论文--中国科学院地理科学与资源研究所

论文

论文题目：	Increasing relative abundance of C4 plants mitigates a dryness-stress effect on gross primary productivity along an aridity gradient in grassland ecosystems
第一作者：	Wang Jing, Wen Xuefa
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发表年度：	2022
摘　　要：	Purpose Impacts 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. Methods We decomposed GPP into canopy stomatal conductance (gs), ratio of intercellular to atmospheric CO2 partial pressure (Ci/Ca), and species composition and investigated the interaction of dryness stress, gs, Ci/Ca, and relative abundance of C4 plants (C4/(C3 + C4)) to determine how they regulate GPP along an aridity gradient in Inner Mongolia Plateau. We used biomass-weighted leaf carbon (delta C-13) and oxygen (delta O-18) isotopes to calculate canopy Ci/Ca and O-18 enrichment in leaf tissue above source water (o(18)O), respectively. Results A positive relationship between 1/o(18)O and canopy gs demonstrated that 1/o(18)O was a reliable indicator for canopy gs. Soil moisture (SM) exhibited a positive effect on 1/o(18)O and Ci/Ca, while Ci/Ca decreased and C4/(C3 + C4) increased with increasing water vapor pressure (VPD). 1/o(18)O and C4/(C3 + C4) indirectly regulated GPP via Ci/Ca, and the effect of C4/(C3 + C4) on the variability in Ci/Ca was stronger than that of 1/o(18)O. Interaction between dryness stressors (SM and VPD) and vegetation properties (1/o(18)O, Ci/Ca, and C4/(C3 + C4)) captured 74.6% of the variability in GPP, indicating that spatial variability in GPP was determined overwhelmingly by indirect effects of dryness on biological processes. Conclusions Increasing relative abundance of C4 plants would effectively mitigate the negative effects of dryness stress on GPP.
英文摘要：
刊物名称：	PLANT AND SOIL
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论文类别：	SCI