Insight into distribution patterns and conservation planning in relation to woody species diversity in Xinjiang, arid northwestern China

Plant species play an important role in maintaining the stability of arid ecosystems. Due to low biodiversity, species distribution patterns and richness are infrequently investigated in arid lands. Here, we take the Xinjiang Urgur Autonomous Region (Province), a large area in arid northwest China, as a case to investigate the patterns of woody species diversity and their relationship to environmental factors. At the same time, we aim to evaluate the current protected areas network and improve conservation planning based on woody plant diversity of Xinjiang. In this study, we sampled 133 woody forest species and 220 woody xerophytic species, which are about 10% of the plant species and near 80% of woody species in this region, and modeled current and last glacial maximum (LGM) distributions of these species using the method of species distribution modeling (SDM). Based on the results of SDMs, species richness and LGM refugia were estimated for forest and xerophytic species. Then, we assessed correlations between current species richness and environmental variables as well as glacial refugia. Finally, we applied the digital approach of systematic conservation planning to determine priority areas based on patterns of species diversity. Precipitation variables and glacial refugia have influenced the distribution patterns of woody species diversity for forest and xerophytic species in this province. In our proposed network for biodiversity conservation, high priority areas mostly coincided with zones having low species diversity, and many of these concerned areas fall outside of the ranges of the current existing conservation network.