Before revision: Dominance by annual plants has traditionally been considered a brief early stage of ecological succession preceding inevitable dominance by competitive perennial plants. A more recent, alternative view suggests that interactions between annuals and perennials can result in priority effects, causing annual dominance to persist for decades if they are initially more common. Such priority effectswould complicate restoration of native perennial grasslands that have been invaded by exotic annuals. However , the conditions under which these priority effects occur remain unknown.
After revision: 1. In many grassland communities, the identity of dominant species may be determined by initial frequency owing to priority effects. Yet , the conditions under which these priority effects occur remain unknown.