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Explore WARC's science publications.

Filter Total Items: 3375

Estimating trends in alligator populations from nightlight survey data

Nightlight surveys are commonly used to evaluate status and trends of crocodilian populations, but imperfect detection caused by survey- and location-specific factors makes it difficult to draw population inferences accurately from uncorrected data. We used a two-stage hierarchical model comprising population abundance and detection probability to examine recent abundance trends of American alliga
Authors
Ikuko Fujisaki, F.J. Mazzotti, R.M. Dorazio, Kenneth G. Rice, M. Cherkiss, B. Jeffery

Geographic profiling to assess the risk of rare plant poaching in natural areas

We demonstrate the use of an expert-assisted spatial model to examine geographic factors influencing the poaching risk of a rare plant (American ginseng, Panax quinquefolius L.) in Shenandoah National Park, Virginia, USA. Following principles of the analytic hierarchy process (AHP), we identified a hierarchy of 11 geographic factors deemed important to poaching risk and requested law enforcement p
Authors
J.A. Young, F.T. Van Manen, C.A. Thatcher

Coal resources for the Chemard Lake (Naborton No. 2) coal zone of the lower Wilcox group (Paleocene), northwestern Louisiana

The lower part of the Wilcox Group of northwest Louisiana contains shallow (less than 500 ft) coal deposits that are mined for use in mine-mouth electric power-generating plants. The coal deposits, which are lignite A in apparent rank (Pierce et al., 2011), occur on the eastern part of the Sabine uplift (Figure 1). The coal zones and associated strata in the assessment area generally dip away from
Authors
Peter D. Warwick, Steven M. Podwysocki, Adam C. Schultz

The black carp in North America: an update

No abstract available.
Authors
Leo G. Nico, Howard L. Jelks

Overview and history of the Beach Vitex Task Force: An interagency partnership in action

Beach vitex (Vitex rotundifolia L. f.), a woody vine from Korea, was introduced into the United States as a dune stabilization plant in the mid-1980s. By the mid- to late-1990s, Beach vitex was observed spreading from landscape plantings along the South Carolina coast, crowding out native dune species. In 2003, in response to concerns about possible impacts of the plant on native dune species, as
Authors
Randy G. Westbrooks, Elizabeth N. Brabson

Overview and status of the witchweed (striga asiatica) eradication program in the Carolinas

Witchweed [(Striga asiatica (L.) O. Kuntze)] is a parasitic weed from Asia and Africa that attaches to the roots of grasses and grass crops such as corn and sorghum. Witchweed was first detected in the western hemisphere in a corn field in Columbus County, North Carolina, in July, 1956. Since that time, a federal/state cooperative program has eliminated over 99% of the 432,000+ acres that have bee
Authors
Richard D. Iverson, Randy G. Westbrooks, Robert E. Eplee, Alan V. Tasker

Overview of prohibited and permitted plant regulatory listing systems

Pest risk analysis is a process that evaluates the risks involved with a proposed species to help determine whether it should be permitted or denied entry into a country, and how the risks could be managed if it is imported. The prohibited listing approach was developed in the late 1800s and early 1900s in response to outbreaks of plant and animals pests such as foot and mouth disease of livestock
Authors
Randy G. Westbrooks, Alan V. Tasker

Evaluating the potential for stock size to limit recruitment in largemouth bass

Compensatory changes in juvenile survival allow fish stocks to maintain relatively constant recruitment across a wide range of stock sizes (and levels of fishing), but few studies have experimentally explored recruitment compensation in fish populations. We evaluated the potential for recruitment compensation in largemouth bass Micropterus salmoides by stocking six 0.4-ha hatchery ponds with adult
Authors
Michael S. Allen, Mark W. Rogers, Mathew J. Catalano, Daniel G. Gwinn, Stephen J. Walsh

Understanding interaction effects of climate change and fire management on bird distributions through combined process and habitat models

Avian conservation efforts must account for changes in vegetation composition and structure associated with climate change. We modeled vegetation change and the probability of occurrence of birds to project changes in winter bird distributions associated with climate change and fire management in the northern Chihuahuan Desert (southwestern U.S.A.). We simulated vegetation change in a process-base
Authors
Joseph D. White, Kevin J. Gutzwiller, Wylie C. Barrow, Lori Johnson-Randall, Lisa Zygo, Pamela Swint

Soil characteristics of sediment-amended baldcypress (Taxodium distichum) swamps of coastal Louisiana

Amendments of sediment from dredging activities have played an important role in raising the elevation of sinking coastal wetlands. This study compared the soil characteristics of sediment- amended coastal swamps in the Barataria Preserve unit of Jean Lafitte National Historical Park and Preserve with natural swamps along Bayou des Familles. The sandy sediment amendments used in the coastal forest
Authors
Ming Jiang, Beth A. Middleton