Filters: Types: OGC WMS Service (X) > partyWithName: Western Alaska Landscape Conservation Cooperative (X) > Categories: Publication (X)
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How local geomorphic and hydrologic features mediate the sensitivity of stream thermal regimes to variation in climatic conditions remains a critical uncertainty in understanding aquatic ecosystem responses to climate change. We used stable isotopes of hydrogen and oxygen to estimate contributions of snow and rainfall to 80 boreal streams and show that differences in snow contribution are controlled by watershed topography. Time series analysis of stream thermal regimes revealed that streams in rain-dominated, low-elevation watersheds were 5–8 times more sensitive to variation in summer air temperature compared to streams draining steeper topography whose flows were dominated by snowmelt. This effect was more pronounced...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: ECOSYSTEM FUNCTIONS,
ECOSYSTEM FUNCTIONS,
Federal resource managers,
LCC Network Science Catalog,
Publication,
Floods, spatially complex water flows, and organism movements all generate important fluxes of aquatic-derived materials into terrestrial habitats, counteracting the gravity-driven downhill transport of matter from terrestrial-to-aquatic ecosystems. The magnitude of these aquatic subsidies isoften smaller than terrestrial subsidies to aquatic ecosystems but higher in nutritional quality, energy density, and nutrient concentration. The lateral extent of biological aquatic subsidies is typically small, extending only a few meters into riparian habitat; however, terrestrial consumers often aggregate on shorelines to capitalize on these high-quality resources. Although the ecological effects of aquatic subsidies remain...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: ECOSYSTEM FUNCTIONS,
ECOSYSTEM FUNCTIONS,
Federal resource managers,
LCC Network Science Catalog,
Publication,
In this first worldwide synthesis of in situ and satellite-derived lake data, we find that lakesummer surface water temperatures rose rapidly (global mean = 0.34°C decade1) between 1985 and2009. Our analyses show that surface water warming rates are dependent on combinations of climate andlocal characteristics, rather than just lake location, leading to the counterintuitive result that regionalconsistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widelygeographically distributed, and their warming is associated with interactions among different climatic factors—from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing whilecloud...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: ECOSYSTEM FUNCTIONS,
ECOSYSTEM FUNCTIONS,
Federal resource managers,
LCC Network Science Catalog,
Publication,
When resources are spatially and temporally variable, consumers can increasetheir foraging success by moving to track ephemeral feeding opportunitiesas these shift across the landscape; the best examples derive from herbivore–plant systems, where grazers migrate to capitalize on the seasonal waves ofvegetation growth. We evaluated whether analogous processes occur in watershedssupporting spawning sockeye salmon (Oncorhynchus nerka), askingwhether seasonal activities ofpredators and scavengers shift spatial distributionsto capitalize on asynchronous spawning among populations of salmon. Bothglaucous-winged gulls and coastal brown bears showed distinct shifts in theirspatial distributions over the course of the summer,...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Academics & scientific researchers,
Federal resource managers,
LAKES,
LAKES,
LCC Network Science Catalog,
The Yukon–Kuskokwim Delta of Alaska,USAis a globally important region for numerous avianspecies including millions of migrating and nesting waterbirds.However, data on the current spatial distributionof critical nesting areas and the importance of environmental variables in the selection of nest locations aregenerally lacking for waterbirds in this region.We modeled nest densities for 6 species of geese and eiders thatcommonly breed on the Yukon–Kuskokwim Delta, including cackling goose (Branta hutchinsii minima),emperor goose (Chen canagica), black brant (B. bernicla nigricans), greater white-fronted goose (Anser albifronsfrontalis), spectacled eider (Somateria fischeri), and common eider (S. mollissima).Thedata...
Categories: Data,
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Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: BIRDS,
BIRDS,
CLIMATE CHANGE IMPACT ASSESSMENT MODELS,
CLIMATE CHANGE IMPACT ASSESSMENT MODELS,
DELTAS,
How local geomorphic and hydrologic features mediate the sensitivity of stream thermal regimesto variation in climatic conditions remains a critical uncertainty in understanding aquatic ecosystem responsesto climate change.We used stable isotopes of hydrogen and oxygen to estimate contributions of snow and rainfallto 80 boreal streams and show that differences in snow contribution are controlled by watershed topography.Time series analysis of streamthermal regimes revealed that streams in rain-dominated, low-elevation watershedswere 5–8 times more sensitive to variation in summer air temperature compared to streams draining steepertopography whose flows were dominated by snowmelt. This effect wasmore pronounced...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Academics & scientific researchers,
Federal resource managers,
LAKES,
LAKES,
LCC Network Science Catalog,
Global environmental change has influenced lake surface temperatures, a key driver of ecosystem structureand function. Recent studies have suggested significant warming of water temperatures in individual lakesacross many different regions around the world. However, the spatial and temporal coherence associatedwith the magnitude of these trends remains unclear. Thus, a global data set of water temperature isrequired to understand and synthesize global, long-term trends in surface water temperatures of inlandbodies of water. We assembled a database of summer lake surface temperatures for 291 lakes collectedin situ and/or by satellites for the period 1985–2009. In addition, corresponding climatic drivers (airtemperatures,...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: ECOSYSTEM FUNCTIONS,
ECOSYSTEM FUNCTIONS,
Federal resource managers,
LCC Network Science Catalog,
Publication,
An important unresolved question is how populations of coldwater-dependent fishes will respond to rapidly warming water temperatures. For example, the culturally and economically important group, Pacific salmon (Oncorhynchus spp.), experience site-specific thermal regimes during early development that could be disrupted by warming. To test for thermal local adaptation and heritable phenotypic plasticity in Pacific salmon embryos, we measured the developmental rate, survival, and body size at hatching in two populations of sockeye salmon (Oncorhynchus nerka) that overlap in timing of spawning but incubate in contrasting natural thermal regimes. Using a split half-sibling design, we exposed embryos of 10 families...
Spawning migrations of Pacific salmon (Oncorhynchus spp.) to coastal watersheds provide a rich resource subsidy to freshwater consumers. However, variation in thermal regimes and spawning activity across the landscape constrain the ability of poikilothermic consumers to assimilate eggs and carcasses. We investigated how sockeye salmon (Oncorhynchus nerka) spawning density and stream temperature affect the growth, body condition, and fatty acid composition of juvenile coho salmon (Oncorhynchus kisutch), a known egg predator, in seven tributaries of the Wood River in Southwest Alaska. We compared mean body size of juvenile coho salmon in late summer among 3–7 years per stream and found that the largest mean size occurred...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: ECOSYSTEM FUNCTIONS,
ECOSYSTEM FUNCTIONS,
Federal resource managers,
LCC Network Science Catalog,
Publication,
Intraspecific variation in the seasonal reproductive timing of Pacific salmon (Oncorhynchus sp.) has importantimplications for the resilience of salmon and for organisms in freshwater and terrestrial communities that dependon salmon resources. Stream temperature has well known associations with salmon spawn timing buthow stream and watershed geomorphology relates to the variation in salmon spawn timing is less understood.We used multivariate statistics applied to five environmental variables to compare conditions across36 watersheds in the Wood River basin in southwest Alaska. We found that the environmental conditionsin the first two axes of a principal components analysis (PCA) explained 76% of the variation in...
Categories: Data,
Publication;
Types: Citation,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Academics & scientific researchers,
Federal resource managers,
LAKES,
LAKES,
LCC Network Science Catalog,
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