Elevated Carbon Dioxide and Ecosystems

Clive G. Jones
Institute of Ecosystem Studies

Replicated model terrestrial ecosystems maintained in the "Ecotron" controlled environment facility at Silwood Park, UK, are being used to investigate the responses of ecosystems to global change in a large collaborative research project. These simplified, but natural ecosystems allow us to measure responses from the chemistry of plant species up to entire ecosystem carbon and nutrient budgets. In a recent series of experiments over three plant generations at elevated concentrations of atmospheric carbon dioxide, increases in photosynthetically fixed carbon were allocated below ground, raising concentrations of dissolved organic carbon in soil. These effects were then transmitted up the decomposer food chain. Soil microbial biomass was unaffected, but the composition of soil fungal species changed, with increases in rates of cellulose decomposition. There were also changes in the abundance and species composition of Collembola, fungal-feeding arthropods. The results have important implications for long-term feedback processes in soil ecosystems that are subject to rising global atmospheric carbon dioxide concentrations. Other studies in progress include effects of elevated temperature and carbon dioxide on both plant chemistry and ecosystem dynamics.

Collaborators
Dr. Susan Hartley, Institute of Terrestrial Ecology, Banchory, UK
Dr. Thomas Hartmann, Institut für Pharmazeutische Biologie der Technischen Universität Braunsweig, Germany
Dr. Hefin Jones, Centre for Population Biology, Imperial College, Silwood Park, UK
Prof. John Lawton, IES Adjunct Scientist, Centre for Population Biology, Imperial College, Silwood Park, UK
Dr. Lindsay Thompson, Centre for Population Biology, Imperial College, Silwood Park, UK
Dr. Alexander Wait, South West Missouri State University, MO

Publication

Jones, T. H., Thompson, L. J., Lawton, J. H., Bezemer, T. M., Bardgett, R. D., Blackburn, T. M., Bruce, K. D., Cannon, P. F., Hall, G. S., Hartley, S. E., Howson, G., Jones, C. G., Kampichler, C., Kandeler, E., and Ritchie, D. A. 1998. Impacts of rising atmospheric carbon dioxide on model terrestrial ecosystems. Science 280: 441-443.

More Information for the Ecotron.

Scientific Correspondence on Elevated CO₂ and Ecosystems
Hu, S., Firestone, M. K., and Chapin, F.S. III 1998. Elevated atmospheric CO₂ and soil biota. Science 281: 517.