The degree to which grassland aboveground biomass responds to climatic variability (e.g. annual and growing season precipitation and temperature) as well as management practices (e.g. harvest frequency) has attracted considerable interest in ecological studies. This understanding is important for maintaining ecosystem stability and sustainable delivery of ecosystem services under climate change. Here, we analyzed grassland biomass observations in 31 study sites in 5 ecoregions (i.e. cold steppe, humid savanna, humid temperate, savanna, and temperate dry steppe) to examine the effects of growing season and annual climatic variability and harvest frequency on aboveground biomass productivity. Annual aboveground biomass productivity showed significant increasing trends in humid temperate and savanna, but the changes of annual biomass in cold steppe, humid savanna, and temperate dry steppe ecoregions were insignificant. Single harvest aboveground biomass in cold steppe, humid savanna and humid temperate ecoregions increased with higher growing season precipitation and temperature. Although annual precipitation had positive effects on annual biomass, we found growing season precipitation sum was a more important determinant in all ecoregions. Impacts of mean annual and growing season temperature on annual biomass in humid temperate were significantly positive, while significant adverse impacts of mean growing season temperature and mean annual temperature were found in savanna and temperate dry steppe ecoregions, respectively. Irrespective of climatic variability, annual biomass consistently increased with increasing harvest frequency across ecoregions. Our study found significant gains in grassland aboveground biomass across ecoregions with increased precipitation and harvest frequency, and significant loses of biomass in savanna and temperate ecoregions with increased temperature. Our results help improve the understanding of the differences in the responses of grassland productivity to climate variability and harvest frequency across various ecoregions, which is of importance to achieve sustainable grassland management in different geographical regions.

草地地上生物量对气候变化（例如，年度和生长季节的降水和温度）以及管理措施（例如，收获频率）的响应程度已经引起了生态学研究的极大兴趣。这种理解对于在气候变化下保持生态系统稳定和可持续提供生态系统服务非常重要。在这里，我们分析了5个生态区（即冷草原，潮湿热带稀树草原，潮湿温带，稀树草原和温带干旱草原）的31个研究地点的草地生物量观测值，以检查生长季节，年度气候变化和收获频率对地上生物量生产力的影响。在湿温带和热带稀树草原上，地上生物量的年生产力呈现出显着增长的趋势，而在寒冷草原上，地上生物量的年变化则 潮湿的稀树草原和温带干旱草原生态区微不足道。随着生长季节降水和温度的升高，在寒冷的草原，潮湿的热带稀树草原和潮湿的温带生态区中，单季收获的地上生物量增加。尽管年降水量对年生物量有积极影响，但我们发现生长期的降水量在所有生态区都是更重要的决定因素。年平均和生长季节温度对湿温带的年生物量的影响是显着正的，而分别在热带稀树草原和温带干旱草原生态区中发现平均生长季节温度和年平均温度的显着不利影响。不论气候如何变化，生态区域的年生物量都随着收获频率的增加而持续增加。我们的研究发现，随着降水和收获频率的增加，整个生态区的草地地上生物量显着增加，而随着温度升高，热带稀树草原和温带生态区的草地生物量显着减少。我们的结果有助于增进对不同生态区域草地生产力对气候变化和收获频率响应的差异的理解，这对于实现不同地理区域的可持续草地管理至关重要。