Predictive equations for leaf area and biomass for sugar bushes in eastern Ontario

In January 1998, an extensive ice storm caused severe damage to sugar bushes in Eastern Ontario. Foliage biomass and foliage area estimates were required to assess effects of the ice storm and remedial treatments on variables related to sugar maple production. Equations were developed to predict leaf biomass of undamaged individual sugar maple trees in the ice-damaged area. The data were collected in early to mid-August 2000 in eastern Ontario. Basal diameter of all third-order branches of 22 trees from two stands was measured, along with tree DBH, total height, and height to the base of live crown. In addition, foliage was collected from two branches (one from the lower and one from the upper part of each tree's crown). Samples were used to develop equations predicting leaf biomass (oven-dried weight) of individual branches from their basal diameter. These equations were applied to estimate total leaf biomass of individual trees, and the resulting estimates were used to develop equations predicting leaf biomass from DBH and the number of branches per tree. The resulting equations accounted for over 90% of the variation in leaf biomass of individual trees. Leaf biomass-DBH equations for the two stands were significantly different (P < 0.0001), while no significant difference was detected in the leaf biomass-number of branches equations (P = 0.1573) for the two stands.