i 



i 



1907] 



YOUNG—FOREST FORMATIONS OF COLORADO 



341 



f A pinus flexilis 



latter grows more densely than the former. I know of no virgin 

 tracts of Pinus scopulorum.'''^ 



In the denser parts of the forniation the under layer is very scanty, 



Arctostaphylo 



Where 



Chimaphila umhellata^ with a few mo^ 



formation is more open frequent invaders from the neighbo 



Carex-grass-shrub formation straggle in. 



>jskya 



Fig. 9. — Pinus Murrayana and Poptilus iremuloides timber, two miles west of 

 iet, Colorado; approximate altitude 2700"^. 



Murray 



Relative to the damage 

 of mistletoe see Jack 



wrought by this and the pre 

 {op. ciL, p. 45). 



The discussion of the deforestation and reforestation of the areas 

 included in this and the succeeding formations I shall rcser\^e for 

 consideration imder "Succession." 



Observations of the physical character of the habitat of this for- 

 mation were taken at two stations. One of these was in a mixed 



^° In this connection see also Jack, Pike's Peak, Plum Creek, and South Platte 

 Reserves, U. S. Geol. Survey, 20th Ann. Rep., pt. 5, p. 50. 



