Estimating oak leaf area index and gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), defoliation using canopy photographs
1988
Oak leaf area index was (LAI) was estimated using wide-angle photographs of the forest canopy taken from the ground at grid points throughout three sites on Cape Cod, Mass. Confidence intervals for these estimates and optimal sample sizes were calculated. Oak LAI estimates leveled off by early June when no defoliation was present. Within-plot two-dimensional spatial distribution of oak LAI was very similar to the spatial distribution of oak basal area. Consequently, there was a positive correlation between local oak leaf area and local basal area. Comparison of LAI estimates taken before and after gypsy moth, Lymantria dispar. (L.), defoliation allowed the estimation of oak leaf area consumed. Leaf area loss was similarin areas of high and low host foliage densities. The correlation of leaf area lost with local density of early instars was greater than the correlation with the density of late instars.
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