Abstract:

This paper utilized methods such as the MaxEnt model and ArcGIS, selected 47 actual planting points of Brassica juncea var. tumida and 20 environmental impact factors, and combined with the data of three future climate scenarios introduced by CMIP6 to predict the suitable climate areas of Brassica juncea var. tumida in Chongqing in the 2050s (2041−2060) and 2070s (2061−2080), providing a scientific reference for the planning and layout of Brassica juncea var. tumida planting in Chongqing. The results showed that the MaxEnt model provided excellent predictions. The cumulative contribution of dominant factors reached as high as 88.3%, including precipitation of the wettest month, annual precipitation, altitude, mean temperature of the coldest season, annual mean temperature and temperature annual range. The threshold of those factors was 178−185mm, 1170−1225mm, 100−380m, 7.8−9.0℃, 17.5−18.6℃ and 27.6−28.6℃, respectively. Under current conditions, Brassica juncea var. tumida had 11.6% of the suitable areas, including 1422 km² of the highly suitable area  and 1.7% were in Fuling, Fengdu, and Zhongxian. Under the SSP1−2.6, SSP2−4.5 and SSP5−8.5 climate scenarios, in the 2050s the suitable areas amounted to 11.0%, 11.4% and 11.2%, respectively, and in the 2070s the suitable areas amounted to 10.8%, 10.6% and 9.6%. Future climate change will have adversely affect the planting and development of Brassica juncea var. tumida. To reduce these adverse effects, suitable planting areas should be selected.

Key words: Brassica juncea var. Tumida, Maximum entropy model, Climate suitability, CMIP6 future climate scenarios