篦子三尖杉在中国的地理分布及潜在分布区预测

Geographical Distribution and Potential Distribution Area Prediction of Cephalotaxus oliveri Mast.in China

【目的】预测不同气候情景下篦子三尖杉(Cephalotaxus oliveri Mast.)的地理分布格局,为其资源保护、合理利用与开发提供指导,也为其起源与地理演化研究奠定基础。【方法】基于100个分布点信息与19个气候因子,采用BIOCLIM模型构建当前(1970—2000年)以及未来(CO_(2)浓度倍增)篦子三尖杉的地理分布趋势,并采用主成分分析法分析影响其地理分布的主要气候因素。【结果】篦子三尖杉在中亚热带地区以低海拔分布为主。BIOCLIM模型结果显示:在当前气候条件下,篦子三尖杉最佳适生区集中在湖南、湖北、贵州和重庆;未来气候变化情境(CCM3)下,其潜在分布面积将减小,并有向西迁移的趋势;该模型受试者工作特征曲线下的面积为0.911±0.023,预测精度较高。主成分分析结果表明:温度季节性、气温年较差和昼夜温差与年温差比值是限制篦子三尖杉地理分布的主要因素,且温度因子的作用大于水分因子。【结论】随着全球气候变暖,篦子三尖杉的适生区有破碎化及丧失的风险,应重视对该物种的动态监测及迁地保护。

[Purpose]To predict the geographic distribution pattern of Cephalotaxus oliveri Mast.under different climate scenarios,providing guidance for resource protection,rational utilization and development,and laying a foundation for study of origin and geographical evolution.[Method]BIOCLIM model was used to construct the current(1970-2000)and future(under CO_(2)concentration doubling)geographical distribution trends,based on the information of 100 distribution points and 19 bioclimatic variables.Principal component analysis(PCA)was used to analyze the main climatic factors affecting geographical distribution.[Results]The vertical distribution of C.oliveri was mostly con-centrated in the low altitude areas in the central subtropical region in China.The results of BIOCLIM model showed that the optimal suitable areas for C.oliveri under current climate scenario were concentrated in Hunan,Hubei,Guizhou and Chongqing.Under the future climate change scenario(CCM3),the potential distribution areas of C.oliveri should decrease with a tendency to move westward.The area under the receiver operation characteristic curve of the model was 0.911±0.023,and the prediction accuracy was high.The results of the PCA showed that temperature seasonality,temperature annual range and isothermality were the main factors limiting the geographical distribution of C.oliveri.The temperature factors played a greater role than the moisture.[Conclusion]With the global warming,the suitable habitat of C.oliveri is at risk of fragmentation and loss,therefore attention should be paid to the dynamic monitoring and relocation of the species for conservation.