Publications

Estimating the age of individuals in wild populations can be of fundamental importance for answering ecological questions, modeling population demographics, and managing exploited or threatened species. Significant effort has been devoted to determining age through the use of growth annuli, secondary physical characteristics related to age, and growth models. Many species, however, either do not e

This report synthesizes the knowledge, opinions, and concerns of many Federal and State land managers, scientists, stakeholders, and partners from a workshop, held at the University of Nevada, Las Vegas, on April 20-22, 2010. Land managers, research scientists, and resource specialists identified common concerns regarding the potential effects of climate change on public lands and natural resource

Changes to the Earth's climate-temperature, precipitation, and other important aspects of climate-pose significant challenges to our Nation's natural resources now and will continue to do so. Managers of land, water, and living resources need to understand the impacts of climate change-which will exacerbate ongoing stresses such as habitat fragmentation and invasive species-so they can design effe

Fisheries management programs, such as the National Fish Habitat Action Plan (NFHAP), urgently need a nationwide spatial framework and database for health assessment and policy development to protect and improve riverine systems. To meet this need, we developed a spatial framework and database using National Hydrography Dataset Plus (I-.100,000-scale); http://www.horizon-systems.com/nhdplus). This

To date, the predominant use of systematic conservation planning has been to evaluate and conserve areas of high terrestrial biodiversity. Although studies in freshwater ecosystems have received recent attention, research has rarely considered the potential trade-offs between protecting different dimensions of biodiversity and the ecological processes that maintain diversity. We provide the first

Model estimates of impervious area as a function of landcover area may be biased and imprecise because of errors in the land-cover classification. This investigation of the effects of land-cover misclassification on impervious surface models that use National Land Cover Data (NLCD) evaluates the consequences of adjusting land-cover within a watershed to reflect uncertainty assessment information.

An illustrated, descriptive atlas of pollen and spores from wetland plants of the Florida Everglades was compiled to facilitate identification of dispersed palynomorphs in sediments. The atlas includes 121 wetland species characteristic of eleven plant associations of the Florida Everglades including sloughs, sawgrass marshes, tree islands, wet prairies, cypress domes, mangrove forests, salt marsh

The Chesapeake Bay is the Nation's largest estuary and historically supported one of the most productive fisheries in the world. In addition to supporting aquatic communities and wildlife, the bay's watershed serves the economic and recreational needs of 15 million people. The fertile soils of the watershed support significant agricultural production. Unfortunately, the commercial, economic, and r

The surficial geologic map of lower Comb Wash was produced as part of a master’s thesis for Northern Arizona University Quaternary Sciences program. The map area includes the portion of the Comb Wash alluvial valley between Highway 163 and Highway 95 on the Colorado Plateau in southeastern Utah. The late Quaternary geology of this part of the Colorado Plateau had not previously been mapped in adeq