Effects of early and late season defoliation on growth and carbohydrate dynamics in Scots pine.

Published online
01 Jan 1982
Content type
Journal article
Journal title
Journal of Applied Ecology

Ericsson, A. & Larsson, S. & Tenow, O.

Publication language
Nordic Countries & Sweden


In a Swedish experiment, 18-yr-old Scots pine were defoliated by hand in early and late summer, simulating different degrees of insect grazing on the youngest or the two youngest needle year-classes on each occasion. Significant negative effects were found on stem annual ring width, shoot length, needle biomass and number of buds. More severe effects were found when two needle-year classes were removed compared to one, and when current-year and 1-yr-old needles were removed in late season compared to 1-yr-old and 2-yr-old needles in early season. The build-up of starch reserves in the needles of defoliated trees was less than normal and the reserves more rapidly drained, especially in trees defoliated in late season. From authors' summary.

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