wetland landscapes, referred to as wetlandscapes, can have far reaching aggregate effects on elemental cycling and solute transport. Here we use forested Delmarva bays or wetlands as a study ecosystem to explore physical and biological controls on wetland chemistry within forested wetlandscapes. The Delmarva wetlandscape consists of thousands of geographically isolated wetlands on the Delmarva Peninsula, United States, which despite their proximity to each other have highly variable sizes, shapes, hydrology, vegetative cover, and biological communities. This physical and biological variation makes the Delmarva wetlandscape an ideal ecosystem to understand spatio-temporal heterogeneity and drivers of biogeochemistry. In this dissertation, I demonstrate that water chemistry within the Delmarva wetlandscape is heterogeneous both within and between surface water and groundwater systems (Chapter 2). Surface water chemistry was primarily influenced by temporal factors (season and month), followed by local hydrology. In contrast, groundwater chemistry was strongly influenced by water level below ground surface and interaction with organic soil layers. These results are important in understanding both internal wetlandscape water chemistry dynamics and export of solutes such as dissolved organic matter (DOM) to adjacent river ecosystems. Further, these results suggest that local biological and hydrological factors strongly affect surface water chemistry in wetlands. To explore these factors, I used an observational approach to determine the role of larval amphibians on wetland biogeochemistry (Chapter 3) and employed high-resolution chemistry sensors to study the effect of hydrological changes on surface water dissolved organic matter concentrations (Chapter 4). Animal waste can contribute substantially to nutrient cycling and ecosystem productivity, yet little is known of the biogeochemical impact of animal excretion in wetland habitats. A common and abundant amphibian in Delmarva wetlands are wood frog (Lithobates sylvaticus) tadpoles. I found that wood frog tadpole aggregations elevated nutrient recycling, microbial metabolism, and carbon cycling in Delmarva wetlands. These results provide evidence for the functional and biogeochemical role of tadpole aggregations in wetland habitats, with important implications for ecosystem processes, biodiversity conservation, and ecosystem management. To further explore the role of hydrology on DOM concentrations, I utilized high-resolution fluorescent dissolved organic matter sensors (fDOM) and applied river solute transport frameworks and metrics to wetland catchments. I found that there was heterogeneity in wetland response to changing hydrology and that seasonality and potentially bathymetry influences fDOM concentrations. Together, these studies inform our understanding of wetlandscape heterogeneity and DOM export, as well as biological and hydrological drivers of biogeochemistry. / Doctor of Philosophy / Wetlands control the movement of nutrients and carbon at local, regional, and global scales. There is a large body of knowledge demonstrating the importance of wetlands to the transport of dissolved water constituents, such as dissolved organic matter (DOM) and nutrients. However, there is little information on what controls surface water chemistry in these wetland landscapes and less is known about belowground water chemistry. In this study I examined the role of water level, wetland shape, and time (i.e., year, month of the year, and season) on surface and groundwater chemistry in wetlands. I found that water chemistry was different between surface and groundwater and that differences were primarily due to seasons or months in surface water wetlands, while water level and flooding of organic matter-rich soil layers controlled groundwater chemistry. These results indicate that there are differences in water chemistry between surface water and groundwater that are controlled by unique drivers. These results also suggested that biological processes such as animal presence may influence wetland chemistry. To understand the role of animals in wetland chemistry, I studied the effect of wood frog (Lithobates sylvaticus) tadpole waste on nutrient concentrations in wetlands and found large tadpole groups are significant recyclers of nitrogen and phosphorous, which were used by microbes as nutrients, leading to enhanced leaf litter break-down in wetlands. These findings imply that tadpoles have an important role in wetland ecosystems by creating locations of enhanced nutrient and carbon cycling and that conservation of amphibian species may also preserve ecosystem processes in wetlands. Additionally, my initial study suggested that hydrology influences DOM concentrations in wetlands. I used high-frequency chemistry sensors to detect fluorescent dissolved organic matter (fDOM) concentrations, which represents a fraction of DOM. I found that relationships and patterns in fDOM concentration were complex, and that season and wetland shape were important in wetland DOM dynamics. Overall, this dynamic behavior across seasons and between wetlands indicates that wetland response to water levels can drive differences in water chemistry between wetlands and is important in our understanding of wetland response to storm events. The information gained from these studies is important in understanding how large wetland landscapes function and control movement of nutrients and carbon. Further, my research has uncovered the role of animal species in controlling nutrient and carbon cycling in wetland environments as well as the complex response of fDOM to water level changes in individual wetlands.

Peatlands are important and common wetland ecosystems where the wet conditions result in formation and accumulation of peat, i.e., not fully decomposed organic matter. Many peatlands have been negatively affected by drainage (i.e., ditches) and restoration is conducted, although the effects on vegetation are not fully understood. This study aimed to investigate the differences in vegetation composition between natural and restored parts of peatlands and the effect of local conditions on vegetation composition. Data was collected on vegetation composition and local environmental conditions (pH, electrical conductivity and water table depth) of natural and restored parts of seven peatlands across Sweden. Statistically significant differences in the species composition between natural and restored parts were detected and natural parts were dominated by Sphagnum species while restored parts were characterised by shrubs and sedges. The environmental variables had a similar impact on the vegetation composition of both northern and southern sites and were in line with the microhabitat preferences of different species. Although restored parts still have a lower cover of Sphagnum, the vegetation community appears to develop towards compositions similar to those of natural peatlands as most plots are dominated by species found in both natural and restored parts. However, this study is based on vegetation data collected in one year and the results only show the current vegetation community composition and should be interpreted cautiously when evaluating the long-term development of vegetation composition after peatland restoration. As peatlands form during long periods of time, differences in vegetation composition after this relatively short time were expected and in line with previous research. Further studies and long-term follow-up surveys are needed to better understand the vegetation development after peatland restoration.

The Great Dismal Swamp (GDS) is a forested peatland located in the Atlantic Coastal Plain. Once a mosaic of wetland communities, disturbances (e.g., timber harvesting and ditching) have resulted in altered hydrologic regime, homogenized forest communities, and increased peat subsidence. In response, hydrologic restoration and forest management aim to enhance community composition and function. To help inform these efforts, we investigated variability and drivers of forest communities by surveying vegetation composition and structure, hydrologic indicators, and soil properties at 79 monitoring plots across GDS. Data were augmented with modeled water levels and peat depths. Our results demonstrate red maple (Acer rubrum) dominance across GDS, which decreases tree density, richness, and diversity. However, hierarchical cluster analysis identified four community types: Gum (G), Maple-Gum (M-G), Sweetgum-Maple (SG-M), and Maple (M). These communities differed in tree composition and structure; differences in other growth forms (shrubs, herbaceous, and regeneration) were limited. Modeled water levels failed to explain vegetation differences, but community associations with soil properties suggest that communities exist along a hydrologic gradient. Specifically, the G community likely exists on wetter sites whereas SG-M communities occur at drier locations. Maple-dominated communities (M and M-G; 78% of plots) likely occur across broader hydrologic gradients, explaining their dominance. However, more characterization of hydrology (i.e., time-varying water levels and soil moisture) and other drivers (e.g., site history and soil hydraulics) is needed to further explain community variation. As such, we propose future strategies for long-term monitoring to inform ongoing hydrologic restoration and forest management efforts. / Master of Science / The Great Dismal Swamp (GDS) is a large forested wetland located in southeastern Virginia and northeastern North Carolina. The GDS provides many ecosystem services such as wildlife habitat, biodiversity, water quality and storage, and carbon storage. Prior to disturbance, the GDS was composed of a variety of forest types, including stands dominated by cypress (Taxodium spp.), cedar (Chamaecyparis spp.), and pocosin (Pinus spp.) species. However, land use activities (e.g., ditching, draining, and timber harvesting) have resulted in drier conditions, forests dominated by red maple (Acer rubrum), land subsidence, and increased fire frequency. To restore the GDS to its pre-disturbance state, water control structures have been installed in drainage ditches to increase wetland water levels throughout the swamp. To inform those efforts, research is needed to understand how forest communities will respond to changing hydrology. In this study, we investigated forest composition throughout the GDS and found that four forested communities exist: Gum (G), Maple-Gum (M-G), Sweetgum-Maple (SG-M), and Maple (M). Our findings demonstrate that the M community is the most abundant community at GDS. Where red maple is present in large quantities, the variety of other tree species decreases. Additionally, we found that these communities exist on different degrees of wetness. The G community is located on wet sites, and the SG-M is located on dry sites. The more mapledominated communities (M and M-G) are found across a larger range of wetness conditions. Our findings will inform future monitoring and management efforts at GDS.

Short term studies have suggested that ground based timber harvesting on wet sites can alter soil properties and inhibit early survival and growth of seedlings. Persistence of such negative effects may translate to losses in forest productivity over a rotation. During the fall and winter of 1989, numerous salvage logging operations were conducted during high soil moisture conditions on wet pine flats in the lower coastal plain of South Carolina following Hurricane Hugo. A long-term experiment (split-plot within an unbalanced randomized complete block design) allowed assessment of long term effects of rutted and compacted primary skid trails and subsequent site preparation on soil properties and loblolly pine (Pinus taeda L.) productivity. The experiment had 12 blocks, four levels of site preparation as the whole plot factor (bedding, disking with bedding, disking, and no site preparation), and two levels of traffic as the subplot factor (primary skid trail, no obvious traffic). After 23 years, bedding and disking with bedding treatments effectively enhanced soil physical properties and stand productivity via promoting greater survival and stocking, but had little effect on the size of individual trees relative to disking and no site preparation treatments. Primary skid trails significantly reduced the size of individual trees, but had no appreciable long term effects on soil properties or stand productivity after 23 years. The study suggests that bedding is the most efficient practice to enhance soil properties, seedling survival, and stand productivity on wet sites. However, site preparation is not necessary for these soils and sites, if strictly intended to restore soil properties and stand productivity in primary skid trails. Reduction in individual tree sizes on primary skid trails emphasizes benefits in minimizing the spatial extent of disturbance. / Master of Science / Heavy equipment traffic associated with ground-based timber harvesting has potential to alter soil properties resulting in lower productivity of the subsequent forest. Various soil tillage techniques have been suggested to offset changes in soil properties and forest productivity on disturbed soils, and to enhance soil properties and forest productivity on undisturbed soils. An experiment was conducted on low-lying Atlantic Coastal Plain sites to compare the effects of four soil tillage treatments (bedding, disking, disking with bedding, no tillage) on soil properties and forest productivity 23 years after treatments were installed. Bedding displaces soil from furrows into continuous, linear mounds called beds, such that bed surfaces are above the original soil surface. Disking is a tillage practice commonly implemented in agriculture. For the disking with bedding treatment, plots were disked followed by bedding. The no tillage treatment served as a control. Additionally, the experiment provided comparison of soil properties and forest productivity between soils heavily disturbed by logging activities and relatively undisturbed soils. Bedding and disking with bedding created favorable, localized soil conditions that promoted greater loblolly pine survival which translated to approximately double the total stand volume per unit area relative to disking and no tillage treatments. Differences in the sizes of individual trees among tillage treatments were minimal. Heavily disturbed soils and soils undisturbed by logging activity were similar in terms of soil properties and loblolly pine volume per unit area; however, individual trees were smaller on heavily disturbed soils. The implications of this study provide practical guidance for forest management decisions. Of treatments compared, bedding is the most efficient to increase total stand productivity on poorly drained sites. Disking with bedding offers no additional benefits, but is more expensive to implement. Results also imply that soils disturbed by logging have potential to recover over time such that long term forest productivity is sustained. However, the reduction in individual tree sizes emphasizes benefits of minimizing soil disturbance during timber harvests.

Yes / User-generated reviews of visitor attractions, on publicly available websites, such as Tripadvisor, are frequently used in tourism research but feature less often in published cultural heritage research. In this paper, we describe a qualitative analysis of the text from user-generated reviews of three peatland heritage landscapes in the United Kingdom – Ilkley Moor, Thorne and Hatfield Moors, and Shapwick Heath – to better understand the role tangible and intangible cultural heritage play in visitor perceptions and narratives of these sites. Our analysis indicates that visitors tend to emphasise natural over cultural heritage of peatland landscapes and hold plural, highly contextual and sometimes dissonant perceptions; there is no single story of peatlands. This presents both challenges and opportunities for building public appreciation of peatland cultural heritage. User-generated reviews offer, as-yet under-explored, potential data for use by heritage researchers and managers who seek to explore how visitors understand and use sites, and may also contribute to the emerging intangible heritage of heritage landscapes. / Research Development Fund Publication Prize Award winner, June 2021.

Wet pine flats are some of the most productive and intensively-managed wetland forests in the eastern United States. Wet-weather logging of these sites causes extensive rutting and churning of the soil surface and may alter the subsurface flow of soil water. An operational-scale experiment was established in 20-year-old loblolly pine (Pinus taeda) plantations to determine the hydrologic response of wet pine flats to wet- and dry-weather harvesting operations. Three 19-ha treatment blocks were established in the coastal plain near Charleston, South Carolina. Site hydrology was monitored monthly with a 20 x 20 m grid of water table wells for 18 months prior to treatment installation. Three treatments were applied to each block: wet-weather harvesting, dry-weather harvesting, and a control (nonharvested). Prior to harvesting, the water table depths followed a uniform pattern throughout the sites with seasonal fluctuations between 5 and 75 cm below the soil surface. The uniform pattern and poor inherent drainage of the site prior to harvest was due to lack of surface topography and impedance of internal vertical drainage by a restricting Btg soil horizon. After harvesting, the hydrologic pattern changed by the degree of soil disturbance as defined by soil physical properties and microtopographic changes. Such hydrologic changes could influence long-term site productivity and interfere with management of this wetland ecosystem. / Master of Science

Le triclosan, un biocide aujourd’hui largement répandu dans l’environnement, peut engendrer des effets négatifs sur les organismes qui y sont exposés. Une infrastructure bleue, les marais filtrants, est proposée comme une solution appropriée pour mitiger les risques liés à ce contaminant. Cependant, les recherches sont toujours incomplètes quant aux impacts du triclosan sur l’état écologique et les performances de cette phytotechnologie. Mon projet de recherche a ainsi pour but d’établir les effets du triclosan en mésocosme de marais filtrants. Pour ce faire, des monocultures et polycultures de trois plantes indigènes au Canada ont été étudiées, en détaillant les impacts du triclosan sur l’efficacité du dispositif expérimental et sur la santé l’écosystème associé. Bien que les végétaux sélectionnés possèdent des taux d’enlèvement des polluants typiques (ammonium, nitrite, nitrate et orthophosphate) très variés, ainsi que des biomasses très divergentes, contrairement à d’autres études, le triclosan n’a pas eu d’impacts sur ces paramètres. Le biocide a toutefois affecté négativement l’Eutrochium maculatum au niveau physiomorphologique, mais Sporobolus michauxianus et Phragmites australis subsp. americanus présentent à l’inverse des signes de résilience. Le potentiel d’oxydo- réduction ainsi que la biomasse algale et bactérienne photosynthétique de l’effluent sont significativement réduits en présence du polluant. Le triclosan a également influencé le microbiote du substrat, des racines et de la rhizosphère, notamment en modifiant la structure des communautés bactériennes et en réduisant significativement la diversité alpha du substrat des monocultures. Cependant, les mésocosmes de polyculture exposés au triclosan semblent résistants, et l'analyse in vivo BIOLOGTM EcoPlate de la caractérisation des fonctions métaboliques des communautés a permis d'identifier la dégradation possible de molécule comparative au triclosan résiduel au sein des mésocosmes.Cette recherche contribue à approfondir la compréhension des conséquences liées au triclosan sur les marais filtrants, en plus de proposer la diversité végétale pour mitiger les impacts sur les communautés microbiennes. / Triclosan, a biocide now widely present in the environment, can have negative effects on exposed organisms. A blue infrastructure, treatment wetlands, is proposed as an appropriate solution to mitigate the risks associated with this contaminant. However, research is still incomplete on the impacts of triclosan on the ecological health and performance of this phytotechnology. The aim of my research project is therefore to establish the effects of triclosan in treatment wetland mesocosms. Thus, monocultures and polycultures of three plants native to Canada were studied, detailing the impacts of triclosan on the efficiency and ecosystem health of the experimental set-up. Although the plants selected had widely differing rates of removal of typical pollutants (ammonium, nitrite, nitrate, and orthophosphate), as well as extensively divergent biomass, unlike other studies, triclosan had no impact on these parameters. The pollutant did, however, adversely affect Eurtochium maculatum physiomorphologically, but Sporobulus michauxianus and Phragmites australis subsp. americanus showed signs of resilience. The oxidation-reduction potential as well as the algal and photosynthetic bacterial biomass of the effluent were significantly reduced in the presence of the contaminant. Triclosan also influenced the substrate and rhizosphere microbiota, notably by modifying the structure of bacterial communities and by significantly reducing the alpha diversity of the monoculture’s substrate. However, "polyculture" mesocosms exposed to triclosan appear to be more resilient, and in vivo BIOLOGTM EcoPlate characterization analysis of the community’s functionalities has even identified the possible degradation of molecule comparable to residual triclosan within the mesocosms. This research contributes to a deeper understanding of the consequences of triclosan on treatment wetlands, as well as proposing plant diversity to mitigate impacts on microbial communities.

Georgian Bay (GB) coastal wetlands are unique in their geomorphology and quality. Though not pollution impaired, these wetlands are currently threatened by regional climate change, and its influence on their water level (WL) regime. Recently, GB coastal wetlands experienced 14-years of prolonged low WLs, followed by an eight-year increase in WLs, which was a departure from the eight-year oscillations modelled from 1865-2007. To conserve these ecosystems, it is critical to understand how these wetlands responded to these atypical WL patterns. First, we compared scores from three wetland health indicators between periods of low and high WLs. We determined that abiotic indicators became falsely inflated during high waters, through the dilution of concentration-dependent parameters. We also established that biotic indicators were unaffected by changing WLs, but masked significant changes in plant and fish communities. During initial low WLs, emergent and rosette basal macrophytes, and certain fish species (blackchin, blacknose, and common shiner, bluntnose minnow, longnose gar, rock bass, and smallmouth bass) that showed a preference for shallow, low-density vegetation dominated. During high WLs, unrooted submergents and canopy macrophyte species, along with fish species (bluegill, bowfin, largemouth bass, and northern sunfish), which were positively associated with dense and deep vegetation, dominated coastal wetlands. Based on these results, I developed 14 macrophyte and 10 fish Indicator Species of low and high WLs. Using independent data, all Indicator Species were supported, although only one macrophyte and two fish species were statistically confirmed. Since the fyke nets I used throughout the two decades of WL fluctuations could not be deployed effectively, due to the development of dead tree zones (DTZs), I developed a camera array, which was not depth or substrate dependent. This research advances our understanding of coastal wetlands’ responses to changes in WLs, and highlights tools to use in similar conditions. / Dissertation / Doctor of Science (PhD) / Coastal wetlands provide critical habitat for a variety of wildlife. Starting in 1999, climate change caused Lake Huron water levels (WLs) to remain low for 14-years, rather than fluctuating periodically as it has in the past century. Then, from 2015-2022, WLs rose and stayed high for another eight-years. The key goal of this thesis was to determine if, and how these two decades of atypical WLs impacted Georgian Bay (GB), Lake Huron coastal wetlands. First, I compared the mean of three wetland health indices to see if WLs impacted their scoring. Then, I identified and validated aquatic plant and fish Indicator Species of low or high WLs. Finally, I developed a method using underwater cameras and volunteers, to survey fish in a wider range of conditions. My thesis provides patterns and methods for stakeholders to better understand and monitor coastal wetlands impacted by regional climate change and altered WLs.