高原植物正构烷烃的奇偶优势及其环境指示意义

摘要

利用气相色谱技术对青藏高原东北部高寒草甸生态系统中高等植物火绒草和蒲公英的正构烷烃分布特征及其碳优势指数( CPI)、奇偶优势指数(OEP)进行分析,发现两种植物抽提物中正构烷烃主要为C11～C35,丰度最大的为C29、C27和C31；正构烷烃具有非常明显的奇偶优势；蒲公英正构烷烃CPI和OEP存在随海拔升高而加强的变化趋势,火绒草正构烷烃奇偶优势随海拔升高虽有一定变化但规律性不强.%The distribution characteristics, carbon preference index (CPI) and odd-even preference (OEP) of n-alkane in Leontopodium leontopodioidie and Taraxacum mongolicum in alpine meadow of northeastern Tibetan Plateau are analyzed by gas chromatograph. The results confirm that the n-alkanes mainly range from C11 to C35in the two plants, and the maximum abundance are C29, C27 and C31; the n-alkane has a strong odd-even preference in higher plants of Taraxacum mongolicum and Leontopodium leontopodioidie. The CPI and OEP show a positive correlation with the altitude in Taraxacum mongolicum, however, the correlation changes irregularly for Leontopodium leontopodioidie.