40 The: Colorado Expe:rime;nt Station 
The Sagebrush (Artemisia tridentata) Steppe .—This is the 
most important plant community of the shrub type occurring in 
the state. The name “sage plains’’ aptly describes this plant com¬ 
munity as it appears in many sections. This applies to a uniform 
and uninterrupted growth over scores of square miles. When 
viewed from a distance, the sagebrush plant itself seems to be the 
only plant present. Closer examination shows a few associated 
shrubby and half-shrubby plants, and a considerable number of 
herbs. But even at the height of their flowering time, these herbs 
rarely modify the aspect of the community. There is considerable 
space between the individual sagebrush plants, and for most of the 
year, especially after the middle of July, the soil is quite bare. The 
average height of sagebrush is about 3j4 feet. In shallow soil, 
underlaid by hardpan or rock, or in habitats with an alkaline sub¬ 
soil, the plants are much smaller, while along streams in deep soil 
which is easily penetrated by water the plants may be 6 or 7 feet 
tall. 
An extremely prevalent condition in western Colorado is an 
admixture of sagebrush and pinyon pine-juniper (Fig. 13). One 
may travel for miles now through sagebrush, now pinyon pine- 
juniper, the two communities alternating frequently. The transi¬ 
tion from one to the other may be abrupt. It is quite obvious that 
both live under similar climatic conditions, as is evinced by their 
frequent alternation, and by the growth of sagebrush between the 
individual pinyon pine and juniper trees, but typical pinyon pine- 
juniper indicates a rocky soil. “Sage plain” may be interrupted by 
Pig. 13.—Alternation of sagebrush and pinyon pine-juniper in west¬ 
ern Dolores County. Pinyon pine-juniper occupies a shallow or stony soil, 
while sagebrush is on a deep, rather fine-grained soil. 
