Centres of neo- and paleo-endemism for Chinese woody flora and their environmental features

Abstract

Separating centres of neo- and paleo-endemism on the clade level from the tree of life could infer their evolutionary history and further pinpoint conservation priorities. Yet, centres of neo- and paleo-endemism in mega-biodiversity China are controversial as their environmental features are unclear. Here, we used a comprehensive species occurrence dataset (4509 woody endemics with 158,028 occurrences) and phylogenetic approach categorical analyses of neo- and paleo-endemism (CANAPE) to identify endemic centres of woody flora in China. A total of 22 major and several minor centres of endemism have been successfully identified, covering 13.36 % of China's total land area, yet capturing 89.60 % of woody endemics. They were roughly in accordance with the previously known centres of endemism. New areas with conservation importance such as northern Xinjiang, eastern Heilongjiang, and western Himalayas were identified. Different centres of endemism presented their preferred environmental features. Centres of neo-endemism were associated with higher elevation, concentrated in central-southeastern Himalaya, southwestern Hengduan (“evolutionary front”) and the northern Altai Mountains. In contrast, centres of paleo-endemism preferred favorable climates (high temperature and precipitation) and long-term climate stability. They were concentrated in southernmost China, in coincidence with one of the world's biodiversity hotspots (Indo-Burma). Centres of mixed-endemism were regarded as a transition type of neo- and paleo-endemism, concentrated in areas with moderate temperature and precipitation. Therefore, highlighting those centres of paleo-endemism should be considered as conservation priority areas due to dominating by old lineages with important evolutionary history and vulnerability to global drought.