The design of wetlands to replace those lost to development requires quantitative understanding of the wetland water budget in order to estimate the amount of water available to the wetland over time. Many methods exist to estimate each component of the wetland water budget. In this study, monthly values of the water budget components namely, precipitation, runoff, evapotranspiration, and groundwater seepage were calculated using a water budget model and compared to on-site field measurements for a wetland in Manassas, Prince William County, VA. The monthly precipitation estimated from a weather station 32.18 km from the site differed from the on-site values by as much as 2.9 times. Runoff estimates calculated by the Soil Conservation Service (SCS) method using antecedent moisture condition (AMC) II underpredicted runoff for every month by as high as 100 percent compared to the on-site measured runoff. The choice of AMC greatly affected the SCS runoff estimates. Runoff was the dominant water budget component at the Manassas wetland. The evapotranspiration (ET) estimates using the Thornthwaite method either over or underestimated ET when compared to ET calculated from diurnal cycles of the water table in the wetland. Groundwater seepage losses were calculated using Darcy's equation with an assumed hydraulic gradient of one, and with gradients measured with nested piezometers. Seepage losses at the Manassas wetland were negligible. Overall, the water budget model provided conservative estimates of the available water in the wetland during the 10-month period of observation. / Master of Science

Over one million hectares of pocosins and wet flats in the southeastern coastal plain are intensively managed for the production of loblolly pine (Pinus taeda) plantations. These management activities may have adverse effects on soil physical properties, site hydrology, and overall site productivity. Substantial quantities of wood residues are often left on these sites by timber harvesting operations, and it was hypothesized that the incorporation of this slash into the soil could improve the soil physical properties and site hydrology. One organic pocosin site and one mineral wet flat site were chosen post-harvest for treatment. The wet flat study was organized as an incomplete block design having four blocks and six treatments: (i) conventional bedding, (ii) strip surface mulching with bedding, (iii) strip surface mulching with tillage and bedding, (iv) broadcast mulch without bedding, (v) broadcast mulch with bedding, and (vi) flat planted control. The pocosin study was organized as a randomized complete block design with four blocks and four treatments. The treatments are identical to those of the wet flat site without the broadcast mulch treatments (iv and v). Soil physical property data was analyzed pre- and post-treatment, while post-treatment site hydrology and soil water chemistry data was analyzed periodically for one year. Seedling survival and height data were analyzed after one growing season. The treatments had little effect on soil physical properties, site hydrology, soil water nutrients, or seedling survival on the wet flat study site. Bedding in general significantly increased tree height growth, but mulching had no significant effects. The treatments had little effect on soil physical properties on the pocosin study site except for soil macroporosity, which was significantly increased by bedding. Site hydrology and soil water nutrients were not significantly affected by the treatments, but seedling survival and height growth were significantly increased by bedding. Mulching had no significant effects on any of the parameters studied. / Master of Science

Human and freshwater ecosystems are intrinsically interconnected. To better design effective policies, modeling tools and valuation methods are necessary to help understanding the complex reciprocal linkages between ecosystem processes and human actions, and coupled human and natural systems (CNHS) sets up a critical paradigm to do so. It is thus of both academic and empirical appeal to integrate reliable economic valuation methods with tools and models from multiple disciplines in order to quantify the feedbacks between human and natural systems and to inform better policy design. Using freshwater resources as an example, this dissertation contains three essays which integrate natural science and economics models to understand how changes in human behavior and societal policies lead to changes in ecosystem services, and how changes in ecosystem services, in return, affect human decisions. The first two essays focus on agricultural nonpoint source pollution problems in United States and examines the impacts of potential water polices on both water polluters and water demanders. Specifically, in the first essay, a novel coupling between an ecological model of within-lake hydrodynamics and an economic model of hedonic property prices has been developed to quantify the connections between nutrient loading, lake water quality, and economic outcomes. Linking ecological processes with human decision-making provides a basis for enhanced evidence-based decision making in the context of reducing nonpoint-source pollution. In the second essay, an economic mathematical programming model is coupled with an agro-ecosystem model to investigate the behavioral adjustments and environmental pollution outcomes of water quality policies. A complete quantification of costs from all regulating sources are necessary to help pinpoint the efficient water policy design and reflecting the connection between human decisions and ecosystem processes. The third essay focus on the water quantity problem in another developed country, Australia. A discrete choice experiment method has been explored and used to provide estimates of willingness to pay for purchasing irrigation rights to restore a Ramsar-convention wetland. Water policy scenario described in this essay could directly affect the feedback between human and ecosystem processes and serve as a baseline for future planning and policy designs. By offering both conceptual and methodological advancements, this dissertation aims to improve the understanding of coupled human and natural systems and the implementation of water policies. This dissertation also provides a framework to establish multi-disciplinary dialogues and cooperation between scientists and economists in the search of efficient water polices. / Doctor of Philosophy / Freshwater resources are one of the most important elements in our daily life. It provides important goods and services to our society, but at the same time, due to human behaviors, freshwater resources are under threat in both their quality and quantity. This dissertation contains three essays which integrate knowledge from multiple disciplines to help understand and quantify the linkages between human and freshwater resources, and provides information to come up with better water polices. In the first essay, I explore the connections between nutrient loading, lake water quality, and the economic outcomes. The essay illustrates how potential change in nutrient loadings affect lake water quality, and how that induces people’s housing purchase behavior, property sales price and local governments’ property tax revenue. In the second essay, I focus on the agricultural production problem, which is one of the largest source for water quality degradation. By exploring the impacts of water policy on farmers’ production decisions, the essay sheds light on how to better design water polices to maintain farmers’ profit while simultaneously alleviating the impact of agricultural production to water qualities. In the third essay, I utilize a survey method, choice experiments, to elicit people’s willingness to pay for wetland ecosystem health. This could better allocate water resources between agricultural production use and residential use and come up with better water quantity polices.

Survival and growth of planted trees are common indices used to evaluate success of wetland restoration efforts used to compensate for wetland losses. Restoration efforts on marginal agricultural lands typically result in less than satisfactory survival and growth of desired tree species. This study evaluated seed source ecotype, greenhouse preconditioning and combinations of five mechanical site preparation techniques (mound, bed, rip, disk, pit), four levels of planting stock (gallon, tubeling, bare root, and direct seed), and three planting aids (mat, tube, none) on the survival and growth of American sycamore (Platanus occidentalis L.) and willow oak (Quercus phellos L.) planted on an old field riparian area in the Virginia Piedmont. American sycamore seedlings subjected to greenhouse flood preconditioning had 25% greater height and willow oak seedlings grown under normal greenhouse conditions had 18% greater diameter, but these greenhouse adaptations did not confer greater survivability or growth after field planting. American sycamore seeds sourced from dry ecotypes were 14% taller than wet ecotype seeds, and willow oak acorns sourced from wet ecotypes were 11% taller than dry ecotype acorns, indicating that parental ecotype may influence survivability and growth. The combination of mounding site preparation and gallon planting stock increased mean survival to 100% and aboveground dry biomass (5.44 Mg/ha/yr) in American sycamore. Willow oak had 45% greater woody stem volume with mounding site preparation 80% greater woody stem volume with gallon and bare root planting stock. Tubeling planting stock provided significant benefit relative to the low planting stock cost for American sycamore, while bare root seedlings were shown to be an effective planting stock for willow oak. The use of appropriate ecotype seed sources, use of mounding mechanical site preparation techniques and planting of species appropriate planting stock increased survival and growth of common early and mid-successional Piedmont tree species on marginal agricultural lands. Treatments that appear to be economically viable for restoration and mitigation efforts could potentially offer other economic incentives such as short rotation woody crops and timber value, which might induce additional private landowners to attempt restoration efforts in marginal old field riparian areas. / Doctor of Philosophy / In order to offset the loss of wetlands due to development, strategies are needed to create wetlands in areas along streams that are unfarmed. Survival and growth of planted trees are commonly used to evaluate the success of these new wetland areas. The goal of this research is to provide alternative methods to increase survival and growth of two common trees planted in the Piedmont of Virginia. The results show that creating mounds of soil before planting trees and planting larger trees will increase tree survival and growth in these wetland areas. Landowners and land managers can use these methods to increase the value of unfarmed land along streams while also increasing water quality and providing habitat animals that use the streams and wetlands.

Yes / Lake-dwellings in the northern Alpine region are renowned for their extraordinary organic preservation. In addition to organic remains, thousands of ceramic sherds are also recovered. This paper addresses ceramic sherds from the Late Bronze Age site Zürich-Alpenquai, and assesses over 2000 sherds for indications of erosion and abrasion in addition to quantifying sherd size and plotting the spatial distribution of these factors. Recording such wear patterns can provide indications of deposition practices in addition to environmental conditions pre- and post-deposition. In this manner the study of ceramic remains from wetland sites for abrasion can complement environmental studies addressing conditions at the time of artefact deposition, and contribute to discussions of influences for lake-settlement abandonment.

The purpose of this study was to determine the effects of amendments (control, (1x) compost, (2x) compost, (TS) topsoil, and 1x+TS) and microtopography (level, pit and mound) on three parameters (plant species composition, above-ground characteristics of Taxodium distichum, and plant root characteristics) of vegetation growing at a created tidal freshwater swamp in Virginia. None of the soil treatments met the traditional vegetation criteria for federal wetland jurisdictional determination, which only considers dominant species. When the same criteria were used for all of the species, the control, 1x, and 2x treatments met jurisdictional criteria. Considering these findings, vegetative criteria should be re-evaluated for young created wetlands. Compost addition produced the highest proportion of obligate wetland species (30%) while topsoil additions created the lowest proportion of wetland obligates (11%) and the highest proportion of upland plants. The 1x treatment generated the greatest species evenness and lowest weighted average (2.57). Topsoil treatments had the lowest diversity and evenness. Therefore, compost amendment is recommended to increase hydrophytes without compromising evenness and diversity. Bald cypress in pits were taller, had larger trunk diameter and basal trunk swelling than trees growing at higher elevations. Roots growing in mounds were more numerous with greater length than roots at lower elevations. Root length and count were highest for the control soil treatment. Amended treatments may have had lower rooting values because nutrient supply was adequate. Overall, incorporating microtopography and compost during wetland creation had a positive effect on vegetative function in this system. / Master of Science

Sediment accumulation and loss were measured in a water tupelo (Nyssa aquatica)- baldcypress (Taxodium distichum) forested wetlandin years 2, 7, 10 and 12 following harvesting disturbance. A 3 X 3 Latin Square design was replicated three times and compared to a psuedo-replicate reference stand (REF). Disturbance treatments were chainsaw fellind of trees with (1) helicopter removal of logs (HELI), (2) helicopter removal of logs followed by a simulated skidder removal (SKID), and helicopter removal of logs follwed by glyphosphate application (GLYPH). Measurements of sediment accretion show little difference between treatments and reference in the first two years following harvest. After two years the harvest treatments accumulate more sediment than the REF. Of the harvest treatments, the GLYPH plots accumulate the greatest quantities of sediment. The difference in sediment accretion between the harvest treatments begins to fade in the 12th year of recovery. Results show that skidder and helicopter removal of logs differ very little in the amount of sediment trapped, while glyphosphate application increased the wetland's ability to trap sediment beginning in the second year. In addition, sediment trappin is associated with herbaceous cover that slows flood waters and allows soil particles to precipitate from flood water. / Master of Science

The river drainages originating in the Cumberland region of Virginia, Tennessee and Kentucky are home to some of the last surviving and most diverse assemblages of native freshwater mussels. This region of the country also has historically and continues to be a major source of coal for the United States. Numerous experiments were carried out in an attempt to determine what ecotoxicological effects these activities have had on mussels as well as what has been done to correct some of the most severe cases of environmental pollution due to historical coal mining operations. Analysis of interstitial water (IW), sediment and in situ toxicity testing and chemical analyses showed that the most likely cause for mussel declines was elevated metal concentrations (Al, Cu, Fe, Pb) found in IW. Ecotoxicological assessments of the two streams (Black and Ely Creeks) most impacted by acid mine drainage (AMD) in the state of Virginia were carried out to determine their potential for future degradation of the Powell River watershed into which they drain. The Powell River is a major system still inhabited by native mussels. Sophisticated wetland systems built at Ely Creek have significantly improved the ecological health of Ely Creek, decreasing the pollution into the Powell River. Reclamation and wetland construction at Black Creek have had a positive impact but active coal mining and un-remediated AMD are still negatively affecting this system. After the watershed has been fully reclaimed the discharge from Black Creek will likely be improved. / Master of Science

Catastrophic wind events can play an important role in the stand structure and composition in Bottomland Hardwood Forests. Regeneration and stand structure following these events depends on a variety of factors, including disturbance severity, past land use, and post-disturbance management. This study revisits a 2004 survey conducted at Mermet Lake State Fish and Wildlife Area in Southern Illinois following a tornado and subsequent salvage logging operation. We established 164 plots on four different disturbance types as mapped by the original survey: Undisturbed, Transition, Wind Damaged Only, and Wind Damaged Salvaged. The objective of this study was to see how recovery differed among these. Data collected included density, basal area, and Shannon’s H, as well as visual evidence of remaining soil rutting resulting from the salvage logging operation, tree height as a metric for productivity, and invasive percent cover. There were slight but significant differences in the densities, basal area, and diversity among disturbance types, although diameter distributions revealed similar age distributions and there was no impact of the salvage logging on productivity. Evidence of soil rutting was still present, adding to microsite diversity that contributed to the significantly higher species diversity of Wind Damaged Salvaged areas. The proportion of Quercus spp. in both Wind Damaged Only and Wind Damaged Salvaged areas was lower than in Undisturbed and Transition areas, while the proportion of other species, including Fraxinus pennsylvanica and key bottomland taxa Salix spp., Taxodium distichum, and Nyssa aquatica, were higher. Invasive non-native species cover was higher in Wind Damaged Salvaged and Wind Damaged Only areas than in Transition and Undisturbed but was confined to forest edges and did not differ between Wind Damaged Salvaged and Wind Damaged Only areas. The results indicate that twenty years after the disturbance, forest structure is still recovering in tornado-damaged areas and has shifted in composition away from Quercus toward domination by Acer spp., Ulmus spp., Fraxinus pennsylvanica, and Liquidambar styraciflua species in both Wind Damaged Only and Wind Damaged Salvaged areas. The salvage logging operation did not have any negative impacts on forest recovery and supported biodiversity by further diversifying overstory community composition to include key wetland species that support the conservation area’s bottomland restoration efforts. Active management should be considered in both Wind Damaged Only and Wind Damaged Salvaged areas to prevent the spread of non-native species and ensure the persistence of Quercus and other key bottomland species in support of conservation objectives.

Depåfynd och anledningarna bakom deras nedläggelser har länge varit forskningsfrågor. Begreppet har definierats olika utav diverse författare. Flera forskare har utvecklat kriterier för vad som utgör ett depåfynd, samt om det har nedlagts i sakralt eller profant syfte. Gemensamt för en rituell tolkning är att depåplatsen har extraordinära naturliga egenskaper, något vattenmiljöer uppfattas besitta. Med området Östra Ljungby i Trolle-Ljungby socken, Skåne som undersökningsområde kommer uppsatsen ställa fyndmaterialet mot dessa kriterier. Fyndmaterialet har påträffats i både fast- och våtmark samt består till stor del av olika typer av yxor, verktyg och dolkar som typologiskt dateras till tidsperioder från mesolitikum till äldre bronsålder. Utifrån en hypotes om vattens personskap utforskas även en möjlig koppling mellan vattendepåfynden och folktrossägen. Tidsmässiga likheter och skillnader analyseras samt diskuteras i syfte att förstå deponeringsplatsernas kontinuitet. Det kan slutledas att flera sakrala depåer har nedlagts i Östra Ljungby, där vissa har gjorts på samma plats över långa tidsspann. Alltså finns det tecken som hänvisar till att undersökningsområdet haft en kontinuerlig deponeringstradition. Vidare finns en koppling till seder som gjorts för att skydda sig mot näcken. Däremot bör det belysas att en sådan koppling är svår att fastställa på grund av svårigheterna att rekonstruera forntida ritualer och ideologier. / Hoards and the reason behind their depositions have long been research questions. The term has been defined differently by various authors. Several researchers have developed criteria for what constitutes a hoard, as well as whether it has been deposited for a sacred or profane purpose. Common for a ritual interpretation is that the deposition place has natural properties that are extraordinary, something watery environments are believed to possess. With the area of Östra Ljungby in the parish of Trolle-Ljungby, Skåne as the research area, the essay will compare the finds against these criteria. The material found have been discovered in both solid ground and wetlands, and consists largely of various types of axes, tools and daggers that are typologically dated to time periods from the Mesolithic to the Early Bronze Age. Based on a hypothesis concerning the personhood of water, a possible connection between the wetland hoards and folklore is explored. Temporal similarities and differences are analysed and discussed in order to further understand the continuity of the deposition sites. It can be concluded that several sacral depositions have been made in Östra Ljungby, where some have been made in the same place over long periods of time. Thus, there are signs that point to the study area having a continuous depositional tradition. Furthermore, there is a connection to customs made in order to protect oneself against näcken. However, such a connection is difficult to establish due to the difficulties in reconstructing prehistoric rituals and ideologies.