The presentation
examines aspects of crown reduction from several different perspectives. An understanding
of tree morphology and natural tree survival strategies informs management approaches
for aging trees. Many mature trees have structural constraints that are not
correctable in one pruning application. These trees can however be improved
over time, utilizing crown reduction and thinning techniques. If too much is cut, large
wounds can lead to significant decay and structural weakness. If too little is
cut, the tree may break, also causing large, obscure wounds. How do we find the
appropriate dose and still leave the tree looking natural and reasonably safe?
Philip van
Wassenaer, a consulting arborist, will introduce
natural tree survival strategies and
discuss several significant trees that have
been evaluated and retained using a variety of risk assessment techniques and
how those assessments resulted in targeted crown reduction prescriptions. Ryan
Redvers, a practicing arborist, will present detailed case studies on trees
which he has successfully reduced and retained for clients in Southern Ontario.
Each case will include; tree description; significant problems seen in the
structure; before and after reduction pruning photos; a detailed prescription;
the number of cuts in each length range; the diameter of cuts in each length
range; the combined mass of removed pieces; an explanation of the process
including tools, technique, objectives, references; explanation of the concepts
practiced
, including taper, form, balance, branch ratio, spacing, reduction,
raising, thinning, reduce/remove/retain.
The audience will
leave with a further understanding of how thoughtful crown reductions can be
incorporated into their repertoire of techniques to help conserve trees
rather than removing them.