Topographic diversity as an indicator for resilience of terrestrial protected areas against climate change

Abstract

Habitat loss from unrelenting human pressure is causing an unprecedented decline in global biodiversity. Protected areas (PAs) are meant to counteract loss and fragmentation of ecosystems and today PAs form the backbone of conservation strategies worldwide. However, anthropogenic climate change can severely reduce the effectiveness of PAs. Conservation professionals are in need of concrete spatial information on climatic changes within PAs in order to put forward practicable strategies to safeguard PA effectiveness in the face of climate change. In this study, we take advantage of openly accessible data on the disappearing climate index (DCI) to examine which PA characteristics are linked to climate change resilience on a global scale. DCI provides a measure of the relative area (percent of total area) within a PA that exhibits certain climatic conditions that will either disappear entirely or move outside the boundaries of the PA by the year 2070. Our results show that topographic diversity is highly correlated with reduced climate change impacts in PAs worldwide. We analyzed three different PA characteristics representing topographic diversity: PA area, maximal elevational difference (MED) and median terrain ruggedness (TR). All three characteristics are highly correlated with a decrease in the disappearing climate index (DCI). These results hold true across localities and even PA management practices. IUCN management category IV (habitat/species management area) and V (protected landscape/seascape) exhibit on average the highest DCI values. As an indicator for PA resilience under climate change, topographic diversity can be assessed easily through publicly available data and remote sensing products. This ease-of-use leaves topographic diversity standing in marked contrast to overall environmental diversity as an actionable conservation metric. Of course, topographic diversity alone is not a sufficient criterion on which to base conservation decisions. However, neither should the potential usefulness of topographic diversity be underestimated. As an actionable and complementary metric in combination with biological information topographic diversity can be an exceptional tool for decision making by PA managers, conservation practitioners and politicians.