两种灌丛化草原小叶锦鸡儿的叶片化学计量特征

本研究分析了内蒙古19个灌丛化草原样地（典型草原区11个、荒漠草原区8个）的小叶锦鸡儿（Caragana microphylla）叶片碳（Carbon，C）：氮（Nitrogen，N）：磷（Phosphorus，P）化学计量特征。结果显示：典型草原中小叶锦鸡儿叶片C含量，C：N，C：P，N：P显著低于荒漠草原，N，P含量显著高于荒漠草原；小叶锦鸡儿叶片N，P含量与土壤N，P含量呈正相关关系，叶片C含量与C：N，C：P呈正相关关系，叶片N与P含量呈正相关关系；小叶锦鸡儿叶片化学计量特征具有环境可塑性；叶片C含量在两种草原类型中，随年平均降水量（Mean annual precipitation，MAP）和年平均气温（Mean annual temperature，MAT）的变化趋势不一致；叶片N，P含量与MAP呈正相关关系，与MAT呈负相关关系；叶片C：N，C：P，N：P与MAP呈负相关关系，与MAT呈正相关关系；小叶锦鸡儿的生长主要受P限制。本研究结果有助于了解小叶锦鸡儿的养分利用策略，并为灌丛化草原植被的保护和恢复工作提供参考。

Leaf Stoichiometric Traits of Caragana microphylla in the Shrub Encroached Grassland

The present study evaluated the leaf carbon:nitrogen:phosphorus (C:N:P) stoichiometric traits of Caragana microphylla among 19 sites across shrub encroached grassland (11 sites in typical grassland region, 8 sites in desert grassland region) in Inner Mongolia, China. We found that the leaf C content and ratios of C:N, C:P, N:P of C. microphylla in typical grassland were significantly lower than that in desert grassland, while the leaf N and P contents were significantly higher than that in desert grassland;leaf N and P contents of C. microphylla were significantly positively correlated with soil N and P contents, leaf C content was significantly positively correlated with ratios of leaf C:N, C:P, leaf N content was significantly positively correlated with leaf P content;leaf stoichiometric traits of C. microphylla has environmental plasticity;leaf C content had different variation trends with MAP and MAT among two grassland types, while leaf N and P contents of C. microphylla were positively correlated with MAP but negatively correlated with MAT, ratios of C:N, C:P and N:P were negatively correlated with MAP but positively with MAT;the development of C. microphylla was mainly limited by P.The results of the study contribute to the further understanding of the nutrient utilization strategy of C. microphylla and provide a reference for the conservation and restoration cause of shrub encroached grassland vegetation.