Fig. 1. Hypothetical relationships between species’ geographical range sizes and temporal changes of occupancy.

a By comparing metacommunities surveyed in two time periods, we illustrate two contrasting scenarios about how two species with different range sizes might change their proportional occupancy through time: (i) large-ranged species increase occupancy but small-ranged species decrease occupancy; (ii) small-ranged species increase occupancy but large-ranged species decrease occupancy. Other scenarios, such as both small- and large-ranged species decreasing or increasing occupancy with differing magnitudes, are not shown for clarity. b Changes of species occupancy through time as a function of their range sizes from the scenarios illustrated in a. The effect of range size on occupancy change is expected to be reduced or removed (iii) in protected areas if the protection works (black arrows in b). For simplicity, the average changes of occupancy are shown as zero when range size has no effect, although it is possible that habitat protection can increase the occupancy of both small and large-ranged species.