|Direct effects of elevated CO2 concentration levels on grass and clover in 'model-ecosystems'|
Overdieck, D. (1990). Direct effects of elevated CO2 concentration levels on grass and clover in 'model-ecosystems', in: Beukema, J.J. et al. (Ed.) Expected effects of climatic change on marine coastal ecosystems. Developments in Hydrobiology, 57: pp. 41-47
In: Beukema, J.J. et al. (Ed.) (1990). Expected effects of climatic change on marine coastal ecosystems. Developments in Hydrobiology, 57. Kluwer Academic: Dordrecht. ISBN 0-7923-0697-X. 221 pp., more
In: Dumont, H.J. (Ed.) Developments in Hydrobiology. Kluwer Academic/Springer: The Hague; London; Boston; Dordrecht. ISSN 0167-8418, more
In long-term experiments (up to 2.5 vegetation periods) grass/clover-mixtures (1: 1) were exposed to 4 CO2 concentration levels (340, 450, 600 and 800 mm³.dm-³) in acrylic-miniglasshouses which were climatized according to the microclimate outside. At 600 mm³.dm-³, plant growth and production were enhanced by 20-40% compared to cultures at 340 mm³.dm-³. Only the seed weight of the clover species increased by max. 28% with elevated CO2 concentration levels. Without clippings, the clover species tended to be more enhanced by additional CO2. With clippings, the grass was more successful in competition. The C/N-, C/P-, C/Ca- and C/K-relationships were higher at elevated CO2 concentration levels. The CO2 net fixation of the whole canopy increased by 40%, when the CO2 concentration was raised from 340 to 600 mm³.dm-³. This enhancement decreased until the end of the third vegetation period to about 10%. The ecological consequences of these findings are discussed.