Planning priority conservation areas under climate change for six plant species with extremely small populations in China

The concept of Plant Species with Extremely Small Populations (PSESP) has been employed to guide conservation of threatened plant species in China. Climate change has a high potential to threaten PSESP. As a result, it is necessary to integrate climate change effects on PSESP into conservation planning in China. Here, ecological niche modelling is used to project current and future habitat distributions of six PSESP in China under climate change scenarios and conservation planning software is applied to identify priority conservation areas (PCAs) for these PSESP based on habitat distributions. These results were used to provide proposals for in-situ and ex-situ conservation measures directed at PSESP. It was found that annual precipitation was important for habitat distributions for all six PSESP (with the percentage contribution to habitat distributions ranging from 18.1 % to 74.9 %) and non-climatic variables including soil and altitude have a large effect on habitat suitability of PSESP. Large quantities of PCAs occurred within some provincial regions for these six PSESP (e.g. Sichuan and Jilin for the PSESP Cathaya argyrophylla, Taxus cuspidata, Annamocarya sinensis and Madhuca pasquieri), indicating that these are likely to be appropriate areas for in-situ and ex-situ conservation measures directed at these PSESP. Those nature reserves with large quantities of PCAs were identified as promising sites for in-situ conservation measures of PSESP; such reserves include Yangzie and Dongdongtinghu for C. argyrophylla, Songhuajiangsanhu and Chang-baishan for T. cuspidata and Shiwandashanshuiyuanlian for Tsoongiodendron odorum. These results suggest that existing seed banks and botanical gardens occurring within identified PCAs should allocate more resources and space to ex-situ conservation of PSESP. In addition, there should be additional botanical gardens established for ex-situ conservation of PSESP in PCAs outside existing nature reserves. To address the risk of negative effects of climate change on PSESP, it is necessary to integrate in-situ and ex-situ conservation as well as climate change monitoring in PSESP conservation planning.