The biology and management of bark beetles in old growth pine forests of Itasca State Park

Matthew P. Ayres, María J. Lombardero, Bruce D. Ayres, and Alyson E. Santoro

From June 1997 through September 1999, we conducted a study of interactions between bark beetles and pine trees in the old growth pine forests of Itasca State Park. The program was initiated in response to severe windstorms in 1996-97 that blew down many large pine trees and led to a dramatic increase in populations of bark beetles within the park. Under some conditions, epidemic populations of bark beetles can overwhelm tree defenses and produce extensive mortality in healthy trees. Consequently, the windstorms created a significant risk for the high-value old-growth forests of Itasca State Park. The objective of our research was to expand knowledge of the bark beetle communities in Itasca State Park, assess patterns of tree resistance and host suitability within the park, evaluate the extent to which bark beetles impact tree survivorship at Itasca, and provide guidance for future management decisions.A complementary research program directed by Dr. Stephen Teale, State University of New York at Syracuse, addressed related issues including the efficacy of beetle control programs.

Appendices
Appendix 1. Growth history from tree cores for mature red pine

Appendix 2. Growth and resin flow in mature red pine

Appendix 3. Soil moisture measurements

Appendix 4. Beetle captures in Lindgren funnel traps

Appendix 5. Growth history of beetle infested trees

Appendix 6. Cold tolerance of bark beetles

Appendix 7. Interactions between fire and bark beetles

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