Treesearch

Elimination of the historic pattern of frequent low-intensity fires in ponderosa pine and pine-mixed conifer forests has resulted in major ecological disruptions. Prior to 1900, open stands of large, long-lived, fire-resistant ponderosa pine were typical. These were accompanied in some areas by other fire-dependent species such as western larch. Today, as a result of fire exclusion, most stands have dense thickets of small trees and are experiencing insect and disease epidemics and severe wildfires. These forests cover about 40 million acres in the Western United States and are the focus...

Forest Service Research Natural Areas are established to preserve examples of all significant natural ecosystems for comparison with those influenced andlor managed by humans, to provide educational and research areas for ecological and environmental studies, and to preserve gene pools for typical and rare and endangered species. The Research Natural Area program in the Northern Rockies and Pacific Northwest regions attempts to protect a wide spectrum of terrestrial and aquatic communities in their "natural" state. At least 79 of the 246 established and proposed Research Natural Areas in...

Covering just over 1 million acres, Glacier National Park straddles the Continental Divide in northwestern Montana. Diverse vegetation communities include moist western cedar- western hemlock (Thuja plicata - Tsuga heterophylla) old growth forests similar to those of the Pacific Coast, dry western grasslands and prairies, dense lodgepole pine forests (Pinus contorta var. latifolia), ponderosa pine (P. ponderosa) savannas, mixed conifer forests, and alpine and subalpine meadows. The diversity and complexity of the park's vegetation and wildlife necessitates innovative, long-term, and...

This proceedings represents scientific and applied papers presented at a symposium of the same title held 18-22 September 1995 at the Four Seasons Hotel in Albuquerque, New Mexico. The symposium brought together scientists, natural resource managers, conservationists, and representatives from the private sector to share their findings, ideas, and visions for managing, conserving, and restoring riparian ecosystems in the Southwest. The Proceedings is divided into sections on the history, ecology, and management of the Rio Grande; general ecosystem hydrology and ecology; human history,...

Though biologists recognize that populations of Colorado River cutthroat trout have declined, the magnitude of the loss remains unquantified. We obtained information from state and federal biologists and from state databases to determine the current distribution and status of populations of Colorado River cutthroat trout. Recent population extinctions have been documented throughout this range. Hybridization with rainbow trout, nonindigenous cutthroat trout (those established or supplemented by stocking of genetically pure fish), and introgressed hatchery stocks has degraded many population...

Arceuthobium (dwarf mistletoes), a well defined but morphologically reduced genus of the family Viscaceae, is parasitic on Pinaceae in the Old and New Worlds and on Cupressaceae in the Old World. Although conifer forests in many parts of the Northern Hemisphere are infested with dwarf mistletoes, those most commonly infested are in western North America and Mexico. In North America, Arceuthobium ranges from central Canada and southeastern Alaska to Honduras. Only A. pusillum occurs in eastern North America, and only A. juniperi-procerae is found in the Southern Hemisphere. Arceuthobium...

This paper's title - "Can we restore the fire process? What awaits us if we don't?" - represents an ecologist's view of the world. I submit that this view is unrealistic. The first clause uses the term "restore" which implies reestablishing the fire process of the past. The second phrase uses the absolute term "don't" which implies that we can. Both of these phrases are too determinant for me. The 1995 International Conference of the Society of Ecological Restoration slogan challenges us to Take a Broader View." If we do that we can see the real challenge.

A laboratory experiment examined the potential for information bias in contingent valuation (CV). Consistent with the view that information about a public or private good can function as a persuasive communication, willingness to pay (WTP) was found to increase with the quality of arguments used to describe the good, especially under conditions of high personal relevance. Under low personal relevance, WTP for a publicbut not for a private. good was higher when an altruistic, as opposed to an individualistic, orientation was activated. It is concluded that the nature of the information...

Increasing awareness of exposure to environmental risks has focused attention on measures that would give greater assurance that such risks are effectively managed and that the adverse consequences of risky activities are mitigated. Implementing such actions is made more difficult by the uncertainties of environmental changes, their often delayed impacts, the great importance attached to extremely small risks, and the lack of clear measures of the values of environmental losses. Findings from recent behavioral studies of people's time preferences, valuations of losses relative to gains,...

Seceral contingent valuation studies hace found that the open-ended format yields lower estimates of willingness to pay (WTP) than does the closed-ended, or dichotomous choice, format. In this study, WTP for a public encironmental good was estimated under four conditions: actual payment in response to open-ended and closed-ended requests, and hypothetical payment in response to open-ended and closed-ended requests. The experimental results, showing that the response format mattered far more for hypothetical than for actual payments, support conclusions about the reasons that the dichotomous...