This
image composite shows the bonsai from the same angle
at three different stages; in 2001 after collection,
in 2003 after two years growing in a pot and finally
in 2009 after 4 years field-growing and a further
2 years cultivation in a bonsai pot.
Over
8 years, the new leader (that the trunk was chopped
to in 2001) has thickened, taper has been created
and there is now a smooth transition from the original
trunk through to the original branch.
However,
despite the new trunkline increasing in diameter
by 3 or 4 times its original size, the original
trunk has not thickened at all. The diameter of
the new trunkline has simply 'caught up' in size
with the original trunk.
Very
often I have seen enthusiasts fail to understand
that when developing a trunk for bonsai in the ground,
the tree must first be grown freely until the base
is the desired thickness intended for the bonsai
that it will one day become. The example above perfectly
illustrates that after trunk-chopping, the trunk
base will barely thicken (if at all) until the new
sections above it have reached the same diameter.
By which point the taper (and the purpose of trunk
chopping) has been lost.