Niche evolution in Quercus section Cyclobalanopsis

We compiled occurrences of 35 species of Quercus section Cyclobalanopsis from GBIF (www.gbif.org), CVH (www.cvh.ac.cn), CFH (www.cfh.ac.cn) under CC-BY 4, as well as our records of feildwork. We checked the data for each species, removed duplicates, artificial plantations, and other unlikely locations. No more than one occurrence was kept in each grid of 2.5 × 2.5 arc minutes, and we finally got 2,924 occurrences. All the 19 climatic factors and elevation for each site were queried by location from bioclimatic factors of WorldClim (version 2.1) for 1970-2000 with the spatial resolution of 2.5 arc minutes (Fick and Hijmans, 2017).