> On Sep 18, 2022, at 11:07 AM, the_tinker  wrote:
> 
> Is there a fundamental difference between working a true sapling versus a
fresh new growth branch from an old tree?

The primary difference in structure between a vertical sapling and a new growth
lateral branch off of a (essentially) vertical trunk is going to be found in the
cross-section of the new growth ‘branch' - the bottom side of the new lateral
branches are going to grow more wood than the top side.  The tree does this to
specifically to support the branch in countering the effects of gravity.  For
the first year of growth on the lateral branch, the extra growth isn’t going to
be all that noticeable until the branch extends itself out far enough to start
pointing downward because of its own weight.  The branch will respond by adding
wood on the bottom side of itself to counter the effect of gravity.  This
natural feature was the inspiration for using a variable thickness in designing
cantilever supports for man-made structures.

Just about everything else in the composition of the two is going to be the same
in the earliest years of its existence.  For a tree that sends up suckers from
its roots, the suckers and the main trunk will both sprout smaller lateral
branches to support leaf growth, both will have vessels to move sap, etc.  The
distance between branching nodes might be different for lateral shoots than for
vertical saplings with some species if the tree canopy denies the sapling as
much sunlight at lower elevations than the tree gets higher up the trunk.

Leaves on either form of branch that receive greater light than the leaves on
other branches will tend to grow faster towards the source of sunlight and their
branch will also grow more.  A book came out last year called “The Hidden Life
of Trees”, written by a researcher who had studied trees and their colonization
practices over 3-4 decades.  The book shows that trees are more complicated life
forms than most of us humans realize.

Charlie Driggs