Treesearch

Ecotones are boundaries between plant assemblages that can represent a physiological or competitive limit of species’ local distributions, usually through one or more biotic or abiotic constraints on species’ resource requirements. However, ecotones also result from the effects of chronic or episodic disturbances, and changes in disturbance regimes may have profound effects on vegetation patterns in transitional areas. In this study, centuries-long chronologies of surface fire events were reconstructed from fire-scarred ponderosa pine (Pinus ponderosa Dougl. ex Laws.) trees in three sites...

When we think of tourism we often dunk of travel to exotic destinations, but modernization has also dispersed and extended our network of relatives, friends, and acquaintances. Fewer people live out their lives in a single place or even a single region of their natal country. Modern forms of dwelling, working, and playing involve circulating through a geographically extended network of social relations and a multiplicity of widely dispersed places and regions. Much of the "postmodern" discourse on tourism leaves the impression that tourists seek out only the exotic, authentic "other" and...

The disparity between willingness to pay (WTP) and willingness to accept compensation (WTA) has been demonstrated repeatedly. Because using WTP estimates of value where a WTA estimate is appropriate tends to undervalue environmental assets, this issue is important to environmental managers. We summarize reasons for the disparity and then discuss some of the implications for management of environmental assets. We end by suggesting some approaches for dealing with the lack of credible methods for estimating WTA values of environmental goods.

We examine habitat size, shape, and arrangement effects on populations using a discrete reaction-diffusion model. Diffusion is modeled passively and applied to a cellular grid of territories forming a coupled map lattice. Dispersal mortality is proportional to the amount of nonhabitat and fully occupied habitat surrounding a given cell, with distance decay. After verifying that our model produces the results expected for single patches of uniform habitat, we investigate heterogeneous and fragmented model landscapes. In heterogeneous single-patch systems near critical patch size, populations...

The Mexican spotted owl (Strix occidentalis lucida) was listed as a threatened species under the Endangered Species Act (ESA) in April 1993 (USDI 1993). Concomitant with the listing of the owl, a recovery team was appointed to develop a plan to recover the owl, allowing for its removal from the list of threatened and endangered species. The recovery plan - "the plan" - was completed and accepted by the U.S. Fish and Wildlife Service in 1995 #U.S. Fish and Wildlife Service 1995#. In developing the plan, the recovery team assembled and reviewed all existing information on the ecology of the...

The U.S. Forest Inventory and Analysis (FIA) and Forest Health Monitoring (FHM) programs utilize a fixed-area mapped-plot design as the national standard for extensive forest inventories. The mapped-plot design is explained, as well as the rationale for its selection as the national standard. Ratio-of-means estimators am presented as a method to process data from mapped inventory plots.

The Forest Health Monitoring (FHM) program seeks to assess the condition and trend of the forests of the United States (Riiters et al. 1992; NAPAP 1993). FHM is linked with the national sampling grid established by the Environmental Monitoring and Assessment Program (EMAP) of the Environmental Protection Agency. Epiphytic lichen communities were included in FHM because they help to answer several key assessment questions. These questions concern the contamination of natural resources, biodiversity, forest health, and sustainability of timber production.

This paper examines public support for new user fees established at the Desolation Wilderness in California as part of the Fee Demonstration Program. Traditional approaches to fee policy evaluations have typically focused on economic or revenue issues and equity impacts of various pricing strategies. Support for fees has been shown to vary by users in terms of attitudes toward fees, nature of usage or behaviors, and demographics. Fee support may also vary by the type of recreation or resource area, especially in the case of dispersed recreation areas such as wilderness or other sites,...

This paper examines wilderness users' response to recently established overnight camping fees at the Desolation Wilderness in California. Fee program evaluations have typically focused on economic or revenue issues, distributional or equity impacts of various pricing strategies, and questions of price fairness. In the case of wilderness recreation fees, it is also important to recognize the complex public purpose of wilderness and the long history of not having access fees in wilderness. To evaluate these various factors, this paper examines the impact of past wilderness experience and...

An intellectual map is a good starting point for any effort to integrate research on the human dimensions of ecosystem management. We must remember going into such exercises, however, that every map maker imposes a certain point of view, sense of order, or set of conventions in the effort to represent the world. Just as there are competing ways to divide the landscape into ecological or social units, there are many ways to divide intellectual territory. One interpretation of the relevant intellectual domains to be inregrated and applicd to ecosystem management is the list of disciplines...