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The time course photodegradation of the Nordic aquatic fulvic and humic acids and Suwannee River XAD-4 acids subjected to UV irradiation with an unfiltered medium pressure mercury lamp was studied by liquid-state 13C nuclear magnetic resonance. Photodecarboxylation was a significant pathway in all cases. Decreases in ketone, aromatic, and O-alkyl...

1. Recent advances in occupancy estimation that adjust for imperfect detection have provided substantial improvements over traditional approaches and are receiving considerable use in applied ecology. To estimate and adjust for detectability, occupancy modelling requires multiple surveys at a site and requires the assumption of 'closure' between surveys, i.e....

The Mid-Pliocene is the most recent interval of sustained global warmth, which can be used to examine conditions predicted for the near future. An accurate spatial representation of the low-latitude Mid-Pliocene Pacific surface ocean is necessary to understand past climate change in the light of forecasts of future change. Mid-Pliocene...

Evaluating the potential involvement of wild avifauna in the emergence of highly pathogenic avian influenza H5N1 (hereafter H5N1) requires detailed analyses of temporal and spatial relationships between wild bird movements and disease emergence. The death of wild swans (Cygnus spp.) has been the first indicator of the presence of H5N1...

Quantifying population genetic heterogeneity within nonbreeding aggregations can inform our understanding of patterns of site fidelity, migratory connectivity, and gene flow between breeding and nonbreeding areas. However, characterizing mechanisms that contribute to heterogeneity, such as migration and dispersal, is required before site fidelity and migratory connectivity can be assessed accurately....

The hypothesis that growth in Pacific salmon Oncorhynchus spp. is dependent on previous growth was tested using annual scale growth measurements of wild Chinook salmon Oncorhynchus tshawytscha returning to the Yukon and Kuskokwim Rivers, Alaska, from 1964 to 2004. First-year marine growth in individual O. tshawytscha was significantly correlated with...

A 10-year study (1997-2006) was conducted to evaluate reproduction and health of aquatic birds in the Carson River Basin of northwestern Nevada (on the U.S. Environmental Protection Agency Natural Priorities List) due to high mercury (Hg) concentrations from past mining activities. This part of the study evaluated physiological associations with...

On October 24th, 2005, Hurricane Wilma made landfall on the south western shore of the Florida peninsula. This major disturbance destroyed approximately 30 percent of the mangrove forests in the area. However, the damage to the ecosystem following the hurricane provided researchers at the Florida Coastal Everglades (FCE) LTER site...

Technology is changing how scientists and natural resource managers describe and study streams and rivers. A new generation of airborne aquatic-terrestrial lidars is being developed that can penetrate water and map the submerged topography inside a stream as well as the adjacent subaerial terrain and vegetation in one integrated mission....

Climate change in the coming centuries will be characterized by interannual, decadal, and multidecadal fluctuations superimposed on anthropogenic trends. Predicting ecological and biogeographic responses to these changes constitutes an immense challenge for ecologists. Perspectives from climatic and ecological history indicate that responses will be laden with contingencies, resulting from episodic...

The history of dome growth and geodetic deflation during the 2004–2008 Mount St. Helens eruption can be fit to theoretical curves with parameters such as reservoir volume, bubble content, initial overpressure, and magma rheology, here assumed to be Newtonian viscous, with or without a solid plug in the conduit center....

On a nationwide basis, few stream restoration projects have long-term programs in place to monitor the effects of floods on channel and floodplain configuration and floodplain vegetation, but long-term and event-based monitoring is required to measure the effects of these stochastic events and to use the knowledge for adaptive management...

Prognostic vegetation models have been widely used to study the interactions between environmental change and biological systems. This study examines the sensitivity of vegetation model simulations to: (i) the selection of input climatologies representing different time periods and their associated atmospheric CO2 concentrations, (ii) the choice of observed vegetation data...

Lignin phenols have proven to be powerful biomarkers in environmental studies; however, the complexity of lignin analysis limits the number of samples and thus spatial and temporal resolution in any given study. In contrast, spectrophotometric characterization of dissolved organic matter (DOM) is rapid, noninvasive, relatively inexpensive, requires small sample volumes,...

The butter clam, Saxidomus gigantea, is one of the most commonly recovered bivalves from archaeological shell middens on the Pacific Coast of North America. This study presents the results of the sclerochronology of modern specimens of S. gigantea, collected monthly from Pender Island (British Columbia), and additional modern specimens from...

The U.S. Geological Survey (USGS) acquired two 1.4-km-long, high-resolution (~5 m vertical resolution) seismic-reflection lines in 2006 that cross near the International Continental Scientific Drilling Program (ICDP)-USGS Eyreville deep drilling site located above the late Eocene Chesapeake Bay impact structure in Virginia, USA. Five-meter spacing of seismic sources and geophones...

The recent development of multistate site occupancy models offers great opportunities to frame and solve decision problems for conservation that can be viewed in terms of site occupancy. These models have several characteristics (e.g., they account for detectability) that make them particularly well suited for addressing management and conservation problems....

The region of western Utopia Planitia (80-105 degreesE, 40-55 degrees N) displays several types of landforms similar to Earth periglacial features, including scallop-shaped depressions and networks of polygonal terrains. The scalloped depressions have been proposed to originate from thermokarstic processes such as sublimation and/or melting of near-surface ground ice. Using...

Low pathogenic avian influenza (LPAI) viruses are well documented to circulate within wild waterfowl populations (Olsen et. al. 2006). It has been assumed that these infections are benign with no subsequent effects on life-history parameters. The study by Latorre-Margalef et al. (2009; hereafter L.-M. et al.) represents an important step,...

The 6-hectare (ha) freshwater tidal Anacostia River Fringe Wetlands (Fringe Wetlands) were reconstructed along the mainstem of the Anacostia River in Washington, DC (Photograph 1, Figure 1) during the summer of 2003. The Fringe Wetlands consist of two separate planting cells. Fringe A, located adjacent to Lower Kingman Island, on...

Although continental populations of avian influenza viruses are genetically distinct, transcontinental reassortment in low pathogenic avian influenza (LPAI) viruses has been detected in migratory birds. Thus, genomic analyses of LPAI viruses could serve as an approach to prioritize species and regions targeted by North American surveillance activities for foreign origin...

The connectivity and frequency of exchange between sub-populations of migratory birds is integral to understanding population dynamics over the entire species' range. True geese are highly philopatric and acquire lifetime mates during the winter, suggesting that the number of distinct sub-populations may be related to the number of distinct wintering...