Table 4. Variance partitioning resulting from the partial canonical analyses of ecological and socioeconomical variables on species richness; data are for Tierra Colorada.

Fraction of variation
Proportion of variation
F ratio
df
P
Ecological (a + b)
0.510
5.27
3,26
0.004
Socioeconomical (b + c)
0.710
10.27
4,26
0.001
Total variation
0.811
8.12
9,26
0.001
Fraction decomposed


 

Ecol. not explained by soc. (a)
0.101
2.27
4,17
n.s.
Soc. explained by ecol. (b)
0.409

 

Soc. not explained by ecol. (c)
0.301
5.42
5,17
0.01
Unexplained variation (d)
0.189




Notes: Three RDAs serve as the basis for the present table. The ecological variation (a + b) was obtained by RDA with ecological variables only, whereas the socioeconomical variation (b + c) was obtained by RDA with socioeconomical variables only. Total variation (a + b + c) was obtained by a joined RDA with ecological and socioeconomic variables. The fractions of variations are then decomposed arithmetically to isolate the effect of the strictly ecological and socioeconomical variation.