Publications
These publications showcase the significant science conducted in our Science Centers.
Filter Total Items: 16784
Regeneration in bottomland forest canopy gaps six years after variable retention harvests to enhance wildlife habitat
To promote desired forest conditions that enhance wildlife habitat in bottomland forests, managers prescribed and implemented variable-retention harvest, a.k.a. wildlife forestry, in four stands on Tensas River National Wildlife Refuge, LA. These treatments created canopy openings (gaps) within which managers sought to regenerate shade-intolerant trees. Six years after prescribed harvests, we asse
Authors
Daniel J. Twedt, Scott G. Somershoe
Proceedings of a workshop on American Eel passage technologies
Recent concerns regarding a decline in recruitment of American eels (Anguilla rostrata) have prompted efforts to restore this species to historic habitats by providing passage for both upstream migrant juveniles and downstream migrant adults at riverine barriers, including low-head and hydroelectric dams (Castonguay et al. 1994, Haro et al. 2000). These efforts include development of management p
Authors
Alexander J. Haro
Foraging habitat for shorebirds in southeastern Missouri and its predicted future availability
Water management to protect agriculture in alluvial floodplains often conflicts with wildlife use of seasonal floodwater. Such is the case along the Mississippi River in southeastern Missouri where migrating shorebirds forage in shallow-flooded fields. I estimated the current availability of habitat for foraging shorebirds within the New Madrid and St. Johns Basins based on daily river elevations
Authors
Daniel J. Twedt
Slab tears and intermediate-depth seismicity
Active tectonic regions where plate boundaries transition from subduction to strike slip can take several forms, such as triple junctions, acute, and obtuse corners. Well-documented slab tears that are associated with high rates of intermediate-depth seismicity are considered here: Gibraltar arc, the southern and northern ends of the Lesser Antilles arc, and the northern end of Tonga trench. Seism
Authors
Hallie E. Meighan, Uri S. ten Brink, Jay Pulliam
Reproductive health of yellow perch, Perca flavescens, in Chesapeake Bay Tributaries
Yellow perch live in creeks, rivers, ponds, lakes, and estuaries across the central and eastern United States and Canada. In Chesapeake Bay, they tolerate salinities up to one-third that of seawater. The adults reside in the brackish waters of the bay’s tributaries and migrate upstream to spawn. Yellow perch are eagerly sought by recreational fishermen for their excellent taste and, because their
Authors
Vicki Blazer, A.E. Pinkney, James H. Uphoff
Significance of headwater streams and perennial springs in ecological monitoring in Shenandoah National Park
Shenandoah National Park has been monitoring water chemistry and benthic macroinvertebrates in stream ecosystems since 1979. These monitoring efforts were designed to assess the status and trends in stream condition associated with atmospheric deposition (acid rain) and changes in forest health due to gypsy moth infestations. The primary objective of the present research was to determine whether t
Authors
Craig D. Snyder, James R. Webb, John A. Young, Zane B. Johnson
Pb-Sr-Nd isotopes in surficial materials at the Pebble Porphyry Cu-Au-Mo Deposit, Southwestern Alaska: can the mineralizing fingerprint be detected through cover?
The Cretaceous Pebble porphyry Cu-Au-Mo deposit is covered by tundra and glacigenic sediments. Pb-Sr-Nd measurements were done on sediments and soils to establish baseline conditions prior to the onset of mining operations and contribute to the development of exploration methods for concealed base metal deposits of this type. Pebble rocks have a moderate range for 206Pb/204Pb = 18.574 to 18.874, 2
Authors
Robert A. Ayuso, Karen D. Kelley, Robert G. Eppinger, Francesca Forni
Occurrence and mobility of mercury in groundwater: Chapter 5
1. Introduction
1.1. FORMS, TOXICITY, AND HEALTH EFFECTS
Mercury (Hg) has long been identified as an element that is injurious, even lethal, to living organisms. Exposure to its inorganic form, mainly from elemental Hg (Hg(0)) vapor (Fitzgerald & Lamborg, 2007) can cause damage to respiratory, neural, and renal systems (Hutton, 1987; USEPA, 2012; WHO, 2012). The organic form, methylmercury (CH3Hg
Authors
Julia L. Barringer, Zoltan Szabo, Pamela A. Reilly
Strategies for fitting nonlinear ecological models in R, AD Model Builder, and BUGS
1. Ecologists often use nonlinear fitting techniques to estimate the parameters of complex ecological models, with attendant frustration. This paper compares three open-source model fitting tools and discusses general strategies for defining and fitting models.
2. R is convenient and (relatively) easy to learn, AD Model Builder is fast and robust but comes with a steep learning curve, while BU
Authors
Benjamin M. Bolker, Beth Gardner, Mark Maunder, Casper W. Berg, Mollie Brooks, Liza Comita, Elizabeth Crone, Sarah Cubaynes, Trevor Davies, Perry de Valpine, Jessica Ford, Olivier Gimenez, Marc Kéry, Eun Jung Kim, Cleridy Lennert-Cody, Arni Magunsson, Steve Martell, John Nash, Anders Nielson, Jim Regentz, Hans Skaug, Elise Zipkin
Spatial education: improving conservation delivery through space-structured decision making
Adaptive management is a form of structured decision making designed to guide management of natural resource systems when their behaviors are uncertain. Where decision making can be replicated across units of a landscape, learning can be accelerated, and biological processes can be understood in a larger spatial context. Broad-based partnerships among land management agencies, exemplified by Lands
Authors
Clinton T. Moore, Terry L. Shaffer, Jill J. Gannon
Streamflow, water quality, and constituent loads and yields, Scituate Reservoir drainage area, Rhode Island, water year 2011
Streamflow and concentrations of sodium and chloride estimated from records of specific conductance were used to calculate loads of sodium and chloride during water year (WY) 2011 (October 1, 2010, to September 30, 2011), for tributaries to the Scituate Reservoir, Rhode Island. Streamflow and water-quality data used in the study were collected by the U.S. Geological Survey (USGS) or the Providence
Authors
Kirk P. Smith
Active adaptive management for reintroduction of an animal population
Captive animals are frequently reintroduced to the wild in the face of uncertainty, but that uncertainty can often be reduced over the course of the reintroduction effort, providing the opportunity for adaptive management. One common uncertainty in reintroductions is the short-term survival rate of released adults (a release cost), an important factor because it can affect whether releasing adults
Authors
Michael C. Runge