蛛网萼的地理分布模拟及迁移趋势预测

Modeling the geographic distribution of Platycrater arguta

为探究国家Ⅱ级野生保护植物蛛网萼Platycrater arguta的地理分布格局,了解它在气候变化下地理迁移的趋势,运用DIVA-GIS软件及其整合的BIOCLIM和DOMAIN模型,结合经过筛选的80个精确分布点信息,对其潜在分布区进行预测并分析影响其分布的主要气候因子。2种模型的预测结果均表明:当下蛛网萼的潜在分布区集中在中国浙赣闽交界处和日本四国岛,且未来气候下蛛网萼的最适生活区有明显的缩小,低度适生区整体向西偏移,并有向高海拔迁移的趋势。受试者工作特征曲线(ROC曲线)检验表明:2种模型的ROC曲线下的面积(AUC值)均达到0.9以上,说明模型预测结果可信。对19个气候变量的主成分分析表明:第1主成分方差贡献率为95%以上,其中年降水量(BIO12),最湿季降水量(BIO16)和最暖季降水量(BIO18)载荷值较高,是影响蛛网萼分布的主要气候因子,表明水分是影响蛛网萼分布的主要因素。建议基于其预测的分布区域开展相应的调查与保护工作。

To find the geographical distribution pattern of the National LevelⅡwild protected plant Platycrater arguta and to understand its geographical migration patterns with climate change,DIVA-GIS software and its integrated BIOCLIM and DOMAIN models were used in combination with 80 precision distribution points.Distribution point information was used to forecast the potential distribution area and analysis included the Receiver Operating Characteristic(ROC)curve test for the main climatic factors affecting distribution and a principal component analysis.The precise distribution information of P.arguta was imported into DIVA-GIS software,and the potential distribution area of P.arguta was predicted through the modelling panel.Prediction results from the two models both indicated that current potential distribution areas of P.arguta were concentrated at the junction of Zhejiang,Jiangxi,and Fujian Provinces in China as well as Shikoku Island in Japan.The optimum living area for P.arguta was greatly reduced with future climate estimates,and the low-grade habitat area shifted overall to the west and to higher altitudes.The ROC curve test showed that the area under the curve(AUC)values of both models reached more than 0.9 indicating that model prediction results were credible.The principal component analysis of 19 climatic variables showed that annual precipitation(BIO12),the most humid seasonal precipitation(BIO16),and the warmest seasonal precipitation(BIO18)were the major climatic factors that affected distribution of Platycrater arguta indicating that water was the main factor.Thus,research and protection strategies should be carried out based on predicted distribution areas.[Ch,1 fig.4 tab.30 ref.]