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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

Wire Netting Reduces African Elephant (<i>LOXODONTA AFRICANA</i>) Impact to Selected Large Trees in South Africa

Derham, Kelly 01 May 2014 (has links)
African elephants (Loxodonta africana) are ecosystem engineers in that they substantially alter the environment through their unique foraging and feeding habits. At high densities, elephants potentially have negative impacts on the environment, specifically to large trees. Because of this, recent increases of elephants in the Associated Private Nature Reserves (APNR) on the Western Boundary of Kruger National Park, South Africa have caused concern regarding the health of several species of tree. My objective was to assess the effectiveness of wrapping protective wire netting around the trunk of the tree in preventing and reducing bark stripping by elephants. 2,668 trees, 1352 marula (Sclerocarya birrea), 857 knobthorn (Acacia Nigrescens), and 459 false marula (Lannea schweinfurti), were assessed for elephant impact in the APNR, 1387 (52%) of which had previously been wrapped in protective wire netting (789, 548, and 50 respectively). For knobthorn and marula, wire netting significantly decreased the number of the trees that were bark stripped. For all trees, wire netting decreased the level of bark stripping especially for the highest impact levels. No trees wrapped with wire were ringbarked, compared to 23 unwired trees. In addition, wire netting had an effect on the distribution of damage for the highest impact class incurred regardless of type. A higher relative frequency of wired trees were found in lower impact categories compared to unwired trees. Wire netting is a low maintenance and ecologically valuable technique that alleviates bark stripping for some species. The judicial use of wire netting on trees could serve to maintain elephant and trees populations in areas of heavy confinement with locally high densities of elephants.
12

Host-Parasite Associations of Small Mammal Communities and Implications for the Spread of Lyme Disease

Buchholz, Matthew J 01 April 2016 (has links)
Many zoonotic pathogens of concern to human and veterinary health are maintained in the environment within small mammal reservoirs and vectored to new hosts by ectoparasitic arthropods. While the ecological relationships among small mammals, ectoparasites, and disease-causing symbiotic microorganisms are important to these dynamics, little is known about them across much of North America. The sylvatic cycle of Borrelia burgdorferi, the etiologic agent of Lyme disease, is of particular interest because Lyme disease is the most common vector-borne disease of humans in the United States. However, cases of Lyme disease are primarily confined to the northeastern and Midwestern United States, with only sporadic cases extending into the southeast. As a result, much of what is known of the ecology of Lyme disease comes from studies conducted in those regions. The goal of this study was to examine the ecological dynamics of the B. burgdorferi/vector/reservoir system in south-central Kentucky and gain insight into the relative paucity of Lyme disease in Kentucky. Small mammals were captured using live traps in three 200x50 m trapping grids within Western Kentucky University’s Green River Preserve from November 2014-October 2015. Captured small mammals were identified to species and standard measurements were recorded. Ectoparasites were removed and retained for identification. Collected blood and tissue were examined for B. burgdorferi DNA by polymerase chain reaction with primers specific to the OspA gene. The Bray-Curtis dissimilarity index, Schnabel population estimates, and the Shannon-Wiener diversity index were used to assess the structure of the small mammal communities. Parasite infestation was low but was affected by age and sex of the host, site, and season in different parasite taxa. Infestation by Ixodes scapularis, the primary vector for B. burgdorferi, was uncommon and prevalence of B. burgdorferi in blood was similar to the lowest prevalence previously observed in the Lyme disease endemic regions. We found that life history characteristics of hosts and ectoparasites drive their associations. We also suggest that the lack of an efficient vector for B. burgdorferi is the likely explanation for the few reported cases of Lyme disease in Kentucky.
13

ROOSTING BEHAVIOR, HABITAT USE, AND RELATIVE ABUNDANCE OF THE NORTHERN LONG-EARED BAT (<em>MYOTIS SEPTENTRIONALIS</em>) FOLLOWING ARRIVAL OF WHITE-NOSE SYNDROME TO MAMMOTH CAVE NATIONAL PARK

Thalken, Marissa M. 01 January 2017 (has links)
White-Nose Syndrome (WNS; Pseudogymnoascus destructans) is responsible for the regional population collapse of many cave-hibernating bat species, including the northern long-eared bat (Myotis septentrionalis), in eastern United States and Canada. I evaluated roosting behavior, habitat selection, and landscape-scale distribution of roosts of the northern long-eared bat during spring emergence and the early maternity season in Mammoth Cave National Park, Kentucky, USA, from 2015 to 2016. Logistic regression analysis comparing habitat features of roosts with random plots indicated selection of roosts reflected the costs of energetic demands by sex and reproductive status. Relative abundance of local bat species was assessed pre- and post-arrival of WNS in the Park during the summer season, with capture rates observed during the progression of WNS indicating that the fungal disease led to declines in the overall abundance of several bat species on the summer landscape, especially the northern long-eared bat. Distributional trends were quantified using spatial point pattern analysis which indicated that bats had clear roosting patterns associated with landscape level features and habitat resources. Monitoring bat populations regionally and at local scales will be imperative to helping conservation efforts for several bat species most affected by WNS.
14

SURVIVAL AND CAUSE-SPECIFIC MORTALITY OF A SOUTHEASTERN KENTUCKY DEER POPULATION

Haymes, Caleb Anderson 01 January 2017 (has links)
White-tailed deer are one of the most sought after game species in Kentucky. While much of the Commonwealth boasts high deer populations, those in southeast Kentucky are viewed as relatively low compared to other regions, even after a decade of restrictive doe harvest and multiple years of population supplementation via translocation. We studied survival and cause specific mortality of a local population of deer near the Redbird District of the Daniel Boone National Forest in Clay and Leslie County, Kentucky from January 2014 - January 2017. We estimated female annual survival at 0.89 (CI: 0.88-0.87), with an overall 3-year survival of 0.69 (CI: 0.56-0.84). Deer vehicle collisions and poaching were the most frequent mortality causes and represented 13 of 18 (72%) of mortalities. Managers should consider all forms of mortality and their relative importance in wildlife population dynamics when making harvest decisions. We recommend longer-term studies similar to ours to better understand population trends and inform regional management of this species in Kentucky.
15

Soil Moisture Profiles and Root growth of Hardwood Trees Planted in Different Groundcovers on the Steep Slopes of Reclaimed Mine Sites

Aubuchon, Elizabeth Anne 01 December 2010 (has links)
Surface mining is a major industry in eastern Tennessee that removes much of the native forest. To restore the forest, reclamation practices are used. These include planting a ground cover species with native hardwoods. Competition between the ground cover and tree species for soil resources could hinder growth and decrease survival of the trees. Northern red oak (Quercus rubra) was used for this study to examine the possible effects of this competition and the relationships between root growth and soil moisture through a field and a greenhouse experiment. A field experiment was designed using four different ground cover treatments (Soldiago nemoralis, Medicago sativa, Panicum virgatum, and bare ground) with four different hardwood species. Northern red oak was measured for this study. The results showed that the site physical factors (slope position, soil temperature, and soil moisture) were not related to each other. Soil moisture varied by depth with the lower depths (46 cm to 76 cm) was much higher than the upper depths (0 to 46 cm). Root growth did not differ by treatment or percent cover. Both soil temperature and ground cover percentage increased over the growing season. Root growth showed a relationship with depth with the upper depths of soil having more roots than the lower depths. Annual rye was used as well as switchgrass, alfalfa, and bare ground treatments for a green house study. Two-year-old Northern red oak seedlings were first planted in pots and then ground covers were established and grown for 9 weeks. Then water stress was imposed over two dry down periods during which transpiration and soil moisture were measured. Root growth was measured after harvest. The results showed a relationship between transpiration and soil moisture. Soil moisture was highest in the bare ground treatment and lowest in the annual rye treatment. Fine root development of trees was greatest in the bare and alfalfa and lowest in the annual rye. Switchgrass had the second highest soil moisture and third highest fine root development. Root growth was related to both soil moisture and transpiration.
16

Caloric Production of Black Bear Foods in Great Smoky Mountains National Park

Inman, Robert Michael 01 December 1997 (has links)
Understanding energetic potential of habitat patches is important for management designed to provide adequate habitat for wildlife species. Great Smoky Mountains National Park (GSMNP) has a high density of black bears that have been studied intensively from 1968-1997; habitats within the Park are relatively undisturbed, and similar vegetative cover types can be found throughout the southern Appalachian mountains. Black bear reproduction in the Park has been correlated to hard mast production, however little work has been done to assess the importance of soft mast. Geographic Information System (GIS) based habitat use models have been developed for bears in the Park, yet the importance of foods in determining habitat selection, and the possibility of sexual habitat segregation due to food availability have not yet been determined. The primary objectives of the study included estimation of the location, timing, and amount of caloric production by 19 important black bear foods and determination of the significance of caloric production by mast type, season, overstory vegetation type, and plant species. Secondary objectives were to test for correlation of bear habitat use with estimated caloric production from mast, and to test for sexual segregation of habitats based on caloric production. This study was limited to the northwest quadrant of GSMNP during 1995.
17

Assessing Organic Matter Breakdown and Associated Macroinvertebrate Community Structure in Headwater Streams: Effects of Hydrologic Gradients and Upland Timber Harvesting

Jarrell, Miller Scott 01 July 2009 (has links)
I examined the effects of hydrologic gradients and upland timber harvesting with different streamside management zone widths on yellow-poplar (Liriodendron tulipifera) processing and the associated macroinvertebrate community structure in the Cumberland Plateau ecophysic region, U.S.A. Prior to upland timber harvesting, 5.0 ± 0.1 g yellow-poplar leaf packs were constructed, zip-tied to gutter nails, and placed into 7 perennial and 6 temporary stream reaches with similar physiochemical and geomorphic characteristics. From December 2007 to May 2008, 3–5 leaf packs were collected per reach monthly. I found significant differences in the functional feeding group composition. Temporary reaches contained higher shredder, gathering-collector, predator, and total macroinvertebrate abundances. Shredder and total macroinvertebrate biomass was also higher in the temporary stream reaches. Gathering-collector biomass along one measurement was higher in the temporary streams. Perennial and temporary stream reaches contained similar macroinvertebrate diversity. Logging operations occurred from May 2008–December 2008. After logging operations ended, yellow-poplar leaf packs were placed into the perennial and temporary reaches of 3 control and 3 treatment streams (2 with same SMZ width, 1 different). From December 2008–May 2009. Leaf packs were collected monthly. Within the temporary and perennial stream reaches, no significant differences were detected between control and treatment yellow-poplar processing rates. No significant differences were detected between the control and treatment functional feeding group composition in abundance and biomass. Post-harvest, taxon richness increased in both the perennial control and treatment streams, while richness declined in the temporary control and increased in the temporary treatment. My findings indicate that when water is present, organic matter processing will function similarly to downstream reaches that have continual water flow. During seasonal flow patterns, macroinvertebrate communities associated with organic matter are present in temporary streams and may exceed perennial stream reaches in their density and biomass. This indicates that temporary streams are physically suitable habitats for macroinvertebrate fauna and contribute to a stream’s form and function. Overall, no observed distinct response in yellow-poplar processing rates or the associated macroinvertebrate community structure was detected within the perennial or temporary streams. Macroinvertebrate community structure varied spatially and temporally. On the taxonomic level, increases in taxa-specific abundance and biomass remain to be explained. Future research assessing interactions on the taxonomic level might help explain increases or decreases in abundance and biomass in relation to treatment effects. This study documented the response of organic matter breakdown and associated macroinvertebrate community structure during the 1st 5 months after logging. Thus, it is only a snapshot of stream ecosystem response to disturbance. Long-term studies are needed to evaluate full ecosystem response and recovery. Due to uncontrollable factors, I was not able to evaluate the success of different SMZ widths. Results documented should be treated with hesitancy, until full ecosystem response has been documented.
18

Caloric Production of Black Bear Foods in Great Smoky Mountains National Park

Inman, Robert Michael 01 December 1997 (has links)
Understanding energetic potential of habitat patches is important for management designed to provide adequate habitat for wildlife species. Great Smoky Mountains National Park (GSMNP) has a high density of black bears that have been studied intensively from 1968-1997; habitats within the Park are relatively undisturbed, and similar vegetative cover types can be found throughout the southern Appalachian mountains. Black bear reproduction in the Park has been correlated to hard mast production, however little work has been done to assess the importance of soft mast. Geographic Information System (GIS) based habitat use models have been developed for bears in the Park, yet the importance of foods in determining habitat selection, and the possibility of sexual habitat segregation due to food availability have not yet been determined. The primary objectives of the study included estimation of the location, timing, and amount of caloric production by 19 important black bear foods and determination of the significance of caloric production by mast type, season, overstory vegetation type, and plant species. Secondary objectives were to test for correlation of bear habitat use with estimated caloric production from mast, and to test for sexual segregation of habitats based on caloric production. This study was limited to the northwest quadrant of GSMNP during 1995.
19

EFFECTS OF STREAMSIDE MANAGEMENT ZONE TIMBER HARVEST ON SALAMANDER COMMUNITIES IN ROBINSON FOREST

Maigret, Thomas 01 January 2013 (has links)
Salamanders are critical components of forest ecosystems, in terms of total biomass, as well as for their value as indicators of ecosystem stress. Considering the worldwide decline in amphibian populations, the known effects of timber harvest on salamander populations, and the importance of the forest products industry in Kentucky and elsewhere, the impacts of silvicultural operations on salamander communities cannot be overlooked. The objective was to investigate the effects of three different silvicultural treatments, each involving different streamside management zone (SMZ) characteristics, on salamander communities in ephemeral streams. Data were collected by regular checks of pitfall traps, coverboards, and transect searches. Using both pre- and post-harvest data, abundance estimates were acquired using binomial mixture models. Declines in some species of terrestrial and stream-breeding salamanders were detected, and were shown to be likely related to characteristics of the corresponding silvicultural treatment. Applying modest SMZ regulations to ephemeral streams would likely alleviate these declines significantly.
20

Influence of Spoil Type on Afforestation Success and Hydrochemical Function on a Surface Coal Mine in Eastern Kentucky

Sena, Kenton L. 01 January 2014 (has links)
Surface coal mining in Appalachia has contributed to a suite of ecological impacts, both terrestrial and aquatic. Conventional reclamation in Appalachia leads to the development of hay/pasture systems dominated by nonnative grasses and legumes, with soils that are chemically and physically unfavorable to native tree growth. Several studies have shown that more weathered minespoils provide a better growth medium than unweathered spoils in Appalachia. Spoil segregation plots were constructed on Bent Mountain in Pike County, KY, to compare the suitability of three mine spoil types (BROWN weathered sandstone, GRAY unweathered sandstone, and MIXED sandstones and shales). In 2013 (after nine growing seasons) volume of planted trees was 50x higher on BROWN than on GRAY. In addition, natural colonization of unplanted groundcover and tree species was much more extensive on BROWN than GRAY or MIXED. Most water chemical parameters were similar across spoil types; however, water chemistry on all plots appears to have stabilized after nine growing seasons. Finally, rapidly developing forest on BROWN appears to be influencing water budgeting on the site, leading to lower discharge during summer months. These results indicate that BROWN weathered spoils provide a better growth medium than GRAY unweathered spoils for native trees.

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