Feb. x6, 1914 
Indicator Significance of Vegetation 
407 
Tabus XIV.— Sporobolus-Chrysothamnus community: Salt content and moisture 
conditions of the soil in typical areas . 1 
Item. 
Depth 
of soil 
(feet). 
Date of collection. 
June 
4 - 
July 
29. 
August 26. 
Aver¬ 
age. 
No. of sample. 
18 SC. 
ioo C. 
S. 
s. 
s. 
SC. 
SC. 
sc. 
C. 
C. 
Salt content. 
i 
1 
f 1 
2 
1 3 
4 
I 5 
I I 
0. 22 
.46 
* 53 
. 26 
• 14 
34-0 
29. 1 
34 -3 
26. 4 
31. 6 
18. s 
15-8 
18.6 
14-3 
17. 1 
-0.8 
+ 4-4 
+ 5.8 
+ 9-8 
+6. 1 
0. 25 
■ 45 
.58 
*30 
o- 85 
.40 
. 20 
. 20 
o- 45 
.40 
. 20 
o -35 
. 60 
• 5 ° 
0. 20 
•25 
. 20 
• 15 
0. 20 
•35 
•30 
0. 25 
•45 
• 15 
0.35 
•6s 
1.05 
0. 20 
•45 
•35 
o *33 
■44 
.40 
•23 
Moisture equivalent.... 
29-5 
35-3 
46. 6 
36. 7 
16. 0 
19. 2 
25-3 
19-9 
Moisture content above 
or below wilting co- 
+ 4*5 
+ 11. 4 
+25. 6 
+ 14*3 
1 All data in this table are stated in percentages of the dry weight of the soil. The moisture contents 
with a plus sign (+) represent moisture available for growth (above the wilting coefficient), while those 
with a minus sign (—) represent a corresponding deficit of available moisture (below the wilting coefficient). 
The unnumbered borings were made on Aug. 26, 1913, and the letters indicate whether the vegetation 
was dominated by Sporobolus without Chrysothamnus (S), Sporobolus with Chrysothamnus (SC), or 
Chrysothamnus without Sporobolus (C). 
Salt-Grass (Distichus) Community 
DisiicMis spicata , well known as salt grass throughout the western 
United States, is a low-growing, harsh-leaved grass which spreads by 
creeping rootstocks. It tends to form a heavy sod, especially where the 
land is grazed, and under such conditions this plant is very efficient in 
adding humus to the soil. 
Salt grass is more or less abundant in all parts of the grass flats and 
also penetrates the salt flats (PI. XLVII, fig. 3), where in some places it 
associates scatteringly with Allenrolfea and in other places forms dense 
mats. In the wetter portions of the grass flats salt grass is the principal 
component of a meadowlike vegetation, with Juncus baUicus, Suaeda 
erecia , Puccinellia airoides , and Glaux maritime, as important associates 
and with numerous other species occasionally present. 
The conditions as regards soil moisture and salinity at borings where 
this community occurs are stated in Table XV. 
