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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://onlinelibrary.wiley.com/doi/10.1111/jawr.12179/abstract): Freshwater mussels (order Unionida) are a highly imperiled group of organisms that are at risk from rising stream temperatures ( T ). There is a need to understand the potential effects of land use (LU) and climate change (CC) on stream T and have a measure of uncertainty. We used available downscaled climate projections and LU change simulations to simulate the potential effects on average daily stream T from 2020 to 2060. Monte Carlo simulations were run, and a novel technique to analyze results was used to assess changes in hydrologic and stream T response. Simulations of daily mean T were used as input to our stochastic...
Abstract (from http://sp.lyellcollection.org/content/early/2015/10/09/SP408.11.abstract): We present a hierarchical series of spatially decreasing and temporally increasing models to evaluate the uncertainty in the atmosphere – ocean global climate model (AOGCM) and the regional climate model (RCM) relative to the uncertainty in the somatic growth of the endangered pallid sturgeon (Scaphirhynchus albus). For effects on fish populations of riverine ecosystems, climate output simulated by coarse-resolution AOGCMs and RCMs must be downscaled to basins to river hydrology to population response. One needs to transfer the information from these climate simulations down to the individual scale in a way that minimizes extrapolation...
[Excerpt from Introduction] "The San Francisco Bay Estuary supports a large and diverse bird community. More than 50% of most Pacific flyway diving duck populations are found in the Estuary during the winter months (Trost 2002; U.S. Fish and Wildlife Service 2002). San Francisco Bay has been designated as a site of international importance for shorebirds (Western Hemisphere Shorebird Reserve Network), supporting millions of individuals (Morrison et al. 2001; Takekawa et al. 2001; Warnock et al. 2002), including species that use tidal marsh habitats. In total, the Bay’s tidal marshes support at least 113 bird species that represent 31 families (Takekawa et al., in press)..."
Abstract (from http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0138759): Future climate change may significantly alter the distributions of many plant taxa. The effects of climate change may be particularly large in mountainous regions where climate can vary significantly with elevation. Understanding potential future vegetation changes in these regions requires methods that can resolve vegetation responses to climate change at fine spatial resolutions. We used LPJ, a dynamic global vegetation model, to assess potential future vegetation changes for a large topographically complex area of the northwest United States and southwest Canada (38.0–58.0°N latitude by 136.6–103.0°W longitude). LPJ is a...
Abstract (from http://link.springer.com/article/10.1007/s10236-013-0684-3): A three-level nested Regional Ocean Modeling System was used to examine the seasonal evolution of the Copper River (CR) plume and how it influences the along- and across-shore transport in the northern Gulf of Alaska (NGoA). A passive tracer was introduced in the model to delineate the growth and decay of the plume and to diagnose the spread of the CR discharge in the shelf, into Prince William Sound (PWS) and offshore. Furthermore, a model experiment with doubled discharge was conducted to investigate potential impacts of accelerated glacier melt in future climate scenarios. The 2010 and 2011 simulation revealed that the upstream (eastward)...
Abstract (from http://link.springer.com/article/10.1007%2Fs10980-015-0160-1): Content Changing aspen distribution in response to climate change and fire is a major focus of biodiversity conservation, yet little is known about the potential response of aspen to these two driving forces along topoclimatic gradients. Objective This study is set to evaluate how aspen distribution might shift in response to different climate-fire scenarios in a semi-arid montane landscape, and quantify the influence of fire regime along topoclimatic gradients. Methods We used a novel integration of a forest landscape succession and disturbance model (LANDIS-II) with a fine-scale climatic water deficit approach to simulate dynamics of...
Habitat loss and alteration from land use change, species invasion, and more recently, climate change have reduced biodiversity and ecosystem function worldwide. Habitat decisions have important implications to individual fitness as well as population dynamics and community structure. Resource limitation, predation, competition, and unfavorable abiotic conditions all have the potential to influence survival and future reproductive potential. Understanding how changes to ecosystem structure and function impact species and populations of conservation concern is essential for conservation delivery to be effective. Similar to many migratory species, shorebird populations are declining worldwide and declines may be related...
Great Lakes fishery managers and stakeholders have little information regarding how climate change could affect the management of recreationally and commercially important fisheries, which have been valued at more than $7 billion USD annually. Our research focused on how climate change could influence fish habitat (including water temperature, ice cover, and water levels), phytoplankton production that supports fish biomass, and ultimately the growth and consumption of many important recreational and commercial fish species. This final report was produced for the NCCWSC-funded project Forecasting Climate Change Induced Effects on Recreational and Commercial Fish Populations in the Great Lakes.
In December 2009, a workshop sponsored by the US Geological Survey and the US Environmental Protection Agency was held to identify on-going sea level rise (SLR) modeling efforts, data gaps, and information needs for management decisions about current and future mitigation and restoration efforts in Oregon estuaries. The workshop brought together 46 non-governmental organizations, federal scientists, state land managers, and SLR modelers and has inspired collaborations for data, knowledge, and technology exchange. A second SLR workshop was scheduled for February 1 and 2, 2011 in Newport, OR to continue to build upon the collaborative efforts established at the first workshop.
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Abstract (from http://www.springerplus.com/content/3/1/589): The growing quality and availability of spatial map layers (e.g., climate, geology, and land use) allow stream studies, which historically have occurred over small areas like a single watershed or stream reach, to increasingly explore questions from a landscape perspective. This large-scale perspective for fluvial studies depends on the ability to characterize influences on streams resulting from throughout entire upstream networks or catchments. While acquiring upstream information for a single reach is relatively straight-forward, this process becomes demanding when attempting to obtain summaries for all streams throughout a stream network and across...
Abstract (from http://sp.lyellcollection.org/content/early/2015/05/21/SP408.10.abstract): In managing fish populations, especially at-risk species, realistic mathematical models are needed to help predict population response to potential management actions in the context of environmental conditions and changing climate while effectively incorporating the stochastic nature of real world conditions. We provide a key component of such a model for the endangered pallid sturgeon ( Scaphirhynchus albus) in the form of an individual-based bioenergetics model influenced not only by temperature but also by flow. This component is based on modification of a known individual-based bioenergetics model through incorporation...
Abstract: The consequences of global climate change on aquatic ecosystems are predicted to result from altered intensity, variability, and distribution of precipitation, and more frequent flooding and droughts. In freshwater systems, these changes may result in degradation or loss of habitat due to dry stream beds or low flows, and increased water temperatures, pollution, and erosion. Freshwater mussels (Order Unionida) are especially vulnerable to disturbance because they are incapable of escaping detrimental changes at any practical temporal scale. Quantitative information on lethal temperatures (LT) to native freshwater mussels is currently limited to fewer than 10 species, and these few studies have been restricted...
There are a number of ways that climate change is beginning to impact wildlife. Temperature increases and changes in precipitation can directly affect species, depending on their physiology and tolerance of environmental changes. Climate change can also alter a species' food supply or its reproductive timing, which indirectly affecting its fitness. Understanding these interactions is an important step in developing management strategies to help species survive the changing climate.
We modeled the current and future breeding ranges of seven bird and five reptile species in the Southwestern United States with sets of landscape, biotic (plant), and climatic global circulation model (GCM) variables. For modeling purposes, we used PRISM data to characterize the climate of the Western United States between 1980 and 2009 (baseline for birds) and between 1940 and 2009 (baseline for reptiles). In contrast, we used a pre-selected set of GCMs that are known to be good predictors of southwestern climate (five individual and one ensemble GCM), for the A1B emission scenario, to characterize future climatic conditions in three time periods (2010–39; 2040–69; and, 2070–99). Our modeling approach relied on...
map background search result map search result map An approach for aggregating upstream catchment information to support research and management of fluvial systems across large landscapes An approach for aggregating upstream catchment information to support research and management of fluvial systems across large landscapes