J Plant Ecol ›› 2022, Vol. 15 ›› Issue (4): 711-720 .DOI: 10.1093/jpe/rtac008

• Research Articles • Previous Articles     Next Articles

Are regional precipitation–productivity relationships robust to decadal-scale dry period?

Zhongmin Hu1,2,3, *, Minqi Liang1, Alan Knapp4, Jianyang Xia5,6, and Wenping Yuan3,7   

  1. 1 School of Geography, South China Normal University, Shipai Campus, Guangzhou 510631, China, 2 College of Ecology and Environment, Hainan University, Haikou 570228, China, 3 Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China,4 Department of Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO 80523, USA, 5 Tiantong National Forest Ecosystem Observation and Research Station, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200062, China, 6 Institute of Eco-Chongming (IEC), Shanghai 200062, China, 7 School of Atmospheric Sciences, Sun Yat-Sen University, Guangzhou 519082, China

    *Corresponding author. E-mail: huzm@m.scnu.edu.cn
  • Received:2021-11-17 Accepted:2021-11-18 Online:2022-01-16 Published:2022-08-01

Abstract: Precipitation (PPT) is the primary climatic determinant of plant growth and aboveground net primary productivity (ANPP) for many of the world’s major terrestrial ecosystems. Thus, relationships between PPT and productivity can provide insight into how changes in climate may alter ecosystem functions globally. Spatial PPT–ANPP relationships for grasslands are found remarkably similar around the world, but whether and how they change during periods of extended climatic anomalies remain unknown. Here, we quantified how regional-scale PPT-ANPP relationships vary between an extended wet and a dry period by taking advantage of a 35-year record of PPT and NDVI (as a surrogate for ANPP) at 1700 sites in the temperate grasslands of northern China. We found a sharp decrease in the strength of the spatial PPT–ANPP relationship during an 11-year period of below average PPT. We attributed the collapse of this relationship to asynchrony in the responses of different grassland types to this decadal period of increased aridity. Our results challenge the robustness of regional PPT–productivity if aridity in grasslands is increased globally by climate change.

Key words: grassland, net primary productivity, precipitation–productivity relation, drought, climate change, NDVI

降水是全球陆地生态系统中植被生长和净初级生产力的主要驱动因素。因此,探究降水和生产力关系有助于深入了解气候变化如何改变生态系统功能。降水-生产力的空间关系在全球不同草地上非常相似,但在连续多年气候异常的情况下,这种关系是否会发生变化以及如何变化尚不清楚。本研究利用 利用中国北方温带草地长达10年低于多年平均降水的时期,基于遥感植被指数数据,量化了区域尺度上降水-植被生产力关系在持续多年的干湿期之间将如何变化。结果表明,在连续10年的干期,降水-生产力空间相关性急剧下降,而该空间关系的下降主要是由于不同草原类型对干旱的响应在空间上存在高度的异质性,即不同生态系统对干旱的响应程度存在差异。因此,如果未来气候变化进一步加剧全球草地的干旱,那么基于历史时期(平水期)得到的降水-生产力空间关系推测区域尺度植被生产力可能导致误差。

关键词: 草地, 净初级生产力, 降水-生产力关系, 干旱, 气候变化, 植被指数