Abstract: Based on a systematic field sampling and lab measurements of 358 native species, the regional stoichiometric patterns of leaf C, N and Pin 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 Pto their petiole counterparts are 1.1, 2.4 and 1.8 for C, Nand P, respectively, as reflectsthe stoichiometric relationship between lamina and petiole. Herbs have higher leaf N and P and lower Cthan woody plants; conifers are significantly 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.

Key words: leaf carbon/nitrogen/phosphorus, petiole, lamina, stoichiometry, Beijing, growth-form

摘要： 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。

关键词: 叶碳氮磷, 叶柄, 叶片, 元素计量, 北京, 植物生长型