The role of protected areas in tropical tree conservation post-2020: A case study using threatened Dipterocarpaceae

Abstract

Protected areas (PAs) are key tools to prevent extinction and preserve ecosystem functions. As countries reiterated their commitment to expand the reach of PAs by up to 30 % by 2030, stronger purpose and pertinence in the establishment of PAs is needed to ensure effective conservation. In this study, we used Dipterocarpaceae as a proxy for threatened and ecologically important trees to determine the role of PAs in tree conservation and the potential shortfalls at a global scale. We quantified the overlap between the geo-referenced occurrence data of 433 Dipterocarpaceae species and the distribution of global PAs, followed by a conservation gap analysis on Borneo, the center of diversity of the family. We found that while Southeast Asia is the hotspot for species diversity and threat to Dipterocarpaceae, a high proportion of threatened species were found at the range edges of Dipterocarpaceae. Half of all the countries with Dipterocarpaceae met the Aichi Target 11 of designating at least 17 % of their land area as PAs, and most had <10 % of their total number of PAs being relevant to Dipterocarpaceae conservation. Our conservation gap analysis demonstrated that only 5.02 % of the total area of habitat (AOH) of endemic and Critically Endangered dipterocarps was formally protected, while 18.6 % of the total AOH was included in the Heart of Borneo complex. Our data highlights the need for a more effective global conservation gap analysis for threatened trees that could inform area-based conservation post-2020.