Treesearch

We used cosmogenic 10Be to measure erosion rates over 10 k.y. time scales at 32 Idaho mountain catchments, ranging from small experimental watersheds (0.2 km2) to large river basins (35 000 km2). These long-term sediment yields are, on average, 17 times higher than stream sediment fluxes measured over 10–84 yr, but are consistent with 10 m.y. erosion rates measured by apatite fission tracks. Our results imply that conventional sediment-yield measurements—even those made over decades—can greatly underestimate long-term average rates of sediment delivery and thus overestimate the life spans...

The fabrication and use of three tools to assist in the manual installation of shallow ground water observation wells are described. These tools are easily fabricated at a local machine shop. A method for calibrating pressure transducers is also described.

The Wilderness Act of 1964 designates wilderness areas as places where natural conditions prevail and humans leave landscapes untrammeled. Managers of wilderness and similarly protected areas have a mandate to maintain wildland fire as a natural ecological process. However, because fire suppression has dominated Federal land management for most of the past century, the natural role of fire has been lost from many wilderness areas. Managers now face the dilemma of how to restore fire to its natural role in wilderness areas affected by fire suppression and other anthropogenic influences...

During the last 150 years, two species of mesquite trees in the Southwestern United States have become increasingly common in what formerly was desert grassland. These trees have spread from nearby watercourses onto relatively xeric upland areas, decreasing rangeland grass production. Management attempts to limit or reverse this spread have been largely unsuccessful. This paper reviews studies regarding mesquite natural history and management strategies, emphasizing studies published during the past decade. Mesquite possess a deep root system and are capable of fixing atmospheric N,...

This study estimates the kinds, uses, amount, and retail value of wood products consumed annually in Colorado from 1997 to 2000. Colorado uses tremendous amounts of wood products, but it imports most of it from other states and countries despite the abundant forests in Colorado that are capable of providing many types of wood products.

This report describes results of research conducted in 2000 to develop models of suitable habitat for juvenile bull trout (Salvelinus confluentus) in Washington State. The research is associated with a cooperative agreement (Agreement #134100H001) between U.S. Fish and Wildlife Service (USFWS) and the U.S. Forest Service, Rocky Mountain Research Station (RMRS). The basic objective for the project is to define characteristics of suitable habitat supporting young juvenile and resident bull trout. This information will be used for the purpose of improving management and recovery of this...

Roads have been a part of human landscapes for more than 40 centuries. During the 20th century, technological advances have increased our ability to construct new roads at unprecedented rates and into steeper terrain. In the last half of that century, an extensive network of roads has been constructed in forests and other wildlands to facilitate use and management of natural resources. They are the transportation system that allows transport of timber and minerals from forests and access for recreationists, land managers, fire fighters, and residents of villages or vacation homes.Unfortunat...

With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern. Here, we tested whether in more fragmented landscapes there was a lower number of area-sensitive species and higher local extinction and turnover rates, which could explain higher temporal variability in species richness. To investigate such potential landscape effects at a regional scale, we merged two independent, large-scale monitoring efforts: the North...

Available methods of valuing environmental changes are often limited in their applicability to current issues such as damage assessment and implementing regulatory controls, or may otherwise not provide reliable readings of community preferences. An alternative is to base decisions on predetermined fixed schedules of sanctions, restrictions, damage awards, and other allocative guides and incentives, which are based on community judgments of the relative importance of different environmental resources and particular changes in their availability and quality. Such schedules can offer...

An optimization model is developed to identify timing and placement strategies for the installation of nest boxes and the harvesting of timber to meet joint timber–wildlife objectives. Optimal management regimes are determined on the basis of their impacts on the local abundance of a threatened species and net present value (NPV) and are identified for a range of NPV levels to identify production possibility frontiers for abundance and NPV. We apply the model to a case study focusing on an area of commercially productive mountain ash (Eucalyptus regnans F. Muell.) forest in the Central...