Does plant size affect growth responses to water availability at glacial, modern and future CO2 concentrations?
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Plant responses to carbon (C) and water availability are strongly connected. Thus, we can learn much about the responses of modern plants to rising atmospheric carbon dioxide (CO2) by studying their performance under a range of carbon and water availabilities, including very low CO2 as in past glacial periods. We hypothesized that, especially in shallow soils, the positive effects of high CO2 and the negative effects of low CO2 on growth response to drought are moderated by plant size-driven feedbacks through transpiration and soil water depletion. We grew two temperate annual C3 species, Avena sativa and Chenopodium album, in glacial (180 ppm), modern (400 ppm) and future (700 ppm) CO2 levels and five soil water regimes in climate chambers. In both species, low CO2 resulted in a much lower relative growth rate, biomass and total leaf area than at ambient CO2 with higher water availability, but this difference disappeared steadily towards severe drought conditions. Elevated CO2 increased relative growth rate, plant biomass and total leaf area of both species slightly compared with ambient CO2. These results were especially pronounced under drought. Our results support the hypothesis that, in annuals, plant size modulates the negative drought effect at low CO2. However, plant size-mediated effects of high CO2 on growth response to drought were inconclusive. Further experiments should reveal the interactive effects of CO2 and water regimes in environments closer to a field setting, both in shallow and in deep soils with unconstrained rooting, as well as in mixed communities.
KeywordsBiomass accumulation Drought CO2 concentration Relative growth rate Water use efficiency
We would like to thank our colleagues at Utrecht University, specifically R. Welschen, B. Robroeck, R. Wagner and M. Hefting, for hosting this research at the experimental CO2 manipulation facility. Feng Lin kindly provided the seeds for this study. This study was financially supported by Grant 142.16.3032 of the Darwin Center for Biogeosciences to R. Aerts; Grant CEP-12CDP007 by the Royal Netherlands Academy of Arts and Sciences to J.H.C. Cornelissen; the National Natural Science Foundation of China (31500399) and the Fundamental Research Funds for the Central Universities (XDJK2014C158) to J.C. Liu. J.C. Liu also gratefully acknowledges the Chinese Scholarship Council and the School of Life Science, SW China University for financially supporting her 1 year research visit to VU University.
- Franks PJ, Adams MA, Amthor JS, Barbour MM, Berry JA, Ellsworth DS, Farquhar GD, Ghannoum O, Lloyd J, McDowell N, Norby RJ, Tissue DT, von Caemmerer S (2013) Sensitivity of plants to changing atmospheric CO2 concentration: from the geological past to the next century. New Phytol 197:1077–1094CrossRefPubMedGoogle Scholar
- IPCC (2013) Summary for policymakers. In: Stocker TF, Qin D, Plattner GK, Tignor M, Allen SK, Boschung J, Nauels A, Xia Y, Bex V, Midgley PM (eds) Climate change 2013: the physical science basis. Contribution of Working Group I to the fifth assessment report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, New YorkGoogle Scholar
- Prior SA, Runion GB, Marble SC, Rogers HH, Gilliam CH, Torbert HA (2011) A review of elevated atmospheric CO2 effects on plant growth and water relations: implications for Horticulture. HortScience 46:158–162Google Scholar
- Sinclair TR, Pinter PJ Jr, Kimball BA, Adamsen FJ, LaMorte RL, Wall GW, Hunsaker DJ, Adam N, Brooks TJ, Garcia RL, Thompson T, Leavitt S, Matthias A (2000) Leaf nitrogen concentration of wheat subjected to elevated [CO2] and either water or N deficits. Agr Ecosyst Environ 79:53–60CrossRefGoogle Scholar
- Woodward FI (1987) Stomatal numbers are sensitive to increases in CO2 from preindustrial levels. New Phytol 69:983–992Google Scholar
- Zheng SX, Shangguan (2005) Comparison of the leaf stomatal characteristic parameters of three plants in Loess Plateau over the last 70 years. J Geochem Soc Meteor Soc 14:1–5Google Scholar