Abstract:

This study optimized the parameter settings of the MaxEnt model by using the ENMeval package in R, selected dominant climatic factors based on the data of 255 rape sample points of China and 19 climatic factors, and further predicted the distribution and change characteristics of climatical suitable areas for rape in China under the climate change scenarios for historical period (1970−2000) and future period (2041−2060) by optimized MaxEnt model. Results indicated that: (1) the optimal parameter setting of MaxEnt for rape in China was a linear combination of Linear, Quadratic, Hinge, Product and Threshold functions with a regularization multiplier of 4.0. This setting achieved the highest simulation accuracy. (2) The dominant climatic factors affecting the distribution of rape climatical suitable areas were minimum temperature of the coldest month, mean temperature of the wettest quarter, and precipitation of the driest month. (3) During the historical period, the low climatical suitable areas were mainly located in the western regions, central Inner Mongolia and Liaoning. The medium and high climatically suitable areas were primarily distributed in the central and eastern regions of China. Compared to the historical period, the future changes in climatical suitable areas were mainly reflected in the transition of unsuitable areas to low suitable areas, low suitable areas to medium suitable areas, and medium suitable areas to high suitable areas. The climatical unsuitable areas will decrease, the climatically suitable areas will increase, and the low, medium, and high climatical suitable areas will expand northward.

Key words: MaxEnt model, Rape, Climate change, Climatical suitable areas