Monday, August 4, 2008 - 2:45 PM

SYMP 2-4: Disturbance and successional theory

Steward T.A. Pickett, Cary Institute of Ecosystem Studies, Scott J. Meiners, Eastern Illinois University, and Mary L. Cadenasso, UC Davis.

Background/Question/Methods

Succession is one of the oldest of ecology’s major theories, and it embodies the pervasive and fundamental idea that ecological systems are dynamic as a result of both internal and external forces. It’s vintage means that it has evolved through shifts in paradigm, growth of long-term studies, and examination of contrasting systems. This has resulted in building a body of significant experiments, and a burgeoning of sophisticated modeling approaches. The theoretical framework of succession has grown and been refined to accommodate this impressive onslaught of changes. Indeed, the contemporary framework identifies both what is lasting and stable within the concept, and suggests how the new perspectives and approaches have been accommodated.

Results/Conclusions

Succession theory consists of propositions about 1) the theoretical domain, which is broad and process-oriented, rather than pattern-oriented, 2) the individualistic nature of the process, involving multiple trophic levels and plant-habitat interactions, 3) the role of disturbance, species availability, and species performance as drivers of succession and which are generalizable to all scales of vegetation dynamics, 4) identification of net effects and the assembly of species groups in response to local environments under constraints imposed by historical contingencies, and 5) the limitations of traditional methodologies. Key idealizations, such as zero force laws and process laws, exist within succession theory. These draw on and contextualize other key ecological principles. Thus, succession theory is a flexible, highly developed, and synthetic conceptual device in ecology with practical applications in management and restoration.