Contributions of climatic factors
Potential distribution of species strongly depended on environmental factors, especially climatic factors. During model simulating, variable importance and response curves were figured out to indicate the relationship between distributions and environmental variables (Fig. 2a). Each factor played a different part in different algorithms, and showed out different importance. Dominant environmental factors were figured out for each algorithm. BIO9 (mean temperature of driest quarter) performed the best among seven variables in all of 10 algorithms. According its response curves plotted out in Fig. 2b, the proper mean temperature of driest quarter for A. annua ranged from 4.8 to 23.3℃.