BOTANICAL OPPORTUNITY IN COLORADO 7 



The plant zones of the state have not been worked out with accuracy 

 and detail. Limits of the foothill, montane, sub-alpine and alpine 

 zones are much in controversy and these should be studied in various 

 parts of the state. Studies of timberline have thus far been of a very 

 cursory type. Observational methods must be first applied, then accurate 

 determination of altitudes of timberline in different parts of the state 

 must be made; finally physical data of air temperature, soil temperature, 

 soil moisture content and wind are needed. The collection and inter- 

 pretation of these data would bring to an end much loose talk about alti- 

 tude and plant life. Some solid basis for the discussion of the effect of 

 altitude on plants is greatly needed and this can be attained only through 

 such accurate studies as are here suggested. 



Ability of a soil to hold or to give up moisture determines in large 

 measure the plants which will grow in it. Large areas of Colorado have 

 a fine-grained soil, other large areas have soil of coarser texture. The 

 Niobrara, the Pierre, the Laramie, the White River formations have 

 different qualities and support different floras. It happens also that over 

 wide areas climatic conditions differ at the same time that the soil does. 

 It should be the work of botanists to separate the effects of soil and 

 climate so as to arrive at a rational explanation of the phenomena of 

 the plains and foothills. 



The continental divide passes north and south through the state 

 separating two nearly equal areas. What the effect of this divide is in 

 determining the flora to the east and west is a problem awaiting solution. 

 A most illuminating study might be made of the plants on the two 

 sides. They could be classified as to probable origin and the number 

 which have crossed the divide determined with some degree of accuracy. 

 It would probably be found that certain vegetation types are represented 

 on both sides of the divide even if species be not the same, while the 

 number of identical species would be found much greater than is ordinarily 

 supposed. Carefully prepared maps illustrating vegetation areas of the 

 eastern and western slopes are greatly needed and would help much to 

 an understanding of the effect of the Rocky Mountains on plant distribu- 

 tion. 



As an essential part of botanical work a thorough study of Colorado 



