Treesearch

Air quality is monitored continuously at GLEES. Air pollutants are considered an important component of the atmosphere that can have an effect on terrestrial and aquatic ecosystems. Atmospheric deposition of gases, wet deposition of chemicals in precipitation including snow and rain, and dry deposition of chemicals are all monitored at GLEES. Although GLEES is a relatively remote and unpolluted site, deposition of pollutants can be important. The effects of ozone on native vegetation in alpine and subalpine ecosystems is generally unknown, but relatively high concentrations of ozone have...

The Glacier Lakes Ecosystem Experiment Site (GLEES), a 600 ha research watershed at 3200-3400 m elevation in the Snowy Range of SE Wyoming, has been established to examine the effects of atmospheric deposition on alpine and subalpine ecosystems. This document provides preliminary data on the landscape habitats, floristics, geology, soils, aquatics, atmospheric environment, hydrology, snow, and air quality conditions occurring at GLEES. Checklists of vascular plants and plankton, detailed soils descriptions, and maps of geology, soils, vegetation, and topography are provided.

Daily fire growth maps display the growth of the 1988 fires in the Greater Yellowstone Area. Information and data sources included daily infrared photography flights, satellite imagery, ground and aerial reconnaissance, command center intelligence, and the personal recollections of fire behavior observers. Fire position was digitized from topographic maps using GRASS GIS software to construct a file of daily fire location in vector format, later converted to raster format for further analysis. The data base is available in electronic form.

Guiding principles based on conservation biology are applied in assessing ecosystem needs. Ecosystem, economic, and social needs are integrated in a decision model in which the guiding principles are used as a primary filter for evaluating proposed actions. Management practices consistent with the guiding principles are likely to lead to ecological, economic, and social well being, while those practices that are not consistent with the guiding principles risk species loss, degraded environments, and long term social problems.

In this study a cross-correlation statistic is used to analyse the spatial relationship among stand characteristics of natural, undisturbed shortleaf pine stands sampled during 1961-72 and 1972-82 in northern Georgia. Stand characteristics included stand age, site index, tree density, hardwood competition, and mortality. In each time period, the spatial cross-correlation statistic was used to construct cross-correlograms and cumulative crosscorrelograms for all significant pairwise combination of stand characteristics. Both the cross-correlograms and cumulative cross-correlograms identified...

A renewed interest in pinyon-juniper woodlands has accelerated debate regarding management of this unique ecosystem. Should these woodlands be managed only to provide livestock forage through overstory removal-popular programs in the 1950s and 1960s-or should they be managed for production of multiple resource products and amenities? Pinyon-juniper woodlands have varying capabilities of producing fuelwood, wildlife habitat, forage for livestock, watershed protection, and other products such as pinyon nuts (Figure 1). In addition to these more traditional resources, we must now consider...

This paper is intended to broaden awareness and help develop consensus among USDA Forest Service scientists and resource managers about the role and significance of disturbance in ecosystem dynamics and, hence, resource management. To have an effective ecosystem management policy, resource managers and the public must understand the nature of ecological resiliency and stability and the role of natural disturbance on sustainability. Disturbances are common and important in virtually all ecosystems.

This guide provides technical descriptions of 23 lntermountain rushes (Juncus spp.), including the common and several less abundant species. Line drawings and color or black and white photos illustrate diagnostic characteristics of each species. An illustrated morphology and a glossary acquaint the layperson with terminology used to classify rushes. The guide is intended as a tool to aid in classification; it is not inclusive.

The fundamental difference between the map presented here and other regional ecosystem classifications is that this map's ecological units are based on climatic processes rather than vegetation communities (map appears at the end of this appendix). Macroclimatic processes are the physical and thermodynamic interaction between climatic controls, or the relatively permanent atmospheric and geographical factors that govern the general nature of specific climates (Marsh 1988). This approach to regional ecological classification has proven useful to resource managers and interest groups in...

This cooperative effort by USDA Forest Service Research and the National Forest System assesses the state of knowledge related to the conservation status of four forest carnivores in the western United States: American marten, fisher, lynx, and wolverine. The conservation assessment reviews the biology and ecology of these species. It also discusses management considerations stemming from what is known and identifies information needed. Overall, we found huge knowledge gaps that make it difficult to evaluate the species' conservation status. In the western United States, the forest...