River, at 2,650 m elevation. The site was a moderately 

 dense Populus tremuloides (aspen) forest (70 percent 

 cover), with scattered Abies lasiocarpa and Picea 

 pungens (blue spruce). The ground cover was a dense, 

 diverse mix of herbs, of which Geranium richardsonii 

 (white geranium) and Fragaria oualis (strawberry) 

 were most abundant (fig. lOA). This vegetation type 

 and similar stands of aspen with a lush herb under- 

 story are common throughout the Central Rockies. It 

 has been termed the Populus tremuloideslThalictrum 

 fendleri habitat type by Hess and Alexander (1986). 



The three other sites were close to the headwaters 

 of the West Fork of Sheep Creek, another tributary 

 of the Cache la Poudre River, in the Comanche Peak 

 Wilderness. One vegetation type was in moderately 

 dense (50 percent cover) Abies lasiocarpa-Picea engel- 

 mannii forest, at 3,350 m elevation. The groimd cover 

 was short and only moderately dense (fig. lOB). Diver- 

 sity was low, given the dominance of the matted shrub, 

 Vaccinium scoparium (grouse whortleberry). This veg- 

 etation type and related variants is abundant through- 

 out the Northern and Central Rockies. It has been 

 termed the Abies lasiocarpa/Vaccinium scoparium 

 habitat type by Hess and Alexander (1986). 



Figure 10 — Vegetation types in Colorado's Rocky Mountains 

 (C) Trifolium, and (D) Kobresia. 



The second high-elevation site was in open meadows 

 adjacent to these spruce-fir forests. Groxmd cover was 

 short and only moderately dense; disturbance by both 

 elk and pocket gophers was common. Species diver- 

 sity was high; Danthonia intermedia (oatgrass), Trifo- 

 lium parryi (clover), Sibbaldia procumbens (sibbaldia), 

 and Potentilla diversifolia (cinquefoil) were all abun- 

 dant (fig. IOC). This type has been termed the Dan- 

 thonia intermedia-Sibbaldia procumbens alpine grass- 

 land by Baker (1984), although Trifolium parryi was 

 the most abundant species on the study sites. Moister 

 areas grade into Deschampsia caespitosa (hairgrass) 

 meadows. 



The final type was located at a shghtly higher eleva- 

 tion (3,450 m), above tree line. Ground cover was a 

 dense, imeven turf, dominated by Kobresia myosuroides 

 (kobresia) (fig. lOD). Geum rossii (alpine avens) and 

 Trifolium dasyphyllum (alpine clover) were common 

 associates. This vegetation type and related variants is 

 a common alpine turf throughout the Colorado Rockies. 

 It has been termed the Kobresia myosuroides-Geum 

 rossii alpine turf by Baker (1984). 



In sum, the Rocky Mountain vegetation types in- 

 clude one type dominated by graminoids {Kobresia), 



(A) Geranium, (B) Vaccinium, 



16 



