Incorporating biological control into ecologically based weed management

Ecologically based weed management involves the identification and manipula tion of processes that direct community dynamics. Of the many processes occ urring in an ecosystem, those with the highest likelihood of causing change in a desired direction should be modified to allow predictable outcomes. B iological control agents modify, interference, stress and dispersal. Incorp orating biological control into ecologically based weed management is criti cal when and where at least one of these three processes drives plant commu nity dynamics. If other processes dominate succession, it is unlikely that biological control will assist in establishing or maintaining desired plant communities. Two models, one conceptual and one mathematical, are proposed for understanding any process modifying factors influencing the plant comm unity. These ecologically based models can be used to direct the developmen t of integrated weed management with predictable outcomes. Assessment of bi ological control, or any, management strategy, must be based on the predict ed impacts on the organization, structure and function of the ecosystem.