Conceptualizing environmental stress: A stress-response model of coastal sandy barriers

The purpose of this paper is to develop and apply a conceptual framework of environmental stress-response for a geomorphic system. Constructs and meth ods generated from the literature were applied in the development of an int egrative stress-response framework using existing environmental assessment techniques: interaction matrices and a systems diagram. Emphasis is on the interaction between environmental stress and the geomorphic environment of a sandy barrier system. The model illustrates a number of stress concepts p ertinent to modeling environmental stress-response, including those related to stress-dependency, frequency-recovery relationships, environmental hete rogeneity, spatial hierarchies and linkages, and temporal change. Sandy bar rier stress-response and recovery are greatly impacted by fluctuating water levels, stress intensity and frequency, as well as environmental gradients such as differences in sediment storage and supply. Aspects of these stres s-response variables are articulated in terms of three main challenges to m anagement: dynamic stability spatial integrity, and temporal variability. T hese in turn form the framework for evaluative principles that may be appli ed to assess how policies and management practices reflect key biophysical processes and human stresses identified by the model.