Pinus albicaulis in Central Montana: Environment, Vegetation and Production

Silvics of whitebark pine (Pinus albicaulis)

“…Weather data from several Despite these general trends, substantial variations whitebark pine sites in the Inland Northwest suggest the climatic interpretations that follow (Arno 1970;Weaver and Dale 1974). Summers are short and cool with mean July temperatures ranging from 55 to 59 OF (13 to 15 OC) in the whitebark pine forest and from 50 to 54 OF (10 to 12 OC) in the adjacent timberline zone.…”

“…Mean pH values of 4.8 to 5.0 were found for the upper mineral soil horizons in three habitat types, probably composed largely of Typic Cryochrepts (Pfister and others 1977). Data on nutrient availability in these soils have been provided (Weaver and Dale 1974).…”

“…In Montana and northern Idaho the whitebark pine stands in the timberline zone (above forest line or where subalpine fir becomes stunted) make up the Pinus albicaulisAbies lasiocarpa habitat types (Daubenmire and Daubenmire 1968; Pi i st er and others 1977). Whitebark pine is also a climax species in other habitat types, mostly on dry sites, in Montana, central Idaho, and western Wyoming, and in Alberta (Baig 1972;Steele and others 1983;Steele and others 1981;Weaver and Dale 1974). Pinus albicaulis/ Vacciniurn scopariurn is probably the most widespread and abundant habitat type that includes pure whitebark pine stands in the Rocky Mountains.…”

“…Pinus albicaulis/ Vacciniurn scopariurn is probably the most widespread and abundant habitat type that includes pure whitebark pine stands in the Rocky Mountains. Various aspects of the ecology of this habitat type in Montana and Wyoming have been described (Forcella 1978;Forcella and Weaver 1977;Weaver and Dale 1974).…”

Ecological types of the eastern slope of the Wind River Range, Shoshone National Forest, Wyoming

“…Soils in whitebark pine forests are derived from a variety of parent materials, including limestone, dolomite, shale, siltstone, sandstone, quartzite, quartz monzonite, quartz diorite, gneiss, basalt, metasedimentary rocks, volcanic ash, and glacial till (Hansen-Bristow and others 1990). Weaver and Dale (1974) and Steele and others (1983) reported that in western Montana, eastern Idaho, and northwestern Wyoming, whitebark pine is virtually absent from soils derived from calcareous parent materials, apparently preferring coarsegrained, non-calcareous soils in this region. Shallow, residual soils typically support pure stands of whitebark pine, while on deeper soils, in glacial till or colluvium, whitebark pine typically occurs in mixed stands with subalpine fir, lodgepole pine, and/or Engelmann spruce.…”