Positive interactions and interdependence in plant communities

A talk by Dr Ragan Callaway, The University of Montana. The individualistic view of plant communities has led to successful research on the importance of the abiotic environment and competition as factors structuring plant communities. Negative interactions such as predation, competition for resources, and allelopathy have been central to the study of ecology and evolution. However, it has become clear that organisms can greatly enhance the performance of their neighbors as well as modify the environment in ways that benefit other species. Positive interactions among plants, or facilitation, occur when the presence of one plant enhances the growth, survival, or reproduction of a neighbor. Until recently, examples of facilitation have been relatively rare; however, this rarity may have been an artifact of scientific disinterest rather than ecological frequency. But in the last 20 years, hundreds of peer-reviewed papers have been published on the positive effects of plants on each other. This research challenges a strict definition of the theory of individualistic plant communities, one of the most basic and widely accepted conceptual models in ecology, as a foundation for understanding how groups of plant species are organized. I will discuss this research and its theoretical implications. At the Zoology Benham Building, 346 Great King Street, behind the Zoology car park by the Captain Cook Hotel. Use the main entrance of the Benham Building to get in and go to the Benham Seminar Room, Rm. 215, 2nd floor. Please be prompt as we have to hold the door open.