未来气候变化下黑沙蒿在中国的潜在地理分布及变迁

Potential geographical distribution and changes of Artemisia ordosica in China under future climate change

黑沙蒿是我国荒漠草原防风固沙的先驱植物,在生态系统恢复和重建中有非常重要的作用,然而其在发挥重要生态功能之余,也给我国北方地区人类的健康带来了一定影响。本研究基于黑沙蒿当前在中国分布的89条有效数据和典型19个气候环境因子,通过MaxEnt模型,模拟了当前和未来(2050s、2070s)2种情景下(RCP 4.5、RCP 8.5)黑沙蒿在中国的潜在分布区,利用ArcGIS软件中SDM工具箱分析黑沙蒿的潜在分布范围及其变化,综合贡献率、刀切法及环境变量响应曲线评估了关键气候因子的重要性,并使用检验受试者工作特征(ROC)曲线下面积(AUC)对模型精度检验和评估。结果表明:MaxEnt模型模拟效果极好(AUC=0.980),预测显示黑沙蒿主要集中分布在毛乌素沙地及周边地区,该结果与当前实际分布范围相吻合;黑沙蒿在未来2种情景下的潜在高适生区分布面积与当前相比减少了5.2%~26.8%,气候变化对黑沙蒿的分布有一定的负面影响,其中,温度季节变化、最冷季度降水量及年平均温度的影响最大;黑沙蒿未来在中国潜在分布核心区位于毛乌素沙地,且有向东北部(吉林、黑龙江、辽宁及河北部分地区)扩散趋势。

Artemisia ordosica is a forerunner species of wind-break and sand-fixation in desert steppe in China, which plays an important role in ecosystem restoration and reconstruction. How-ever, it could influence human health. Based on 89 valid data of current distribution of A. ordosica in China and 19 typical climatic factors, the MaxEnt model was used to simulate the potential distribution of A. ordosica in China under current and two scenarios(RCP 4.5 and RCP 8.5;2050 s and 2070 s). The SDM toolbox of ArcGIS software was used to analyze the potential distribution range of A. ordosica and its changes in China. The importance of key climatic factors was evaluated by comprehensive contribution rate, Jackknife method, and response curve of environmental variables. The accuracy of model was tested and evaluated by area under the curve(AUC) of the test subject working characteristic(ROC). The results showed that the MaxEnt model worked well(AUC=0.980). which predicted that A. ordosica was mainly concentrated in and around Mu Us Sandy Land, consistent with the current actual distribution range. The distribution area of A. ordosica of potential high fitness under the future two scenarios decreased by 5.2%-26.8%, which was negatively affected by future climate change. Seasonal variation of temperature, mean precipitation in the coldest season, and mean annual temperature had the greatest impact. The core area of future potential distribution of A. ordosica in China was located in Mu Us Sandy Land, with a tendency for spreading to northeast(Jilin, Heilongjiang, Liaoning and some parts of Hebei).