The precautionary principle and ecosystem health: a case study from the jarrah forest of Southwestern Australia.

Abstract

Maintaining a healthy ecosystem does not preclude economic use of ecosystem components and such use may be an essential part of maintaining healthy human communities within the ecosystem. The precautionary principle is one mechanism for assessing which economic uses or developments are least likely to degrade ecosystem health. It argues that: “Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation. In the application of the precautionary principle, public and private decisions should be guided by: (i) careful evaluation to avoid, wherever practicable, serious or irreversible damage to the environment; and (ii) an assessment of the risk-weighted consequences of various options” (The Intergovernmental Agreement on the Environment, May 1992, quoted in Deville and Harding 1997, “Applying the precautionary principle”, Federation Press, Sydney, p.13). However, scientific suspicion of the precautionary principle is based largely on confusion as to procedures for incorporating scientific data into a philosophical-political process. Here we take published guidelines on applying the precautionary principle and illustrate how they allow scientific input to the question of whether or not current multiple-use forestry takes a precautionary approach to maintaining ecosystem health in the jarrah forest of Western Australia. The scientific input involved (i) identification of outcomes in similar situations elsewhere in Australia, (ii) selection of indicator species/processes for monitoring based on predictions made on the basis of (i) above and published accounts of processes and indicator species’ biology, and (iii) a prescription for monitoring/experimentation that includes a quantitative requirement for a probability of detecting impacts based on statistical power analysis. On the standards suggested, contemporary management falls short of a quantitative definition of precaution that involves adherence to measurable standards and cannot provide a strong assurance that it will maintain ecosystem health.