ibclogo XVI International Botanical Congess


Abstract Number: 4901
Poster No. = 1482


HOW TREE CANOPIES CLOSE FOREST EDGES?


Cristina Mourelle and Martin Kellman. York University, Canada


Trees at the edges of long isolated fragments develop lateral canopies that promote effective edge closure and a protected interior microclimate. We test the hypothesis that tree species vary in their capacity to close an edge canopy as a consequence of differences in branching patterns, foliage density and foliage arrangement. Light levels and architectural characteristics were measured for 6 species of differing shade-tolerance (Sugar Maple, American Beech, Red Oak, Black Cherry, Black Walnut and Bigtooth Aspen) at the edges of forest fragments in a deciduous forest. For all trees collectively, total foliage biomass facing the field, number of branches and crown width were the most important predictors for light occlusion while significant differences in light occlusion capacity were observed between species. Maple and Beech appeared to be most effective at canopy closures, while Walnut and Aspen showed the lowest light reduction. Crown depth and crown width was significantly higher among the most shade tolerant species (Maple, Beech and Oak) while the highest branch density and clumping was found in Maple, Beech and Cherry.


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