(c) Variation with time of the taper of a given tree
Considering first species which retain an undivided central stem
throughout life. As a result of progressive increase in height and in size of
crown, wind-pressures on the crown of a dominant tree are increased, and
this is associated with progressively more rapid taper of the stem, i.e. the
taper-line slope becomes more gentle. An example is shown in Fig. IS (a)
the data being taken from published stem analysis data [22] of a dominant
specimen of Douglas fir.