Global assessment of lagged and cumulative effects of drought on grassland gross primary production

Ecological Indicators

Xing Li¹  Yanlian Zhou²  Shuhao Xu²  Weimin Ju³  Wenjun Bi⁴  Nuo Cheng⁵  Wei He⁶  Xiaonan Wei⁶  Jingfeng Xiao⁶  Yibo Liu⁶  Xiaoyu Zhang⁷ 

[1] Corresponding author.;International Institute for Earth System Science, Nanjing University, Nanjing, Jiangsu 210023, China;State Key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100854, China;Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA;Jiangsu Key Laboratory of Agricultural Meteorology, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, Jiangsu 210044, China;Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources, School of Geography and Ocean Science, Nanjing University, Nanjing, Jiangsu 210023, China;Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, South Korea;

关键词: Gross primary productivity;    Water stress;    Lagged effect;    Cumulative effect;    Carbon cycle;    Grassland;   

DOI  :  

来源: DOAJ

【 摘 要 】

Drought has large impacts on the vegetation growth of global terrestrial ecosystems, particularly grasslands. Extensive in-situ studies have shown that the impact of drought on vegetation growth has lagged and cumulative effects, but it is not well known how grassland productivity (gross primary production or GPP) responds to drought over time at large scales. Here, we investigated the spatiotemporal patterns of lagged and cumulative effects of drought on global grassland GPP using an OCO-2 solar-induced chlorophyll fluorescence (SIF) based GPP product (GOSIF GPP) and the Standardized Precipitation Evapotranspiration Index (SPEI). The results showed that globally, 88.37% of the grassland had a lagged response to drought, with a lagged time scale of mainly 1 month. With the increase in soil water availability, the magnitude of the lagged effect gradually weakened. Grasslands in semiarid and semi humid conditions that were adaptable to periodic drought responded fastest to drought. Globally, more than three quarters (78.55%) of the grassland was affected by the cumulative effect of drought. The accumulated months occurred at longer time scales (8 ∼ 10 months) for the region at 40°N–55°N, which is relatively arid. The cumulative effect in relatively arid areas was stronger than that in relatively humid areas, indicating that grasslands in more arid areas had stronger tolerance to drought. More importantly, we found that the cumulative effect of drought on grassland GPP was stronger than the lagged effect. This study highlights the great importance of considering the legacy effect, especially the cumulative effect, of drought on grassland productivity, which would advance our understanding of the impact of climate change on the carbon and water cycles of terrestrial ecosystems.

【 授权许可】

Unknown