Treesearch

Quaking aspen is the most widely distributed native North American tree species (Little 1971, Sargent 1890). It grows in a great diversity of regions, environments, and communities (Harshberger 1911). Only one deciduous tree species in the world, the closely related Eurasian aspen (Populus tremula), has a wider range (Weigle and Frothingham 1911).

In the past, markets for quaking aspen timber from the Rocky Mountains have been insufficient to support significant harvesting. This shortage of markets severely restrained the potential for aspen management. As a result, many stands protected from wildfire gradually reverted to conifers (see the VEGETATIVE REGENERATION and FIRE chapters).

Quaking aspen, or trembling aspen (Populus tremuloides), was named and described by Michaux in 1803. It exhibits marked phenotypic variability throughout its transcontinental range. Numerous authors, especially the early ones, tried to give order to the variability by subdividing it taxonomically. Quahng aspen has been subdivided by various taxonomists at one time or another into 4 species and 13 varieties or forms (Barnes 1969, Beetle 1974). However, Little (1953, 1979) recognized quaking aspen as a single heterogeneous species without subspecific taxa. Barnes (1969) found that much of...

Aspen has not been cut extensively in the West; in fact, it has been grossly underutilized. For example, as recently as 1975, the aspen harvest from National Forests in four Forest Service regions in the Rocky Mountain area was 7.64 million board feet. Additional minor volumes were cut on special-use permits for products such as fuel and corral poles. The total amount cut represented only 0.1% of the net volume available in these aspen forests.

This paper reviews the discussion contained in the 11 presentations given at a symposium on recreation choice behavior. It addresses major points of commonality in the papers, as well as areas where differences exist. It also suggests a number of areas in which additional research on recreation choice behavior is needed.

Aspen trees grow along moist stream bottoms as well as on dry ridges and southerly exposures, on talus slopes, and on shallow to deep soils of varied origins. Quaking aspen is one of the few plant species that can grow in all mountain vegetational zones from the alpine to the basal plain (Daubenmire 1943). As a consequence, aspen dominated communities are found intermixed with such divergent vegetation as semiarid shrublands and wet sprucefir forests.

The broad genotypic variability in quaking aspen (Populus tremuloides Michx.), that results in equally broad phenotypic variability among clones is important to the ecology and management of this species. This chapter considers principles of aspen genetics and variation, variation in aspen over its range, and local variation among clones. For a more detailed review of the genetics of qualung aspen, especially with wider geographic application and with emphasis on tree breeding, see Einspahr and Winton (1976).

Twenty-seven water quality parameters were measured in coal surface mine impoundments, bentonite surface mine impoundments, and livestock ponds in the Northern High Plains. Most impoundments were safe for use as a source for livestock drinking water. Eight water quality parameters were different (a

Breeding chronology and reproductive success of the Merlin (Falco columbarius richarsonii) were studied in southeastern Montana from 1978 - 1981. Breeding activity spanned 5 mo from the earliest observation of adults to the latest dispersal of adults and young from nesting areas. Clutch size, brood size and fledging success at active nests were similar (P > 0.05) among the 4 yrs. Mortality tended to be highest before the hatching stage. Breeding chronology and reproductive success were similar to results of studies in Canada.

This field guide - designed for use by people with minimal botanical training - is an identification aid for nearly 200 plant species having ecological indicator value in northern Idaho forest habitat types. It contains line drawings, simplified taxonomic descriptions , characteristics tables, conspectuses, and keys. It emphasizes characteristics useful for field identification of many common and special interest plants. This is not a comprehensive taxonomy of northern Idaho flora.PLEASE NOTE: This publication was revised with RMRS-GTR-118