The final form
of a
mature tree is determined by the dominant growth of
some buds and shoots at the expense of others, a phenomenon known as
apical dominance. In pines and most conifers, the trunk or main
stem grows more each year than the other branches, and the branches
attached to the trunk grow more than the secondary branches. Strong
apical dominance in these species results in a very orderly growth
habit
that forms a conical tree; this type of growth habit referred to as
excurrent growth.
Most
deciduous trees do
not show strong apical dominance and therefore
typically exhibit less orderly growth. Instead, many shoots grow at the
same rate, many branches form, and it sometimes becomes difficult to
identify the main stem. These species are referred to as decurrent
or deliquescent growers, and usually have large spreading crowns.
Contact: Paul Wray