Increasing relative abundance of C4 plants mitigates a dryness-stress effect on gross primary productivity along an aridity gradient in grassland ecosystems
Increasing relative abundance of C4 plants mitigates a dryness-stress effect on gross primary productivity along an aridity gradient in grassland ecosystems
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DOI：
10.1007/s11104-022-05529-8
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发表时间：
2022-06
期刊：
影响因子：
4.9
通讯作者：
Jing Wang;X. Wen
中科院分区：
文献类型：
--
作者：
Jing Wang;X. Wen
PurposeImpacts of dryness stress (i.e., low soil moisture [SM] and high vapor pressure deficit [VPD]) on gross primary production (GPP) have received considerable attention in recent years, however, their biological mechanism still needs to be elucidated.MethodsWe decomposedGPPinto canopy stomatal conductance (gs), ratio of intercellular to atmospheric CO2partial pressure (Ci/Ca), and species composition and investigated the interaction of dryness stress,gs,Ci/Ca, and relative abundance ofC4 plants (C4/(C3 +C4)) to determine how they regulateGPPalong an aridity gradient in Inner Mongolia Plateau. We used biomass-weighted leaf carbon (δ13C) and oxygen (δ18O) isotopes to calculate canopyCi/Caand18O enrichment in leaf tissue above source water (△18O), respectively.ResultsA positive relationship between 1/△18O and canopygsdemonstrated that 1/△18O was a reliable indicator for canopygs. Soil moisture (SM) exhibited a positive effect on 1/△18O andCi/Ca, whileCi/Cadecreased andC4/(C3 +C4) increased with increasing water vapor pressure (VPD). 1/△18O andC4/(C3 +C4) indirectly regulatedGPPviaCi/Ca, and the effect ofC4/(C3 +C4) on the variability inCi/Cawas stronger than that of 1/△18O. Interaction between dryness stressors (SMandVPD) and vegetation properties (1/△18O,Ci/Ca, andC4/(C3 +C4)) captured 74.6% of the variability inGPP, indicating that spatial variability inGPPwas determined overwhelmingly by indirect effects of dryness on biological processes.ConclusionsIncreasing relative abundance of C4 plants would effectively mitigate the negative effects of dryness stress onGPP.
