Figure 2
From: Evolutionary diversity in tropical tree communities peaks at intermediate precipitation
Relationship between mean annual precipitation (MAP) and lineage diversity (standardised effect size of phylogenetic diversity, a measure of the evolutionary diversity of communities) across 2,025 lowland tree communities of tropical South America. (a) Effect of MAP on lineage diversity (LD). Break point (1,490 mm) was determined by piecewise regression. r2 = coefficient of determination from generalized least squares (GLS) models that account for spatial autocorrelation. GLS was calculated for before (y = 0.002326x − 2.634307) and after (y = −0.0006x + 0.711) the break point. (b) Geographical variation of lineage diversity and MAP. Colours of the symbols illustrate lineage diversity and are identical to colours in (a) (warmer colours indicate higher values). Circles indicate communities below and triangles above the precipitation break point (1,490 mm). Grey areas around the curves in (a) are 99% confidence intervals. These represent, for a given value of MAP, the interval estimate for the mean of LD, thus reflecting the uncertainty around this mean. Dashed lines represent national borders and contours represent mean annual precipitation in (b).
