Treesearch

General warming in the Northern Hemisphere has been recorded since the end of the 1800s following the Little Ice Age. Records of glacier retreat during the last 100 years over the entire globe independently confirmed the recorded trend in global temperature rise. Several studies have illustrated various responses to this climate forcing, i.e., the recorded changes in temperature and precipitation concurrent with the increase in atmospheric CO2 concentration, increases in density of tree populations, declines in tree populations, treeline displacement or lack thereof, lengthening of the...

Large-scale wildlands reserve systems offer one of the best hopes for slowing, if not reversing, the loss of biodiversity and wilderness. Establishing such reserves requires both sound biology and effective advocacy. Attempts by The Wildlands Project and its cooperators to meld science and advocacy in the service of conservation is working, but is not without some problems. Scientists and advocates have differences in methods of work, different understandings of the origins and place of values in conservation, and differing expectations about the efficacy of biological information in...

The dialogue session was a continuation of a debate about norms and the application of normative standards to wilderness management that has taken place throughout the 1990s at national meetings and in the research literature. Researchers who have made significant contributions to the normative approach to wilderness recreation management presented three approaches to the norm problem. Doug Whittaker and Bo Shelby presented the structural norm approach, Robert Manning presented the evaluative standards and photo approach, and John Heywood presented the behavioral norm approach. Each...

The exponential growth of recreation and tourism or ecotourism activities is affecting ecological processes in protected areas of Chile. In order to protect protected areas integrity, all projects inside their boundaries must pass through the Environmental Impact Assessment (EIA). The purpose of this research was to design a multiscale method to assess vegetation for the EIA baseline in protected areas of Chile and developing countries. The data obtained could be used to indicate patterns of biodiversity of the ecosystem at different scales, and at the same time monitor changes due to...

Big sagebrush (Artemisia tridentata Nutt.) is the most common and widespread sagebrush species in the Intermountain region. Climatic patterns, elevation gradients, soil characteristics and fire are among the factors regulating the distribution of its three major subspecies. Each of these subspecies is considered a topographic climax dominant. Reproductive strategies of big sagebrush subspecies have evolved that favor the development of both regional and localized populations.

The paper identifies and discusses two major themes in wilderness social science. First, that wilderness studies (and its advocates) have been limited by an ontological tension between those who mainly approach the relationship between humans and nature on the basis of material factors and constraints and those who approach it through an examination of shifting concepts and ideas. Rather than pitting these against each other, I argue that a dialogue between how nature and humans relation to it has been culturally constructed and physically altered is critically needed. Second, while I...

This study mapped and analyzed the alpine-treeline ecotone (ATE) boundary and alpine plant communities on the Presidential Range, New Hampshire and Mount Katahdin, Maine. These are sensitive biomonitoring parameters for plant community responses to climatic change. The ATE boundary spans a considerable elevational range, suggesting that shorter growing seasons with increasing elevation only partially explain the upper limits for this boundary. This ecotone boundary may be influenced by topographic exposure factors related to mechanical damage caused by winter ice events and wind. Climatic...

We used pellets collected from roosts to supplement incidental foraging observations to identify prey species of Bald Eagles (Haliaeetus leucoughalus) and to evaluate spatial and temporal trends in their food habits while wintering in northern Arizona between 1994-96. We analyzed 1057 pellets collected from 14 roosts, and identified five mammal and 13 bird species. American Coot (Fulica americana, N = 447) and elk/deer (Cervus elaphus/Odocmleus hemoinus, N = 412) were the most common prey remains we identified and they varied annually and inversely with each other (11-58% for coots and...

Proper management of air resources is vital to maintaining the wilderness character of an area. Air pollution can affect natural resources and has caused injury to vegetation, bioaccumulation of mercury in fish, eutrophication of coastal ecosystems and visibility impairment in U.S. Fish and Wildlife Service (FWS) wilderness areas. Sources of air pollution include power plants, incinerators, industry, automobiles, dust and fires. Emissions from these sources can be transported long distances and affect areas otherwise considered to be pristine. The FWS uses a combination of monitoring,...

This paper presents a structured framework for evaluating proposals for scientific activities in wilderness. Wilderness managers receive proposals for scientific activities ranging from unobtrusive inventorying of plants and animals to the use of chainsaws and helicopters for collecting information. Currently, there is no consistent process for evaluating proposals, resulting in confused and frustrated scientists and managers, as well as lost opportunities for gaining valuable information about a wilderness. The framework presented here is based on two premises: that both benefits and...