Treesearch

The slope stability equation and values for material properties recommended by USGS geologist Dr. Raymond Wilson were used to map the stability regime of the four units of THP 1-97-307 HUM and the two units of THP 1-96-413 HUM. When calculations are carried out for conditions without trees, results indicate that each unit includes significant areas that would be expected to fail during storms of a size that occurs regularly in the area.

Nearly all mountain lakes in the western United States were historically fishless, but most now contain introduced trout populations. As a result of the impacts of these introductions on ecosystem structure and function, there is increasing interest in restoring some lakes to a fishless condition. To date, however, the only effective method of fish eradication is the application of rotenone, a pesticide that is also toxic to nontarget native species. The objective of this study was to assess the effectiveness of intensive gill netting in eradicating the trout population from a small...

In January, 1998, the Pacific Southwest Region and Pacific Southwest Research Station of the Forest Service initiated a collaborative effort to incorporate new information into planning future management of Sierra Nevada national forests. The project, known as the Sierra Nevada Framework for Conservation and Collaboration, will incorporate the latest scientific information and broad public and intergovernmental participation in watershed-scale ecosystem planning. The national forest portion of the project, which allows for forest plan amendment, is expected to be completed by mid-summer, 1999.

Abstract - Suction dredging for gold in river channels is a small-scale mining practice whereby streambed material is sucked up a pipe, passed over a sluice box to sort out the gold, and discarded as tailings over another area of bed. Natural resource managers should be concerned about suction dredging because it is common in streams in western North America that contain populations of sensitive aquatic species. It also is subject to both state and federal regulations, and has provided the basis for litigation. The scientific literature contains few peer-reviewed studies of the effects of...

Abstract. Populations of stream-dwelling salmonids (e.g., salmon and trout) are generally believed to be regulated by strong density-dependent mortality acting on the age-0 life stage, which produces a dome-shaped stock-recruitment curve. Although this paradigm is based largely on data from anadromous species, it has been widely applied to streamresident salmonids despite the fact that the processes limiting or regulating stream-resident populations remain poorly understood. The purpose of the present study was to determine whether stream channel morphology affects the availability of...

Diameter growth rates of understory trees were measured for periods both before and after overstory removal on six study areas in northern California. All the species responded with increased diameter growth after adjusting to their new environments. Linear regression equations that predict periodic annual increment of the diameters of the residual trees after treatment are presented for the six species in the study areas.

Historic observations and research indicate that the ponderosa pine (Pinus ponderosa) ecosystem in the southwestern U.S. is now very different compared to pre-European settlement. Timber harvest, livestock grazing, and fire suppression have transformed an open ponderosa pine-bunch grass community into a dense forest overloaded with flammable organic material, which increases the likelihood of devastating wildfire. Prescribed fire research during the past 20 years has demonstrated the benefits and potential problems with reestablishing burning techniques into one of the most fire-dependent...

The variation associated with sampling live fuel moisture was examined for several shrub and canopy fuels in southern California, Arizona, and Colorado. Ninety-five % confidence intervals ranged from 5 to % . Estimated sample sizes varied greatly. The value of knowing the live fuel moisture content in fire decision making is unknown. If the fuel moisture is highly variable, then it is possible for the confidence intervals to span one or more fire behavior or danger classes. Errors in live fuel moisture data may directly affect the costs in safety and resources associated with prescribed...

You have asked for my response to the following questions. In each case, references to the "ROD" indicate the Record of Decision and Standards and Guidelines for Management of Habitat for Late-Successional and Old-Growth Forest Related Species Within the Range of the Northern Spotted Owl, the document published by the USDA and USDI in 1994 that outlines the provisions of the Northwest Forest Plan, and which is based on the 1993 FEMAT report.