Additive, antagonistic and synergistic interactions of future climate and land use change on Theaceae species assemblages in China

While climate and land use change are commonly known to interactively affect biodiversity worldwide, their interactive effects have rarely been explored, hindering our understanding of the attribution of biodiversity change to each of these two drivers. Here, we used ensemble species distribution models to project the potential distribution of 200 Chinese Theaceae species in the 2070s under three types of climate and land use change scenarios: (1) dynamic climate and constant land use, (2) constant climate and dynamic land use and (3) dynamic climate and dynamic land use. We further assessed the single and combined effects of climate and land use change on Theaceae species assemblages in China, and their interactive effects (i.e., additive, antagonistic and synergistic effects) on species losses and gains. Our results revealed that the mean species richness is predicted to change ranging from - 3.43-0.07 species by the 2070 s in China and the predicted species turnover values range from 1.38% to 18.65%. Additive and antagonistic interactions would dominate species losses and gains in at least 26.54% and 30.17% of the study area, respectively, while synergistical interactions would only occur in < 9.14% of the study area. Moreover, there were significant negative correlations between the single effects of land use and climate change and their interactive effects. These findings highlight the importance of understanding the interactive effects of climate and land use change on biodiversity and will help to better minimize risks of future biodiversity loss and exploit opportunities provided by land use-climate change interactions.