نتایج جستجو برای: forest service
تعداد نتایج: 431278 فیلتر نتایج به سال:
A. D. Wilson The USDA Forest Service has been involved in Texas oak wilt research since 1976. Despite research successes, there are still many important research areas that have not been addressed or sufficiently investigated to answer the key questions required for making sound disease management decisions. Some of the priority areas planned for future research by the Southern Hardwoods Labora...
Loblolly pine (Pinus taeda L.) decline has been prevalent on upland sites of central Alabama since the 1960’s. The purpose of this study was to compare Forest Health Monitoring (FHM) standards and protocols with root health evaluations relative to crown, stem, and site measurements. Thirty-nine 1/6 acre plots were established on loblolly decline sites in nine central Alabama counties. Sites wer...
This study compared two alternative techniques for predicting forest cover types from cartographic variables. The study evaluated four wilderness areas in the Roosevelt National Forest, located in the Front Range of northern Colorado. Cover type data came from US Forest Service inventory information, while the cartographic variables used to predict cover type consisted of elevation, aspect, and...
In 1948 the United States Forest Service drastically reduced grazing permits for the El Rito Ranger District in the Carson National Forest in Rio Arriba County, New Mexico. The decision was based on a 1947 case study in which local forest rangers claimed that smallholder Hispano ranchers “caused surrounding national forest ranges to become depleted of vegetative cover to such an extent that a r...
Research on forest recreation over the last 60 years has been voluminous. Research on nontimber forest products (NTFP) has been much less voluminous. In this chapter the history of these two tracks of research has been reviewed. Not all studies are mentioned; rather, a representative selection of the subject matter is discussed. Forest recreation research had its beginnings in the late 1950s wi...
College of Forest Resources, University of Washington, Box 352100, Seattle, WA 98195, United States USDA Forest Service, Northern Research Station, 1992 Folwell Ave., St. Paul, MN 55108, United States c School of Forest Resources, Penn State University, 203 Forest Resources Bldg., University Park, PA 16802, United States Department of Natural Resources and Environmental Sciences, University of ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید