interactions such as competition and facilitate the
coexistence of competing species. However, in some
cases, mutualist interactions may enhance the
competitive ability of the dominant species and con-
sequently cause the exclusion of subordinate
species. An in-depth understanding of mutualist in-
teractions would allow us to effectively predict the
effects of natural perturbation and human interfer-
ences in functioning of communities.
Acknowledgements
The authors thank DST (BOYSCAST), Government
of India, for funding (D.K.); NWO for funding (E.T.
K.); Deepika Sharma for preparing Fig. 13.3;
Springer-Verlag for permission to use Fig. 13.5
and portions of text fromEcological Studies, vol.
157:Mycorrhizal Ecology; and Elsevier for permis-
sion to use Fig. 13.1 fromCurrent Biology, vol. 17.192 FUTURE DIRECTIONS