270 UNIVERSITY OF COLORADO STUDIES 



The shrubby cinquefoil {Potentilla fruticosa), buffalo berry, 

 honeysuckle and elder occur in the moist soil. Edwinia and ninebark 

 grow in drier soil near the edge of the forest. The rose, kinnikinic 

 and juniper occur here also, but seldom form as dense mats as in the 

 close formation, since herbs occur more abundantly here. Herbs of 

 many species occur, hence changes take place in the general appearance 

 of the forest floor from week to week. This subject will be treated 

 under a separate heading. 



Other Trees of the Forest, — The coniferous trees are Engelmann 

 spruce, subalpine fir, limber pine, Douglas spruce and rock pine. 

 None of these form associations or societies excepting the Engelmann 

 spruce and subalpine fir. They occur either solitary or in small 

 groups. As has already been mentioned, a well-developed forest 

 of Engelmann spruce and subalpine fir may be found at the west 

 end of the park and on the high mountain south of East Lake. In 

 these places the slope is very steep and the soil cold and wet. 



On dry exposed situations along Baltimore Ridge and on the top 

 of the Giant's Ladder, limber pines invade the forest. A few rock 

 pines occur among the aspens at the western edge of the forest near 

 Jenny Creek. In this locality there are also some Douglas spruces. 

 One tree is of especial interest on account of its size, being about 

 80 feet high and four feet in diameter. This Douglas spruce is older 

 than any of the surrounding trees; indeed it is probably 400 years 

 old. 



The aspens {Populus tremuloides) and willows are the only deciduous 

 trees found in the lodgepole forest. The aspen association represents 

 a stage in reforestration of conifers, the trees being often the first 

 to appear after an area has been burnt over. They are gradually 

 replaced by the lodgepole pine but may maintain themselves for some 

 time in moist areas. The largest aspen groves are seen on the south- 

 facing slope at the base of the Giant's Ladder and north of Park 

 Lake. Smaller assemblages of aspens occur in depressions (glacial 

 sink holes) on the slope south of Tolland. The soil in such depres- 

 sions is very moist, due to seepage. The fact that the spring snows 

 remain here longer than on the slopes may also account for the exist- 



