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Filters: Tags: Climate Change (X) > Date Range: {"choice":"month"} (X) > partyWithName: U.S. Geological Survey (X)

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This product used species distribution modeling (SDM) to model the geographic distribution fire promoting grasses across the islands of Hawaii under both current climate conditions and under future climate change scenarios (RCP 8.5 at year 2100). The RCP 8.5 scenario assumes unmitigated and continued release of greenhouse grasses and continued human population growth. Six species of well established and widely distributed grasses (Andropogon virginicus (broomsedge), Cenchrus ciliaris (buffelgrass), Cenchrus setaceus (fountain grass), Megathyrus maximus (guinea grass, Urochloa maxima, Pancicum maximum), Melinis minutiflora (mollasses grass), and Schizachyrium microstachyum (formerly referred to as S. condensatum...
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The timing of biological events in plants and animals, such as migration and reproduction, is shifting due to climate change. Anadromous fishes are particularly susceptible to these shifts, as they are subject to strong seasonal cycles when transitioning between marine and freshwater habitats to spawn. We used linear models to determine the extent of phenological shifts in adult alewife (Alosa pseudoharengus) as they migrated from ocean to freshwater environments during spring to spawn at 12 sites along the northeast U.S. We also evaluated broad-scale oceanic and atmospheric drivers that trigger their movements from offshore to inland habitats including sea surface temperature (SST), North Atlantic Oscillation index,...
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A temperature-dependent surplus production model has been used to estimate the historical productivity of freshwater fish populations. The data utilized in this analysis includes: (1) an index of relative abundance; (2) fishery removals and subsidies from stocking programs; and (3) lake growing degree days. Surplus production represents the net change in population biomass in the absence of fishing, reflecting the interplay of population dynamics such as recruitment (gain), individual fish growth (gain), and natural mortality (loss).
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These model objects are the outputs of three Boosted Regression Tree models (for three different time periods) to explore the role of climate change and variability in driving ecological change and transformation. Response variables were the proportion of sites in each ecoregion with peak rates of change at 100-year time steps. Predictor variables included temperature anomaly, temperature trend, temperature variability, precipitation anomaly, precipitation trend, precipitation variability and ecoregion, also at 100-yr time steps. Models focused on the most distant time periods (0-21000 BP and 7500 - 21000 BP) show that rapid vegetation change was initiated across these landscapes once a 2 ℃ temperature increase...
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These model objects are the outputs of two Bayesian hierarchical models (one for the Middle Rockies and one for the Southern Rockies) to explore the role of landscape characteristics in climate-driven ecological change and transformation. We used the rate of change for each site at 100-yr time steps as the response variable, and included elevation, CHILI, aspect, slope, and TPI as fixed effects in the models, run separately for each ecoregion. We included a random intercept of site to quantify the magnitude of site-level variation in rate-of-change that may be unaccounted for by our covariates.
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This database integrates a list of vegetation transformations that occurred across the Southern and Middle Rockies since 21,000 years ago, the age of occurrence, the type of vegetation switch that occurred, whether the rates of vegetation change peaked at that time, and when applicable, the duration of peak rates of vegetation change.
    map background search result map search result map Climate drivers of rapid ecological change at the landscape scale over the last 21,000 years in the Middle and Southern Rockies, U.S.A. The role of landscape characteristics in climate-driven rapid ecological change over the last 21,000 years in the Middle and Southern Rockies, U.S.A. Type and speed of vegetation transformations over the past 21,000 years in the Middle and Southern Rockies, U.S.A. Massachusetts River Herring Daily Counts and Environmental data Species Distribution Modeling of Invasive, Fire Promoting Grasses, Across the Hawaiian Islands in Both 2023 and Under a Future Scenario of Unmitigated Climate Change in 2100 Estimates of Historical Surplus Production of Freshwater Fish Populations Across Minnesota, Wisconsin, and South Dakota from 1980-2021 Massachusetts River Herring Daily Counts and Environmental data Species Distribution Modeling of Invasive, Fire Promoting Grasses, Across the Hawaiian Islands in Both 2023 and Under a Future Scenario of Unmitigated Climate Change in 2100 Estimates of Historical Surplus Production of Freshwater Fish Populations Across Minnesota, Wisconsin, and South Dakota from 1980-2021 Climate drivers of rapid ecological change at the landscape scale over the last 21,000 years in the Middle and Southern Rockies, U.S.A. The role of landscape characteristics in climate-driven rapid ecological change over the last 21,000 years in the Middle and Southern Rockies, U.S.A. Type and speed of vegetation transformations over the past 21,000 years in the Middle and Southern Rockies, U.S.A.