Under global change scenario, precipitation pattern has significantly changed, mainly in the aspects of annual precipitation amount, precipitation seasonal distribution and precipitation event characteristics (size of individual precipitation event, periods length between two precipitation events, and number of precipitation events in a year), which combined to affect various processes of terrestrial ecosystems, especially productivity. Grassland ecosystem is one of the most sensitive ecosystems to the changes of precipitation regime. Therefore, it is necessary to clarify the responses of productivity to altered precipitation regime in grasslands. In this study, I firstly reviewed the responses of grassland productivity to each characteristic of the altered precipitation regime. Then, I summarized the methods that employed in the study of productivity-precipitation relationship, including long-term observations, manipulative field experiments, and modelling. Finally, I came up with several theoretical and methodological problems that needed to be solved in the future. This work would facilitate the understanding of how grasslands response to the global climate change, with implications for grassland management in the context of climate change.
全球变化背景下降水格局发生了显著改变,主要表现在年降水量、降水季节分配以及降水事件特征(单次降水事件雨量大小、两次降水之间的间隔时长和一年中降水事件的次数等)等几个方面,降水格局的改变将显著影响陆地生态系统功能,尤其是对生产力的影响.草原生态系统是对降水格局改变最敏感的生态系统之一,因此有必要了解草原生态系统生产力对降水格局响应的研究现状及存在的问题.本文首先综述了草原生态系统生产力对降水格局各个特征响应的国内外研究进展,进而从长期观测、控制试验、模型模拟3方面综述了目前降水格局对生产力影响的研究方法,最后从理论研究、研究方法两个方面提出了目前研究存在的问题以及未来的研究方向.本文将为预测草原生态系统如何响应未来气候变化以及在气候变化情景下进行草原生态系统管理提供重要科学依据.
Keywords: grassland; precipitation regime; productivity.