Drought dominates the interannual variability in global terrestrial net primary production by controlling semi-arid ecosystems.
Drought is a main driver of interannual variation in global terrestrial net primary production. However, how and to what extent drought impacts global NPP variability is unclear. Based on the multi-timescale drought index SPEI and a satellite-based annual global terrestrial NPP dataset, we observed a robust relationship between drought and NPP in both hemispheres. In the Northern Hemisphere, the annual NPP trend is driven by 19-month drought variation, whereas that in the Southern Hemisphere is driven by 16-month drought variation. Drought-dominated NPP, which mainly occurs in semi-arid ecosystems, explains 29% of the interannual variation in global NPP, despite its 16% contribution to total global NPP. More surprisingly, drought prone ecosystems in the Southern Hemisphere, which only account for 7% of the total global NPP, contribute to 33% of the interannual variation in global NPP. Our observations support the leading role of semi-arid ecosystems in interannual variability in global NPP and highlight the great impacts of long-term drought on the global carbon cycle.
State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
Ling
L
Huang
State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
Bin
B
He
Department of Earth Sciences, University of Gothenburg, Gothenburg 450 30, Sweden.
Aifang
A
Chen
College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
Haiyan
H
Wang
College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
Junjie
J
Liu
Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China.
Aifeng
A
Lű
College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
Ziyue
Z
Chen
D018533:Biomass; D057486:Carbon Cycle; D055864:Droughts; D017753:Ecosystem; D018521:Plant Physiological Phenomena