Treesearch

Over 360 exotic forest insects and about 20 exotic diseases have become established in the U.S. Many of these organisms have become serious pests, causing great economic impacts and irreversible ecological harm. Despite efforts to exclude exotic species, forest insects and disease organisms continue to be introduced at a rather rapid rate. In the last few years, one disease organism and six forest insects have been introduced or discovered in the U.S. Some of these organisms have the potential to become serious pests. Preventing introductions of exotic organisms is a global problem that...

A Stand Hazard Rating System for Central ldaho forests has been incorporated into the Central ldaho Prognosis variant of the Forest Vegetation Simulator to evaluate how insects, disease and fire hazards within the Deadwood River Drainage change over time. A custom interface, BOISE.COMPUTE.PR, has been developed so hazard ratings can be electronically downloaded directly to the District's GIS. Spatial and temporal evaluation of hazards can now be made when comparing management alternatives. GIs maps depicting hazard ratings through time generated from the FVS simulations provide ID team...

The fact that endemic root disease causing pathogens have evolved with forest ecosystems does not necessarily mean they are inconsequential. A pathogen such as the P group of Heterobasidion annosum has become an intractable problem in many Sierra east side pine stands in California because the fungus is adapted to colonization of freshly cut stump surfaces. The S group of Ha is wide spread among true fir forests in California and may be responsible for maintenance of endemic populations of the fir engraver bark beetles that are attracted to tree roots after site disturbances such as...

Despite a century of attempts to control populations of the gypsy moth, it remains one of the most destructive forest pests introduced to North America. Research has yielded valuable, albeit sometimes conflicting information about the effects of gypsy moth on forests. Anecdotal accounts and scientific data indicate that impacts of gypsy moth defoliation can range from inconsequential to devastating. When defoliation caused by the gypsy moth results in widespread mortality, successional patterns may be modified substantially and species composition may be altered.The most notable change in...

Of 1814 foraging attempts, prey captures, or nest deliveries by Bald Eagles (Haliaeetus leucocephalus) in 14 Arizona breeding areas during 1983-1985, 1471 observations were identifiable to at least class: fish (76%), mammal (18%), bird (4%), and reptile/amphibian (2%). Forty-five species were recorded: catfish (Ictalurus punctatus, Pylodictis olivaris), suckers (Catostomus insignis, C. clarki), and carp (Cyprinus carpio) were most common. Mean population dietary heterogeneity was 2.03 (SD = 0.43). During 1983-1985, 22 successful sites had a wider dietary breadth than nine unsuccessful ones...

This update reports changes in the Nation's timber resource since the 1989 RPA timber assessment. The timber resource situation is analyzed to provide projections for future cost and availability of timber products to meet demands. Prospective trends in demands for and supplies of timber, and the factors that affect these trends are examined. These include changes in the land and timber resource base. Changing resource conditions that may lead to policy changes or that may represent opportunities for private or public investment also are identified. Market and resource trends are interprete...

Land mangement activities can result in the delivery of fine sediment to streams. Over time, such delivery can lead to cumulative impacts to the aquactic ecosystem. Because numerous laws require Federal land managers to analyze watershed cumulative effects, field personnel need simple monitoring procedures that can be used directly and consistently. One approach to such monitoring is described. The approach involves sampling a longitudinal reach of stream channel several hundred feet long using a zig-zag pebble count procedure that crosses all habitat features within a stream channel. The...

Habitat capability (HABCAP) models for wildlife assist land managers in predicting the consequences of their management decisions. Models must be tested and refined prior to using them in management planning. We tested the predicted patterns of habitat selection of the R2 HABCAP model using observed patterns of habitats selected by radio-marked Merriam’s turkey (Meleagris gallopavo merriami) in the Black Hills, South Dakota. Coefficients for winter required substantial revision, coefficients for summer were modified to a lesser extent. Coefficients are recommended for winter, summer, and...

The Colorado Water Division 1 Water Rights Trial was one of the most significant federal reserved instream flow water rights cases to occur since the Supreme Court of the United States ruled in the case of United States v. New Mexico in 1978. This document summarize the large amount of technical data and information pertaining to the disciplines of geomorphology, hydrology, and sediment transport mechanics compiled and presented to the judge during the Water Division 1 trial. The summary discusses channel formation and maintenance as viewed by scientists with differing opinions and allows...

Natural disturbance in western U.S.A. forest ecosystems is related to forest succession, growth, and structural development. Natural disturbance may be biotic (insects and diseases) or abiotic (fire, wind, avalanche, etc.). Natural disturbances are more appropriately thought of as natural processes; disturbance is a social connotation implicating economic loss. Forest development influences the amplitude of natural processes, which in turn influences forest development. Understanding balances among ecological processes, and how these processes influence wildlife, timber, and other valued...