408 
Journal of Agricultural Research 
Vol. I, No. s 
Table XV.— Salt-grass community: Moisture conditions and salt content of the soil in 
typical areas . 1 
Depth 
of soil 
(feet). 
Date of collection. 
Item. 
June. 
July. 
August. 
4 
6 
12 
12 
29 
6 
Aver¬ 
age. 
No. of sample. 
20 
73 
83 
84 
ior 
109 
f 1 
28. s 
32. 6 
28. 4 
17 - 1 
3 °* 9 
22. 6 
48.9 
54-9 
65-8 
62. 2 
34 - 1 
31.8 
Moisture equivalent. 
1 \ 
1 4 
35 - 1 
19. 4 
36. 1 
15-4 
13. 2 
33 * 3 
49 -1 
18. 5 
f 1 
15-5 
17. 7 
16. 5 
26. 6 
Wilting coefficient. 
12. 3 
29. 6 
-ip « 
2 
i \ 
18. 1 
26. 7 
+ 9-6 
+ 13 * 5 
+ 11. 4 
+ 13-8 
1.07 
•97 
• 7 <> 
.64 
[ l 
19. 1 
io. 5 
7. 2 
35 - e 
33* 8 
+ 16. 7 
+ 24. 2 
Moisture content above or below 
+ 8.9 
+ 6.9 
wilting coefficient. 
3 
+ 11. 5 
I * 3 
“ 4-5 
2. 30 
1. 64 
1-36 
1. 14 
+ 24. 2 
+ 32 - 2 
• 59 
• 72 
Salt content. 
j ; 
•25 
< 56 
0. 57 
.80 
. 60 
. 24 
• 53 
• 24 
2.18 
1.85 
1 4 
I. 02 
• 34 
. 18 
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). 
salt-flat COMMUNITIES 1 
Topographical Relations 
Along the margin of Great Salt Lake there is a belt of low land which 
varies in width from about 4 miles, near the axis of the valley, to a mere 
fringe on the east and west sides where the mountain ranges approach 
the lake shore. Much of this area (see map, PI. XLII) is covered with 
water at times, but in summer presents a dazzling white surface due to 
the heavy crust of salts (Pi. XLIII, fig. 1, and PI. XLVIII, fig. 1). These 
flats are divided into shallow basins of greater or less extent, separated 
by low ridges and hummocks. (See PI. XLII, detail of vegetation west 
of Grants.) All but the lowest of these elevations are occupied by the 
greasewood-shadscale association (see foreground of PI. XLIII, fig. 1), 
while the basins and flats when not altogether devoid of vegetation 
support a few extremely halophytic species (Pi. XLVIII, figs. 1 and 2), 
which occur either as scattered individuals or in crowded colonies. 
The two environments are ecologically quite distinct, but it is impracti¬ 
cable to indicate on a map of the small scale used in Plate XLII the areas 
actually occupied by elevations and by depressions, with their respective 
types of vegetation. Greasewood occurs not only on the higher ridges in 
association with shadscale, but also on the lower hummocks and at the 
edges of the depressions, in association with Allenrolfea. Shadscale, on 
the other hand, is not found in the depressions, nor do the typical salt- 
flat species occur on the higher ridges. 
1 The ecological status of the salt-flat vegetation, like that of the grass-flat vegetation, can not be deter¬ 
mined without more extensive investigation in the Great Basin region. In the present paper it seems ad¬ 
visable to use the general term ' ‘community ” in referring to these types. 
