A TEST OF MYCORRHIZAL BENEFIT IN AN EARLY SUCCESSIONAL PLANT COMMUNITY

The fungicide ‘Rovral’ (iprodione) was applied in granular form in an attempt to reduce VA mycorrhizal infection of plants during the early stages of secondary plant succession, namely the first year of colonization of bare ground. In 7 out of 11 plant species examined, infection levels were reduced by the fungicide. Four of these also showed reduced cover abundance as a result of fungicide application. Since three were annual forbs, which as a plant life‐history grouping comprised 73 % of the community, total cover of the vegetation (as measured by point quadrats) was significantly reduced by the fungicide. In three species, reduced infection levels did not appear to result in reduced vegetation cover. The reasons for this are discussed in relation to the dependency of plants on mycorrhizal infection. It was found that fewer plant species recruited into communities where iprodione was applied. The implications of these results, in terms of the role that mycorrhizas play in the structuring of early successional plant communities, are discussed. Copyright © 1990, Wiley Blackwell. All rights reserved