Exotic Brome-Grasses in Arid and Semiarid Ecosystems of the Western US

235

Table 8.2

Ranges of nutrients, nutrient ratios, and annual and perennial plant cover in the different deserts sampled

Mojave (

n = 172)

Colorado Plateau (

n = 195)

Great Basin (

n = 30)

Chihuahuan (

n = 14)

Minimum

Maximum

Minimum

Maximum

Minimum

Maximum

Minimum

Maximum

Sand (%)

42

95

22

93

13

77

33

70

Very coarse sand (%)

0

49

0

14

0

10

0

20

Coarse sand (%)

0

36

0

21

0

21

1

22

Medium sand (%)

2

58

0

39

0

34

1

60

Fine sand (%)

8

51

4

72

1

34

5

47

Very fi

ne sand

(%)

4

35

3

42

5

25

3

29

Clay (%)

4

28

4

51

12

40

14

35

Silt (%)

1

40

0

52

11

59

21

40

pH

6.4

8.0

7.0

9.0

4.9

8.1

7

8.0

ANP (%)

<1

27

0

63

0

28

<1

35

Ca

(^) ex
500
5796
1012
26,880
960
4842
2384
54,620
Cu
0.12
1.7
0.05
5.2
0.88
3.7
0.01
1.5
Fe
0.9
14
1
63
3.8
84
0.4
3.1
Mg
(^) ex
29
692
31
820
120
849
10
7272
Mn
<1
14
<1
32
6
113
<1
10
Total N
1
1463
39
6994
369
2551
33
1427
Na
(^) ex
0.1
1013
0.2
912
52
980
26
30,180
K
(^) ex
30
1053
26
887
270
1724
<1
1554
K
(^) be
40
529
38
816
125
1130
10
1004
P be
0.8
27
0.9
37
11
60
0.1
26
(continued)
8 Soil Moisture and Biogeochemical Factors Infl uence the Distribution of Annual...