内蒙古草地植物叶片氮、磷元素化学计量学特征分析

Stoichiometry of Leaf Nitrogen and Phosphorus in Plants in Grasslands in Inner Mongolia

在内蒙古草地采集了92个植物叶片样品,测定了植物叶片的N、P元素含量,并针对植物叶片的元素含量和比例,依据类群进行了分析。结果显示,在植物种间、群落间和生态系统间3个植物组织水平中,N、P含量和N/P的差异以植物种间差异最为显著,而生态系统间的差异最不显著,这表明植物物种的差异是决定草地植物N、P元素化学计量学特征格局的最基本因素;在植物科组、碳代谢途径类组和生活型类组3个植物功能群中,植物科组间叶片元素含量和比例的差异最为明显;同时,与全国草地和全球植被的平均水平相比,内蒙古草地植物N、P元素含量明显偏低,而N/P明显偏高,表明P元素可能为内蒙古草地植被的受限制元素。

Based on chemical analysis for 92 leaf samples collected in Inner Mongolia grassland tran sect, the contents and ratios of leaf nitrogen and phosphorus elements were analyzed based on the plant groups. The results showed that the difference of the leaf nitrogen （N） and phosphorus （P） contents and their ratios were mostly significantly different among species, whereas least significant among ecosystems for the three plant organizational levels of species, community, and ecosystem, suggesting that the stoichi ometry pattern of leaf N and P for grasslands in Inner Mongolia was mainly determined species. The differ- ences of the leaf N, P, and N/P were mostly significant among families for the three functional groups of families, carbon metabolism pathway, and life form. In addition, the contents of leaf N and P in Inner Mongolia grassland were significantly lower than the average values of the national grassland and global vegetation. In contrast, N/P was higher than the average value of the national grassland and global vegeta tion, indicating that the grassland in Inner Mongolia may be more limited by the P element.