Filters: Types: Shapefile (X) > Extensions: Shapefile (X) > Extensions: Citation (X) > Types: Citation (X) > Types: Downloadable (X) > partyWithName: Chapin, F. S., III (X) > Types: OGC WFS Layer (X)
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Categories: Data,
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Tags: P3b-Vegatation Productivity Changes Due to Temperature change
Categories: Data,
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Types: Citation,
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Tags: P2-Changes in Plant and Animal Species Due to Climate Change
Categories: Data,
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Tags: Projecting Future States 3a-Future Vulnerability to Land use Change
To determine the influence of fire and thermokarst in a boreal landscape, we investigated peat cores within and adjacent to a permafrost collapse feature on the Tanana River Floodplain of Interior Alaska. Radioisotope dating, diatom assemblages, plant macrofossils, charcoal fragments, and carbon and nitrogen content of the peat profile indicate ~600 years of vegetation succession with a transition from a terrestrial forest to a sedge-dominated wetland over 100 years ago, and to a Sphagnum-dominated peatland in approximately 1970. The shift from sedge to Sphagnum, and a decrease in the detrended tree-ring width index of black spruce trees adjacent to the collapse coincided with an increase in the growing season temperature...
In the boreal biome, fire is the major disturbance agent affecting ecosystem change, and fire dynamics will likely change in response to climatic warming. We modified a spatially explicit model of Alaskan subarctic treeline dynamics (ALFRESCO) to simulate boreal vegetation dynamics in interior Alaska. The model is used to investigate the role of black spruce ecosystems in the fire regime of interior Alaska boreal forest. Model simulations revealed that vegetation shifts caused substantial changes to the fire regime. The number of fires and the total area burned increased as black spruce forest became an increasingly dominant component of the landscape. The most significant impact of adding black spruce to the model...
Categories: Data,
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Types: Citation,
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Tags: R1-Vulnerability Forest Species and Communities to Climate Change
Categories: Data,
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Types: Citation,
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Tags: Paleo and Holocene
Categories: Data,
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Tags: Modeling,
Monitoring 3-Improve Permafrost Mapping,
and Monitoring
Categories: Data,
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Types: Citation,
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Tags: Monitoring 1-Changes in Plant and Animal Distribution: Ecosystems
The response of terrestrial ecosystems to climate warming has important implications to potential feedbacks to climate. The interactions between topography, climate, and disturbance could alter recruitment patterns to reduce or offset current predicted positive feedbacks to warming at high latitudes. In northern Alaska the Brooks Range poses a complex environmental and ecological barrier to species migration. We use a spatially explicit model (ALFRESCO) to simulate the transient response of subarctic vegetation to climatic warming in the Kobuk/Noatak River Valley (200 x 400 km) in northwest Alaska. The model simulations showed that a significantly warmer (+6 degrees C) summer climate would cause expansion of forest...
Categories: Data,
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Types: Citation,
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OGC WMS Layer,
Shapefile;
Tags: Monitoring 1-Changes in Plant and Animal Distribution: Ecosystems
Categories: Data,
Publication;
Types: Citation,
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Tags: Monitoring 1-Changes in Plant and Animal Distribution: Ecosystems
Categories: Data,
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Types: Citation,
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Tags: P2-Changes in Plant and Animal Species Due to Climate Change
Abstract: In this article we extend the theory of community prediction by presenting seven hypotheses for predicting community structure in a directionally changing world. The first three address well-studied community responses to environmental and ecological change: ecological communities are most likely to exhibit threshold changes in structure when perturbations cause large changes in limiting soil or sediment resources, dominant or keystone species, or attributes of disturbance regime that influence community recruitment. Four additional hypotheses address social-ecological interactions and apply to both ecological communities and social-ecological systems. Human responsiveness to short-term and local costs...
Categories: Data,
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Types: Citation,
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Tags: Adaptation Planning 1-Best Management Practices,
Landscape Scale Conservation
To determine the influence of fire and thermokarst in a boreal landscape, we investigated peat cores within and adjacent to a permafrost collapse feature on the Tanana River Floodplain of Interior Alaska. Radioisotope dating, diatom assemblages, plant macrofossils, charcoal fragments, and carbon and nitrogen content of the peat profile indicate approximately 600 years of vegetation succession with a transition from a terrestrial forest to a sedge-dominated wetland over 100 years ago, and to a Sphagnum-dominated peatland in approximately 1970. The shift from sedge to Sphagnum, and a decrease in the detrended tree-ring width index of black spruce trees adjacent to the collapse coincided with an increase in the growing...
Categories: Data,
Publication;
Types: Citation,
Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Projecting Future States 1-Predict or Map the Impact of Changing Permafrost
Categories: Data,
Publication;
Types: Citation,
Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
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Tags: Monitoring 1-Changes in Plant and Animal Distribution: Ecosystems
We used a combination of surveys of natural vegetation and seed-sowing and seedling transplant experiments to determine the relative importance of competition and microenvironmental modification as mechanisms by which understory vegetation influences the establishment of tree seedlings in an Alaskan postfire boreal forest. Seedlings of white spruce (Picea glauca) and paper birch (Betula papyrifera) became established more frequently than expected in patches that were dominated by horsetail (Equisetum arvense), and less frequently than expected in patches of bluestem (Calamagrostis canadensis) and other vegetation. Similarly, birch and spruce, whether sown directly or transplanted as seedlings into horsetail-dominated...
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Categories: Data,
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Types: Citation,
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Tags: R2a-Impact Climate Change Vegatation and Subsistence
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