Age-dependent changes in needle-fascicle dynamics of Pinus sylvestris (L.)

Age-dependent dynamics of needle fascicles on the main stem of Scots pine trees in Estonia and Finland were investigated by the needle trace method. Mean fascicle longevity increased with tree age. Fascicle pool size, fascicle production and shedding were not related to tree age for trees less than 50 yrs old. Thereafter, the mean values of these characteristics declined linearly. Thus, younger trees had more fascicles attached to the stem, but fascicle survival in the third and fourth age classes tended to be greater in older trees. A short-term pattern of variation in dynamics was seen: higher values in the rates of fascicle shedding and production. and in the quotient of fascicle loss, in any one year were regularly followed by lower values in the following year.