Stem dissection and dendroecological methods were used to examine the effects of thinning and defoliation by gypsy moth (Lymantria dispar
L.) on wood volume increment in oaks (Quercus rubra
L., Q. alba
L., Q. prinus
L.). A model was developed to evaluate radial volume increment growth at three time periods: before defoliation, during defoliation and after defoliation, as a function of species, defoliation intensity and crown position. Volume increment during these same time periods was also compared at different stem locations. Trees were defoliated for two consecutive years and results indicated that volume loss was greater during the second year of defoliation with complete recovery taking 2-3 years after defoliation. Oaks in thinned stands had similar reductions in annual volume increment during defoliation as those in the unthinned stand.
repeated measures analysis
Fajvan, Mary Ann; Rentch, Jim; Gottschalk, Kurt. 2008. The effects of thinning and gypsy moth defoliation on wood volume growth in oaks. Trees. 22: 257-268.