Variability in young stands of Sitka spruce
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1969Author
Mountfort, C. J.
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Abstract
The aim of this project is to ascertain the variation in height growth,
diameter growth and crown development, between individual stems in young
stands of Sitka. Spruce (Picea sitchensis (Beng) Carr) up to canopy closure,
to elucidate the development of the storied structure of the canopy, found at
the time of first thinning. The variation in height, diameter, branchlet number
and dry weight of root, shoot and needles of planting stock will be analysed.
Similar measurements of height, height increment, diameter and branchlet
number will be obtained in the 1-; 3-; 6- and 9-year old stands to assess the
effect of transplant size on establishment and subsequent growth. At each age
the height range will be divided into four equal vigour classes and the processes
associated with the development of dominance will be examined. The spatial
distribution of individuals of each vigour class will be analysed to determine
whether the distribution is random or clumped.
The study originated from an interest in general stand development from
time of planting to maturity, in relation to the effects of spacing and
different grades of thinning, on the composition and performance of the
vigour classes constituting the stand. Due to the time available, the study
has been restricted to the determination of the variability within planting
stock and its effect on establishment, subsequent growth and differentiation
into vigour classes, within young stands up to time of canopy closure. It
was decided to terminate the study at canopy closure, because the additional
factors of crown and root competition which then become important, would
constitute a separate study.
In order to reduce the variation from climatic and site factors, the
areas of study were restricted to one general soil type, Peaty Gley, with
a similar vegetation. To reduce altitudinal variation sites between 900-
1100 feet were chosen in the Wauchope Forest in the Scottish Borders.