放牧对草原植物功能性状及其权衡关系的调控

Plant Functional Traits and Their Trade-offs in Response to Grazing:A Review

放牧是草原生态系统利用与管理的主要方式;而过度放牧导致的草原退化和生产力衰减问题已成为当前生产及理论上的一个棘手难题。近年来,植物功能性状及其权衡等新理论与方法的引入,为解析放牧对草原的影响机制提供了新工具,成为草原生态学的一个新兴领域,但目前尚缺乏系统的回顾总结。该文综述了近年来国内外关于草原植物功能性状对放牧的响应及其权衡关系的研究进展,综合分析了植物性状权衡变化的主要特征、成因与机制,针对学界关于放牧下植物矮化型变机制的"避牧适应假说"与"生长受阻假说"的争论,提出了下一步需重点关注的科学问题。

Grazing represents the main way for utilization and management of grassland ecosystems. Grassland deg- radation and productivity caused by overgrazing has become an issue in theory and practice in China. The introduction of new theories and methods, such as plant functional traits and their trade-offs, provides new tools to understand the mechanism of grassland degradation, an emerging area of grassland ecology. However, summary data are lacking. This paper reviews the recent research progress in plant functional traits and their trade-offs in response to grazing in China and worldwide. We performed a comprehensive analysis of the main characteristics of plant trait changes, causes and mechanisms. Furthermore, based on the argument about the reason of plant dwarf of grazing-induced between two theories of ＂adaptive grazing avoidance hypothesis＂ and ＂pant growth limitation hypothesis＂ in current academic commu- nity, we suggest important scientific questions that need further research.