AUTHORS: Jennifer Fraterrigo*, University of Illinois at Urbana-Champaign
ABSTRACT: Site history and context can act as abiotic and biotic filters that affect plant community dynamics. Sites with a history of intensive agriculture, for example, often have high levels of resource availability that favor plant species with life-history strategies associated with rapid growth. Once these species become established, internal feedbacks can reinforce patterns of high resource availability slowing the establishment of mid- and late-successional species with more conservative life-history strategies. Site history can also create biotic legacies that influence the direction and pace of succession. Species with persistent seedbanks can quickly recolonize a site when conditions become suitable. The ways in which site context acts as a filter on species is less clear. There is strong support for direct effects of context on propagule availability, with many studies demonstrating that dispersal capacity is positively related to recovery rate in secondary forests. Fewer studies have addressed the indirect effects of site context. Indirect effects could be important if context alters abiotic and biotic conditions in ways that affect fitness or competition among species. I will use examples to highlight how site history and context can shape successional communities through these processes, potentially leading to alternative successional trajectories.
