Treesearch

The boreal owl's fairly specific habitat requirements restrict its range in the conterminous U.S. to subalpine forests (see Chapter 9). These forests provide tree cavities, uncrusted snow that facilitates preying on small mammals, and cool microclimates essential for summer roosting. Such forests also provide habitat for the owl's prey which consists primarily of red-backed voles, mice, and other small mammals. Significantly these prey animals often eat lichens and the sporocarps of fungi. Both are common at high elevations or along drainages in the middle and northern Rocky Mountains, the...

The flammulated owl (Otus flammeolus) is a western mountain species associated mainly with ponderosa (Pinus ponderosa) and Jeffrey pine (Pinus jefferyi) forests in the United States and Canada (see Chapter 4). As a neotropical migrant, this small forest owl occurs on national forests in the United States during the breeding season and winters mainly south of the border but also in southern Texas, Arizona, and California. Based on the owl's documented distribution (see National Geographic Society 1987, Johnsgard 1988), it may occur on 89 National Forests across 6 Regions. To establish the...

Ponderosa (Pinus ponderosa) and Jeffrey pine (Pinus jefferyi) forests are ecologically diverse ecosystems. The communities and landscapes in which these trees dominate are variable and often complex. Because of the economic value of resources, people have used these forests extensively.

This forest owl conservation assessment focuses on three species of forest owls that occur on national forest lands in the United States. Sixteen other species of owls also regularly breed in the United States, but these three species were designated "sensitive" on forests in more than one region of the Forest Service in 1992. Within the National Forest System, "sensitive species" are plants and animals whose population viability is identified as a concern by a regional forester. Sensitive species require special management, so knowledge of their biology and ecology is critical. The...

Flammulated (Otus flammeolus), boreal (Aegolius funereus), and great gray (Strix nebulosa) owls occur over a broad portion of North America and each is designated as a "sensitive species" in four or more USDA Forest Service regions. The insectivorous flammulated owl is a neotropical migrant requiring suitable wintering habitat in the extreme southwestern United States, Mexico, and Central America as well as breeding habitat in the mountains of the western United States. Flammulated owls breed predominantly in yellow-pine (Pinus ponderosa and Pinus jeffreyi) forests and are cavity nesters....

The forest owl conservation assessments emphasize the relationship between flammulated, boreal, and great gray owls and the forests in which they occur. The habitat requirements of the owls and their principal prey bear strongly on the conservation status of the owls. Establishing the characteristics of the owl/habitat relationship is not a trivial or straightforward process. This discussion provides background on the study of habitat associations that will place the literature on owl habitat in theoretical perspective.

This report describes the soils of the Lost Lake, West Glacier Lake, and East Glacier Lake watersheds of GLEES and presents the methods used in conducting both the field and laboratory work. In addition, general statements about the nature of the mapping units used in making the soil maps are provided.

GLEES is contained within the Snowy Range Observatory. This Observatory consists of many weather stations, precipitation monitors, and stream gages scattered throughout the Snowy Range. These sites have been operated by the Wyoming Water Research Center (WWRC) since 1968. Data from the sites are available from the WWRC and were last summarized by Wesche (1982).

Generally, the annual snowpack at GLEES is established in November and lasts into July. Figure 10.1 is the 1987-91 recession curve of the snow-covered area fraction versus degree days. About 20% of the area consists of rocks, which are usually blown clear of snow, and trees. The trees may hide some of the snow in the aerial photographs that were used to develop the curve. The remnant area fraction of snow cover represents the permanent snowfield on the cliff face overlooking the lakes.

Wilderness ecosystems in the United States are federally mandated and set aside by the Wilderness Act. They are managed to minimize human impact using methods that leave these systems, to the extent possible, in their natural state uninfluenced by manipulation or disruption by humans. Management often involves controlling or minimizing visual impact by enforcing strict use rules such as no roads, motorized or mechanized equipment, structures, or harvesting. In addition to human-caused impacts, natural and anthropogenic environmental stresses affect the rates and magnitudes of natural...