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Full-Text Articles in Life Sciences
Tree Responses To Moderate And Extreme Drought In The Northeastern United States, Ruth A. Van Kampen
Tree Responses To Moderate And Extreme Drought In The Northeastern United States, Ruth A. Van Kampen
Electronic Theses and Dissertations
Climate change is expected to lead to novel drought conditions in the Northeastern United States. Therefore, experimental studies that mimic these conditions are crucial to understand the potential impact on forests. Further, recent large scale dendrochronological studies suggest that spring and summer droughts may immediately impact tree growth while fall droughts may cause delayed impacts on growth the following growing season. Therefore, in this study, we investigated the impacts of six-week-long spring, summer, and fall droughts on the physiology and intra-annual growth on 288 saplings of six tree species native to the Northeastern United States. These species (deciduous broadleaf angiosperms, …
Modeling Hydrochemical And Vegetation Responses Of High-Elevation Forested Watersheds To Future Climate And Atmospheric Deposition Changes In The Southeastern U.S., Hailong Huang
Dissertations
Changes in climate and atmospheric acidic deposition alter biogeochemical cycles in forested ecosystems. I investigated the responses of vegetation, soil, and hydro-related processes to changes in climate and acidic deposition at five high-elevation forests in the southeastern U.S. using a biogeochemical model - PnET-BGC model. I focused on change-points and thresholds concepts that were less studied in forest ecosystems as well as seasonal variability of responses and extreme events. I applied principal component analysis (PCA) to reduce the dimensionality of data. I developed a Bayesian multi-level model to derive key biogeochemical variables response to temperature and precipitation (local) and latitude …
The Ecological Resilience Of A Tropical Montane Pine Forest To Droughts, Fire, And Hurricane Disturbance, Daniel Erland Brugger Swann
The Ecological Resilience Of A Tropical Montane Pine Forest To Droughts, Fire, And Hurricane Disturbance, Daniel Erland Brugger Swann
Electronic Theses and Dissertations
Owing to the geographic isolation and unique climatic conditions which occur in tropical montane forests (TMFs), these systems are highly sensitive to changes in both climate and disturbance. Therefore, as ongoing climate change alters disturbance regimes – potentially facilitating multiple disturbance interactions much greater than that of isolated disturbances – TMFs may be shifted to alternate stable states. However, study of TMF resilience is essentially unknown given the lack of long-term studies in these systems. We address the resiliency of the tropical montane pine forests of the Cordillera Central, Dominican Republic using long-term climate records, remeasured vegetation data, and reconstructed …
Forest Development And Regeneration Dynamics In The Context Of Global Change And Associated Adaptation Strategies, Peter Clark
Forest Development And Regeneration Dynamics In The Context Of Global Change And Associated Adaptation Strategies, Peter Clark
Graduate College Dissertations and Theses
Over the past century, forested ecosystems in northeastern North America have undergone significant changes characterized by the recovery from intensive land use and impacts from the introduction of invasive insects and disease. These changes, coupled with emerging threats posed by a changing climate present challenges to the maintenance and conservation of biodiversity, ecological functions, and delivery of critical forest ecosystem services. While management strategies to increase forest resilience and mitigate impacts from climate change have been broadly proposed, there are nascent empirical evaluations of their effectiveness. To address this uncertainty, this dissertation couples field manipulations with long-term measurements to examine …
The Impacts Of Asian Longhorned Beetle On Forests In Southern New England, Olivia Fay Box
The Impacts Of Asian Longhorned Beetle On Forests In Southern New England, Olivia Fay Box
Graduate College Dissertations and Theses
Over the past several decades, the United States has been experiencing an influx of nonnative pests due to increased globalization, and many of these pests have the potential to permanently alter the composition, structure, and function of forests. Asian longhorned beetle (ALB) is an invasive pest that came into Worcester county, MA in 2008, where the first instance of this species invading both urban and natural forested areas was documented. Within the quarantine area for this novel invasion, 30,000 trees were removed over the course of 10 years as part of management efforts focused on harvesting all host species, primarily …
Effects Of Prescribed Fire On Drought Resistance And Recovery In Mixed Conifer Forests Of Lassen Volcanic National Park, California, Zachary J. Wenderott
Effects Of Prescribed Fire On Drought Resistance And Recovery In Mixed Conifer Forests Of Lassen Volcanic National Park, California, Zachary J. Wenderott
Cal Poly Humboldt theses and projects
Forests throughout much of the western United States are experiencing increasing climatic variability, often resulting in decreased forest productivity and elevated likelihood of tree mortality. Severe drought, such California’s recent 2012-2015 drought, are projected to increase in intensity, frequency, and severity throughout much of this region in coming years. Forest management has long relied on prescribed fire and mechanical thinning to reduce fuel loads and ameliorate potential fire hazards. These treatments may also have the ability to reduce stand density, alleviate competitive pressures, and allow residual trees access to critical resources during periods of extreme stress. Utilizing a long-term National …