Publications

We assessed the impacts of co‐occurring invasive plant species on fire regimes and postfire native communities in the Mojave Desert, western USA. We analyzed the distribution and co‐occurrence patterns of three invasive annual grasses (Bromus rubens, Bromus tectorum, and Schismus spp.) known to alter fuel conditions and community structure, and an invasive forb (Erodium cicutarium) which...

The Additional Supplemental Appropriations for Disaster Relief Act of 2019 (H.R. 2157) was signed by the President on June 6, 2019. The U.S. Geological Survey received $98.5 million for repair and replacement of facilities and equipment, collection of high-resolution elevation data in affected areas, and scientific assessments to support recovery and rebuilding decisions for declared...

Serum iron concentration is usually decreased in true iron deficiency and with inflammatory disease in man and domestic animals. Serum total iron binding capacity (TIBC) may be increased in true iron deficiency and decreased with inflammatory disease. This prospective study was designed to measure serum iron analytes in healthy free-ranging and housed Florida manatees (Trichechus manatus

Tracking data have led to evidence-based conservation of marine megafauna, but a disconnect remains between the many thousands of individual animals that have been tracked and the use of these data in conservation and management actions. Furthermore, the focus of most conservation efforts is within Exclusive Economic Zones despite the ability of these species to move thousands of...

The purpose of this study was to determine the elevation dynamics of a created tidal marsh on the North Carolina coast. Deep rod surface elevation tables (RSET) and feldspar marker horizons (MH) were installed in plots to measure net surface elevation changes and to quantify contributing processes. Twelve total plots were placed on four elevation gradient transects (three transects...

The African Jewelfish, Hemichromis letourneuxi, is an invasive, predatory cichlid fish introduced at least once to Florida. Its native range is in northern Africa. First encountered in Miami in the 1960s, it has since been found west and north within the State of Florida. It thrives in a wide range of aquatic habitats, including shallow, vegetated or rocky areas of canals, tidal creeks...

Land clearing, river impoundments, and other human modifications to the upland landscape and within estuarine systems can drive coastal change at local to regional scales. However, as compared with mid-latitude coasts, the impacts of human modifications along sediment-starved formerly glaciated coastal landscapes are relatively understudied. To address this gap, we present a late...

Structured decision making is a systematic, transparent process for improving the quality of complex decisions by identifying measurable management objectives and feasible management actions; predicting the potential consequences of management actions relative to the stated objectives; and selecting a course of action that maximizes the total benefit achieved and balances tradeoffs among

The U.S. Geological Survey Columbia Environmental Research Center performs research to solve challenging environmental problems related to contaminants and habitat alterations in aquatic and terrestrial ecosystems. The research is interdisciplinary and pursued through partnerships within the U.S. Geological Survey and with national, international, state, and local agencies...

No abstract available.

E. Pennisi (“Forest giants are the trees most at risk,” News, 6 September, p. 962) interprets presentations of three studies as suggesting that “for trees, size is not strength, and forest giants are disproportionately vulnerable.” However, this conclusion is not well supported. The observation that lightning is a major cause of large-tree mortality on Barro Colorado Island (BCI) is best

This chapter provides a general review of grazing disturbance by large mammalian grazers and the role of ecological context in moderating its effects, with emphasis on North American deserts. It discusses the ecological consequences of cessation of livestock grazing and present a case study from the Mojave Desert, United States of America. A primary effect of grazing is selective removal...