Figure 4.

Geographical gradients in phylogenetic diversity of tree communities in 245 forest plots distributed across the Andes (Figure 2). The y-axes show the standardized mean pairwise phylogenetic distance (MPD_ses) after controlling for plot area (i.e., residuals of a regression between MPD_ses and plot area). These results demonstrate that phylogenetic diversity increases towards temperate latitudes (A) and higher elevations (B). The black lines show the main effect of latitude or elevation, and the gray broken lines indicate their confidence intervals. Color indicates mean annual temperature in each plot. Asterisks indicate slope significance: *** indicates high significance of p < 0.001.