Elevated CO2 concentrations affect the growth patterns of dominant C3 and C4 shrub species differently in the Mu Us Sandy Land of Inner Mongolia

• Published in: Botany Vol. 95; no. 9; pp. 869 - 877
• Main Authors: Li, Qiaoyan, Lai, Liming, Du, Hui, Cai, Wentao, Guan, Tianyu, Zhang, Xiaolong, Jiang, Lianhe, Zheng, Yuanrun, Yu, Yi, Gao, Yong, An, Ping, Shimizu, Hideyuki
• Format: Journal Article
• Language: English
• Published: NRC Research Press 2017
• Subjects: Artemisia ordosica; Artemisia sphaerocephala; biomass; C3 plants; C4 plants; Caragana korshinskii; carbon dioxide; carbon dioxide enrichment; China; ecological restoration; elevated CO; growth chambers; Hedysarum; Hedysarum laeve; leaf area; photosynthesis; seedlings; shrubs; transpiration; water use efficiency; élevé; China
• ISSN: 1916-2790; 1916-2804; 1916-2804
• DOI: 10.1139/cjb-2017-0014

Elevated CO 2 levels can improve growth and water use efficiency (WUE). However, the influence of atmospheric CO 2 concentrations higher than 800 ppm has been less of a concern and has received little attention. In this study, experiments were conducted to explore the responses of four species to elevated CO 2 levels. Seedlings of the four species were grown in growth chambers under four different CO 2 concentrations. The results showed that elevated CO 2 levels resulted in increased net assimilation rates (NARs) (12%–90%) and WUEs (1%–258%) as well as decreased leaf area ratios (LARs) (11%–72%) for the four species. For the two Artemisia species (Artemisia sphaerocephala Krasch. and Artemisia ordosica Krasch.), elevated CO 2 significantly increased the relative growth rate (RGRs) (4%–8%) and total biomass increment (19%–44%), while elevated CO 2 concentrations resulted in decreased RGRs (2%–20%) and transpiration rates (49%–61%) for Hedysarum laeve Maxim., and increased the height increment (7%–96%) of Caragana korshinskii Kom. The differences among the two Artemisia species (C 4 species), and C. korshinskii and H. laeve (C 3 species) might be associated with their different photosynthetic pathways. These findings suggest that the two Artemisia species had a stronger ability to adapt to CO 2 concentration elevation. Considering its high WUE, C. korshinskii should be applied for vegetation restoration in water-limited areas affected by a warming climate.