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Full-Text Articles in Life Sciences
Impacts Of Climate And Wildfire On Western Larch Regeneration, Spencer T. Vieira
Impacts Of Climate And Wildfire On Western Larch Regeneration, Spencer T. Vieira
Graduate Student Theses, Dissertations, & Professional Papers
Fire plays a critical role in forests of the western United States (US), but as wildfire and climate deviate from historical patterns, increasing fire activity may significantly alter forest ecosystems. To understand the impacts of changing climate and wildfire activity on conifer forests, we studied the impact of wildfire and annual post-fire climate on western larch (Larix occidentalis) regeneration. We destructively sampled 1651 seedlings from 57 sites within 32 fires that burned at moderate or high severity from 2000-2015 in the northwestern US. Using dendrochronological methods, we estimated germination years of seedlings to calculate annual recruitment rates. We …
Quantifying The Carbon Stored And Sequestered By The Trees On Pomona College’S Campus, Paola A. Giron-Carson
Quantifying The Carbon Stored And Sequestered By The Trees On Pomona College’S Campus, Paola A. Giron-Carson
Scripps Senior Theses
We are experiencing a climate crisis that must be confronted with strategic mitigation. Pomona College contributes to the climate crisis through its emissions for which there is a baseline record. However there is no baseline record of the climate mitigation currently performed by the trees on Pomona’s campus through carbon storage. This study seeks to determine a current baseline quantity of carbon stored and sequestrated by Pomona’s trees as well as possible courses of climate mitigation for Pomona College to take. Initial information gathering was conducted through interviews with several stakeholders. This study was conducted using data collected prior to …
Climate Sensitive Diameter Growth Models For Major Tree Species In Mississippi, Sujan Subedi
Climate Sensitive Diameter Growth Models For Major Tree Species In Mississippi, Sujan Subedi
Theses and Dissertations
Anticipated climate change and increasing wood demand require dependable diameter growth models for adaptive forest management. We used a mixed-effects modeling approach with Forest Inventory and Analysis (FIA) data to fit diameter growth models for loblolly pine, other softwood species (slash pine, shortleaf pine, and longleaf pine), sweetgum, and other hardwood (southern red oak, red maple, and water oak) species. Climatic variables coupled with individual tree attributes and competition factors improved climate insensitive models. Growth of loblolly pine and sweetgum was positively correlated with mean temperature of the coldest month. Mean temperature of the warmest month negatively influenced diameter growth …
Common Garden Study Reveals Frost-Tolerant, Generalist Northern Seed Sources Are Best Suited To Expand Range Of Quercus Rubra, Emily Lindback
Common Garden Study Reveals Frost-Tolerant, Generalist Northern Seed Sources Are Best Suited To Expand Range Of Quercus Rubra, Emily Lindback
Dissertations, Master's Theses and Master's Reports
Climate change is shifting the potential suitable range of northern red oak (Quercus rubra L.) faster than it can migrate, creating an adaptation lag. Quercus rubra is prominent in eastern North American forests and important for its carbon sequestration, ecological roles, and economic significance. Our study addresses which populations of Q. rubra are best suited for climatic conditions at the northern and central range limits. Our findings can inform forestry management policies such as assisted migration, where species are transferred within their native range to mitigate the effects of climate change. We planted over 800 Q. rubra seedlings …
Drought, Tree Mortality, And Regeneration In Northen California, Sophia Lb Lemmo
Drought, Tree Mortality, And Regeneration In Northen California, Sophia Lb Lemmo
Cal Poly Humboldt theses and projects
The 2012-2016 California drought was the most severe in the state’s recorded history, contributing to the death of millions of trees. While the effects of this drought on forests are relatively well studied in the central and southern Sierra Nevada, less is known about its effects on the heavily timbered and diverse forests of northern California. Through sampling 54 0.25 ha plots in northern California, this study compared tree mortality and regeneration patterns before, during, and after California’s most recent record-setting drought. This study evaluated 1) the influence of habitat and competitive covariates on mortality and regeneration trends using ridge …
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 Future Of Maine's Forests Under Alternative Socioeconomic, Climate And Conservation Pathways, Jianheng Zhao
The Future Of Maine's Forests Under Alternative Socioeconomic, Climate And Conservation Pathways, Jianheng Zhao
Electronic Theses and Dissertations
Maine is a historically important timber supply region in North America and understanding the potential change in forestlands and their product industries affected by climate change and various socio-economic conditions can better improve the forest healthy and sustain a sustainable product industry. A statistical harvest choice model for the state of Maine was developed in chapter 1. It was estimated using a multinomial logit model of two products, under varying management intensities, and ownership classifications across varying market conditions. Results indicate that stumpage prices have a significant effect on forest landowners' harvest decisions and that the expansion of conservation land …
A Comparison Of Fuel Reduction Methods For Wildfire Risk Management And Climate Change Resiliency In Mixed Conifer Forests In The Sierra Nevada, Heather Navle
Master's Projects and Capstones
Wildfires in the mixed conifer forests of California’s Sierra Nevada have been a common and natural disturbance for thousands of years, historically occurring every 3 to 30 years. The flora and fauna of the mixed conifer forest have evolved to depend on low to moderate severity wildfires for reproduction, foraging, and habitat. However, the Sierra Nevada has experienced dramatic environmental changes over the past ~150 years as a result of three main factors: wildfire suppression, climate change, and habitat loss. Because of the threat wildfires pose to human lives, property and timber harvest, they have been suppressed to an extent …
Ecological Considerations And Application Of Urban Tree Selection In Massachusetts, Ashley Mcelhinney
Ecological Considerations And Application Of Urban Tree Selection In Massachusetts, Ashley Mcelhinney
Masters Theses
Trees provide countless environmental, economic, and societal benefits to the urban environment, and may become increasingly important to maintaining environmental quality and human well-being in the face of increasing urbanization and climate change. However, trees in these urban areas are rapidly diminishing across the United States. Much of this loss can be prevented with proper planning and management, focused on selecting tree species that are both well-suited to the area’s growing conditions and able to survive the many stress factors in an urban setting. Choosing which tree species to plant in Massachusetts is especially challenging considering the lack of resources …
A Systems Approach To Modelling The Effects Of Climate Change On Agroforestry: A Case Study In Western Tanzania, Elaine M. Samuel
A Systems Approach To Modelling The Effects Of Climate Change On Agroforestry: A Case Study In Western Tanzania, Elaine M. Samuel
Electronic Thesis and Dissertation Repository
Climate change is anticipated to have significant effects on agricultural production in sub-Saharan Africa as the magnitude of weather events increase in severity. Smallholder farmers in western Tanzania are potentially vulnerable to climate change impact as crops rely on precipitation as the only source of water. It is prudent to evaluate different modes of agricultural adaptations, such as agroforestry, that these farmers can easily adopt to improve their resiliency to the effects of climate change. System dynamics modelling is a cost-effective tool to simulate the long-term behaviour of agroforestry systems under future climate conditions. Water, Nutrient, and Light Capture in …
Carbon Life-Cycle And Economic Analysis Of Forest Carbon Sequestration And Woody Bioenergy Production, Prativa Shrestha
Carbon Life-Cycle And Economic Analysis Of Forest Carbon Sequestration And Woody Bioenergy Production, Prativa Shrestha
Theses and Dissertations--Forestry and Natural Resources
Sequestering carbon in standing biomass, using woody bioenergy, and using woody products are the three potential ways to utilize forests in reducing greenhouse gases (GHGs) and mitigating climate change. These forestry related strategies are, however, greatly influenced by the existing markets and market based policies. This study focuses on the first two forest strategies. It investigates the combined impact of carbon and woody bioenergy markets on two different types of forests in the US – oak dominated mixed hardwood forests in the Central Hardwood Forests Region and loblolly pine forests in the southeastern US. A modification of the Harman model …