Figure 3: Effects of key predictor variables on species richness of agamid lizards across Africa.

In (a), the relative importance (standardized coefficients) of six key predictor variables from the non-spatial regression model is illustrated. The variables are those that show significant effects in both spatial and non-spatial models (compare Table 2). The direction of effect is indicated as + or −. In (b), partial residual plots illustrate the relationship between a predictor and species richness once all other predictors have been statistically accounted for in a multiple-predictor model (see ‘OLS’ in Table 2). Abbreviations, units and sources of predictor variables are explained in Table 1. Each dot represents one 110 × 110 km grid cell. Plots were created using the statistical programming language R.