The conservation potential of protected areas over time measured through design and ecological integrity indicators is affected by land conversion

Abstract

Protected Areas are one of the main tools of conservation to protect wildlife and ecosystems. The amount of area being gazetted for protection has been rapidly increasing over time in response to the Strategy for Biodiversity outlined by the Convention on Biological Diversity in 2000 and 2010. The post-2020 Global Biodiversity Framework contains the largest area target yet. However, more area does not always equal a better protected area network for biodiversity. Here I propose a set of indicators to assess the conservation potential of Protected Area networks focusing on design (ecoregion and species representation), and ecological integrity (ecosystem service provision and climate stability). Using Australia as a case study, I investigate conservation potential of protected areas over time (1980–2020) and show that the return on investment into protected areas is lower than expected for the ecological integrity indicators in particular and varies between strict and non-strict PAs and by ecoregions. As the network is converted through ongoing anthropogenic processes, there is a land conversion debt on the conservation potential of the PA network, in particular in strict PAs. As countries increase the size of their protected area networks to 30 % or more, threatened species may benefit. However, contributions to ecosystem service provision and climate stability has not been increasing alongside the growing network. This analysis lends support to the idea that business as usual for designating protected areas is not appropriate, and multiple benefits, which include climate stability and ecosystem service provision should be part of decision-making.