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Abstract (from http://www.sciencedirect.com/science/article/pii/S1873965215000110): The goal of this study was to assess the importance of the 2007 sea ice retreat for hydrologic conditions on the Alaskan North Slope, and how this may have influenced the outbreak of tundra fires in this region. This study concentrates on two years, 2007 and 1996, with different arctic sea ice conditions and tundra fire activity. The year of 2007 is characterized by a low summer sea ice extent (second lowest) and high tundra fire activity, while 1996 had high sea ice extent, and few tundra fires. Atmospheric lateral boundary forcing from the NCEP/NCAR Reanalysis drove the Weather Research and Forecast (WRF) model, along with varying...
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This data set describes the predicted daily climate (temperature and rainfall) for low, mid, and high-elevations on Mona Loa, Island of Hawaii from 2098-2100. Climate predictions are based on 3 alternative climate scenarios (RCP 4.5, A1B, and RCP 8.5) - see Liao et al. 2015 for more details and climate references. The predicted daily risk of susceptible Hawaiian honeycreepers are based on the daily climate data, mosquito abundance and other factors. Also see Samuel et al. 2011 The dynamics, transmission, and population impacts of avian malaria in native Hawaiian birds: a modeling approach. Ecological Applications 21:2960-2973 for description of the epidemiological model used for avian malaria risk predictions.
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/gcb.12875/abstract): Permafrost thaw can alter the soil environment through changes in soil moisture, frequently resulting in soil saturation, a shift to anaerobic decomposition, and changes in the plant community. These changes, along with thawing of previously frozen organic material, can alter the form and magnitude of greenhouse gas production from permafrost ecosystems. We synthesized existing methane (CH 4) and carbon dioxide (CO 2) production measurements from anaerobic incubations of boreal and tundra soils from the geographic permafrost region to evaluate large-scale controls of anaerobic CO 2 and CH 4 production and compare the relative importance...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2016GB005493/abstract): Phytoplankton growth in the Gulf of Alaska (GoA) is limited by iron (Fe), yet Fe sources are poorly constrained. We examine the temporal and spatial distributions of Fe, and its sources in the GoA, based on data from three cruises carried out in 2010 from the Copper River (AK) mouth to beyond the shelf break. April data are the first to describe late winter Fe behavior before surface water nitrate depletion began. Sediment resuspension during winter and spring storms generated high “total dissolvable Fe” (TDFe) concentrations of ~1000 nmol kg−1 along the entire continental shelf, which decreased beyond the shelf break. In July, high...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/fwb.12290/abstract): Freshwater mussels (Unionidae) are a highly imperilled faunal group. One critical threat is thermal sensitivity, because global climate change and other anthropogenic activities contribute to increasing stream temperature and altered hydrologic flow that may be detrimental to freshwater mussels. We incorporated four benthic environmental components – temperature, sediment, water level (a surrogate for flow) and a vertical thermal gradient in the sediment column – in laboratory mesocosm experiments with juveniles of two species of freshwater mussels (Lampsilis abrupta and Lampsilis radiata) and tested their effects on survival, burrowing...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2014GL060199/abstract): While recent work demonstrates that glacial meltwater provides a substantial and relatively labile flux of the micronutrient iron to oceans, the role of high-latitude estuary environments as a potential sink of glacial iron is unknown. Here we present the first quantitative description of iron removal in a meltwater-dominated estuary. We find that 85% of “dissolved” Fe is removed in the low-salinity region of the estuary along with 41% of “total dissolvable” iron associated with glacial flour. We couple these findings with hydrologic and geochemical data from Gulf of Alaska (GoA) glacierized catchments to calculate meltwater-derived...
Abstract (from http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173844): Urban habitats are characterized by impervious surfaces, which increase temperatures and reduce water availability to plants. The effects of these conditions on herbivorous insects are not well understood, but may provide insight into future conditions. Three primary hypotheses have been proposed to explain why multiple herbivorous arthropods are more abundant and damaging in cities, and support has been found for each. First, less complex vegetation may reduce biological control of pests. Second, plant stress can increase plant quality for pests. And third, urban warming can directly increase pest fitness and abundance. These...
Population changes and shifts in geographic range boundaries induced by climate change have been documented for many insect species. On the basis of such studies, ecological forecasting models predict that, in the absence of dispersal and resource barriers, many species will exhibit large shifts in abundance and geographic range in response to warming. However, species are composed of individual populations, which may be subject to different selection pressures and therefore may be differentially responsive to environmental change. Asystematic responses across populations and species to warming will alter ecological communities differently across space. Common garden experiments can provide a more mechanistic understanding...
Abstract (from http://www.esajournals.org/doi/abs/10.1890/11-2296.1): Physiological tolerance of environmental conditions can influence species-level responses to climate change. Here, we used species-specific thermal tolerances to predict the community responses of ant species to experimental forest-floor warming at the northern and southern boundaries of temperate hardwood forests in eastern North America. We then compared the predictive ability of thermal tolerance vs. correlative species distribution models (SDMs) which are popular forecasting tools for modeling the effects of climate change. Thermal tolerances predicted the responses of 19 ant species to experimental climate warming at the southern site,...
The Software for Assisted Habitat Modeling (SAHM) has been created to both expedite habitat modeling and help maintain a record of the various input data, pre- and post-processing steps and modeling options incorporated in the construction of a species distribution model through the established workflow management and visualization VisTrails software. This paper provides an overview of the VisTrails:SAHM software including a link to the open source code, a table detailing the current SAHM modules, and a simple example modeling an invasive weed species in Rocky Mountain National Park, USA.
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This landcover raster was generated through a Random Forest predictive model developed in R using a combination of image-derived and ancillary variables, and field-derived training points grouped into 18 classes. Overall accuracy, generated internally through bootstrapping, was 75.5%. A series of post-modeling steps brought the final number of land cover classes to 28.
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Training points collected in the field between 2012 and 2013 were grouped into 18 classes: Forested Burn (66), Foothill Woodland Steppe Transition (73), Greasewood Flat (73), Greasewood Steppe (239), Greasewood Sage Steppe (277), Great Plains Badlands (166), Great Plains Riparian (255), Low Density Sage Steppe (776), Medium Density Sage Steppe (783), Mixed Grass Prairie (555), Mixed Grass Prairie Burned (278), Ponderosa Pine Woodland and Shrubland (512), Riparian Floodplain (223), Semi-Desert Grassland (103), Sparsely Vegetated Mixed Shrub (252), Silver Sage Flat (70) , Silver Sage Steppe (64), and Water (246). When insufficient field data were available for a class, we augmented it through photointerpretation of...
Abstract: A significant number of historically existing wetlands that naturally stored rainwater and attenuated flood peaks have now been drained and employed as new farming areas. Beyond the water quality and flow problem, this has resulted in loss of natural habitats of diverse ecological species. Restoring wetlands have hence been proposed as a potential conservation strategy to help attenuate many of these problems. In this study a spatial, multi-objective optimization study of new potential wetlands was carried out to achieve biodiversity improvements in addition to flood reduction benefits and water quality improvements. The Soil and Water Assessment Tool (SWAT) was used to simulate flow and water quality,...
Abstract (from http://www.tandfonline.com/doi/full/10.1080/00028487.2016.1150879): Long-term sampling of fisheries data is an important source of information for making inferences about the temporal dynamics of populations that support ecologically and economically important fisheries. For example, time series of catch-per-effort data are often examined for the presence of long-term trends. However, it is also of interest to know whether certain sampled locations are exhibiting temporal patterns that deviate from the overall pattern exhibited across all sampled locations. Patterns at these “unusual” sites may be the result of site-specific abiotic (e.g., habitat) or biotic (e.g., the presence of an invasive species)...
Concern over global environmental change and associated uncertainty has given rise to greater emphasis on fostering resilience through forest management. We examined the impact of standard silvicultural systems (including clearcutting, shelterwood, and selection) compared with unharvested controls on tree functional identity and functional diversity in three forest types distributed across the northeastern United States. Sites included the Argonne, Bartlett, and Penobscot Experimental Forests located in Wisconsin, New Hampshire, and Maine, respectively. We quantified functional trait means for leaf mass per area, specific gravity, maximum height, height achieved at 20 years, seed mass, drought tolerance, shade tolerance,...
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Sage-grouse habitat areas divided into proposed management categories within Nevada and California project study boundaries. HABITAT CATEGORY DETERMINATION The process for category determination was directed by the Nevada Sagebrush Ecosystem Technical team. Sage-grouse habitat was determined from a statewide resource selection function model and first categorized into 4 classes: high, moderate, low, and non-habitat. The standard deviations (SD) from a normal distribution of RSF values created from a set of validation points (10% of the entire telemetry dataset) were used to categorize habitat ‘quality’ classes. 1) High quality habitat comprised pixels with RSF values < 0.5 SD. 2) Moderate > 0.5 and < 1.0 SD. 3)...
map background search result map search result map Sage-grouse Habitat Categories in Nevada and NE California (August 2014) Charles M. Russell National Wildlife Refuge Spot Landcover Classification in Relation to Greater Sage Grouse Training Points Predicted climate and avian malaria risk to Hawaiian honeycreepers on the Island of Hawaii from 2098-2100 Predicted climate and avian malaria risk to Hawaiian honeycreepers on the Island of Hawaii from 2098-2100 Training Points Charles M. Russell National Wildlife Refuge Spot Landcover Classification in Relation to Greater Sage Grouse Sage-grouse Habitat Categories in Nevada and NE California (August 2014)