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

Change prediction of potential suitable area of cultivated land in Northeast China under the future climate change situation based on MaxEnt model

东北是中国重要的商品粮基地,其耕地主要分布于东北平原林耕资源大区。研究该区域耕地的未来潜在适宜区,对于提升其在未来气候变化背景下的适应性具有重大意义。基于2000—2020年耕地分布数据与31个气候、地形、水文、土壤等多类环境变量,通过最大熵模型(MaxEnt)和空间统计分析,构建未来近期(2021—2040年)和未来中期(2041—2060年)4种共享经济路径(SSP126、SSP245、SSP370和SSP585)情景下的耕地预测模型,揭示东北平原林耕资源大区耕地潜在适宜区空间分布规律和未来演变趋势。结果显示:(1)旱地面积为29.21×10~4 km^(2),其高适生区、中适生区、低适生区和不适生区面积分别为5.39×10~4 km^(2)、48.71×10~4 km^(2)、19.82×10~4 km^(2)和30.18×10~4 km^(2)。高适生面积区占旱地面积的15.27%,主要分布在海拔较低的辽河平原和松嫩平原。影响旱地适宜性的主要环境因素是最湿季度平均温度、坡度、最干季度降水量和气温季节变化标准差。旱地最优分布环境条件为:平均温度为18.58~24.8℃、坡度为-1.25°~8.03°、降水量为0~16.3 mm、气温季节变化标准差为930~1400。(2)水田面积为6.07×10~4 km^(2),其高适生区、中适生区、低适生区和不适生区面积分别为4.06×10~4 km^(2)、13.67×10~4 km^(2)、20.22×10~4 km^(2)和66.17×10~4 km^(2)。高适生区面积占水田面积的66.89%,主要集中在三江平原,零散分布于松嫩平原和辽河平原。影响水田适宜性的主要环境因素是海拔、年平均气温、坡度和等温性。水田最优分布环境条件为:海拔低于225.9 m、年平均气温为1.69~6.03℃、坡度低于2.28°、等温性低于25.53。(3)在未来气候情境下,旱地和水田适宜区分布与历史气候情景相似,但适生区面积有所变化。在未来近期,旱地高适生区面积在SSP245-30模式下增量最高,为0.4×10~4 km^(2);水田高适生区面积在SSP126-30模式下面积增量最高,为0.03×10~4 km^(2)。在未来中期,旱地和水田高适生区在4种模式下均降低,旱地在SSP126-50模式下降低最多,水田在SSP585-50模式下降低最多。研究结果可为东北平原林耕资源大区土地国土空间规划提供科学支撑,为耕地的开发与利用提供参考。

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:(1) The area of dry land was 29.21×10~4 km~2,and the areas of high suitable area,medium suitable area,low suitable area and unsuitable area of dry land were 5.39×10~4 km~2,48.71×10~4 km~2,19.82×10~4 km~2 and 30.18×10~4 km~2,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.(2) The paddy field area is 6.07×10~4 km~2,and the areas of high suitable area,medium suitable area,low suitable area and unsuitable area of paddy field were 4.06×10~4 km~2,13.67×10~4 km~2,20.22×10~4km~2 and 66.17×10~4 km~2,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.(3) In 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 0.4×10~4 km~2.The area increment of high suitable area in SSP126-30 mode was the highest,which was 0.03×10~4 km~2.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 (1.46×10~4 km~2),and the paddy field decreased the most under the SSP585-50 mode (0.29×10~4 km~2).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.