Photosynthetic performance (CO 2-compensation point, carboxylation efficiency, and net photosynthesis) of timothy grass ( Phleum pratense L.) is affected by elevated carbon dioxide in post-volcanic mofette areas

• Published in: Environmental and experimental botany Vol. 61; no. 1; pp. 41 - 48
• Main Authors: Pfanz, H., Vodnik, D., Wittmann, C., Aschan, G., Batic, F., Turk, B., Macek, I.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.09.2007; Elsevier Science
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agronomy. Soil science and plant productions; Biological and medical sciences; Carbon dioxide springs; Carboxylation efficiency; Climatic adaptation. Acclimatization; CO 2 compensation point; Elevated CO 2; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Mofettes; Natural CO 2 springs NCDS; Phleum; Photosynthesis; Timothy grass; Volcanic gases; Phleum; Volcanic gases; Timothy grass; CO 2 compensation point; Carboxylation efficiency; Photosynthesis; Carbon dioxide springs; Mofettes; Natural CO 2 springs NCDS; Elevated CO 2; Monocotyledones; Phleum pratense; Natural CO2 springs NCDS; Carbon dioxide; Elevated CO2;Mofettes; CO2 compensation point; Gramineae; Angiospermae; Spermatophyta
• ISSN: 0098-8472; 1873-7307
• DOI: 10.1016/j.envexpbot.2007.02.008

Photosynthesis and growth of timothy grass ( Phleum pratense) exposed to a naturally elevated CO 2 regime in a post-volcanic mofette (cold CO 2 emitting gas vents) area were drastically influenced. Plants carefully selected according to the soil CO 2 within the rooting horizon showed a strong correlation between emitted CO 2 and total plant height. Net photosynthesis measured at 2000 ppm CO 2 ( A 2000) and even more net photosynthesis measured at 350 and 700 ppm CO 2 ( A 350 and A 700) were higher in “low-CO 2-grown” plants (0.4% CO 2 in the soil) than in plants that were exposed to medium (3.3%) or high (26%) soil CO 2 levels during germination and growth. Carboxylation efficiency (CE) and the compensation point (CP) also drastically differed, with CE being much lower in high-CO 2-grown plants (0.0023 μmol m −2 s −1 as compared to 0.0042 μmol m −2 s −1) and the compensation point being considerably higher (36, 93, and 144 μmol mol −1) within an increasing CO 2 environment.