Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 36 for “"natural disturbances"”.
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Hydrological and erosion responses to man-made and natural disturbances : insights from forested catchments in South-central Chile
Logging and large earthquakes are disturbances that may significantly affect hydrological and erosional processes and process rates, although in decisively different ways. Despite numerous studies that have documented the impacts of both deforestation and earthquakes on water and sediment fluxes, a …
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Detection of Mortality in Tropical Forests Using Remote Sensing: From Treefall Gaps to Large Disturbances
<p>The frequency, severity, and intensity of natural disturbances in tropical forests continually re-shape forest structure. At small scale, branch or tree-falls gaps and subsequent recovery are important mechanisms for carbon cycling. At landscape scale, large disturbances (blow-downs) may also …
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Demografía y ecología evolutiva del subarbusto carnívoro Drosophyllum lusitanicum (L.) Link. (Drosophyllaceae)
Natural disturbances occur in various ecosystems and have resulted in the evolution of life histories to buffer or even benefit from disturbance regimes. However, human activities increasingly interact with natural disturbances, posing potentially significant threats to the viability of …
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Integrating Forest Ecological Processes, Management, and Carbon Payments to Assess Ecosystem Service Tradeoffs
… management regimes; ii. carbon prices; and iii. natural disturbances; interact with each other. The first step is to develop a model that quantifies the relationship between forest management activities and the amount of timber harvested annually. To provide a general understanding of the …
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Three essays on forestry economics and management
… landowner welfare, and factors ranging from natural disturbances to institutional environments play important roles in influencing the outcomes for both landowners and society. This dissertation, consisting of three essays, delves into the forest sectors in both developed and developing …
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A spatial stochastic programming model for timber and core area management under risk of stand-replacing fire
… management concerns under the influence of natural disturbances. In this research study, we employ multistage full recourse stochastic programming models to explore the challenges and advantages of building spatial optimization models that account for the influences of random stand-replacing …
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Soil microbial response to land management practices and wildfire in Appalachian ecosystems
… result of different land management practices or natural disturbances can provide insight into the effects of these perturbations on ecosystem health, such as water quality and organismal growth. The studies presented in this thesis address how relevant land management or natural disturbances in …
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Bird perches and soil amendments as revegetation techniques for landslides in Puerto Rico
Landslides represent one of the most severe natural disturbances in tropical rainforests. The loss of the topsoil layer is detrimental to plant establishment and plant succession as it contains the soil seed bank, as well as the majority of the nutrients essential for plant growth. In this study, I …
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Breeding Bird Response to Post Oak Savanna Restoration Seven Years Post Management In Eastern Texas
… of their original distribution. Historically, natural disturbances such as periodic fire and grazing maintained oak savannas, but these have been reduced or eliminated, resulting in woody encroachment and subsequent habitat loss and degradation. In 2009-10, a baseline, pre-restoration study was …
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Effects of anthropogenic and natural disturbance on sedimentary organic matter quantity, nutritional quality and degradation in river, lagoon, and coastal marine ecosystems
… appear to be more sensitive to anthropogenic and natural disturbances than terrestrial ones, whose ecological consequences are more tangible. Changes in the trophic status of aquatic ecosystems and biogeochemical cycling are recurrently being reported due to either natural or anthropogenic …
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Oceanic storm surges in the outer Mackenzie Delta, NWT Canada: Remote Sensing of tundra disturbance and restoration from saline intrusion
… temperatures and decreased sea ice cover - natural disturbances are occurring at frequencies and magnitudes never before recorded (Chapin et al. 2000; Manson and Solomon 2007; Shaver and Kummerow 1992). Coastlines and low-lying terrain have been predicted to be among the environments most …
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Modeling gap dynamics, succession, and disturbance regimes of mangrove forests
… due to human activity. Aside from these impacts, natural forest disturbances exist more commonly in mangroves compared to other forests as a direct consequence of their exposed coastal location. Within this thesis I investigate the influence of natural disturbance regimes on the mangrove forest …
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Constraining natural and anthropogenic disturbances in the delivery of coastal ecosystem services
… yet are undergoing rapid degradation due to natural and anthropogenic pressures. This thesis seeks to understand how disturbances impact salt marsh and estuarine ecosystem functioning in order to refine their role in coastal ecosystem service delivery and predict future resilience. Salt marsh …
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Effects of an intermediate-scale wind event on forest composition, structure, and structural complexity
Forest disturbances alter environmental conditions, influence species composition and stand structure, and affect successional and developmental pathways. Natural disturbances differ in magnitude, severity, and return interval and range from frequent, gap-scale disturbances, to infrequent …
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Fire-Derived Charcoal Along an Ecological Gradient in the Colorado Front Range
<p>Terrestrial ecosystems are shaped by natural disturbances such as wildland fire. In the intermountain western United States, forests, shrub and grasslands adapt to repeated fires. An important long-term legacy of wildland fires is black C (BC) commonly referred to as char or charcoal. Black C is …
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Constraining Natural and Anthropogenic Disturbances in the Delivery of Coastal Ecosystem Services
… yet are undergoing rapid degradation due to natural and anthropogenic pressures. This thesis seeks to understand how disturbances impact salt marsh and estuarine ecosystem functioning in order to refine their role in coastal ecosystem service delivery and predict future resilience. Salt marsh …
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Ice storms as a disturbance factor in Appalachian oak forests
Ice (glaze) storms are frequent natural disturbances in eastern deciduous forests. Two opposing hypotheses exist in the literature regarding the effect of glaze on forest succession. In the first view, succession is said to be accelerated as pioneer species sustain greater damage than equilibrium …
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Clearcut Solutions? An Evaluation of Partial Harvesting in the Black Spruce Boreal Forest
… experiment, and a critical analysis of the natural disturbance emulation paradigm, this thesis evaluates partial harvesting in the black spruce boreal forest. Forest management in Ontario is required to emulate natural disturbances, but in regions of the boreal forest where fire cycles are …
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Mechanisms of nutrient limitation and nutrient acquisition in managed and unmanaged forest ecosystems
… interactions between global change, human and natural disturbances, and other factors on biogeochemical processes in forests is necessary to ensure the sustainability of forest management. Here I report the results of several investigations into nutrient acquisition processes in the forests of …
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