Figure 4

Vascular plant species specialism and anthropogenic disturbance extent (%). Jaccard dissimilarity is an index of ‘specialism’ (lower values) to ‘generalism’ (higher values) ranging from 0 to 1. It is calculated based on species co-occurrence; in effect it measures turnover in co-occupants experienced by the focal species. (a) Frequency histogram of species specialism. Species with high Jaccard dissimilarity co-occur with a wide variety of other species. No species were observed with low dissimilarity, indicating little fidelity to co-occurring species. (b) Species generalism as a function of the mean anthropogenic disturbance extent across sites occupied by the focal species. Dots represent individual species and darker shading indicates species occurring in more sites. (c) Species generalism relative to site occupancy. Dots represent species, and warmer colours indicate species with higher mean anthropogenic disturbance in occupied sites. (d) Community homogeneity relative to percent anthropogenic disturbance extent. Each dot represents a site, and the mean Jaccard dissimilarity is the average Jaccard index across species occurring at that site. Note that the scales differ for (b) - (d).