Theoretical framework, indicator system and practical application of key biodiversity areas.

With the continuous decline of global biodiversity, biodiversity conservation has attracted more and more attention from the international society. In order to slow down the trend of biodiversity decline, it is particularly important to identify key areas for biodiversity conservation. However, most of current methods for identifying important areas have different assessment criteria and focus on different biological assemblages (species or communities) and ecosystem types. Key biodiversity areas (KBAs) are sites that contribute significantly to global biodiversity persistence. Unlike traditional research and identification methods, KBAs identification is based on a unified global standard to explore habitats that are critical to endangered plants and animals in terrestrial, freshwater, and marine ecosystems. Based on the theoretical and technical framework of KBAs, we summarized the system of identification criteria and assessment parameters for KBAs. The five high-level criteria are separated into eleven sub-level criteria. Among the eleven evaluation parameters, there is one evaluation parameter for the ecosystem level, eight evaluation parameters for the species level, one evaluation parameter for the gene level, and one comprehensive evaluation parameter. In addition, we analyzed the application of KBAs identification in biodiversity research and conservation combined with relevant domestic and foreign research cases. Furthermore, we discussed the future development direction and application prospect of KBAs identification method in China. This method could provide a new perspective for the formulation of ecological protection policies and the planning of naturally protected areas in China.