486 
PACIFIC SCIENCE, VoL XX, October 1966 
quantities of Sehima nervosum, Sorghum niti- 
dum, and Heteropogon contortus, and double 
that amount of Theme da australis, with a little 
Dichanthium superciliatum. The third series, 
the Sehima-Heteropogon series, with a produc- 
tion almost the same as the Themeda-Sehima 
group, consists of about equal quantities of 
Heteropogon contortus and Sehima nervosum, 
with Theme da australis accounting for only 
6% of the dry matter. 
DISTRIBUTION PATTERNS (Fig. 2) : The The- 
meda-Heteropogon group occupies the lowest 
parts of both transects, with slopes varying be- 
tween 0°30' and 3°, and occurs on black clay 
soil as well as on texture-contrast soil, the for- 
mer with a 20 or 30 cm deep crumbly topsoil, 
the latter with a crumbly topsoil of only 5 or 10 
cm. Deeper layers have a blocky, lenticular, or 
columnar structure, are black, dark grey, or dark 
brown, and frequently have calcium carbonate 
concretions. The pH in upper layers varies be- 
tween 5.5 and 7.0, and increases at depth to 
8.5. Some 20% of the ground is covered by 
litter, mainly of the eucalypts, and 10% is cov- 
ered by grit and gravel, both showing a great 
local variation. 
The T hemeda-Capillipedium group occupies 
the intermediate parts of the transects. At 
transect 1 it occurs on texture-contrast soil al- 
ternating with the Themeda-Heteropogon 
group, at transect 2 on texture-contrast soil and 
adjacent regosol; consequently it occurs over 
TABLE 3 
Specific Data of the Ground Cover Groups 
(T-H = Themeda-Heteropogon group; T-C = T hemeda-Capillipedium group; 
T-S = T hemeda-Sehima group) 
T. aus- 
H. con- 
C. spici- 
Sorghum 
Sehima 
OTHER 
tralis 
tortus 
gerum 
nitidum 
nervosum 
GRASSES 
TOTALS 
Weight (g/m 2 ) 
T-H 517 
87 
10 
13 
2 
- 
629 
T-C 407 
76 
78 
3 
12 
1 
577 
T-S 218 
50 
3 
- 
131 
4 
406 
Percentage composition of sward by weight 
T-H 82 
14 
2 
2 
- 
- 
100 
T-C 72 
13 
13 
- 
2 
- 
100 
T-S 53 
12 
1 
- 
33 
1 
100 
Basal cover of tussocks (%) 
T-H 4.05 
0.84 
0.10 
0.06 
0.005 
- 
5.08 
T-C 3.24 
0.73 
0.95 
0.01 
0.2 
0.01 
5.02 
T-S 1.66 
0.54 
0.02 
- 
1.36 
0.11 
3.67 
Percentage areas of tussock bases 
T-H 81 
16 
2 
1 
- 
- 
ICO 
T-C 63 
14 
19 
- 
4 
- 
100 
T-S 45 
15 
- 
- 
37 
3 
100 
Number of tussocks per m 2 
T-H 14.7 
3.4 
1.6 
0.5 
0.2 
- 
20.4 
T-C 15.6 
3.1 
4.2 
0.1 
0.3 
0.2 
23.5 
T-S 15.3 
4.8 
0.7 
- 
6.9 
0.2 
27.9 
Frequency (%) 
T-H 96 
43 
10 
10 
2 
- 
T-C 93 
33 
32 
3 
7 
3 
T-S 84 
43 
4 
- 
73 
3 
Average length of longest culms (cm) 
T-H 143 
111 
135 
102 
95 
T-C 139 
111 
135 
115 
95 
T-S 117 
96 
105 
- 
89 
