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Anthropogenic impacts on riparian forest loss in East Tennessee a GIS analysis /Burhenn, Karen Elizabeth. January 2001 (has links) (PDF)
Thesis (M.S.)--University of Tennessee, Knoxville, 2001. / Vita. Includes bibliographical references (leaves 67-73).
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Fate of Microbial Indicators and Viruses in a Forested WetlandScheuerman, Phillip R., Bitton, G., Farrah, S. R. 13 June 1988 (has links)
No description available.
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Factors affecting root system response to nutrient heterogeneity in forested wetland ecosystemsNeatrour, Matthew Aaron 03 May 2005 (has links)
Soil nutrients are often heterogeneously distributed in space and time at scales relevant to individual plants, and plants can respond by selectively proliferating their roots within nutrient-rich patches. However, many environmental factors may increase or decrease the degree of root proliferation by plants. I explored how soil fertility, nitrogen (N) or phosphorus (P) limitation, and soil oxygen availability affected root system response to nutrient heterogeneity in forested wetland ecosystems of southeastern United States. Fine root biomass was not correlated with soil nutrient availability within wetland ecosystems, but was related to ecosystem-scale fertility. Root systems generally did not respond to P-rich patches in both floodplain (nutrient-rich) and depressional swamps (nutrient-poor) swamps, but results were inconclusive because the growth medium (sand) potentially hindered root growth. In floodplain forests, roots proliferated into N-rich patches but not P-rich patches, even though litterfall N:P ratios were > 15, which suggested that these ecosystems were P-limited. The combination of nutrient and oxygen heterogeneity affected root proliferation and biomass growth of three common floodplain forest species (Liquidambar styraciflua, Fraxinus pennsylvanica, and Nyssa aquatica) in a potted study, which was related to species' flood tolerance. My results suggest that the environmental context of plants can affect roots system response to nutrient heterogeneity in forested wetland ecosystems and highlights the need for field studies that investigate this phenomenon. Learning how environmental conditions affect plant response to nutrient heterogeneity at a fine-scale will provide better predictions of nutrient cycling, plant competition and succession, and forest productivity, which are important factors that determine carbon sequestration and timber production. / Ph. D.
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A comparison of three rapid evaluation procedures for pine savanna wetlandsHenderson, Cynthia Joan. January 2001 (has links)
Thesis (M.S.)--Mississippi State University. Department of Agricultural and Biological Engineering. / Title from title screen. Includes bibliographical references.
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Growth rates and the definition of old-growth in forested wetlands of the Puget Sound regionPainter, Luke. January 2007 (has links) (PDF)
Thesis (M.E.S.)--The Evergreen State College, 2007. / Title from title screen (viewed on 1/10/2008). Includes bibliographical references (p. 48-51).
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Factors influencing avian community structure in bottomland hardwood forests of the southeastern United StatesHusak, Michael Scott, January 2007 (has links)
Thesis (Ph.D.)--Mississippi State University. Department of Biological Sciences. / Title from title screen. Includes bibliographical references.
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Long term effects of wet site timber harvesting and site preparation on soil properties and loblolly pine (Pinus taeda L.) productivity in the lower Atlantic Coastal PlainNeaves, Charles Mitchell III 22 May 2017 (has links)
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
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Forest Disturbances: Occurrences and Impacts of Recreational, Hydrogeomorphic, and Climatic DisturbancesKidd, Kathryn Rebecca Booker 22 April 2015 (has links)
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.
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Variability and Drivers of Forest Communities at the Great Dismal SwampLudwig, Raymond Francis 20 July 2018 (has links)
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
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Long-Term (24-Year) Effects of Harvest Disturbances on Ecosystem Productivity and Carbon Sequestration in Tupelo-Cypress Swamps in the Mobile-Tensaw River DeltaMcKee, Scott Edward 25 April 2011 (has links)
Due to the paucity of long-term harvest impact data, the primary goals of this study were to quantify the long-term effects of different harvest disturbances twenty-four years after harvest on two major wetland functions: stand productivity and C storage. This study evaluated the effects of three harvest types that were originally applied in 1986 to a tupelo (Nyssa aquatic)-cypress (Taxodium distichum) forested wetland in the Mobile-Tensaw River Delta of southwestern Alabama. Treatments were: 1. Helicopter harvest (HELI), 2. Skidder simulation where 50% of the site was rutted to a depth of 30 cm (SKID), and 3. Helicopter harvest followed by glyphosate herbicide removal of all sprouts and seedbank regeneration for two years following harvest (GLYPH). An adjacent mature stand (94 years old) within the same original composition represented mature forest or pre-harvest reference conditions (REF). Above- and belowground plant biomass, belowground woody debris, soil C, and soil CO2 efflux were measured. Twenty-four years after treatments were applied, forest C levels were higher in SKID treatments (206.1 Mg C ha-1) than in HELI treatments (168.7 Mg C ha-1). GLYPH treatments are holding less (144.2 Mg C ha-1) while REF areas hold 332.6 Mg C ha-1. SKID treatments are also holding the most biomass of all treatments with 243.2 Mg ha-1 of overstory biomass. Ecosystem C and biomass patterns indicate HELI and SKID are becoming similar to the original site conditions represented by the REF areas. The resiliency of these highly disturbed stands are explained by the frequent inputs of non-compacted sediments, presence of species well adapted to very poorly drained and aerated conditions, high rates of coppice regeneration, shrink-swell ameliorative properties of the soil and creation of more complex microtopography within SKID treatments. / Master of Science
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