Total Growth of the Aerial Parts of a White Spruce Tree at Chalk River, Ontario, Canada

Apical and radial growth in trunk and branches, and needle distribution were studied in a white spruce tree 11 meters high and 36 years old. Growth was summarized according to (1) years of formation (Oblique Summation), (2) transversely by trunk internodes (Horizontal Summation), and (3) position of the annual rings and branch internodes (and needles) relative to the pith or trunk respectively (Vertical Summation). In this study summations 1 and 3 were considered to reflect internal (nutritional and hormonal) controls of growth, whereas summation 2 represented the effect of environmental factors including periodicity of flower and seed formation.The tree studied possessed [Formula: see text] million needles when sampled in 1961, two-fifths of which were formed during the last 2 years of growth. The percentage of ash in the needles varied from 4 in the new needles to almost 8% in those 10 years old. The productive capacity of one "average" needle in terms of apical growth, trunk wood, and new needle formation was estimated.