Treesearch

Herbicides can be an effective, necessary, and environmentally sound tool for the control of weeds and brush on rangelands (Young and others 1981b). As a result, chemical control is a widely used means of removing unwanted or noxious plants from range and other pasture lands. Selective plant control by mechanical, biological, fire, or manual means should also be considered but is not always a satisfactory alternative to chemical control.

Plant responses to fire differ because of phenological variations at the time of burning, inherently different susceptibilities to heat damage, differing regenerative abilities, and different responses to the postfire environment. Individual plants of the same or different species may have different responses to fire because of local variations in fire temperature or microenvironment. The postfire assemblage of plants may have few species changes, as is often the case after grassland fires, or may be dramatically different in both species composition and structure, following some forest...

Selection and use of seeds of different species must be carefully considered in range and wildland improvement projects. The selection of species to be planted in any restoration program usually takes place after the decision has been made to restore or rehabilitate an area, and the objectives of the project have been determined. However, availability of seed and planting stock can delay and alter seeding programs. Seeding and planting involves an introduction of seeds and plants to a site that alters existing plant communities and influences successional processes. Most seeding projects...

Restoring Western Ranges and Wildlands has had a fairly long gestation period. The final product of three volumes had its beginnings in 1983. At that time research administrators of the Intermountain Forest and Range Experiment Station (now part of the Rocky Mountain Research Station) had obtained funding from the Four Corners Regional Commission (FCRC) to produce a series of research summary syntheses to aid agriculture and natural resource values and management for the Four Corner States (Arizona, Colorado, New Mexico, and Utah) and surrounding areas.

Plummer and others (1968) proposed 10 principles to follow when planning and implementing rangeland revegetation programs. These principles - or basic considerations for rangeland managers - are applicable to most sites in the Western United States (Jordan 1981; Merkel and Herbal 1973), and many projects in the Intermountain area have been conducted successfully by following them. This chapter provides a discussion of each principle and refers the reader to the other chapters of this book where more information may be found. These should be considered general guidelines and may require...

This book is intended to assist range managers throughout the Intermountain West (fig. 1). The areas of greatest applicability are the Middle and Southern Rocky Mountains, Wyoming Basin, Columbia and Colorado Plateaus, and much of the basin and range physiographic provinces of Fenneman (1981) or about 14° latitude, from the Mohave, Sonoran, and Chihuahuan deserts to the northern Rocky Mountains, and 15° longitude, from the Great Plains to the Sierra Nevada-Cascade Mountain axis. This large area contains diverse landforms and several major vegetational communities. Nevertheless, landform...

Improvement of vegetative and edaphic conditions on some wildland sites can be achieved through proper management as well as by manipulative plantings (Vallentine 1980). Sites that have been subjected to serious abuse or that lack needed cover, habitat, or forage resources can be improved by various methods (Vallentine 1980). Prior to the development of any site improvement program, land managers must first discern the resource needs and suitability of an area for treatment (Plummer and others 1968). Then appropriate methods and techniques can be developed.

A previously unknown group of flies is described whose males exhibit directional asymmetry, in that the left wing is larger than, and of a different shape from, the right wing. To our knowledge, wing asymmetry of this degree has not previously been reported in an animal capable of flight. Such consistent asymmetry must result from a left­right axis during development, a level of differentiation whose existence has been questioned for insects. Wing asymmetry of this magnitude has implications for questions in areas of development, natural selection, flight, mate selection and communication...

This report discusses valid use of data produced by the Forest Service?s Forest Inventory and Analysis (FIA) program and used by the Northern Region of the National Forest System to analyze the compliance of individual National Forests with their Standards and Guidelines. It emphasizes use of FIA data on snag density and the percentage of forest area that meets the definition of old growth. This report does not give the results of such analyses. Rather, it gives the rationale for use of FIA data for such analyses.

Birds associated with prairie ecosystems are declining and the ecological condition (seral stage) of remaining grassland communities may be a factor. Livestock grazing intensity influences the seral stage of grassland communities and resource managers lack information to assess how grassland birds are affected by these changes. We estimated bird density, species diversity, and species richness on 37 sites in 4 seral stages of western wheatgrass [Pascopyrum smithii (Rydb.) A. Löve]-green needlegrass [Nassella viridula (Trin.) Barkworth] communities of the Fort Pierre National Grassland....