Positive and negative effects of a dominant competitor on the settlement, growth, and survival of competing species in an epibenthic community

摘要: Because dominant competitors can monopolize resources, any positive effects they have on other species large community impacts. The solitary tunicate Ascidia ceratodes is a competitor in the fouling Bodega Harbor, CA. This preempts primary substratum from competitors, but its thick tunic also allows to grow surface. net effect of as whole therefore depends balance between competitive and facilitative effects. In this study we evaluate different life stages common competing species. We quantified larval settlement onto compared unoccupied space; growth rate small colonies two species; measured whether established could escape overgrowth by growing tunic. found evidence for high rates Ascidia, with some showing higher others lower relative that observed free space. settlers was generally substratum. colonial space commonly occurs about half all encounters. indicates total will depend species-specific stage-specific effects, likely long-term consequences diversity composition community.