Table 6. Variance partitioning resulting from the partial canonical analyses of ecological and socioeconomical variables on species richness; data are for San Fernando. Fraction of variation Propor. of variation F ratio df P Ecological (a + b) 0.696 8.6 3,19 0.002 Socioeconomical (b + c) 0.745 4.0 7,19 0.05 Total variation 0.860 3.6 11,19 0.04 Fraction decomposed Ecol. not explained by soc. (a) 0.115 1.4 4,7 n.s. Soc. explained by ecol. (b) 0.581 Soc. not explained by ecol. (c) 0.164 1.0 8,7 n.s. Unexplained variation (d) 0.140 Note: Calculations are explained in Table 4.