PARENT SESSION
Organized Oral Session 32: Forest disturbance regimes in the circumboreal forest zone: Natural variability and implications for forest management and biodiversity conservation
Organizer(s): S Gauthier, T Kuuluvainen, and D Kneeshaw
Wednesday, August 10, 8:00 AM - 11:30 AM, Meeting Room 516 C, Level 5, Palais des congrès de Montréal
On the importance of secondary disturbances in boreal forest of eastern Canada.
De Grandpré, Louis1, Boucher, Dominique1, 2, 1 Canadian Forest Service, Sainte-Foy, Québec, Canada2 Université du Québec à Montréal, Montréal, Québec, Canada
ABSTRACT- The eastern boreal forest of Québec is subject to a fire cycle over 300 years. Forest development characterized by species or individual replacement in the canopy is frequently observed. Non fire disturbances, such as insects outbreaks, windthrow and tree senescence become driving processes controlling forest dynamics. The impact of such disturbances consist of gaps varying in size from few m2, in the case of single tree mortality or partial windthrow, to many thousands m2, with severe insects outbreak or windthrow. Complex spatial patterns will emerge as a result of such processes and from the physical setting of the landscape. The objectives of this study is to describe the patterns resulting from non-fire disturbances at multiple spatial scales (landscape to stand level) and to better understand the associated forest dynamic. Satellite images (LANDSAT TM 30m), aerial photos and field surveys were used to describe the patterns resulting from non-fire disturbances, within a territory of 14 000 km2, located in the North-Shore region of Québec. With the classified LANDSAT image at a resolution of 1 : 250 000, the landscape was divided in more than 130 polygons, varying in size from 20 to 600 km2. Each polygon was described in terms of cover (coniferous, mixed or deciduous) and density type, and by the spatial arrangement of the descriptors. We identified and described 20 different groups of patches at this scale. The analyses will be pursued with finer resolutions to characterized the impact of these disturbances on stand composition, structure and dynamics. The implications of these results for forest management will be discussed.
Key words: disturbance, boreal