基于MaxEnt模型预测未来气候变化情境下东北耕地潜在适宜区的变化OA北大核心CSTPCD

Northeast China is an important commodity grain base in China,and its cultivated land is mainly distributed in the Northeast Plain forest-farming resources area.Studying the future potential suitable areas of cultivated land in this region is of great significance for improving its adaptability in the context of future climate change.Based on the distribution data of cultivated land(dry land and paddy field)and 31 environmental variables such as climate,topography,hydrology and soil from 2000 to 2020,this study used the maximum entropy model(MaxEnt)and spatial statistical analysis to construct cultivated land prediction models under the scenarios of four shared economic paths(SSP126,SSP245,SSP370 and SSP585)in different periods(2021-2040,2041-2060)in the future,and revealed the spatial distribution and future evolution trend of the potential suitable areas of cultivated land in the forest and cultivated resources area of the Northeast Plain.The results showed that:①The area of dry land was 29.21×104 km2,and the areas of high suitable area,medium suitable area,low suitable area and unsuitable area of dry land were 5.39×104 km2,48.71×104 km2,19.82×104 km2 and 30.18×104 km2,respectively.The high suitable area accounted for 15.27%of the dry land area,mainly distributed in the Liaohe Plain and Songnen Plain with low altitude.The main environmental factors affecting the suitability of dry land are the average temperature of the wettest quarter(bio8),slope(slope),precipitation of the driest quarter(bio17)and the standard deviation of seasonal variation of temperature(bio4).The optimal environmental conditions for dry land distribution are as follows:bio8 is 18.58～24.8℃,slope is-1.25°～8.03°,bio17 is 0～16.3 mm,and bio4 is 930～1400.②The paddy field area is 6.07×104 km2,and the areas of high suitable area,medium suitable area,low suitable area and unsuitable area of paddy field were 4.06×104 km2,13.67×104 km2,20.22×104 km2 and 66.17×104 km2,respectively.The high suitable area accounted for 66.89%of the paddy field area,which was mainly concentrated in Sanjiang Plain and scattered in Songnen Plain and Liaohe Plain.The main environmental factors affecting the suitability of paddy fields are altitude(dem),annual average temperature(bio1),slope and isothermality(bio3).The optimal environmental conditions for the distribution of paddy fields are as follows:dem is lower than 225.9 m,bio1 is 1.69～6.03℃,slope is lower than 2.28°,bio3 is lower than 25.53.③In the future climate scenario,the distribution of suitable areas for dry land and paddy fields is basically consistent with the current climate scenario,but the area of suitable areas has changed.During the early future period,the area of high suitable area of dry land increased the most under the SSP245-30 mode,which was 0.4×104 km2.The area increment of high suitable area in SSP126-30 mode was the highest,which was 0.03×104 km2.During the mid future period,the high suitable areas of dry land and paddy field decreased under the four modes.The dry land decreased the most under the SSP126-50 mode(1.46×104 km2),and the paddy field decreased the most under the SSP585-50 mode(0.29×104 km2).The research results can provide scientific support for the spatial planning of land in the Northeast Plain forest-farming resources area,and provide reference and suggestions for the development and utilization of cultivated land.