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Confusion regarding the identification of Placobdella hollensis (Whitman, 1892) (Hirudinida: Glossiphoniidae) has led to an unclear understanding of the distribution of the species. Two specimens of P. hollensis were collected from Merchants Millpond State Park, Gates County, North Carolina, U.S.A., representing a new geographic distribution record. Specimens were confirmed...

We investigated biogeochemical conditions and watershed features controlling the extent of nitrate removal through microbial dinitrogen (N2) production within the surficial glacial aquifer located on the north and south shores of Long Island, NY, USA. The extent of N2 production differs within portions of the...

Many coastal dune ecosystems have been degraded by non-native dune vegetation, but these systems might still provide valuable habitat for some taxa, including amphibians. Because restoration of degraded dune systems is occurring and likely to continue, we examined the occurrence of amphibians in drainages associated with a coastal dune ecosystem...

Using a geology-based assessment methodology, the U.S. Geological Survey assessed undiscovered, technically recoverable mean continuous resources of 14.4 billion barrels of oil and 38 trillion cubic feet of gas in the Neuquén Basin Province, Argentina....

The economic growth of an industrialized nation such as the United States requires raw materials for construction (buildings, bridges, highways, and so forth), defense, and processing and manufacture of goods and services. Since the beginning of the 20th century, the types and quantities of raw materials used have increased and...

The U.S. Geological Survey (USGS) serves the Nation by providing reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life. In support of this mission, the USGS...

Brine (also referred to as ‘produced water’) samples were collected from 28 wells producing oil from the Late Devonian-Early Mississippian Bakken and Three Forks Formations in the Williston Basin of eastern Montana and western North Dakota. The samples were analyzed for major ions, trace metals, stable isotopes, and strontium isotopes. The brines in...

Context Landscape complementation, or how landscapes that contain two or more non-substitutable and spatially separated resources facilitate resource use, is critical for many populations. Implicit to the problem of landscape complementation is the movement of individuals to access multiple resources. Conventional measures of complementation, such as habitat area or distance between...

Recent increases in the magnitude and occurrence of insect-induced tree mortality are disruptingevergreen forests globally. To resolve potentially conflicting ecosystem responses, we investigatedwhether surrounding trees exert compensatory effects on biogeochemical signatures following beetleinfestation. To this end, plots were surveyed within a Colorado Rocky Mountain watershed that expe-rienced beetle infestation almost...

Submarine canyons are often hotspots of biomass and productivity in the deep sea. However, the majority of deep-sea canyons remain poorly sampled. Using a multi-tracer approach, results from a detailed geochemical investigation from a year-long sediment trap deployment reveals details concerning the source, transport, and fate of particulate matter...

Population cycling is a widespread phenomenon, observed across a multitude of taxa in both laboratory and natural conditions. Historically, the theory associated with population cycles was tightly linked to pairwise consumer–resource interactions and studied via deterministic models, but current empirical and theoretical research reveals a much richer basis for ecological...

A middle to late Pleistocene sedimentary sequence in the upper Las Vegas Wash, north of Las Vegas, Nevada, has yielded the largest open-site Rancholabrean vertebrate fossil assemblage in the southern Great Basin and Mojave Deserts. Recent paleontologic field studies have led to the discovery of hundreds of fossil localities...

Cross-species disease transmission between wildlife, domestic animals and humans is an increasing threat to public and veterinary health. Wild pigs are increasingly a potential veterinary and public health threat. Here we investigate 84 pathogens and the host species most at risk for transmission with wild pigs using a network approach....

A global inventory of data from gas hydrate drilling expeditions is used to develop relationships between the base of structure I gas hydrate stability, top of gas hydrate occurrence, sulfate-methane transition depth, pressure (water depth), and geothermal gradients. The motivation of this study is to provide first-order estimates of the...

Adaptive management involves learning-oriented decision making in the presence of uncertainty about the responses of a resource system to management. It is implemented through an iterative sequence of decision making, monitoring and assessment of system responses, and incorporating what is learned into future decision making. Decision making at each point...

The North American Breeding Bird Survey (BBS) was established in 1966 in response to a lack of quantitative data on changes in the populations of many bird species at a continental scale, especially songbirds. The BBS now provides the most reliable regional and continental trends and annual indices of abundance...

Management interest in North American birds has increasingly focused on species that breed in Alaska, USA, and Canada, where habitats are changing rapidly in response to climatic and anthropogenic factors. We used a series of hierarchical models to estimate rates of population change in 2 forested Bird Conservation Regions (BCRs)...

Successful species conservation is dependent on adequate estimates of population dynamics, but age-specific demographics are generally lacking for many long-lived iteroparous species such as large reptiles. Accurate demographic information allows estimation of population growth rate, as well as projection of future population sizes and quantitative analyses of...

The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States (https://doi. org/10.5066/F7WH2N65) represents a seamless, spatial database of 48 State geologic maps that range from 1:50,000 to 1:1,000,000 scale. A national digital geologic map database is essential in interpreting other datasets that support numerous types of national-scale studies...

The last 2500 years of activity at Kīlauea Volcano (Hawai‘i) have been characterized by centuries-long periods dominated by either effusive or explosive eruptions. The most recent period of explosive activity produced the Keanakāko‘i Tephra (KT; ca. 1500–1820 C.E.) and occurred after the collapse of the summit caldera (1470–1510 C.E.). Previous studies...

Ratios of Na/Br, Br/Cl, and I/Cl were determined on leachates of fluid inclusions from the Broken Hill Pb-ZnAg deposit in Australia. Paragenetic relations suggest that whereas all analyzed inclusions formed during or after regional metamorphism, ion ratios are not greatly changed from those of the...

The southern part of the Cascades Arc formed in two distinct, extended periods of activity: “High Cascades” volcanoes erupted during about the past 6 million years and were built on a wider platform of Tertiary volcanoes and shallow plutons as old as about 30 Ma, generally called the “Western Cascades.”...

Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered, technically recoverable continuous resources of 35.1 trillion cubic feet of gas in the Amu Darya Basin Province of Turkmenistan, Uzbekistan, Iran, and Afghanistan....

This field-trip guide provides an overview of Quaternary volcanism in and around Lassen Volcanic National Park, California, emphasizing the stratigraphy of the Lassen Volcanic Center. The guide is designed to be self-guided and to focus on geologic features and stratigraphy that can be seen easily from the road network....