Gap dynamics in trembling aspen stands, dendroclimatology of jack pine and tree-ring anomalies in conifers from Manitoba

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The proposed research program is a continuity of my previous NSERC research proposals and it has three major components. My first interest is to pursue research on forest disturbances and dynamics. I intend to focus particularly on secondary forest disturbances in trembling aspen dominated forests of the boreal plains of Manitoba. One of the questions that needs to be elucidated concerns the relationship that exist between gap formation in aspen stands and the frequency/severity of forest tent caterpillar (FTC) outbreaks. In the boreal plains of Manitoba, hazelnut also constitutes a major competitor to forest regeneration and we want to quantify the response of understory species to change in environmental condition resulting from the opening of the canopy. The second component concerns the climate sensitivity of the boreal tree species jack pine across its range in Manitoba. This project will be in continuity with our recent work on light rings in the Duck Mountain region of Manitoba and will also involved, among others, the use of tree-ring densitometry to reconstruct past cool growing season. The third component will involve studying tree-ring anomalies (wood anatomy) and also the study of the influence of defoliation on xylem formation in jack pine trees. We recently started to look at light rings in jack pine from western Manitoba and we also initiated some work on density fluctuation in jack pine trees from eastern Manitoba. Across our sampling we also observed a new tree-ring anomaly in the form of white earlywood ring in numerous conifer species. We will specifically look at the impact of jack pine budworm on tree ring anatomy and also look at jack pine plantation outside the current range of distribution of the species in Manitoba. These research projects will have specific outcomes related to forest management in central Canada as well as better understand of how climate is affecting tree growth in central Canada. These projects are unique to Manitoba and our analysis of numerous tree-ring anomalies is essential 1) to understand how environmental fluctuations are affecting tree growth and 2) to provide better reconstruction of past climate fluctuations using tree-ring analysis.