T. H. Jones, ^* L. J. Thompson, J. H. Lawton, T. M. Bezemer, R. D. Bardgett, T. M. Blackburn, K. D. Bruce, P. F. Cannon, G. S. Hall, S. E. Hartley, G. Howson, C. G. Jones, C. Kampichler, E. Kandeler, D. A. Ritchie

In model terrestrial ecosystems maintained for 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. These results have implications for long-term feedback processes in soil ecosystems that are subject to rising global atmospheric carbon dioxide concentrations.

T. H. Jones, L. J. Thompson, J. H. Lawton, T. M. Bezemer, T. M. Blackburn, Natural Environment Research Council (NERC) Centre for Population Biology, Imperial College at Silwood Park, Ascot, Berkshire SL5 7PY, UK.
R. D. Bardgett, School of Biological Sciences, 3.614 Stopford Building, University of Manchester, Oxford Road, Manchester M13 9PT, UK.
K. D. Bruce and D. A. Ritchie, School of Biological Sciences, Donnan Laboratories, University of Liverpool, Post Office Box 147, Liverpool L69 7ZD, UK.
P. F. Cannon, CABI Biosciences, Bakeham Lane, Egham, Surrey TW20 9TY, UK.
G. S. Hall, Forge Cottage, Well Cross, Edith Weston, Oakham LE15 8HG, UK.
S. E. Hartley, Institute of Terrestrial Ecology, Banchory Research Station, Banchory, Aberdeenshire, AB31 4BY, UK.
G. Howson, Institute of Terrestrial Ecology, Merlewood Research Station, Grange-over-Sands, Cumbria LA11 6JU, UK.
C. G. Jones, Institute of Ecosystem Studies, Post Office Box AB, Millbrook, NY 12545, USA.
C. Kampichler, Institute of Zoology, University of Vienna, Althanstrae 14, A-1090 Vienna, Austria.
E. Kandeler, Federal Agency and Research Centre for Agriculture, Institute of Soil Management, Spargelfeldstrae 191, A-1226 Vienna, Austria.
^*   To whom correspondence should be addressed. E-mail: t.h.jones{at}ic.ac.uk

   Present address: GSF National Research Centre for Environment and Health, Institute of Soil Ecology, Ingolstädter Landstrae 1, D-85764 Neuherberg, Germany.