Treesearch

Aspen's geographic and elevational ranges indicate a species that tolerates severe cold but does not tolerate sustained high temperatures, or semiarid or even dry, subhumid conditions. Much can be inferred from observation of the sites on which quaking aspen grows in the West. Aspen's distribution is related to its regeneration characteristics, its pathology, and its relations with other plants. Water and temperature, to some degree, affects each of these relationships.

This review discusses concepts and theories of substitution in recreation choice. It brings together the literature of recreation research, psychology, geography, economics, and transportation. Parallel and complementary developments need integration into an improved theory of substitution. Recreation decision behavior is characterized as a nested or sequential choice process. Examples are included from urban and dispersed recreation research.

Edaphic and climatic characteristics of a site quite well define the quality of that site for plant growth. The importance of soil characteristics to the growth and well-being of aspen in the West is apparent from observations by many authors, from inferences resulting from work with other trees and agricultural crops, and from detailed study of aspen soils and site quality in the Lake States. However, there are not many descriptions of aspen-soil-site relations in the West. Only in recent years has enough soil survey information been collected from the forested areas of the West to define...

The broad range of aspen in North America is evidence of its equally broad tolerance of wide variations in climate (Fowells 1965). Given open space for establishment and not too severe competition from other plants, aspen can survive from timberline on the tundra's edge to very warm temperate climates, and from the wet maritime climates of the coasts to very severe and often quite dry continental climates of the interior. Therefore, to describe the climates typical of this species' range is extremely difficult, especially in the mountainous West, where climates vary greatly. However, aspen...

Wooded draws and natural prairie woodlands occupy about 1.1 percent of the northern Great Plains. While the extent of wooded draws is extremely limited, their importance and value is much greater. These unique communities are important for wildlife and livestock habitats, soil stabilization, watershed maintenance, firewood, esthetics, and species diversity (Fig. 1). An estimate of their value has been placed at $10 million annually, primarily production of fuelwood, and wildlife habitat and hunting. However, the dominant use is cattle grazing which requires management to control overuse.

Data from wildlife habitat use, wood production, and values of hunting, trapping, and firewood reflect the contribution to values of wooded draws on the northern High Plains. Values included expenditures and net willingness to pay. Approximate values per annum derived were: deer hunting $26 million; turkey hunting $1 million; fur trapping $4 million; and firewood $7 million for a total annual value of $38 million from wooded draws.

The Daubenmire habitat type method was used to classify the upland hardwood draws of southwestern North Dakota. Preliminary data analysis indicates there are four upland habitat types: Fraxinus pennsylvanica/Prunus virginiana; F. pnnseanica-Ulmus americana/P. virginiana; Populus tremuloides/Prunus virginiana, and Quercus macrocarpa/P. virginiana.

Long-eared Owls nest at high densities locally over the Great Plains where suitable habitat is limited (Bent 1938), yet , according to Whitney et al. (1978), this species is rare to uncommon in South Dakota. Especially west of the Missouri River, few nesting records have been reported. This paper reports the occurrence of Long-eared Owls in the Badlands National Park between May 1981 and June 1983. The birds were observed by Paulson and Bob Hodorff, a Forest Service technician, during monthly, 4-day bird censuses of Rocky Mountain Juniper (Juniperus scopulorum) stands, and by Paulson alone...

In the West, aspen forests have not been actively managed for wood products largely because of the lack of markets for quaking aspen timber from the Rocky Mountains (see the WOOD UTILIZATION chapter). Despite this, the aspen ecosystem has been used to provide a variety of resources and opportunities (see PART 111. RESOURCES AND USES).

Natural genetic interchange and extensive colonization of aspen by seed strongly depends upon favorable climatic and microclimatic conditions and upon human intervention. At times, in regions with the right combination of environmental conditions, there is significant L, reproduction by seed; elsewhere such establishment is rare. Seed production generally is profuse; but this potential for regeneration is considerably reduced by the exacting survival requirements of aspen seedlings. Under the marginal conditions that prevail in some regions, aspen can consistently reproduce only vegetativel...