Feb. 16,1914 
Indicator Significance of Vegetation 
379 
appearance, due to the hairy covering of the young leaves. From the 
middle of summer to the following spring the plants having lost many of 
their leaves and the dark stems being more in evidence, the appearance 
of the vegetation is decidedly different. Still another aspect is that of 
the early fall when the Artemisia plants are in flower and give a yellow¬ 
ish color to the vegetation. The contrast between the comparatively 
vivid and varied appearance of the vegetation in early summer and its 
monotonous aspect during the rest of the year is heightened by the 
fact that nearly all of the flowering herbs belonging to this association die, 
at least to the ground, 
long before the close 
of the summer. 
In some parts of 
the valley, especially 
where the soil is sandy, 
the plants of sagebrush 
are tall, vigorous, and 
stand close together. 
In other and more 
extensive areas, where 
the moisture condi¬ 
tions are less favor¬ 
able, they are scat¬ 
tered and stunted, and 
the proportion of new 
growth to old wood is 
small. 1 The plants, in 
fact, look as if they 
were slowly dying in 
such areas. By far 
the best growth of 
Artemisia tridentata? is 
found on the sand hills 
and along irrigating 
ditches. In the greater part of the area occupied by this association the 
plants are from 2)4 to 4 feet high. Their frequency is indicated in figure 
3, which represents a quadrat 2 platted early in the month of August in a 
typical portion of this association as it occurs in Tooele Valley. 
The associated herbs, although of many species, are not sufficiently 
numerous individually nor sufficiently large in size to materially affect 
the aspect of the vegetation, even when they are at the height of their 
Fig. 3.—A representative 10-meter quadrat of the sagebrush association, 
showing the location of each individual of Artemisia tridentata (A) 
and of Gutierrezia sarothrae (G), these being the only woody species 
present. The figures show the number of main branches of the Arte¬ 
misia plants and hence indicate their relative size. The absence of a 
figure indicates that there was only one large stem. A circle around 
the A indicates a dead plant of Artemisia. Bromus teetorum was 
very abundant around the Artemisia bushes, and Sitanion was also 
present. These two grasses are not shown on the quadrat. 
1 These slow-growing plants reach a considerable age without attaining a large stem diameter. Twenty- 
three annual rings were counted in a stem barely -2% inches in cross section. 
2 For descriptions of the method of quadrats, see Clements, F. E., Research Methods in Ecology, Lincoln, 
1905, p. 161-176; and also his Plant Physiology and Ecology, New York, 1907, p. 202-310. 
