*2.3. Functional Diversity Indices*

The functional diversity of each grid cell was estimated by metrics previously evaluated for their relationship with species richness [36], and amongst them [37] were (a) functional richness, defined by the convex hull volume occupied by the species of each grid cell; and (b) functional Rao's quadratic entropy, measured as the distance between two randomly selected species within the grid cell. We applied a Gower distance matrix to capture both the numeric and binary variables in our trait dataset and then performed principal coordinates analysis (PCoA) to ordinate species along the major axes and arrange them in a multidimensional functional trait space. Metrics were calculated using the "dbFD" function in the R package "FD" [38]. Furthermore, we estimated species richness per grid cell.
