Estimating species extinction rates: Spatial distribution of species and geometry of habitat destruction

Background/Question/Methods In a previous study (He & Hubbell, Nature 473:368-371, 2011), we showed that the backwards power-law species-area relationship (SAR) systematically overestimates species extinction rates from habitat loss. The backwards SAR is a method for estimating imminent extinction, not committed extinction. Here, we implemented intensive simulations to show how spatial distribution of species and spatial configuration of habitat destruction may affect the overestimation.

Results/Conclusions The results show that the overestimation becomes higher with the increase of spatial aggregation of species and this result is independent of spatial configuration of habitat destruction. We further show that the random placement endemics-area relationship is an accurate model for quantifying imminent extinction rates for any spatial distribution of species, random or nonrandom.