Akasaka M, Kadoya T, Ishihama F, Fujita T & Fuller RA (2017) Smart protected area placement decelerates biodiversity loss: A representation-extinction feedback leads rare species to extinction. Conservation Letters, 10, 539-546.
Protected areas (PAs) spearhead global conservation efforts, but it has been repeatedly demonstrated that narrowly distributed species are more likely to be unrepresented in PAs. This means that where local extinctions are more likely outside PAs, a positive feedback loop could render PAs largely ineffective in decelerating extinctions, even where PAs effectively abate threats. Here we empirically test the elements of this feedback loop using distribution data for 1,572 threatened plants in Japan. Narrowly distributed species were indeed less likely to overlap PAs than widespread species, and local extinction rates for unprotected populations over 15 years were 1.5 times higher than those inside PAs. A simulation model showed that new PAs will substantially reduce extinction risk for widespread species, but not for narrowly distributed species, unless they are placed very precisely in the landscape. Our results suggest that a representation-extinction feedback will limit the effectiveness of PAs in preventing extinctions unless PA placement is carefully targeted.