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Subterranean estuaries extend inland into density-stratified coastal carbonate aquifers that contain a surprising diversity of endemic animals (mostly crustaceans) within a highly oligotrophic environment. How complex ecosystems thrive in this globally-distributed, cryptic habitat (termed anchialine) is poorly understood. The northeastern margin of the Yucatan Peninsula contains over 250 km of mapped, diver-accessible caves passages where previous studies have suggested chemoautotrophic processes are the source of carbon and energy sustaining the anchialine food web. This dataset, collected during four field events during U.S. Geological Survey (USGS) Coastal and Marine Geology Program Field Activities 2015-013-FA...
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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...
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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...
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Interactions and feedbacks between abundant surface waters and permafrost fundamentally shapelowland Arctic landscapes. Sublake permafrost is maintained when the maximum ice thickness (MIT) exceedslake depth and mean annual bed temperatures (MABTs) remain below freezing. However, decliningMIT since the1970s is likely causing talik development below shallow lakes. Here we show high-temperature sensitivity towinter ice growth at the water-sediment interface of shallow lakes based on year-round lake sensor data.Empirical model experiments suggest that shallow (1m depth) lakes have warmed substantially over the last30years (2.4°C), withMABT above freezing5 of the last 7years.This is incomparison to slower ratesofwarming...
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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...
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This project provides a better understanding how linkages among surface-water availability, connectivity, and temperature mediate habitat and trophic dynamics of the Fish Creek Watershed (FCW). These interrelated processes form a shifting mosaic of freshwater habitats across the landscape that can be classified, mapped, understood, and modeled in response to past and future climate and land-use change in a spatial and temporal context. Developing scenarios of freshwater habitat change in this context provides managers and scientists with a flexible template to evaluate a range of potential responses to climate and land-use change. Applying this approach in the FCW is made feasible because of the availability of...
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These data were acquired from 7 study sites distributed across the range of Gopherus agassizii. Data were collected from 1997 to 2002 as part of three separate studies, although data were not collected at all sites in each year. Radio-transmitters were attached to the carapace of 151 females and VHF radio-telemetry was used to relocate animals to assess reproductive status. Egg production was determined from X-radiographs taken weekly/biweekly intervals (depending on the study) using a portable X-ray machine between April and July or August of each year. In addition, the mean carapace length (MCL) of each tortoise was measured at each time of capture or recapture using calipers (mm). A nesting event was recorded...
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Lakes are dominant and diverse landscapefeatures in the Arctic, but conventional land coverclassification schemes typically map them as a singleuniform class. Here, we present a detailed lake-centricgeospatial database for an Arctic watershed in northernAlaska. We developed a GIS dataset consisting of 4362lakes that provides information on lake morphometry,hydrologic connectivity, surface area dynamics,surrounding terrestrial ecotypes, and other importantconditions describing Arctic lakes. Analyzing thegeospatial database relative to fish and bird survey datashows relations to lake depth and hydrologic connectivity,which are being used to guide research and aid in themanagement of aquatic resources in the NationalPetroleum...
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The Yukon-Kuskokwim Delta (YKD) encompasses the southernmost, warmest parts of the arctic tundra biome and is renowned for its high biological productivity and large subsistence-based human population. Ice-rich permafrost currently is widespread and strongly influences terrestrial and aquatic habitats, including local topography, vegetation, soil hydrology, and the water balance of lakes. Ground temperatures are near the freezing point, however, and recent projections indicate that the YKD is poised for widespread loss of permafrost by the end of this century. This has implications for the region’s extensive and heretofore stable terrestrial and aquatic habitats. Tundra wildfire is a common ecological “pulse” disturbance...
Categories: Data, Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: 2016, AK-00, Academics & scientific researchers, Academics & scientific researchers, Conservation NGOs, All tags...
This project integrates projections from two climate downscaling approaches into a series of future climate scenarios that will be used to assess the vulnerability of resources and ecosystem services within the Aleutian and Bering Sea Islands LCC. It consists of 4 phases: 1) downscaled climate model integration and synthesis, and engagement with key researchers; 2) the development of a set of likely future climate scenarios based on common model projections; 3) an evaluation and synthesis of vulnerabilities of key resources and ecosystem services; and 4) presentation of results and engagement of regional managers and stakeholders in a dialogue about further research and implications. This project will occur as collaboration...
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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,...
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Beaded streams are widespread in permafrost regionsand are considered a common thermokarst landform.However, little is known about their distribution, how andunder what conditions they form, and how their intriguingmorphology translates to ecosystem functions and habitat.Here we report on a circum-Arctic survey of beaded streamsand a watershed-scale analysis in northern Alaska using remotesensing and field studies.We mapped over 400 channelnetworks with beaded morphology throughout the continuouspermafrost zone of northern Alaska, Canada, and Russiaand found the highest abundance associated with mediumto high ground-ice content permafrost in moderately slopingterrain. In one Arctic coastal plain watershed, beaded...
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We used NLCD 2011, SSURGO, and SEGAP data to map the density of desired resources for open pine ecosystems and six focal species of birds and 2 reptiles within the historic range of longleaf pine east of the Mississippi River. Binary rasters were created of sites with desired characteristics such as land form, hydrology, land use and land cover, soils, potential habitat for focal species, and putative source populations of focal species. Each raster was smoothed using a kernel density estimator. Rasters were combined and scaled to map priority locations for the management of each focal species. Species’ rasters were combined and scaled to provide maps of overall priority for birds and for birds and reptiles. For...
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Lakes are prevalent in the Arctic and thus play a key role in regional hydrology. Since manyArctic lakes are shallow and ice grows thick (historically 2 m or greater), seasonal ice commonly freezes tothe lake bed (bedfast ice) by winter’s end. Bedfast ice fundamentally alters lake energy balance and meltoutprocesses compared to deeper lakes that exceed the maximum ice thickness (floating ice) and maintainperennial liquid water below floating ice. Our analysis of lakes in northern Alaska indicated that ice-out ofbedfast ice lakes occurred on average 17 days earlier (22 June) than ice-out on adjacent floating ice lakes (9July). Earlier ice-free conditions in bedfast ice lakes caused higher open-water evaporation,...
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Southwest Alaska is one of the fastest warming regions on Earth and its aquatic resources are at distinct risk from changing climate. Previous work has demonstrated that a variety of physical and biological processes are sensitive to changing climate regimes in this region, including those that support wildlife and fisheries that are of substantial importance for subsistence and commercial activities. This collaborative project resulted in the compilation of a database of existing stream, river and lake temperatures that is unmatched anywhere else in Alaska in terms of its spatial and temporal coverage. Analysis of these data resulted in refinement of the monitoring plan developed to characterize thermal responses...
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Hourly carbon dioxide (CO2) measurements from four locations of snowpack profiles with vertical spacing of 20 cm over seven winters (2010-2016) at the Glacier Lakes Ecosystem Experiments Site (GLEES) in southern Wyoming. All supporting data on snowpack properties (mostly modeled) are included to calculate hourly snowpack CO2 fluxes from raw data. In addition, turbulence from the adjacent AmeriFlux eddy covariance scaffold are included for statistical analyses. For comparison purposes, manual CO2 measurements collected at the site from 1998-1999 and 2004-2010 are also included. In addition to data, all scripts are provided to calculate fluxes and determine statistical effects of year, replicate and turbulence on...
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In Arctic ecosystems, freshwater fish migrateseasonally between productive shallow water habitatsthat freeze in winter and deep overwinter refuge in riversand lakes. How these movements relate to seasonal hydrologyis not well understood.We used passive integratedtransponder tags and stream wide antennae to track1035 Arctic grayling in Crea Creek, a seasonally flowingbeaded stream on the Arctic Coastal Plain, Alaska. Migrationof juvenile and adult fish into Crea Creek peakedin June immediately after ice break-up in the stream. Fishthat entered the stream during periods of high flow andcold stream temperature traveled farther upstream thanthose entering during periods of lower flow and warmertemperature. We used generalized...
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Numerous studies utilizing remote sensing imagery and other methods have documented that thermokarst lakes are undergoing varied hydrological transitions in response to recent climate changes, from surface area expansion to drainage and evaporative desiccation. Here, we provide a synthesis of hydrological conditions for 376 lakes of mainly thermokarst origin across high-latitude North America. We assemble surface water isotope compositions measured during the past decade at five lake-rich landscapes including Arctic Coastal Plain (Alaska), Yukon Flats (Alaska), Old Crow Flats (Yukon), northwestern Hudson Bay Lowlands (Manitoba), and Nunavik (Quebec). These landscapes represent the broad range of thermokarst environments...
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Field measurements, satellite observations, and models document a thinning trend in seasonal Arcticlake ice growth, causing a shift from bedfast to floating ice conditions. September sea iceconcentrations in the Arctic Ocean since 1991 correlate well (r=+0.69, p<0.001) to this lakeregime shift. To understand how and to what extent sea ice affects lakes, we conducted modelexperiments to simulate winters with years of high (1991/92) and low (2007/08) sea ice extent forwhich we also had field measurements and satellite imagery characterizing lake ice conditions. Alakeice growth model forced with Weather Research and Forecasting model output produced a 7%decrease in lake ice growth when 2007/08 sea ice was imposed on...
map background search result map search result map Ecosystem Dynamics and Fate of Warm Permafrost after Tundra Wildfire and Lake Drainage on the Yukon-Kuskokwim Delta Prioritization of areas for open pine ecosystem restoration in the Southeastern United States: All Species Sonde data to characterize physical and chemical properties of the Cenote Bang, a component of the Ox Bel Ha cave network within the subterranean estuary coastal aquifer of the Yucatan Peninsula, from December 2013 to January 2016 Vertical snowpack CO2 profile measurements from 2010-2016 in a subalpine forest in southern Wyoming FishCAFE: Response of an Arctic Freshwater Ecosystem to Climate and Land-use Change Distribution and biophysical processes of beaded streams in Arctic permafrost landscapes Depth, ice thickness, and ice-out timing cause divergent hydrologic responses among Arctic lakes Threshold sensitivity of shallow Arctic lakes and sublake permafrost to changing winter climate A lake-centric geospatial database to guide research and inform management decisions in an Arctic watershed in northern Alaska... Arctic sea ice decline contributes to thinning lake ice trend in northern Alaska A synthesis of thermokarst lake water balance in high-latitude regions of North America from isotope tracers Rapid and highly variable warming of lake surface waters around the globe Watershed geomorphology and snowmelt control stream thermal sensitivity to air temperature Webinar: Effects of winter climate and watershed features on summer stream temperatures in Bristol Bay, Alaska Final Report Water Temperature Regimes in the Togiak NWR and Wood-Tikchik State Park Subsidies of Aquatic Resources in Terrestrial Ecosystems A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009 Seasonal cues of Arctic grayling movement in a small Arctic stream: the importance of surface water connectivity Mojave Desert Tortoise (Gopherus agassizii) Morphometrics and Egg Data from Seven Sites across the Mojave, (1997-2002) Vertical snowpack CO2 profile measurements from 2010-2016 in a subalpine forest in southern Wyoming Sonde data to characterize physical and chemical properties of the Cenote Bang, a component of the Ox Bel Ha cave network within the subterranean estuary coastal aquifer of the Yucatan Peninsula, from December 2013 to January 2016 Ecosystem Dynamics and Fate of Warm Permafrost after Tundra Wildfire and Lake Drainage on the Yukon-Kuskokwim Delta FishCAFE: Response of an Arctic Freshwater Ecosystem to Climate and Land-use Change Distribution and biophysical processes of beaded streams in Arctic permafrost landscapes Depth, ice thickness, and ice-out timing cause divergent hydrologic responses among Arctic lakes Threshold sensitivity of shallow Arctic lakes and sublake permafrost to changing winter climate A lake-centric geospatial database to guide research and inform management decisions in an Arctic watershed in northern Alaska... Arctic sea ice decline contributes to thinning lake ice trend in northern Alaska A synthesis of thermokarst lake water balance in high-latitude regions of North America from isotope tracers Seasonal cues of Arctic grayling movement in a small Arctic stream: the importance of surface water connectivity Rapid and highly variable warming of lake surface waters around the globe Watershed geomorphology and snowmelt control stream thermal sensitivity to air temperature Webinar: Effects of winter climate and watershed features on summer stream temperatures in Bristol Bay, Alaska Final Report Water Temperature Regimes in the Togiak NWR and Wood-Tikchik State Park Subsidies of Aquatic Resources in Terrestrial Ecosystems A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009 Mojave Desert Tortoise (Gopherus agassizii) Morphometrics and Egg Data from Seven Sites across the Mojave, (1997-2002) Prioritization of areas for open pine ecosystem restoration in the Southeastern United States: All Species