BIODIVERSITY AND CLIMATE 187Fig. 6. The distribution of total reptile species diversity for North America, Europe, southern Africa and
Australia.diversity gradients in southern Africa. Regional
correlations for amphibian diversity show
similar relationships (Table 5).
Mammal species diversity shows greater
complexity than either amphibian or reptile
diversity (Fig. 3b), and the greatest hemispheric
asymmetry. Although the highest diversities are
also in the lowest latitudes, there is a secondary
peak in mid-latitudes (about 45-50°) for North
America and Europe, but not for South
America. Geographically, the highest diversities
in North America are in the western interior,
while in Australia, diversity is highest along the
NE coast, as it is for amphibians (Fig. 9). This
complexity is apparent from the correlations in
Table 2 (see also Table 6), which are consistently
lower for mammals than for the other major
groups. The highest correlation is with mean
annual NDVI, although note the similarity
between mammal species diversity and the
Table 4. Spearman rank test rho values for environmental variables and reptile species diversity by region
n
Absolute latitude
Elevation
MAT
MART
CMM
WMM
Radiation
Cumulative T 0
Cumulative T 5
Annual precipitation
P range
Months T 10 P 40
PET
Mean annual NDVI
NDVI 1SD
South
America_ - - - - _ - - - _ - - - - _ -North
America144
-0.936
NS
0.932
-0.490
0.847
0.931
NS
0.939
0.946
0.360
NS
0.690
0.940
0.746
-0.890Europe204
-0.928
NS
0.784
NS
0.524
0.887
0.901
0.801
0.860
NS
NS
0.399
0.817
0.638
-0.861Arabia_
_
_
__
_ _ _ _ _ _ _ - - ___Southern
Africa21
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NS
NSAustralia40
-0.726
NS
0.638
NS
NS
NS
NS
0.637
0.637
NS
NS
NS
0.640
NS
NS(p < 0.0001; NS, not significant, p > 0.0001)