Estimating Defoliation of Hardwoods Using Blade-petiole Relations
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Res. Pap. NE-405. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 5p.
Prediction equations for estimating leaf blade area and dry weight from measurements of petiole thickness were used to estimate defoliation of Populus tremuloides, Acer rubrum, Quercus rubra, and Q. alba. On one tree of each species, a sample of leaves was artifically browsed in May and harvested in July. The fractions of leaf blade tissue remaining in the samples after treatment in May were compared to the fractions remaining after harvest in July, which were calculated using the blade-petiole relations. Significant differences were found between the fractions for all species except P. tremuloides. Late browsing treatments were applied to leaf samples of the same trees in July. Except for the remaining fraction of Acer rubrum blade dry weight, all fractions calculated after harvest in August were reasonably close to measured fractions after treatment, although some statistically significant differences were found.
Valentine, Harry T. 1978. Estimating Defoliation of Hardwoods Using Blade-petiole Relations. Res. Pap. NE-405. Broomall, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 5p.