Publications

Contemporary cost projections were computed for several alternative strategies that could be used by BLM to manage three wild horse populations. The alternatives included existing gather and selective removal methods, combined with potential contraceptive applications of varying duration and other potentially useful management techniques. Costs were projected for a 20-year economic life...

No abstract available.

This paper presents data analyses based on information gathered from a recreation survey distributed during the spring of 1997 at Lake Powell. Recreation-linked management issues are the foci of the survey and this discussion. Survey responses to contingent valuation method (CVM) queries included in the questionnaire quantify visitor recreation values. The CVM estimates of the benefits...

The diverse set of wetlands in southern altiplano of South America supports a number of endemic and migratory waterbirds. These species include endangered endemic flamingos and shorebirds that nest in North America and winter in the altiplano. This research developed maps from nine Landsat Thematic Mapper (TM) images (254,300 km2) to provide an inventory of aquatic waterbird habitats...

In the 1850s, bighorn sheep (Ovis canadensis) were numerous and distributed throughout the Bighorn and Pryor Mountains of Montana and Wyoming. After European settlement, bighorn sheep populations declined, and local extinctions occurred in much of their historic range in the western United States. The current bighorn sheep population of Bighorn Canyon National Recreation Area (BICA) is...

We conducted enclosure experiments to examine the cumulative effects of nutrient enrichment and acidification on the plankton of two mountain lakes with differing nutrient conditions. The low-nitrate lake responded to N, N plus acid, and N plus acid plus P additions, showing four- to seven-fold increases in chlorophyll a, increased photosynthetic rate, compositional shifts toward large

This article links intended National Park visitation estimates to regional economic models to calculate the employment impacts of alternative bison and elk management strategies. The survey described alternative National Elk Refuge (NER) management actions and the effects on elk and bison populations at the NER and adjacent Grand Teton National Park (GTNP). Park visitors were then asked...

At the request of National Park Service resource managers, we began a study in 2000 to evaluate causes for the decline of the bighorn sheep (Ovis canadensis) population inhabiting Bighorn Canyon National Recreation Area (BICA), the Pryor Mountain Wild Horse Range, and surrounding state and U.S. Forest Service lands in Montana and Wyoming. Our study consisted of radio-collaring adult rams...

Although acidifying deposition in western North America is lower than in many parts of the world, many high-elevation ecosystems there are extremely sensitive to acidification. Previous studies determined that the Mount Zirkel Wilderness Area (MZWA) has the most acidic snowpack and aquatic ecosystems that are among the most sensitive in the region. In this study, spatial and temporal...

This paper discusses sampling techniques for archaeological survey that are directed toward evaluating the properties of surface artifact distributions. The sampling techniques we experimented with consist of a multi-scale sampling plot developed in plant ecology and the use of a nested-intensity survey design. We present results from the initial application of these methods. The...

Most resource management decisions involve the integrated use of biological, sociological, and economic information. Combining this information provides a more comprehensive basis for making effective land management and conservation decisions. Toward this end, scientists in the Policy Analysis and Science Assistance Branch (PASA) of the Fort Collins Science Center (FORT) contribute...

Risk analysis tools have been successfully used to determine the potential hazard associated with disease introductions and have facilitated management decisions designed to limit the potential for disease introduction. Chronic Wasting Disease (CWD) poses significant challenges for resource managers due to an incomplete understanding of disease etiology and epidemiology and the...