Variation in Leaf Quality of Two Oak Species : Implications for Stand Susceptibility to Gypsy Moth Defoliation

1989

1 Abb., 3 Tab., 21 Lit. Ang.

Unselbständiges Werk

9716

200088458

Variation in phenolic leaf traits was measured for red oaks (Quercus rubra L.) and chestnut oaks (Quercus prinus L.) growing in a resistant stand (on a mesic lowland) and in a susceptible stand (on a xeric ridgetop). Chestnut oak foliage had significantly greater measures of protein binding capacity, total phenolics, and hydrolyzable tannins than red oak, regardless of stand location. Foliage from both species in the susceptible stand had significantly greater measures of condensed tannin than did foliage from the resistant stand. Seasonal changes in phenolic content were the largest sources of intraspecific variation. Chestnut oak was more abundant in the susceptible stand than in the resistant stand. Species and site factors thus results in high tannin levels in oak foliage in susceptible stands compared with resistant stands. The significance of this in relation to gypsy moth population dynamics is discussed.