Suitable distribution area of drought-resistant afforestation tree species in north China based on MaxEnt model

  Objective  Pinus sylvestris var. mongolica, Pinus tabuliformis, Amygdalus davidiana and Armeniaca sibirica are commonly used afforestation tree species in semi-arid and semi-humid areas, which have drought-resistant and cold-resistant characteristics and the function of soil and water conservation. Studying their suitable spatial distribution can guide the vegetation restoration in northern China.

  Method  Based on the ecological characteristics of tree species, with the data of tree species distribution and 24 environmental variables (topography, soil and meteorology), based on the Co-Kriging method, the limiting factor superposition method and the maximum entropy model (MaxEnt) were combined to study the distribution of the suitable areas of 4 tree species.

  Result  (1) The prediction accuracy of MaxEnt model of four tree species reached the accurate level (AUC > 0.90). （2）The dominant factors affecting the distribution of Pinus sylvestris var. mongolica were ordered as soil type, average temperature in the coldest month and average wind speed in the coldest month. The dominant factors of Pinus tabuliformis were ordered as elevation, standard deviation of annual average temperature, soil type and annual precipitation; the dominant factors of Amygdalus davidiana were ordered as the average temperature of the warmest month, elevation, annual extreme minimum temperature, standard deviation of annual precipitation, slope and soil type; the dominant factors of Prunus armeniaca were elevation, soil type, average precipitation in the warmest month, wetting coefficient and average temperature in the warmest month in turn. (3) The middle and high suitable areas of Pinus sylvestris var. mongolica were mainly distributed in Inner Mongolia of northern China, Heilongjiang and Jilin provinces of northeastern China, Pinus tabuliformis, Amygdalus davidiana and Armeniaca sibirica were mainly distributed in Shanxi, Hebei provinces and Inner Mongolia of northern China, Shaanxi, Gansu provinces of northwestern China,

  Conclusion  In this study, MaxEnt model can accurately reflect the distribution of four tree species, and the results can provide scientific guidance for the afforestation in the semi-arid and semi-humid climate regions of China.