Figures 3a-d. Metrics of familial distributions along
elevational gradients, used to test mechanisms shaping the slope of ERR
via cross-family analyses.
Each point represents a species-rich plant family (n = 60), with size of
point representative of Malesian richness . Three families labeled
as examples for comparisons between scatterplots: 1) Dipterocarpaceae,
2) Ericaceae, 3) Pteridaceae. On the y-axis, slope of average
elevational range-size (m), abbreviated as ERR, as a function of
position along an elevational gradient (m a.s.l.). On the x-axis,
familial metrics of richness and elevational distribution. Plots include
a) the localized richness ratio , which is defined as the greatest
richness observed at any section of the elevation gradient, divided by
total family richness across all of Malesia; b) elevation with
peak in richness (highest point of the predicted richness curve); c)familial elevational
extent (breadth of the richness curve), calculated as the highest
elevation minus the lowest elevation values for any species within a
family; d) the average upper elevational limit for species
occurrence. Other metrics not shown include e) Malesian richnessand f) average lower elevational limit . Linear regression results
shown as a black slope, phylogenetic independent contrasts as a red
slope, both plotted without scaling; dashed lined represent
non-significance. Point colors (CMYK model) represent the combined
metrics of biogeographic association of each family, with endemism to
Sundaland represented as magenta tones, Wallacea as yellow, Sahul as
cyan, and cosmopolitan as black, with 25% transparency. Full color
legend for the 60 families in Supporting information.