Fig. 3: Functional diversity plotted against species diversity, for various dimensions of trait space (rows), levels of environmental trait variance (columns), and competition widths (colors).
From: The evolution of trait variance creates a tension between species diversity and functional diversity
Each point is a single replicate model run, across 10 replicates per parameterization; n = 240 independent samples per panel. Functional diversity was obtained by dividing each trait dimension into 101 equally-sized bins in the [−1, 1] range (Supplementary Note 5; note the log scale along the ordinate). Since higher-dimensional trait spaces have more room and therefore can harbor more species all other things equal, the competition widths were chosen larger for higher-dimensional trait spaces to create comparable species diversities for different trait dimensions. The lines in each panel are locally weighted polynomial regression fits on corresponding results from an appropriate null model with 99% confidence intervals around them (these errors are so small that they are barely visible). The null model consists of an exact re-run of the replicates, with the sole difference that the trait covariances are not allowed to evolve. In the null model, the relationship between species- and functional diversity is positive, as expected. They do not reach as far along the x axis because without the trait breadths being allowed to shrink, only fewer species can be packed into the trait space, limiting species diversity.
