喀斯特山区植物碳同位素组成特征及其对水分利用效率的指示——以贵州花溪杨中小流域为例  

Characteristics of carbon isotopic compositions in karst mountain plants and their indication to water use efficiency——A case study on Yangzhong catchment in Huaxi, Guizhou

作　　者：杨成[1] 刘丛强[1] 宋照亮[2] 郑厚义[1] 刘占民[1] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室 [2]浙江林学院,浙江临安311300

出　　处：《中国岩溶》2007年第2期105-110,共6页Carsologica Sinica

基　　金：国家重点基础研究发展计划(973)项目(2006CB403200);中国科学院重要方向项目(KZCX3-SW-140);中国科学院知识创新工程项目(KZCX2-105)

摘　　要：测定了贵州喀斯特山区灌丛12种主要植物叶片的δ13C值,研究了植物叶片碳同位素组成特征,并分析了植物的水分利用效率。结果表明:该区植物叶片的碳同位素组成的变化范围为-26.98‰～-29.15‰,平均值为-28.14‰。研究区δ13C值的分布相对均匀,除高于我国热带雨林区植物外,低于其它地区。此外,植物的碳同位素组成存在较大的种间差异,生境的变化对植物的碳同位素组成有着一定的影响,但不同植物种对生境的响应不同。植物的δ13C值从生长初期到末期有降低的趋势,但不同植物种的变化趋势存在差异。植物δ13C值随海拔的增加而增大,但不同植物种δ13C值随海拔增加的程度存在差异。不同植物种之间的水分利用效率不同,相同植物种在不同的生境条件下其水分利用效率也有差异。植物生长初期的水分利用效率要比后期的高;高海拔处植物水分利用效率要比低海拔处植物的高。The foliar δ^13C value of 12 main plants alyzed, and the characteristics of foliar carbon collected from Guizhou karst mountain shrubbery area is anisotopic compositions and water use efficiency （WUE） of plants are studied in the paper. The results show that the foliar δ^13C value from this area, with an average of -28. 14‰, range from -26. 98‰～-29. 15‰. The mean value of δ^13C is lower than that from other areas except for tropical rain area in China, and the change extent is narrower than that in other areas. There are great differences between the δ^13C values of different species. Habitats affect the carbon isotopic compositions of plants to some extent, but different species have different response to habitat. The newly-developed leaves have higher δ^13C value than the mature ones, but the change extents of the δ^13C values are different among different plants. The δ^13C value increases with altitude. However, the change extents of the δ^13C value are different. The WUEs among different plant species are different, and those of same plant species which grow in different habitats are also different. WUE of plants in early growing stage is higher than that in late stage, and that in high altitude is higher than in low altitude.

关 键 词：喀斯特山区 植物 碳同位素组成 水分利用效率 

分 类 号：P611.7[天文地球—矿床学] Q945.17[天文地球—地质学]