If you read his research with Grabosky on pruning you can get a lot more Pile high and Deep citations. Link below.
December starts the season for one of the most devastating events ever for trees: ice storms. When trees in your area suffer catastrophic branch breakage, what will you do? Before Nature forces you to confront that question, I’d like to share my experiences following an ice storm in 2002. Canopy trees in central North Carolina, many of them willow oak, Quercus phellos, lost more than half of their crowns. Instead of being removed, the branches were cleaned, headed back to buds at nodes where lateral branches used to be. That tale was told in TCIA magazine’s April 2003 issue; please review the background article at the website link…..The present article looks at the responses that those trees have made since that time and the recent restoration pruning done in response to the trees’ growth. In conclusion, we will look at ways to apply the lessons the trees seem to be teaching us to trees and branches damaged by storms, topping, and other catastrophes.
HEADING for BETTER FORM, and STABILITY
Trees with 50% or greater crown loss used to be candidates for basal pruning. In 2002, leaving large stubs in trees was even more controversial than it it is today. One urban forester reviewed our alternative specifications that would allow this practice, and pronounced them “a preposterous truckload of tripe”. After looking up “tripe” in the dictionary, it became clear that we would not be working for that municipality. But after looking at the science behind the practice, most professionals agree that it is a proper technique. However, a few still hold the view that there is no proper heading cut in a mature tree. I hope those few will consider these results, and reconsider that view. Before we think about ice storms, let’s look to the subtropics, and the protocol followed by arborists in Florida after catastrophic hurricanes in 2004-5.
“Immediately after the storm, the canopy should be cleaned by removing hazards such as…broken limbs. Cleaning also includes making smooth pruning cuts behind jagged branch tips to allow healthy development of new growth. Very little live wood should be removed because the tree is stressed, and needs to use energy stored in the limbs to recover.” In Assessing and Restoring Trees after a Hurricane: Urban Forest Hurricane Recovery Program,
http://edis.ifas.ufl.edu/pdffiles/EP/EP29100.pdf Dr. Ed Gilman’s team at the University of Florida goes on to say: “Storm damaged trees may not have a lateral branch present for making a good reduction cut. In that case, a heading cut may be preferred over removing the limb. Removing an entire limb could reduce energy reserves in the tree, create a large trunk wound, and lead to decay...A heading cut is made at a node along the stem, leaving a stub.”
These nodes are located where former lateral branches were first shaded, as the tree grew outward, then shed, because they were no longer harvesting enough sunlight to earn their keep. When they fall to the ground, the same concentration of undifferentiated “scar” tissue that can readily close over the wounds, so they are the best places to make heading cuts. However, the trees were not pretty after this treatment. The big fat stubs looking to inexperienced viewers like the victims of a partial topping job. But is a heading cut the same as topping? Again from Florida: “No! Topping is a harmful practice where the entire canopy of a (n undamaged) tree is severely reduced with many large heading cuts. Topping (also called lopping, hatracking, and dehorning) can lead to decay and reduce tree vigor. Heading cuts should not be used as a standard practice on healthy trees.”
RETRENCHMENT
REJUVENATION
REITERATIONS
IMPLICATIONS
