Little knowledge exists about the role of antibiotics in fungal life cycles an activities. One hypothesis is that antibiotics are important determinants of competitive interactions among fungi; experimental evidence to support this hypothesis, however is lacking. A freshwater fungal community on wood will be used experimentally determine: (1) the degree to which competition occurs among fungal species; (2) how the competitive ability of initial colonizers influences the development of fungal communities over time; and (3) whether the ability of fungi to produce antifungal antibiotics confers a competitive advantage. Competition will be assessed by pre- colonizing wood in the laboratory with pairs of species (antibiotic producers and non-producers) in various proportions at different densities and then submerging the wood in a stream. Species reproduction over time will be measured as an indicator of species success. %%% Results should demonstrate the degree to which competition occurs, the role of competition in organizing fungal communities, how well species interaction in culture predict species interactions in the field, the relative importance of antibiotic production in fungal species interactions, and the process and pattern of fungal colonization of submerged wood. This knowledge will contribute to understanding the role of competition, the evolutionary significance of antibiotic production, and life strategies of saprophytic organisms.
