High and Far: Biases in the Location of Protected Areas

TLDR

About one‑eighth of the earth’s land is protected, most established in the 20th century, and these areas are vital for species persistence and climate policy. The authors assess national PA networks for bias in elevation, slope, proximity to roads and cities, and agricultural suitability, and examine whether protection level correlates with these factors. The study finds that most national PA networks are biased toward higher elevations, steeper slopes, and remote locations, with higher‑status PAs even more biased, indicating that protected areas are often situated where land‑conversion pressures are low and suggesting that siting rules and REDD schemes should account for threat levels.

Abstract

About an eighth of the earth's land surface is in protected areas (hereafter "PAs"), most created during the 20(th) century. Natural landscapes are critical for species persistence and PAs can play a major role in conservation and in climate policy. Such contributions may be harder than expected to implement if new PAs are constrained to the same kinds of locations that PAs currently occupy.Quantitatively extending the perception that PAs occupy "rock and ice", we show that across 147 nations PA networks are biased towards places that are unlikely to face land conversion pressures even in the absence of protection. We test each country's PA network for bias in elevation, slope, distances to roads and cities, and suitability for agriculture. Further, within each country's set of PAs, we also ask if the level of protection is biased in these ways. We find that the significant majority of national PA networks are biased to higher elevations, steeper slopes and greater distances to roads and cities. Also, within a country, PAs with higher protection status are more biased than are the PAs with lower protection statuses.In sum, PAs are biased towards where they can least prevent land conversion (even if they offer perfect protection). These globally comprehensive results extend findings from nation-level analyses. They imply that siting rules such as the Convention on Biological Diversity's 2010 Target [to protect 10% of all ecoregions] might raise PA impacts if applied at the country level. In light of the potential for global carbon-based payments for avoided deforestation or REDD, these results suggest that attention to threat could improve outcomes from the creation and management of PAs.