Figure 3: Similarity over space and time.

(a) Contour plot illustrating the relationship between Jaccard similarity and geographical distance (between latitudinal bands) over the duration of the study. The scale bar is to the right of the plot. The plot highlights increasing similarity through time, and greater homogenization across distant localities. (bottom) Distance-decay plots for an early ((b) 1986) and late ((c) 2013) year in the study. Median slopes shown. Distances (km) are between latitudinal bands. Compositional similarity of more distant localities increases through time (See Supplementary Figure 4 for further analysis of distance decay).