[Responses of grassland ecosystem productivity to altered precipitation regime: A review.]

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.