Soils are typically gravelly to very gravelly, feature a 

 cryic temperature regime, and may be strongly to violently 

 effervescent. Textures are sandy loams to loams. Soil depth 

 is shallow to moderately deep. Available water holding 

 capacity varies from low to medium. 



Adjacent Communities. — This type occurs at, or near, upper 

 timberline. It is often bordered below by the Abies lasio- 

 carpa - Pinus albicaulis/Vaccinium scoparium type and above by 

 alpine scrub. Unvegetated talus slopes sometimes interfinger 

 with this type. 



Other Studies. --This type has been described in Montana by 

 Pfister et al. (1977) . 



2 . Pinus flexilis/Aqropyron spicatum Type 

 (PINFLE/AGRSPI; limber pine/bluebunch wheatgrass; G5 S4) 



Vegetation. — Pinus f lexilis characterizes the very open tree 

 layer. Artemisia spp. are often present in the shrub layer. 

 Aqropyron spicatum is well represented to abundant and 

 Hesperochloa kingii may be common. 



Physical Setting. --This type occurs on steep, dry forested 

 slopes at elevations around 7000 feet. The total cover of 

 soil, gravel, and rock, exceeds 50%. The soil surface is often 

 unstable because of a lack of adequate vegetation cover. 



Soils are generally Entisols derived from calcareous 

 parent materials, are moderately deep, and are often violently 

 effervescent and very gravelly. Textures range from loams to 

 silts. Available water holding capacity varies from low to 

 medium. 



Adjacent Communities. --The type occurs adjacent to, or within, 

 the grassland/ shrubland zone and is often transitional to 

 communities in the Aqropyron spicatum , Artemisia tridentata , 

 and Cercocarpus ledifolius series. Unvegetated talus slopes 

 and limestone outcrops sometimes interfinger with this type. 



Other Studies. — This type has been described in Montana by 

 Pfister et al. (1977) . 



3. Pinus f lexilis/Cercocarpus ledifolius Type 

 (PINFLE/CERLED; limber pine/mountain mahogany; G3? S3?) 



Vegetation. -- Pinus f lexilis and Juniperus scopulorum charac- 

 terize the very open tree layer. Abundant Cercocarpus ledifo- 

 lius characterizes the undergrowth. Other species that are 

 generally present with cover exceeding 1% include Arcto- 



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