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Full-Text Articles in Life Sciences
Incorporating Biodiversity-Ecosystem Function Relationships Into Models And Conservation Planning, Sarah R. Weiskopf
Incorporating Biodiversity-Ecosystem Function Relationships Into Models And Conservation Planning, Sarah R. Weiskopf
Doctoral Dissertations
Unsustainable use of nature and climate change are leading to unprecedented biodiversity declines. These declines have cascading impacts on ecosystem function and ecosystem services, and ultimately on human well-being. International agreements have been adopted that aim to address both crises. The Paris Agreement, adopted in 2015, set global emission reductions targets. In 2022, most countries agreed to the Kunming-Montreal Global Biodiversity Framework (GBF). The GBF sets 23 ambitious targets for 2030 ranging from reducing threats to biodiversity, meeting people’s needs through sustainable use and benefit sharing, and solutions for implementation. Although adopting global goals and targets is an important first …
Timing Is Everything: Climate Change Implications For Phenological Events And Reproductive Success In River Herring, Meghna N. Marjadi
Timing Is Everything: Climate Change Implications For Phenological Events And Reproductive Success In River Herring, Meghna N. Marjadi
Doctoral Dissertations
Anadromous river herring (alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis)) make annual spring spawning migrations from the ocean to freshwater, where juveniles reside before emigrating to the ocean. Climate change may alter environmental and biological cues that prompt both adult migration and juvenile emigration, with implications for adult spawning success and offspring survival for these imperiled species. Shifts in adult migration have been observed in some rivers, while impacts on reproductive success and juvenile survival remain unknown. Cues for juvenile emigration are poorly understood as they have been explored at limited spatial and temporal scales. …
The Influence Of Climate Change On The Ecology Of The Arctic Ground Squirrel In Denali National Park, Ak., Nigel A. Golden
The Influence Of Climate Change On The Ecology Of The Arctic Ground Squirrel In Denali National Park, Ak., Nigel A. Golden
Doctoral Dissertations
This dissertation research focuses on the ecology of the Arctic ground squirrel (Urocitellus parryii) in Denali National Park and Preserve, AK. The Arctic ground squirrels is a species of interest for monitoring efforts under the National Park Services’ Vital Signs Monitoring Program under the Vital Signs Monitoring program. The focus of this program is to monitor what is considered to be the most significant indicators of ecological conditions of the specific park resources that are of the greatest concern. The CAKN designated the Arctic ground squirrel (Urocitellus parryii) as one indicator species of park ecosystems. Despite being easy to observe …
Patterns And Mechanisms Of Intraspecific Trait Variation Across Thermal Gradients In A Marine Gastropod, Andrew R. Villeneuve
Patterns And Mechanisms Of Intraspecific Trait Variation Across Thermal Gradients In A Marine Gastropod, Andrew R. Villeneuve
Masters Theses
As the earth’s climate changes due to anthropogenic emissions, it has increasingly become an imperative within the ecological community to understand existing species adaptations to climate change. Much focus has been paid to how a species might react to climate change, but the role of locally adapted traits and responsible environmental mechanisms have received less attention. Quantifying how sublethal (e.g. growth rates) and lethal (e.g. thermal tolerance) trait performance vary between populations can thus improve our understanding of how populations, and the entire species, will react to climate change. Here, I quantified the spatial patterns of performance of several traits …
Interacting Effects Of Climate And Biotic Factors On Mesocarnivore Distribution And Snowshoe Hare Demography Along The Boreal-Temperate Ecotone, Alexej P. Siren
Interacting Effects Of Climate And Biotic Factors On Mesocarnivore Distribution And Snowshoe Hare Demography Along The Boreal-Temperate Ecotone, Alexej P. Siren
Doctoral Dissertations
The motivation of my dissertation research was to understand the influence of climate and biotic factors on range limits with a focus on winter-adapted species, including the Canada lynx (Lynx canadensis), American marten (Martes americana), and snowshoe hare (Lepus americanus). I investigated range dynamics along the boreal-temperate ecotone of the northeastern US. Through an integrative literature review, I developed a theoretical framework building from existing thinking on range limits and ecological theory. I used this theory for my second chapter to evaluate direct and indirect causes of carnivore range limits in the northeastern US, …
Modeling The Abundance And Distribution Of Terrestrial Plants Through Space And Time, Caroline Curtis
Modeling The Abundance And Distribution Of Terrestrial Plants Through Space And Time, Caroline Curtis
Doctoral Dissertations
Anthropogenically-driven changes threaten ecosystems and species over regional to global scales. I addressed several questions related to how species ranges will respond to these changes over large spatial and temporal extents to better understand what determines where a species occurs. First, I modeled presence and abundance of two widespread invasive plants in the southwest U.S. under current and projected future climatic conditions, from which I inferred impact risk. These results provide more insight than presence modeling alone and highlight the possibility of increased invasion pressure in the future. Second, I tested the assumption that expert-based climatic tolerance data will better …
The Effects Of Anthropogenic Stress On Nitrogen-Cycling Microbial Communities In Temperate And Tropical Soils, George S. Hamaoui Jr.
The Effects Of Anthropogenic Stress On Nitrogen-Cycling Microbial Communities In Temperate And Tropical Soils, George S. Hamaoui Jr.
Doctoral Dissertations
In this dissertation several research studies are discussed that characterize the effects of anthropogenic, or human-induced, stress on both ammonia-oxidizing and total bacterial soil microbial communities. The disturbances of land-use change in tropical, South American rainforests and artificial warming and nitrogen (N) fertilization in temperate, North American forests were investigated as these disturbances represent past and current disturbances caused by human landscape alteration and climate change. Initially, the response of soil ammonia-oxidizing microbial communities to land-use change from primary rainforest to pasture and, finally, back to secondary forest was determined. Next, these analyses of land-use change effects were expanded to …
Methods For Incorporating Ecological Impacts With Climate Uncertainty To Support Robust Flood Management Decision-Making, Caitlin M. Spence
Methods For Incorporating Ecological Impacts With Climate Uncertainty To Support Robust Flood Management Decision-Making, Caitlin M. Spence
Doctoral Dissertations
Modern and historic flood risk management involves accommodating multiple sources of sources of uncertainty and potential impacts across a broad range of interrelated sectors. Sources of uncertainty that affect planning include internal climate variability, anthropogenic changes such as land use and system performance expectations, and more recently changes in climatology that affect the resources supporting the system. Flood management systems potentially impact human settlements within and beyond the systems’ scope of planning, local weather patterns, and associated ecological systems. Federal guidelines across nations have called for greater consideration of uncertainty and impacts of water resources planning projects, but methods for …
Modeling Historical And Future Range Of Variability Scenarios In The Yuba River Watershed, Tahoe National Forest, California, Maritza Mallek
Modeling Historical And Future Range Of Variability Scenarios In The Yuba River Watershed, Tahoe National Forest, California, Maritza Mallek
Masters Theses
In California's northern Sierra Nevada mountains, the fire-dependent processes of forest ecosystems have been interrupted and altered by human land use and fire suppression. U.S. Forest Service policy directs land managers to plan for a future that includes multiple use and the restoration of resilient ecosystems. Planning decisions are to be informed by an analysis of the range of variability of ecological processes at multiple scales. Current climate trends in the northern Sierra are of increasing temperatures, increased precipitation, and earlier snowmelt, as well as changes to the frequency and duration of drought. These climate changes have and continue to …
Integrated Modeling Of Land Use And Climate Change Impacts On Multiscale Ecosystems Of Central African Watersheds, Simon Nampindo
Integrated Modeling Of Land Use And Climate Change Impacts On Multiscale Ecosystems Of Central African Watersheds, Simon Nampindo
Doctoral Dissertations
Assessment and management of ecosystem services demands diverse knowledge of the system components. Land use change occurring mainly through deforestation, expansion of agriculture and unregulated extraction of natural resources are the greatest challenges of the Congo basin and yet is central to supporting over 100 million people. This study undertook to implement an integrated modeling of multiscale ecosystems of central African watersheds and model the impact of anthropogenic factors on elephant population in Greater Virunga landscape. The study was conducted at varied scales, regional, landscape, and community. Regional study included watershed analysis and hydrological assessment using remotely sensed data implemented …