Ecological Succession Theory

From P2P Foundation
Jump to navigation Jump to search


Thomas K. Rudel:

"For the past 20 years natural scientists (Botkin 1990) and social scientists (Thornton 2005) have routinely disparaged the grand theories of development in the natural and the social sciences. These approaches have been characterized as ‘ahistorical’ and ‘teleological’ in their emphases (Thornton 2005, 232). Developmentalism is probably best exemplified in human ecology by Eugene Odum’s (1969) “The Strategy of Ecosystem Development.” Odum’s theoretical scheme had its origins in the early 20th century work of Frederic Clements, an ecologist, who conceived of change in ecological communities as an endogenously driven process in which a ‘developmental’ stage gives way to a ‘mature’ stage of vegetation. Clements (1916) referred to this process as ‘succession.’ His depiction of the process became ‘succession theory.’

Despite its currency as a grand theoretical construct in ecology, succession theory did not figure centrally in the efforts of social scientists to build a comprehensive human ecology during the 20th century (Hawley 1950, 1986). Only biological ecologists like Odum made any attempt to use succession theory to model the relationship between economic development and environmental change, and these efforts offered no more than a sketch about how one might use succession theory to understand interrelated changes in plant and animal communities (Odum 1969).

Critics of this approach assert that, contrary to the central tenet of succession theory, history has no discernible direction (Worster 1994, 424), that its course reflects irreproducible conjunctures of historical conditions and events.

Certainly, the critics’ contentions are correct in some basic respects. The idea (Clements 1916; Odum 1969) that ecological or human ecological communities represent organisms that guide themselves through ‘stages’ of succession, an idea that anticipates ‘the gaia hypothesis,’ seems difficult to substantiate. While the critics’ argument has to be correct at a high level of detail, it takes on some of the characteristics of the approach that it means to criticize. Like ‘anti-essentialism’ in women’s studies which becomes ‘essentialist’ in its assertions about the primacy of subjective ways of knowing (Fuss 1989), this argument verges on becoming essentialist through its denials of the possibility that empirical conjunctures of events could occur through a gradual unfolding of endogenously driven processes.

Some ecologists have not rejected succession theory so much as they have reformulated it. While some, like Botkin (1990), see random, externally determined disturbances as the predominant pattern of change, other ecologists have argued that the source of change is an empirical question. For them, the endogenously driven trajectories of change outlined in succession theory may characterize places and peoples for limited periods of time which follow or precede reorienting, externally driven disturbances (Pickett et al. 1987; Odum et al. 1995).

This ‘stop and start’ understanding of succession allows for disturbances to influence or redirect succession without stopping it. During the periods of relative stasis in ecological communities it might be appropriate to think that largely endogenous processes would, as outlined in succession theory, govern change in ecological communities." (