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As the Earth’s climate changed in the ancient past, many species moved across the landscape to track adequate environmental conditions. Some species took shelter in remaining pockets of suitable climates, referred to as refugia. For example, refugia harbored species when vast glaciers covered much of the land, allowing them to survive and migrate again across the landscape as temperatures warmed and ice melted. Modern changes in climate are similarly compelling species to move, and some of those species may seek shelter from increasingly hostile conditions in refugia. Modern climate refugia will likely take many different forms. For example, larger-scale macrorefugia may be areas of relative climate stability that...
Droughts and insect outbreaks are primary disturbance processes linking climate change to tree mortality in western North America. Refugia from these disturbances—locations where impacts are less severe relative to the surrounding landscape—may be priorities for conservation, restoration, and monitoring. In this study, hypotheses concerning physical and biological processes supporting refugia were investigated by modelling the landscape controls on disturbance refugia that were identified using remotely sensed vegetation indicators. Refugia were identified at 30-m resolution using anomalies of Landsat-derived Normalized Difference Moisture Index in lodgepole and whitebark pine forests in southern Oregon, USA, in...
During droughts, localized areas of the landscape (drought refugia) retain surface water and soil moisture needed to sustain wildlife and vegetation. Remote sensing from satellite imagery offers powerful tools to identify refugia and study their responses to changing weather patterns over time. This talk will present two recent applications of remote-sensing analysis related to drought refugia research in southern Oregon. In one study, hydrologic resilience of springs was inferred using remote sensing of groundwater-dependent vegetation in a semi-arid sage steppe ecosystem. In another, refugia from drought and mountain pine beetle were identified in lodgepole pine and whitebark pine forest. Efforts are currently...
Project Summary: Warmer temperatures and less precipitation in the western U.S. related to climate change are harming many important natural resources, including forests, rivers, and many fish and wildlife species. Climate refugia provide a potential opportunity for conserving resources and biodiversity in the face of climate change. These refugia are places where the climate will likely change less than the surrounding landscape and/or places in a landscape where species may move to find more suitable climates. For example, because climate change may alter the frequency, duration, or severity of droughts, small habitats that naturally retain water (drought refugia) may become increasingly important to many natural...
Spring‐fed wetlands are ecologically important habitats in arid and semi‐arid regions. Springs have been suggested as possible hydrologic refugia from droughts and climate change; however, springs that depend on recent precipitation or snowmelt for recharge may be vulnerable to warming and drought intensification. Springs that are expected to maintain their ecohydrologic function in a warmer, drier climate may be priorities for conservation and restoration. Identifying such springs is difficult because many springs lack hydrologic records of adequate temporal extent and resolution to assess their resilience to water cycle changes. This study demonstrates proof‐of‐concept for the assessment of certain spring types...
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This data release includes data processing scripts, data products, and associated metadata for a novel remote-sensing based approach to assess resilience of spring-dependent ecosystems to inter-annual changes in water availability. This approach uses remotely-sensed Normalized Difference Vegetation Index (NDVI) to (1) delineate surface moisture zones (SMZs) in the vicinity of mapped springs in a semi-arid sage-steppe landscape, (2) derive quantitative indicators of the relative resilience of these SMZs to inter-annual changes in water availability, and (3) synthesize these indicators into an overall resilience score for each cluster of springs. Specifically, for 39 spring clusters mapped in the National Hydrography...
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This data release includes data-processing scripts, data products, and associated metadata for a remote-sensing based approach to characterize vegetation conditions within a dry, mixed conifer forest study area in southern Oregon in 2001 (a single year drought without any widespread insect mortality) and 2009 (during a multi-year drought that coincided with a severe outbreak of mountain pine beetle; MPB). This analysis involved several steps. First, time-series climate data were compiled and plotted to identify drought periods. Similarly, time-series data representing insect outbreaks were compiled and plotted to identify trends in insect mortality. The study area was classified into forest canopy types using existing...
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The southeastern U.S. contains a unique diversity of ecosystems that provide important benefits, including habitat for rare wildlife and plants, improved water quality, and recreation opportunities. Understanding how climate change will affect these ecosystems is vital for knowing how best to protect them and the services they supply. The goal of this project was to assess the climate change vulnerability of 12 key ecosystems in the southeastern U.S. and Caribbean, ranging from Caribbean coastal mangrove to Nashville Basin limestone glade and woodland. Scientists used the existing scientific literature and geospatial analysis to determine each ecosystem’s sensitivity to changes in climate, its exposure level to...
Background/Question/Methods In arid and semi-arid landscapes, springs are important sources of surface water and soil moisture for wildlife and vegetation. Springs have been suggested as possible climate-change refugia, however, springs that depend on recent precipitation or snowmelt for recharge may be vulnerable to warming and drought intensification. Effective conservation of spring-dependent ecosystems—and the biodiversity they support—requires empirical approaches to assess resilience of springs to water cycle changes. Unfortunately, hydrologic data is unavailable for most springs, and those hydrologic records that do exist typically have inadequate temporal extent and resolution to adequately characterize...
    map background search result map search result map Assessing Climate-Sensitive Ecosystems in the Southeastern U.S. Delineation and characterization of remotely sensed vegetation conditions in spring-dependent ecosystems, Harney County, Oregon Analysis of remotely-sensed vegetation conditions during droughts and a mountain pine beetle outbreak, Gearhart Mountain Wilderness, Oregon Delineation and characterization of remotely sensed vegetation conditions in spring-dependent ecosystems, Harney County, Oregon Assessing Climate-Sensitive Ecosystems in the Southeastern U.S.