Abstract: The element content and stoichiometric ratio of plant leaves are important for understanding the ecological characteristics of plants and their response to environment. In this study, the content of carbon (C), nitrogen (N) and phosphorus (P) was determined by sampling and testing of the leaves of dominant species in Xilingol steppe transbelt. The stoichiometric characteristics, interrelationships and influencing factors of leaves were explored by means of coefficient of variation, correlation analysis and redundancy analysis. The results showed that the content of C element in Xilingol steppe was meadow steppe > typical steppe > desert steppe, and the content of N and P element was typical steppe > desert steppe > meadow steppe. The mean stoichiometric ratios were the highest in meadow steppe and the lowest in typical steppe. The content of C, N and P in plant leaves and their stoichiometric ratios were correlated to different degrees. Soil pH value and climate factors are the main factors affecting the content of C, N and P in plant leaves and their stoichiometric characteristics. The relationships among leaf elements and stoichiometric characteristics indicate the regulatory capacity and allocation strategies of local plants in the process of growth and reproduction and resource balancing.

Key words: Ecological stoichiometry, Plant leaf, Xilingol steppe

摘要： 植物叶片元素含量和化学计量比对于了解植物的生态学特征及对环境的响应具有重要意义。本研究通过对锡林郭勒草原样带内优势种植物叶片进行采样和试验，测定了碳(C)、氮(N)、磷(P)含量，采用变异系数、相关分析、冗余分析等方法探究了叶片化学计量特征、相互关系及影响因素。结果表明：植物叶片C元素在锡林郭勒草原的含量为草甸草原>典型草原>荒漠草原，N、P元素含量为典型草原>荒漠草原>草甸草原，化学计量比均值均在草甸草原最高，在典型草原最低；植物叶片C、N、P含量及其化学计量比间呈现出不同程度的相关关系；土壤pH值、气候因素是影响植物叶片C、N、P含量及其化学计量特征的主要因子。叶片各元素以及各化学计量特征间的联系表达了当地植物在生长繁殖过程以及资源权衡中对营养元素的调节能力和分配策略。

关键词: 生态化学计量, 植物叶片, 锡林郭勒草原