气候变化背景下川西北高原多年生垂穗披碱草种植适生区分布预测

本文以川西北高原主要栽种的多年生禾本科属垂穗披碱草（Elymus nutans）为研究对象，利用生态位模型（MaxEnt）模拟分析影响多年生垂穗披碱草种植的主要气候因子，预测当前及未来气候变化情景下的适生区分布格局。结果显示：湿润指数、≥ 0℃积温、等温性、气温年较差是影响川西北高原多年生垂穗披碱草分布的4个主要气候因子，其适宜值范围分别为>48.60，1 118.20℃·d~2 350.50℃·d，>36.10%，31.40℃~36.20℃。构建模型训练数据的受试者工作曲线下面积（Area under curve，AUC）值均大于0.85，测试数据AUC值均大于0.90，达到良好和极好的水平。气候变暖背景下，从当前到未来（21世纪80年代），川西北高原多年生垂穗披碱草的潜在分布气候适宜区面积将增加52.70%，海拔将升高252 m。本研究可为维持草地生态系统稳定、推动沙化治理乃至农牧业产业结构调整提供科学决策依据。

Distribution Prediction of Suitable Growth Area of Perennial Elymus nutans in the Northwest Plateau of Sichuan Province under Climate Change

In this study,the perennial Elymus nutans in the northwestern Sichuan Plateau was studied using the niche model (MaxEnt) to simulate the main climatic factors affecting the perennial planting of Elymus nutans,and to predict the distribution pattern of the suitable area under current and future climate change scenarios. The results showed that wetting index, ≥ 0℃ accumulated temperature,isothermal temperature and poor temperature were the four main climatic factors affecting the distribution of perennial cultivated grasses in the northwestern Sichuan Plateau. The suitable values were >48.60,1 118.20℃·d~2 350.50℃·d,>36.10%,31.40℃~36.20℃,respectively. The area under the work curve (AUC) of the model training data was greater than 0.85,and the test data AUC values were greater than 0.90,achieving a good and excellent level,respectively. Under the background of global warming,from the present to the future (2080s),the potential distribution of the perennial cultivated grasses of the northwestern Sichuan Plateau will increase by 52.7% and the elevation will increase by 252 m. The study provided scientific decision-making basis for maintaining grassland ecosystem stability,promoting desertification control and even industrial restructuring of agriculture and animal husbandry.