AUTHOR=Ma Rong , Xia Chunlin , Liu Yiwen , Wang Yanji , Zhang Jiaqi , Shen Xiangjin , Lu Xianguo , Jiang Ming TITLE=Spatiotemporal Change of Net Primary Productivity and Its Response to Climate Change in Temperate Grasslands of China JOURNAL=Frontiers in Plant Science VOLUME=Volume 13 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.899800 DOI=10.3389/fpls.2022.899800 ISSN=1664-462X ABSTRACT=The temperate grasslands in China play a vital part in regulating regional carbon cycle and climatic change. Net primary productivity (NPP) is an important index that reflects ecological function of plants and the carbon sequestration capacity of grassland ecosystem. Climate change can affect NPP by changing vegetation growth, but the effects of climatic change on the NPP of China's temperate grasslands remain unclear. Based on MODIS data and monthly climate data during 2000-2020, this study explored the spatiotemporal changes in grassland NPP and its response to climatic change in temperate grasslands of China. We found that the annual NPP over the entire temperate grasslands of China increased significantly by 4.00 gC/m2/a from 2000 to 2020. For the different grassland types, the annual NPP showed an increasing trend, with the smallest trend for temperate desert steppe (2.16 gC/m2/a) and the largest trend for temperate meadow (5.42 gC/m2/a). The correlation results showed that increased annual precipitation had a positive influence on the NPP of temperate grasslands. Increased summer and autumn precipitation could increase grassland NPP, particularly for the temperate meadow. With regard to the effects of temperatures, increased temperature, particularly the summer maximum temperature, could decrease annual NPP. However, increased spring minimum temperature could increase the NPP of temperate desert steppe. In addition, this study found, for the first time, an asymmetric impact of summer nighttime and daytime warming on the NPP of temperate meadow. Specifically, nighttime warming can increase NPP, while daytime warming can reduce NPP in temperate meadow. Our results highlight the importance of including seasonal climate conditions in assessing the vegetation productivity for different grassland types of temperate grasslands and predicting the effects of future climatic change on temperate grassland ecosystems.