Prediction of suitable distribution areas of the endangered plant wild Nelumbo nucifera Gaertn. in China

Based on data of 136 distribution points and 14 environmental factor parameters, we applied both the GARP and MaxEnt niche models to predict the suitable distribution areas of wild Nelumbo nucifera Gaertn. in China. The average AUC values under the ROC curves from the GARP and MaxEnt models were 0.861 and 0.964, respectively, indicating that the MaxEnt model had more accurate prediction results. Furthermore, the MaxEnt model results showed that the optimal distribution areas of N. nucifera were mainly located in Sichuan, Hubei, and Hunan provinces, northern Jiangxi province, and a small part of Heilongjiang, Liaoning, Zhejiang, and Guangdong provinces. The Jackknife test indicated that the main environmental factors determining the potential distribution areas of N. nucifera were vapor pressure, elevation, mean annual temperature, annual average precipitation, average temperature in the hottest season, average temperature in the coldest season, the driest monthly precipitation, the lowest temperature in the coldest month, and the highest temperature in the hottest month. Statistical analysis of the environmental factors related to the potential distribution demonstrated that the most appropriate habitat conditions for N. nucifera were an elevation of 1-2216 m, high annual average precipitation (1202.50 mm), mean annual temperature of 16.19℃, average temperature in the hottest month from 24.60℃ to 35.10℃, and mean tolerated temperature in the coldest month of -0.53℃. These results will provide a favorable basis for the effective conservation of wild resources of N. nucifera in China.