A cost-effective approach to identify conservation priority for 30 × 30 biodiversity target on the premise of food security

There is a growing consensus on expanding protected and conserved areas for biodiversity conservation. Nevertheless, it remains uncertain where to expand conserved areas as well as what appropriate management modalities to choose. Moreover, conserved areas expansion should be balanced with crop-related food security challenges. We developed a framework to identify cost-effective areas for expanding protected areas and other effective area-based conservation measures (OECMs), and applied it to China. By combining templates for biodiversity conservation priorities at global scale and the priority conservation areas based on 2413 vertebrates' extinction risk in China, we identified areas with high biodiversity conservation value. We then categorized the priority areas according to human impact, indicating the potential cost of management. As a result of combining the two aspects above, we identified the most cost-effective areas for expanding protected areas and OECMs while excluding both the current and predicted croplands that can be used for food security. The results show that China could expand its protected areas to 22.81 % of the country's land area and establish OECMs in areas accounting for 9.82 % and 17.37 % of the country's land area in a cost-effective approach in two scenarios. In the ambitious scenario, protected and conserved areas would account for a maximum of 40.18 % of terrestrial area, with an average 62.67 % coverage of the 2413 species' suitable habitat. To achieve the goals of protected and conserved areas in Kunming-Montreal Global Biodiversity Framework, countries could apply this framework to identify their protected areas and OECM expansion priorities.