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Transient electromagnetic soundings were used to obtain information needed to refine hydrologic models of the San Luis Valley, Colorado. The soundings were able to map an aquitard called the blue clay that separates an unconfined surface aquifer from a deeper confined aquifer. The blue clay forms a conductor with an average...

After more than 50 close flybys of Titan by the Cassini spacecraft, it has become evident that features similar in morphology to terrestrial lakes and seas exist in Titan's polar regions. As Titan progresses into northern spring, the much more numerous and larger lakes and seas in the north-polar region...

Hydrothermal systems currently are active near some gold deposits in northwestern Nevada. Possible links of these modern systems to gold mineralization were evaluated by chemically and isotopically analyzing water samples from the Brady, Dixie Valley, Humboldt House, San Emidio-Empire, Soda Lake, and Wabuska geothermal areas. In addition, quartz veins from...

In stratified sampling, methods for the allocation of effort among strata usually rely on some measure of within-stratum variance. If we do not have enough information about these variances, adaptive allocation can be used. In adaptive allocation designs, surveys are conducted in two phases. Information from the first phase is...

Tropical forest destruction and fragmentation of habitat patches may reduce population persistence at the landscape level. Given the complex nature of simultaneously evaluating the effects of these factors on biotic populations, statistical presence/absence modelling has become an important tool in conservation biology. This study uses logistic regression to evaluate the...

Tamarisk species (genus Tamarix), also commonly known as saltcedar, are among the most successful plant invaders in the western United States. At the same time, tamarisk has been cited as having enormous economic costs. Accordingly, local, state, and federal agencies have undertaken considerable efforts to eradicate this invasive plant and...

We report estimates of mercury (Hg) flux to the sediments of Lake Tahoe, California–Nevada: 2 and 15–20 µg/m2/year in preindustrial and modern sediments, respectively. These values result in a modern to preindustrial flux ratio of 7.5–10, which is similar to flux ratios recently reported for other alpine lakes in California, and...

High spatial and spectral resolution thermal infrared imagery (8.0–13.5 μm) from the SEBASS airborne sensor was used to analyze and map tree canopy spectral features at the State Arboretum of Virginia, near Boyce, Virginia. Fifty tree species were analyzed and about half were directly identified with varying degrees of success on...

Short‐term effects of forest harvest on fish habitat have been well documented, including sediment inputs, leaf litter reductions, and stream warming. However, few studies have considered changes in local climate when examining postlogging changes in fish communities. To address this need, we examined fish abundances between 1997 and 2007 in...

No abstract available....

Wind erosion and associated dust emissions play a fundamental role in many ecological processes and provide important biogeochemical connectivity at scales ranging from individual plants up to the entire globe. Yet, most ecological studies do not explicitly consider dust‐driven processes, perhaps because most relevant research on aeolian (wind‐driven) processes has...

A highly automated algorithm called vegetation change tracker (VCT) has been developed for reconstructing recent forest disturbance history using Landsat time series stacks (LTSS). This algorithm is based on the spectral–temporal properties of land cover and forest change processes, and requires little or no fine tuning for most forests with...

Changes in the biomass and structure of soil microbial communities have the potential to impact ecosystems via interactions with plants and weathering minerals. Previous studies of forested long-term (1000s – 100,000s of years) chronosequences suggest that surface microbial communities change with soil age. However, significant gaps remain in our understanding...

Nesting belted kingfishers (hereafter kingfishers, Ceryle alcyon) were studied on the Hudson River near Fort Edward south to New Baltimore (NY, USA) and three nearby river drainages in 2004. Concentrations of 28 organochlorine pesticides, 160 polychlorinated biphenyl (PCB) congeners, and 17 dioxin and furan (PCDD‐F) congeners were quantified in kingfisher eggs....

The combined effect of salinity and temperature on density-driven convection was evaluated in this study for a large (28 km2) cooling canal system (CCS) at a thermoelectric power plant in south Florida, USA. A two-dimensional cross-section model was used to evaluate the effects of hydraulic heterogeneities, cooling canal salinity, heat transport,...

We examined the spatial and temporal dynamics of health indicators in four lake whitefish (Coregonus clupeaformis) stocks located in northern lakes Michigan and Huron from 2003 to 2006. The specific objectives were to (1) quantify spatial and temporal variability in health indicators; (2) examine relationships among nutritional indicators and stock-specific...

Chemical weathering of silicate minerals has long been known as a sink for atmospheric CO2, and feedbacks between weathering and climate are believed to affect global climate. While warmer temperatures are believed to increase rates of weathering, weathering in cool climates can be accelerated by increased mineral exposure due...

Since January 2008, the U.S. Department of Interior / U.S. Geological Survey have been providing free terrain-corrected (Level 1T) Landsat Enhanced Thematic Mapper Plus (ETM+) data via the Internet, currently for acquisitions with less than 40% cloud cover. With this rich dataset, temporally composited, mosaics of the conterminous United States (CONUS) were...

Streamflow and water-quality data were collected by the U.S. Geological Survey (USGS) or the Providence Water Supply Board, Rhode Island's largest drinking-water supplier. Streamflow was measured or estimated by the USGS following standard methods at 23 streamflow-gaging stations; 10 of these stations were also equipped with instrumentation capable of continuously...

Mercury concentrations in largemouth bass and mercury accumulation rates in age-dated sediment cores were examined at Lake Ozette and Lake Dickey in Washington State. Goals of the study were to compare concentrations in fish tissues at the two lakes with a larger statewide dataset and examine mercury pathways to the...

Rapid weathering and erosion rates in mountainous tropical watersheds lead to highly variable soil and saprolite thicknesses which in turn impact nutrient fluxes and biological populations. In the Luquillo Mountains of Puerto Rico, a 5-m thick saprolite contains high microorganism densities at the surface and at depth overlying bedrock....

Regional land-use models must address several foundational elements, including understanding geographic setting, establishing regional land-use histories, modeling process and representing drivers of change, representing local land-use patterns, managing issues of scale and complexity, and development of scenarios. Key difficulties include managing an array of biophysical and socioeconomic processes across multiple...

Background aim and scopeSoil organic carbon (SOC) accumulation is strongly affected by soil erosion and deposition that differ at slope positions of a watershed. However, studies on the effects of topography on soil aggregation and SOC dynamics, especially after the implementation of vegetation restoration, are rare....

The Diviner Lunar Radiometer Experiment on NASA’s Lunar Reconnaissance Orbiter will be the first instrument to systematically map the global thermal state of the Moon and its diurnal and seasonal variability. Diviner will measure reflected solar and emitted infrared radiation in nine spectral channels with wavelengths ranging from 0.3 to...

Two-dimensional hydrodynamic models are now widely used in aquatic habitat studies. To test the sensitivity of calculated habitat outcomes to limitations of such a model and of typical field data, bathmetry, depth and velocity data were collected for three discharges in the vicinity of two large boulders in the...