a a eotig 
A STUDY OF THE VEGETATION OF THE MESA REGION r 
EAST OF PIKE’S PEAK: THE BOUTELOUA FORMA- 
TION 
I. STRUCTURE OF THE FORMATION. 
H. LL: SHANTZ: 
(WITH MAP AND SEVEN FIGURES) 
THE region under consideration in this study lies at the base 
of Pike’s Peak and north and west of Colorado Springs. It is the 
portion known as the Mesa and the Garden of the Gods and contains | 
3200 to 4ooo hectares (map). While my attention has been confined — 
largely to this region, studies have been pushed out in all directions, — 
and I have attempted to make myself familiar with the mountain | 
and plains conditions of vegetation, as well as that of the area — 
under consideration. Especial attention was given to the plains — 
which extend eastward from the area first studied. 7: 
METHODS. 4 
The methods used in the study of the structure and development a 
of the vegetation, as well as in the study of the physical factors, are 
those used by CLEMENTs' in his ecological studies and need not — 
be mentioned here. The exact methods have been supplemented _ 
by careful field notes and photographs. The greatest care was 
exercised in physical factor readings. The soil samples for the 
determination of water content were taken with a soil borer, which _ 
gave a column of soil reaching to a depth of 15°™ and about 2° _ 
in diameter. : 
Relative humidity readings were taken as near as possible to ; 
the surface, and also one meter above. A constant record of relative 
humidity was obtained by means of the hygrometer at Colorado — 
City, and the isolated readings were compared with this record aS 
well as with the record of the United States Weather Bureau at ; 
Colorado Springs. Temperature readings were taken in the soil 
* CLEMENTS, F. S., Research methods in ecology. Univ. Pub. Co., Lincoln, 
Neb. 1905. 
Botanical 
Gazette, vol. 42] 
