While traditional management of the boreal forests results in even-aged forests with low landscape scale variability, recent work has suggested that much of the eastern boreal forest of North America is subject to long natural fire return-intervals. This has led to the development of new management strategies to maintain a mosaic of even and multi-aged stands. In this context I investigated the relationships between diameter-distributions, stand age, forest structure and bird communities. Results showed weak associations of the bird community with cohort classes, but that diameter-distributions can work to succinctly describe some of the variation in stand structure and bird communities. I also explored the utility of LiDAR to measure important structural features for bird communities. Results showed that LiDAR can outperform traditional measures of stand structure at explaining bird communities at differing scales.

While traditional management of the boreal forests results in even-aged forests with low landscape scale variability, recent work has suggested that much of the eastern boreal forest of North America is subject to long natural fire return-intervals. This has led to the development of new management strategies to maintain a mosaic of even and multi-aged stands. In this context I investigated the relationships between diameter-distributions, stand age, forest structure and bird communities. Results showed weak associations of the bird community with cohort classes, but that diameter-distributions can work to succinctly describe some of the variation in stand structure and bird communities. I also explored the utility of LiDAR to measure important structural features for bird communities. Results showed that LiDAR can outperform traditional measures of stand structure at explaining bird communities at differing scales.

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.

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.