Ecology and Society Ecology and Society
E&S Home > Vol. 2, Iss. 2 > Art. 7 > Abstract Open Access Publishing 
Disturbance Severity and Threshold Responses in the Boreal Forest

Lee E Frelich, University of Minnesota
Peter B Reich, University of Minnesota


Full Text: HTML   
Download Citation


This essay discusses three potential models relating disturbance severity to post-disturbance stand composition in the boreal forest: (1) continuous, where changes in disturbance severity cause a proportional and continuous change in stand composition; (2) discontinuous, where a threshold disturbance severity exists beyond which major changes in composition occur; and (3) the cusp, where thresholds exist and coexistence of two alternative compositional states is possible at the same disturbance severity. Any of the three models may be appropriate in different stands or different parts of the boreal forest. If the actual model does not correspond to that assumed by forest managers, then forest harvesting practices may cause unexpected sudden changes in forest composition. Disturbance severity under the natural disturbance regime changes so dramatically, from one disturbance to the next, that oscillations in composition over time are likely to be individualistic and irregular, rather than stable. Harvesting operations are mainly done during winter, resulting in a very low disturbance severity in comparison to the natural regime, which included crown fires. Major changes in species compositon over large parts of the boreal forest are likely to result.

Key words

alternative stable states; disturbance in boreal forest; disturbance severity; forest response to changes in; Minnesota boreal forest; stability in boreal forest; forest response to changes in disturbance severity.

Copyright © 1998 by the author(s). Published here under license by The Resilience Alliance. This article is under a Creative Commons Attribution 4.0 International License. You may share and adapt the work provided the original author and source are credited, you indicate whether any changes were made, and you include a link to the license.

Ecology and Society. ISSN: 1708-3087