Figure 3. Residual variance in species diversity after area was factored out.

The figure shows the actual species numbers plotted against the predicted variance for the model with the highest R² and lowest AIC_c (adj. R² = 0.84, P<0.0001) for all species based on three factors: number of geology types, latitude and the amount of acidic sedimentary bedrock (negative). Dashed line indicates 95% confidence interval. See Figure 1. for state and province legend.