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 61 for “"tree mortality"”.
-
Modeling red pine tree mortality: An artificial neural network approach
… techniques to improve the ability of projecting tree mortality in forest growth and yield simulation. Multi-layer feed-forward artificial neural networks (ANN) are adopted to achieve the goal. The premise of ANN modeling approach is the ability of such networks to approximate any measurable or …
-
Effect of tree mortality on biogeochemical response after mountain pine beetle forest infestation, The
… are experiencing large-scale, bark beetleinduced mortality in association with a changing climate. As resulting terrestrial biogeochemical responses to this ecosystem disturbance are unclear, we hypothesized that a threshold of localized tree mortality must be exceeded before disruption of carbon …
-
Variation in tree mortality and regeneration affect forest carbon recovery following fuel treatments and wildfire
… Although fire severity and post-fire tree regeneration have been indicated as important influences on long-term carbon dynamics, it remains unclear how natural variability in these processes might affect the ability of fuel treatments to protect forest carbon resources. We surveyed a …
-
Variation in tree mortality and regeneration affect forest carbon recovery following fuel treatments and wildfire
… Although fire severity and post-fire tree regeneration have been indicated as important influences on long-term carbon dynamics, it remains unclear how natural variability in these processes might affect the ability of fuel treatments to protect forest carbon resources. We surveyed a …
-
Monitoring Abundance of Ips Bark Beetles and Determining Related Tree Mortality in Arkansas and Texas
… and confirm the amount of dead and fading trees in each trapping site. Pine engraver beetles have historically been recognized as secondary invaders of healthy trees, but observations of pine mortality in Texas and Arkansas appeared to correspond with high population densities of Ips spp. …
-
Classification of Plot-Level Fire-Caused Tree Mortality in a Redwood Forest Using Digital Orthophotography and Lidar
… the property, with variable fire intensity and mortality. This study used existing inventory data from 47 permanent 0.08 ha (1/5 ac) plots to compare the accuracy of classifying mortality resulting from the fire using digital multispectral imagery and LiDAR. The percent mortality of trees at …
-
Spatial Patterns on Virginia's Second Highest Peak: Land Cover Dynamics and Tree Mortality in Two Rare Ecosystems
… aerial vehicle (UAV) to survey the health of all trees within a 46 ha sample plot. We assessed (dead, dying, healthy) over 9,000 individual trees based on visual patterns in the imagery and produced spatial products that will inform land managers about where resources are most needed. About 7.4% …
-
The Effect of Mountain Pine Beetle Induced Tree Mortality on Home Values in the Colorado Front Range
… epidemic of Mountain Pine Beetle (MPB) induced tree mortality. This thesis estimates the losses to home values caused by deteriorating forest quality in the Front Range Counties of Larimer and Boulder Colorado. We employ a repeat sales model that allows for region specific price indices, and …
-
Modeling the impact of gypsy moth defoliation in individual tree mortality and basal area growth of northern hardwoods of central Pennsylvania
… on nearly 600 plots in central Pennsylvania. Tree and stand characteristics recorded between 1978 and 1985 include estimates of percent defoliation on individual trees. Logistic regression using maximum likelihood estimation was employed to model individual-tree mortality of 15 species in …
-
Modeling Mortality of Loblolly Pine Plantations
Accurate prediction of mortality is an important component of forest growth and yield prediction systems, yet mortality remains one of the least understood components of the system. Whole-stand and individual-tree mortality models were developed for loblolly pine plantations throughout its …
-
Effects of European Gypsy Moth Defoliation in Mixed Pine-Hardwood Stands in the Atlantic Coastal Plain
… potential exists for defoliation and possible tree mortality in mixed pine-hardwood stands. This dissertation describes a field study that was initiated to determine the susceptibility and vulnerability of pure and mixed stands of loblolly pine, oaks and sweetgum in pine-oak and pine-sweetgum …
-
Mortality Assessment of Redwood and Mixed Conifer Forest Types in Santa Cruz County Following Wildfire
… with challenging decisions on how to evaluate tree mortality. Big Creek Lumber Company, California Polytechnic State University, San Luis Obispo (Cal Poly)’s Swanton Pacific Ranch (SPR), and other resource professionals familiar with this region teamed up to develop a method for evaluating …
-
Causal factors and consequences of mixed-severity fire in Black Hills ponderosa pine forests
… during the Jasper fire. Relative density, tree size, and slope, ranked in order of importance, were influential in predicting burn severity. Relative density < 40 % and slope < 18 % represent critical thresholds where low and moderate severity were more likely to occur. High stand density …
-
Incorporating Climate Sensitivity for Eastern United States Tree Species into the Forest Vegetation Simulator
… prediction models for eastern U.S. forest tree species with climate and soil properties as predictors in order to incorporate the effects of climate and soils-based variables on forest growth and yield into FVS-Sn. Development of climate- sensitive models for site index, individual-tree …
-
Combining remotely sensed estimates of structure and function to improve quantification of forest productivity
… The last study detects insect-induced tree mortality with separated and combined models of structure from lidar and physiology from satellite imagery. Although all models tend to overestimate tree mortality, integrating lidar data enhances predictions by 6% offering valuable structural …
-
Future Forests of Bainbridge Island; Climate Change Vulnerability and Continuing Progressive Management
… island. Environmental impacts include increased tree mortality and modified forest disturbance regimes. Using GIS as a tool for spatial analysis, I identify probable physical vulnerabilities, then develop and apply a survey protocol to reveal canopy conditions and changes using a small Unmanned …
-
Ecology and Conservation of Birds of Pinyon -Juniper Woodlands
… bird species had declined in response to pine mortality between 2001 and 2005. In 2004, during the drought, and 2005, a wet year, I studied avian nesting success on study plots with different levels of pine mortality. Nest predation rates were low, and no species showed any difference in nest …
-
Modeling Endemic Bark Beetle Populations in Southwestern Ponderosa Pine Forests
… spatial distribution and susceptibility of host trees in southwestern US forested landscapes. To do this, I (1) analyzed 21 years of field data to examine the population dynamics of bark beetles and the factors that affect them, (2) created a statistical model for predicting the absolute risk of …
-
Detection of Mortality in Tropical Forests Using Remote Sensing: From Treefall Gaps to Large Disturbances
… 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 play a role on the structure and composition of tropical forests. Quantitative studies of natural …
Page 1 of 4