Treesearch

The Southern Region USDA Forest Service recently completed the Southern Appalachian Assessment (SAA). The Assessment is a broad scale interagency analysis and sharing of existing information relative to the natural and human resources of the region. The SAA encompasses over 36 million acres extending from Northern Virginia to Northern Alabama. It was clear early in the Assessment that a uniform land cover data layer would be required to support analysis and modeling.

This proceedings contains 50 papers including an overview of shrubland ecosystem dynamics in a changing environment and several papers each on vegetation dynamics, management concerns and options, and plant ecophysiology as well as an account of a Jornada Basin field trip. Contributions emphasize the impact of changing environmental conditions on vegetative composition especially in the Jornada Basin and Chihuahuan Desert but also in other parts of western North America and the world.

This publication is the result of a half-day symposium, "Ecology, management, and sustainability of western grassland ecosystems" held at The Wildlife Society's First Annual Technical Conference, September 22-26, 1994 in Albuquerque, NM. The purpose of the symposium was to review and synthesize information about the structure, function, and components of steppe and desert grassland ecosystems in the western United States with special emphasis on the ecological roles and requirements of wildlife species. This work, designed to draw attention to some wildlife topics that have been particularl...

Due to economic and political pressures placed on timber production, information from timber inventories needs to be broken down into information on particular value groups, which are groupings based on individual tree characteristics. Thus estimates of totals and variances need to be computed for individual value groups, all value groups combined, and any collection of value groups. A method for reporting these estimates using a variance-covariance matrix is given. This is followed by two examples of the estimation of totals and variances for value groups applied to a population comprising...

Adaptive management uses an experimental approach in the stewardship of our natural resources. This paper advocates the complementary concept of "adaptive monitoring" to observe and evaluate the outcomes of these experiments. Adaptive management acknowledges that decisions must be made in spite of imperfect understanding of their consequences; likewise, adaptive monitoring is designed to accommodate the unknown objectives and technologies of the future. Adaptive monitoring must be extremely flexible to accommodate constant change in natural resources and management paradigms, in addition...

Fire has been an important evolutionary influence in forests, affecting species composition, structure, and functional aspects of forest biology. Restoration of wildland forests of the future will depend in part on restoring fire to an appropriate role in forest ecosystems. This may include the "range of natural variability" or other concepts associated with fire as a disturbance factor. Yet fire on the forested landscape has not been a constant in either space or time. Its frequency, intensity, seasonality, extent, and other characters - collectively know as a fire regime-varied considerab...

Periodic forest, grassland, and shrubland fires are part of the natural environment-as natural and vital as rain, snow, or wind (Heinselman 1978). Evidence of past fires is found in charcoal layers in lakes and bogs, and in the fire-scarred cross sections of trees. Recurring disturbances by fire are essential to the functioning of many ecosystems, termed "fire-dependent," that are found throughout North America (Heinselman 1978). Many examples are available to describe how fire affects the functioning of ecosystems, such as influencing plant succession, fuel accumulations, structure and...

In September 1995, the Society for Ecological Restoration (SER) held its Annual Meeting at the University of Washington in Seattle. The meeting included two dozen conferences and several symposia and field trips dealing with various aspects of applying ecological restoration on both site-specific and landscape scales. More than a thousand scientists, educators, land managers, and others interested in issues relating to ecosystem-based management attended. The keynote speaker, Professor Daniel Botkin of George Mason University, exhorted the assembly to think of the natural landscape as an...

The Klamath Province, straddling the Oregon and California border along the north Pacific coast, roughly forms a square between Coos Bay and Crater Lake, Oregon, to the north, and Eureka and Redding, California, to the south. It is recognized as geologically unique (Dott 1971; Orr 1992) and is the most floristically diverse province in the western United States (Whittaker 1961).

Fire is the single most important ecological disturbance process throughout the interior Pacific Northwest (Mutch and others 1993; Agee 1994). It is also a natural process that helps maintain a diverse ecological landscape. Fire suppression and timber harvesting have drastically altered this process during the past 50 to 90 years. Natural resource specialists generally agree that the forests of the interior Pacific Northwest are less healthy, less diverse, and more susceptible to larger and more destructive wildfires as a result of this human intervention (Everett 1994). Analysis of...