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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Interpreting Paleoclimate and Species Distributions of Red Spruce and Fraser Firs in the Southern Appalachians to Predict Impacts of Climate Change on Forest Habitats

Mosher, Danika L., Joyner, T. Andrew 12 April 2019 (has links)
Spruce-Fir forests are relicts from the Pleistocene and have migrated back north after the previous warming period as well as up in elevation in the southern Appalachian mountains. This in turn created sky islands of isolated, endemic, and disjunct species. These refugal forests require certain climatic parameters similar to Canada’s boreal mountains but also need additional cloud immersion and precipitation. These forests have experienced stressors in the past, but face continued threats such as air pollution and climate change. Due to limited immigration for the majority of the species on these mountains, a significant number of organisms are at risk of being endangered or extinct. Analyzing the relationships and patterns between species distribution and climatic parameters both in the past and present will help create future prediction maps. These will potentially anticipate where habitat reduction might occur and will benefit management and conservation purposes. The first study will analyze current distributions of Spruce-Fir forests to see which model and variable combination best approximates the unique mountain forests environments. Using the optimal model from the first study, the second study will examine which distributional changes may occur in the future and how these changes compare to paleo-environmental distributions. Anticipated results will show a reduction of habitat in lower peaks with minimal impact at higher peaks based on the known projected trends of cloud ceilings. This research will help with forest and conservation management and will impact a multitude of species that rely on this forest to survive.
12

Aquatic tardigrades in the Great Smoky Mountains National Park, North Carolina and Tennessee, U.S.A., with the description of a new species of Thulinius (Tardigrada, Isohypsibiidae)

Bertolani, Roberto, Bartels, Paul J., Guidetti, Roberto, Cesari, Michele, Nelson, Diane R. 13 February 2014 (has links)
As part of the All Taxa Biodiversity Inventory (http://www.dlia.org), an extensive survey of tardigrades has been conducted in the Great Smoky Mountains National Park (GSMNP) in Tennessee and North Carolina, U.S.A., by Bartels and Nelson. Freshwater tardigrades include three species in the aquatic genus Thulinius (Eutardigrada, Isohypsibiidae). A new species, Thulinius romanoi, described from stream sediment, is distinguished from all other congeners by having a sculptured cuticle. In addition, the presence of Thulinius augusti (Murray, 1907) was verified by combined morphological and molecular analysis, and nine specimens of a third species, Thulinius cf. saltursus, were also found. Thulinius augusti is a new record for the United States. Thulinius saltursus (Schuster, Toftner & Grigarick, 1978) was previously recorded in California and Ohio, but our specimens vary slightly in morphology. The list of tardigrades from streams in the GSMNP was updated to a total of 44 species, 22 of which were predominantly or exclusively aquatic.
13

A Large-Scale, Multihabitat Inventory of the Phylum Tardigrada in the Great Smoky Mountains National Park, USA: A Preliminary Report

Bartels, Paul, Nelson, Diane R. 01 March 2006 (has links)
An All Taxa Biodiversity Inventory (ATBI) is underway in the Great Smoky Mountains National Park (GSMNP), with the goal of attempting to identify all species of life in the 2000 km2 park. The GSMNP is a hotbed of biodiversity, a U.N. Biosphere Reserve, and one of the largest protected, deciduous forests in the temperate world. We have completed two field seasons of work on the tardigrades in the park (2001-2002). As of July 2003, we have collected 420 samples from soil/decomposed leaf litter, lichens and mosses on trees, and stream sediment and periphyton. A few samples from caves, bird nests, and lichens/mosses on rocks were also collected. Samples were taken from within permanent plots established for the ATBI, representing the major biological communities of the GSMNP. Tardigrades were extracted from samples using centrifugation with Ludox AM™, individually mounted on microscope slides in Hoyer's medium, and studied with phase contrast and DIC microscopy. We have examined 1524 slides from 60 samples as of July 2003. Prior to our work, only three species of tardigrades had been previously reported from a few samples in the park. We have now recorded 42 species, 8 of which we believe may be new to science. Species richness estimates were calculated using EstimateS 6 software for each of the major tardigrade habitats. Overall, we predict that there are 47 to 76 species in the GSMNP, with generally similar species richness in soil, lichen, moss, and stream habitats. Species richness estimates were also used to determine that the number of tardigrade species was greater in mosses at breast height on trees than in mosses at the base of trees.
14

Habitat Partitioning and Niche Overlap of Two Forest Thrushes in the Southern Appalachian Spruce-Fir Forests

Laughlin, Andrew J., Karsai, Istvan, Alsop, Fred J. 10 June 2013 (has links)
Guilds of species that share ecological similarities or recent ancestors are often the basis of studies concerning habitat partitioning. An interesting result of many of these studies is that means of partitioning in one area of sympatry may be different from those in disjunct areas of overlap. Here, we quantified the differences in habitat preference of two forest thrushes in the southern Appalachian Mountains. The Hermit Thrush (Catharus guttatus) has recently expanded its breeding range south along the spine of the Appalachians into the spruce-fir forests of Virginia, North Carolina, and Tennessee. There, it shares breeding habitat with the congeneric Veery (C. fuscescens), previously the only forest thrush breeding in this area. We used several multivariate analyses of habitat variables within both species' territories to understand how these species partition the available habitat and to test if these means of partitioning are similar to those found by other studies. We calculated the niche overlap to be 0.248, indicating that the habitat structures preferred by these two species are highly distinct. Hermit Thrushes generally preferred forest with a high degree of canopy closure, high percent coverage of leaf litter, and low percent cover below 3.0 m. Veery territories generally had a high percent of cover between 0.5 and 3.0 m (i.e., the shrub layer) and less canopy closure than the Hermit Thrush plots. Our data suggest that the Hermit Thrush is expanding south because it is attracted to the maturing of the spruce forests in this region.
15

Habitat Partitioning and Niche Overlap of Two Forest Thrushes in the Southern Appalachian Spruce-Fir Forests

Laughlin, Andrew J., Karsai, Istvan, Alsop, Fred J. 10 June 2013 (has links)
Guilds of species that share ecological similarities or recent ancestors are often the basis of studies concerning habitat partitioning. An interesting result of many of these studies is that means of partitioning in one area of sympatry may be different from those in disjunct areas of overlap. Here, we quantified the differences in habitat preference of two forest thrushes in the southern Appalachian Mountains. The Hermit Thrush (Catharus guttatus) has recently expanded its breeding range south along the spine of the Appalachians into the spruce-fir forests of Virginia, North Carolina, and Tennessee. There, it shares breeding habitat with the congeneric Veery (C. fuscescens), previously the only forest thrush breeding in this area. We used several multivariate analyses of habitat variables within both species' territories to understand how these species partition the available habitat and to test if these means of partitioning are similar to those found by other studies. We calculated the niche overlap to be 0.248, indicating that the habitat structures preferred by these two species are highly distinct. Hermit Thrushes generally preferred forest with a high degree of canopy closure, high percent coverage of leaf litter, and low percent cover below 3.0 m. Veery territories generally had a high percent of cover between 0.5 and 3.0 m (i.e., the shrub layer) and less canopy closure than the Hermit Thrush plots. Our data suggest that the Hermit Thrush is expanding south because it is attracted to the maturing of the spruce forests in this region.
16

An Examination of Net Primary Production in Southern Appalachian Wetlands

Maguigan, Mike 14 August 2015 (has links)
Southern Appalachian wetlands have yet to be studied in terms of net primary production (NPP), thus few studies have been conducted to examine what environmental factors have relationships with NPP. To that end, this research investigates several facets of southern Appalachian wetland production. The research was divided into three studies. The first study was conducted to answer the question of what environmental factors have relationships with NPP. It appears that stream discharge and annual precipitation had the strongest relationships with NPP (r = 0.91, p <0.05 and r = 0.81, p <0.05, respectively), yet both factors showed multicolinearity (r = 0.97, p <0.05). The strong relationships between hydrologic factors and NPP is similar to montane wetlands in the western United States. The second study was conducted to examine the relationship between water chemistry and NPP. Calcium (Ca), Magnesium (Mg), and pH were examined in order to determine if any of the aforementioned factors had a relationship with NPP. Neither Ca (r = -0.34, p = 0.0835) nor Mg (r =-0.38, p = 0.0535) had strong relationships with NPP, though pH (r = -0.66, p <0.05) had a strong negative relationship with NPP. The acidity of the stream water, driven by the acid rain in the southern Appalachians, creates enhanced conditions for wetland plants to grow. The third study was conducted to establish which vegetation index was best for estimating NPP from proximally and remotely sensed data. The findings suggest that VARIRed Edge was best for examining NPP at the in situ level, NDVI was best for examining NPP at the airborne level, and the DVI was the best for examining NPP at the satellite level. NPP in southern Appalachian wetlands is driven by the chemistry, specifically the pH, of stream discharge and annual precipitation and can be monitored by NDVI using NAIP data or DVI using Landsat data. The examination of NPP in southern Appalachians in response to environmental factors and water chemistry along with the examination of vegetation indices at three levels of platforms will help to monitor and manage these rare and unique ecosystems in the future.
17

The Magnolia Warbler <em>Dendroica magnolia</em> on Unaka Mountain, Unicoi County, TN: Possible Breeding and Habitat Analysis.

Elam, Kevin Patrick 01 August 2004 (has links) (PDF)
The chief purpose of this study is to provide information on the habitat and breeding information of Magnolia Warblers on Unaka Mountain. Magnolia Warblers breed in Canada and the Northeastern United States. There are no current breeding records for this species in Tennessee. For the habitat analysis, trees were identified on individual subplots. Shrubs were analyzed using the point-intercept method. Most of the major tree and shrub species were different than those found in Maine, which is a major breeding region for this species. Therefore, it's the structure of the habitat that is important for nesting. Fledglings were seen, giving solid proof of breeding. This study is important because it provides proof of a new breeding bird in Tennessee, and establishes habitat information necessary for its conservation.
18

The Effects of Prescribed Fire on the Herbaceous Layer in the Southern Appalachian Mountains.

Zimmerman, Michael Lee 15 August 2006 (has links) (PDF)
Prescribed fire in the southern Appalachians is a frequently used and controversial forest management practice. Research is limited on the effects of prescribed fire in the mesic southern Appalachians, where many of Tennessee's rare and regionally endemic plant species occur. This study examined the effects of prescribed fire on the herbaceous layer. Field work was conducted on six previously burned sites within the Cherokee National Forest in northeast Tennessee. Complimentary non-burned sites were selected based on similarity of physical characteristics and forest structure. The numbers of herbaceous species and individuals and the total numbers of species and individuals were determined and used to compare burned and unburned forest. Following prescribed fires there were significant reductions in the number of herbaceous species and individuals. Species with myrmecochorous (ant-dispersed) seeds were markedly reduced on burned sites. Despite considerable variation among sites, the negative impact of fire on forest herbs was clearly evident.
19

Desired Future Conditions of Riparian Areas on Southeastern National Forests

Pert, Heather Anne 19 June 2001 (has links)
Development of goals (desired future conditions (DFCs)) based on substantial public involvement is critical to the success of ecosystem management on public lands. I evaluated DFCs of riparian areas on national forests in the southern Appalachian mountains and evaluated a process for involving the public in development of DFCs for riparian areas on the Jefferson National Forest. First, I identified the major components, structures, and functions that are essential to riparian health through a literature review. Second, I examined how the key components, structures, and functions identified in the literature review were addressed in the DFCs and standards and guidelines for eight southeastern national forest management plans. In reviewing forest plans, I found a clear shift from emphasizing water quality in older forest plans to a more comprehensive incorporation of the values and functions of riparian areas in more recent plans. Riparian attributes included in DFCs varied widely and disparities between DFCs for forest plans and measurable criteria in the standards and guidelines often occurred. Finally, I designed, tested, and evaluated a public involvement process that identified public values for use in the development of DFCs for riparian areas on the Jefferson National Forest. I used a combination of alternative dispute resolution techniques and the Analytic Hierarchy Process (AHP), a participatory decision-making tool. I used surveys before and after the riparian meetings to evaluate the effectiveness of the public involvement process. Survey respondents generally were middle-aged, well-educated, high-income males who were long-time residents of the area. Riparian meeting participants indicated that the DFC for riparian areas on the JNF should strongly emphasize water quality and quantity, protection of riparian-dependent species and their habitats, and maintenance of the integrity of the relationship between riparian areas and the surrounding environment. Participants indicated recreational and commodity uses of riparian areas could occur as long as they did not negatively affect the other, more highly valued characteristics of riparian areas. Participants felt that the meetings were fair, that diverse interests were represented, that they had enough information to participate in the process, and that it was a wise use of their time. / Ph. D.
20

Species Distribution and Richness Patterns of Bird Communities in the High Elevation Forests of Virginia

Lessig, Heather 04 December 2008 (has links)
Island biogeography theory predicts that the patterns and distributions of spatially isolated populations are governed by large scale processes. The high elevations forests in the Southern Appalachians represent a series of naturally fragmented islands that harbor many isolated populations of species at the southern limits of their range. Understanding the governing forces of population dynamics in this region will enhance the probability of species persistence in the face of threats such as global warming and human development. We surveyed bird populations across multiple elevations in Virginia and combined this with a multi-scale habitat analysis to determine influences of species presence and species richness. We detected 101 species across the elevation gradient, including 12 species with special conservation status and ten species whose presence increased with increasing elevation. These ten elevation sensitive species responded to habitat variables at both the microhabitat and landscape scale, with species-specific patterns of habitat variable correlation emerging. Habitat type was least effective in predicting species presence for any elevation sensitive species. Species richness declined over the elevation gradient until the highest elevations, where this trend reversed and richness began to increase. This pattern was driven by an increase in short-distance migrants beginning at mid-elevations, which ultimately overpowered a corresponding decrease in long-distance migrants beginning at similar elevations. Habitat analysis linked these patterns to a preference of short-distance migrants for smaller, more isolated non-forested patches, and a historical lack of persistence for long-distance migrants. Conservation and management decisions for the region should focus on a multi-scale approach that preserves all habitat types for continued species presence and high species richness, although the persistence of particular elevation sensitive species is compounded by unique species-habitat relationships and the perception of islands as species-specific. Continued monitoring of these fragmented populations in light of both short- and long-term threats which span multiple scales of influence will maintain high species richness and ensure the persistence of crucial breeding habitat. / Master of Science

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