Altitudinal variation in growth, bud break and susceptibility to balsam twig aphid damage of balsam fir from 6 Vermont seed sources
- Download PDF (2770558)
- This publication is available only online.
In: Proceedings of the 1st northern forest genetics conference; 1991 July 23-25; Burlington, VT. The University of Vermont: 171-180.
Differences in 10-year heights, 4-year growth from 1987 through 1990, relative timing of budbreak and damage by the balsam twig aphid (Mindarus abietinus Koch.) among balsam fir (Abies balsamea (L.) Mill.) from 6 Vermont seed sources originating from different elevations were examined. Height differences among seed sources were highly significant and trees from high elevation seed sources tended to be the shortest. Differences in 4-year growth among seed sources were also highly significant and followed the same trend as total height. Although differences in the amount of twig aphid damage (1990) among seed sources were highly significant, there was no consistent pattern of damage associated with elevation of origin. Trees from the 872 m seed source on Mount Mansfield had considerably more aphid damage than trees from any other seed source including those from 1173 m on the same mountain. Differences in budbreak (1991) among seed sources were highly significant. Seed sources were segregated into 3 groups . Low elevation seed sources had the earliest average budbreak, high elevation sources had the latest average budbreak and mid elevation sources were intermediate. The correlation between seed source means in percent aphid damage (1990) and relative budbreak (1991) was significant, but the biological interpretation of this statistic is complicated by the fact that measurements of these variables were made in different years. Although differences in the relative timing of budbreak between seed sources may partially contribute to differences in aphid damage, data from the two highest elevation seed sources suggests that factors other than budbreak timing alone can greatly affect seed source susceptibility to damage.
Wilkinson, Ronald C.; Schaberg, Paul G. 1992. Altitudinal variation in growth, bud break and susceptibility to balsam twig aphid damage of balsam fir from 6 Vermont seed sources. In: Proceedings of the 1st northern forest genetics conference; 1991 July 23-25; Burlington, VT. The University of Vermont: 171-180.