In nature, the roots of most plants are infected by symbiotic fungi to form mycorrhiza which play a central role in the capture of nutrients from the soil. Most of our knowledge of the biology of the mycorrhizal symbiosis has been derived from studies carried out under controlled conditions in
the laboratory or glasshouse. There is an increasing awareness of the need to extend these studies to the more natural situations in which the symbiosis evolved and in which it normally functions. This volume brings together a series of papers which place major emphasis upon mycorrhizal function in
nature. They consist of edited and revised contributions to the Third European Symposium on Mycorrhizas, held at the University of Sheffield, 19-23 August 1991.