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Effects of elevated CO 2 on Stipa baicalensis photosynthesis depend on precipitation and growth phase
Author(s) -
Wang Hui,
Zhou Guangsheng,
Jiang Yanling,
Shi Yaohui,
Xu Zhenzhu
Publication year - 2019
Publication title -
ecological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.628
H-Index - 68
eISSN - 1440-1703
pISSN - 0912-3814
DOI - 10.1111/1440-1703.12044
Subject(s) - photosynthesis , precipitation , water use efficiency , biomass (ecology) , chemistry , agronomy , relative growth rate , zoology , botany , growth rate , biology , physics , geometry , mathematics , meteorology
Elevated atmospheric CO 2 concentration and simultaneous precipitation change affect plant physiology and growth either directly or indirectly. The main objective of this study was to investigate the effects of elevated CO 2 and precipitation change, alone or in combination, on photosynthesis and growth in Stipa baicalensis under differential growth phases. Elevated CO 2 showed a consistently significant increase in net photosynthesis rate ( A net ), water‐use efficiency (WUE), leaf area and biomass. However, elevated CO 2 did not mitigate the negative effects of severe drought stress. Increase of A net under elevated CO 2 attributed to C i in the early growth phase, but WUE and Rubisco carboxylation ( V cmax ) was the main inductor in the later growth phase. Effects of elevated CO 2 on S. baicalensis were closely associated with precipitation conditions, and the influence on photosynthetic capacity was also related to the growth phase. Drought significantly reduced A net in June and August, increased WUE in June but did not show effect in August. Precipitation enhancement was beneficial to leaf area and biomass accumulation. Elevated CO 2 and enhanced precipitation in combination promoted A net by 158% and 93.4% in June and August, respectively; moreover, their interaction increased the total biomass by 44.4%. Our results suggested that the elevated CO 2 concentration in the future might be beneficial to the growth of S. baicalensis , but elevated CO 2 influence on S. baicalensis might strongly depend on precipitation conditions and the growth phase.