230 UNIVERSITY OF COLORADO STUDIES 



spruces seen here and there in the vicinity of Corona station is best 

 considered a sub-alpine association which has come up the hill from its 

 natural home. 



Areas of bog or moor are scattered here and there throughout the 

 alpine zone. Everywhere there is slight depth of soil. Low places 

 become wet from the run-off of adjacent elevations. In walking a 

 distance of 100 feet across the alpine "tundra" one may pass through 

 ten or more bog areas alternating with as many bits of meadow or of dry 

 "rock desert." These moors are characterized by species of Carex, by 

 Caltha leptosepala, Trollius albijiorus and Elephantella among other 

 species. 



Alpine meadows are characterized by a somewhat close vegetation of 

 profusely-flowering low herbs such as clovers, together with some con- 

 spicuous taller plants as Rydbergia, Campanula and Mertensia. Sieversia 

 turbinata often forms considerable carpets. Like the meadow at 

 Boulder Park this particular formation, or association, changes its 

 appearance much from time to time depending on the flowering of the 

 more conspicuous species. 



Much of the vegetation in alpine regions is of the alpine mat type 

 found in what may be called rock desert areas (dry tundra.) The sub- 

 stratum is dry because of rapid run-off and slight depth of soil. The 

 characteristic plants have the well-known "alpine" habit with low, 

 matted, much-branched stems and an abundance of flowers. Some of 

 the conspicuous plants are Silene acaulis, Eritrichium argenteum, 

 Tetraneuris, Selaginella and Arenaria. 



it 



General Discussion of Conditions at Boulder Park 



Subsidiary Species. — The study of the principal and secondary 

 species of different associations I leave to the individual student who has 

 here the opportunity to practice the methods used by professional 

 botanists in carrying on ecological research. It will be necessary at 

 present merely to call attention to a few of the more obvious plant 

 relations and thus point the way for individual work by those who wish 

 to pursue the subject. 



Since spring snows in Boulder Park are very deep and lie late in the 



