SCALE AND GENERAL LAWS OF VEGETATION DYNAMICS

In the recent theoretical proposal of S. T. A. Pickett and colleagues, a patch dynamic concept of secondary succession is used to develop general laws of vegetational change. While this proposal is an important step in the formalization of vegetation theory, its basis in secondary succession limits its applicability at larger spatial or temporal scales than those of single disturbance patches. We show that general theory must incorporate a more inclusive concept of environmental constraints on species behaviors than advanced in their proposal, as well as an expanded account of those behaviors. Our modifications of the original proposal allow its unrestricted applicability at all scales relevant to vegetation dynamics, and emphasize the fundamentally continuous, interactive nature of these dynamics.