Integrating ecological and social ranges of variability in conservation of biodiversity: Past, present, and future

Abstract

Historical range of variability has been proposed as a concept that can be used by forest land managers to guide conservation of ecosystem functions and biodiversity conservation. The role of humans in historical range of variability has remained somewhat murky and unsettled, even though it is clear that humans have been, are, and will continue to be forces of disturbance and recovery in forested landscapes. We attempt to develop concepts that integrate the ecological and social forces affecting landscape variability. Toward that end, we present a conceptual framework that places range of variability into a broader context and integrates the ecological and social forces affecting landscapes past, present, and future. We use two terms to aid us in understanding the utility of historical range of variability as a context and future range of variability as a point of comparison: (1) the ecological range of variability is the estimated range of some ecological condition as a function of the biophysical and social forces affecting the area and (2) the social range of variability is the range of an ecological condition that society finds acceptable at a given time. We find it is important to recognize that future range of variability represents a constantly emerging and changing set of conditions, and that the more humans push a system to depart from its historical range of variabiloity domain, the less likely it becomes that historical range of variability processes will prove useful as benchmarks in recovering a system. Copyright © 2010 by the author(s).