Treesearch

Long-term monitoring of ecological and hydrological processes is critical to understanding ecosystem function and responses to anthropogenic and natural disturbances. Much of the world's knowledge of ecosystem responses to disturbance comes from long-term studies on gaged watersheds. However, there are relatively few long-term sites due to the large cost and commitment required to establish and maintain them. Knowledge gained from these sites is also important for predicting responses to future disturbances, such as climatic change, and these sites should be the focal point for the...

This paper investigates an optimization approach to determining the placement and timing of habitat protection for the western prairie fringed orchid. This plant’s population dynamics are complex, creating a challenging optimization problem. The sensitivity of the orchid to random climate conditions is handled probabilistically. The plant’s seed, protocorm and above-ground stages are all accounted for in a case example from the Sheyenne National Grassland in North Dakota. Sensitivity of the case example model to dispersal assumptions and climate condition probabilities is demonstrated.

An online bibliography was compiled to furnish a literature basis for implementing of land management activities and planning research endeavors in the Madrean Biogeographic Province, which includes the Madrean Archipelago region in the southwestern United States. Citations are listed alphabetically by author in categories appropriate to the subject-matter presented. The large number of citations preclude hard-copy publication. The complete bibliography is available on the USDA Forest Service, Rocky Mountain Research Station's Flagstaff office web site at www.rmrs.nau.edu/publications/madre...

Forest scientists ask that everyone, from the home gardener to the forest manager, help revive western white pine by planting it everywhere, even in nonforest environments such as our neighborhood streets, parks, and backyards. White pine, long ago considered the "King Pine," once dominated the moist inland forests of the Northwest, eventually spawning whole industries and historical movements. Now-since the arrival of Euro-Americans and the stubborn blister rust disease-this sun-loving giant barely survives on about 5 percent of its former domain. This is the story of the decline of the...

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.