Insect Communities and Multicohort Stand Structure in Boreal Mixedwood Forests of Northeastern Ontario

Current forest management in boreal northeastern Ontario results in young, even-aged forests; however, fire history research has found old stands with multiple cohorts of trees are common, supporting the value of Multi-cohort Management. I investigated relationships between insect communities and stand live-tree diameter distribution, cohort class and structure. Results showed that variation in abundances of Carabidae, Diapriidae, Diptera and Hymenoptera were not strongly predicted by cohort class. The concept showed greater strength when parameters of live-tree diameter distributions were used. Forest structure, not age, was important for all communities, including heterogeneity of understory and/or overstory vegetation. Trap height was a strong predictor of aerial insect community structure, with insect abundance higher in the understory than in the canopy. In summary, a more diversified classification approach which includes important habitat features in addition to simple characterization of diameter distributions should be considered to better assess forest structural variation and management.MAS