北京及周边地区植物叶的碳氮磷元素计量特征

Leaf Carbon,Nitrogen and Phosphorus Stoichiometry across Plant Species in Beijing and Its Periphery

通过测量北京及周边地区358种植物的叶碳、氮和磷(C,N,P)含量,系统分析了该区域不同生长型植物的叶C,N,P的计量规律。结果显示,本区植物叶C,N,P的几何均值分别是45.1%,2.61%和0.20%(干重),且叶片中C,N,P含量分别是叶柄中相应元素含量的1.1,2.4和1.8倍,反映了与器官功能相适应的元素计量分配关系。草本相比于木本植物具有高叶N(P)低C的特点,而针叶树的叶N(C)显著低于(高于)阔叶树,但二者P含量没有显著差异。叶的C,N,P彼此显著相关,其中C和N(或P)负相关,N和P正相关;叶C∶N,C∶P和N∶P的几何均值是17.3,242和13.9。

Based on a systematic field sampling and lab measurements of 358 native species, the regional stoichiometric patterns of leaf C, N and P in Beijing and its periphery were investigated. The geometric means of leaf C, N and P are 45.1% ,2.61% and 0.20% （dry weight）, respectively. The content ratios of lamina C, N and P to their petiole counterparts are 1,1, 2.4 and 1.8 for C, N and P, respectively, as reflects the stoichiometrie relationship between lamina and petiole. Herbs have higher leaf N and P and lower C than woody plants; conifers are significandy lower in leaf N （or higher in leaf C）, compared with broadleaves, but there is no significant difference in leaf P between the two growth-forms. Leaf C, N and P are correlated significantly between each other across all species or within growth-forms, with positive relationship between N and P, and negative between C and N （P）. The geometric mean mass ratios of leaf C：N, C：P and N：P are 17.3, 242 and 13.9, respectively.