Prediction of the Climatically Suitable Areas of Rice in China Based on Optimized MaxEnt Model

Predicting the distribution of climatically suitable areas for rice in China and identifying the key climatic factors can help optimize the rice planting layout and ensure food security. According to rice planting system in China, rice can be divided into early-season rice (ESR), mid-season rice and single-cropping late rice (MRSLR), and double-season late rice (DSLR). According to the actual growth period of ESR, MRSLR and DSLR, we calculated 36 climatic factors which may influence the distribution of climatically suitable areas and we employed MaxEnt model for prediction the climatically suitable areas of ESR, MRSLR and DSLR in historical period (2001–2020) and future periods (2041–2060 and 2081–2100). The key climatic factors for ESR are minimum air temperature of July, precipitation of driest month, precipitation of growth period and average air temperature of March; for MRSLR, the key climatic factors are minimum air temperature of coldest month, minimum air temperature of July and precipitation of wettest month; for DSLR, the key climatic factors are minimum air temperature of June, maximum air temperature of October and minimum air temperature of July. For ESR and DSLR, climatically suitable areas expand northwestward, with almost no climatically unsuitable areas. For MRSLR, climatically suitable areas expand northeastward, but climatically unsuitable areas appear in Guangxi, Guangdong, and Taiwan. The influence of climate change on the climatically suitable areas of rice in China exhibits significant regional differences, the unsuitable areas of rice are transforming into suitable areas. Attention should be focused on new suitable areas and new unsuitable areas. This study offers important scientific insights for the effective management and cultivation of rice.