Abstract
Aim: A fundamental challenge to protected area-based conservation is that protected areas are typically established under assumptions of environmental stationarity. With a rapidly changing climate, this assumption of stationarity is violated, and climate change could push some species beyond the bounds of currently protected areas. Here, we evaluate the efficacy of protected areas in conserving threatened plant biodiversity under future climate projections.
Location: South Africa.
Methods: We use ensemble species distribution modelling to map the projected distribution of South Africa's similar to 1200 threatened endemic plant species under present-day and projected climate scenarios for 2050. We quantify the performance of the existing protected area network by examining changes in the relative proportion of species' projected geographic extents within protected areas. We then examine whether current IUCN Red List status is a good predictor of climate 'winners' and 'losers.'
Results: We find that 56%-66% of species may have a greater proportion of their projected range extent falling within protected areas in 2050 under climate scenarios of mitigated and upsurge greenhouse gas emissions (Representative Concertation Pathways 4.5 and 8.5). However, this increase in the proportion of range protected is frequently associated with range contraction outside of protected areas. We also show that current threat intensity is not a good indicator of which species will lose versus gain increased protection.
Main conclusions: Our results suggest that the existing reserve network is surprisingly robust to projected range shifts; however, we also identify regions where species protection needs to be improved. In addition, we suggest that there is an urgent need to better incorporate future climate threats into the assessment of species extinction risks.