Last summer a favorite tree in the woods behind my house "broke" (left photo). It was not an optimally configured tree because it was positioned at the edge of the woods and therefore "leaned out" to maximize its sun exposure, and the limbs on the south side were more heavily leafed. The fracture occurred near the location of a woodpecker hole and could have been related to that or to some intrinsic rot. I cleaned up the crown that fell to the ground, then debated what to do with the trunk.
The black cherry (Prunus serotina) is one of the food plants for Tiger Swallowtails, and I was pleased to see that before its demise, this tree had generated a seedling near its base, which was blooming last spring (and where it will be log powers easier to find Tiger Swallowtail caterpillars than up in the inaccessible canopy.
But what to do with the fragmented residuum? I did nothing last summer or fall because the broken trunk was a magnet for woodpeckers, who had enhanced access to various beetle larvae. The visuals from the dining area window and back deck were irrelevant because it's a natural development, so no need to "clean it up" in that regard. Then this past week I saw this photo (cropped for emphasis) and question:
"My town has done some cleaning up in a nearby forest but a few trees were cut like this. What is the purpose of cutting them like this? The lowest ones were at about 2-3 meters above the ground."
The answer was in the marijuanaenthusiasts [tree-lovers] subreddit thread: "It's called a coronet cut. It's supposed to mimic a natural break and encourages natural decay to create wildlife habitats." A couple more clicks took me to Dr. Stump:
When limb failure occurs naturally, these new features create a micro habitat for microorganisms and successive species- wood louse, earwigs, etc. These in turn, support birds and bats’ and other organisms with food and shelter.Coronet cuts are designed to promote decay and therefore benefit microorganisms that live off the decaying wood. Whilst good for the local ecology, generally, this isn’t good for the tree. It prevents the branch sealing the wound and preventing pathogens from entering... we tend to only employ fracture pruning on trees earmarked for monolith, veteranisation or severe decline. This allows colonisation of the tree by the local fauna to encourage improved biodiversity of the area – a feeding ground and bat/bird hotel.If the tree is over a road/ bus stop, play area or near a dwelling, we may look to remove the tree for safety reasons. However, in parkland with low footfall, woodland or reserve, where risks to public health are much lower, this technique is a valuable tool in creating habitat for the wildlife.
You learn something every day.
A tip of the blogging cap to reader Alexander, who realized that "veteranisation" is an active process of creating veteran-like trees.
I camp in Virginia National Forests - we can collect firewood but will never cut down standing dead - too many times they are habit.
ReplyDeleteGlad I learned today about the how also the snapped remaining shorter trunks also have a purpose in the ecosystem.
Your 'My town' photo looks like the trees were hit with a bush hog! Those (bush hogged) resulting splintered ends probably do as good a job of introducing rot and decay as do the coronet cuts.
ReplyDeleteVeteranization seems to be another method of creating wildlife habitat while leaving a tree mostly alive:
ReplyDeletehttps://www.interregeurope.eu/good-practices/veteranisation-of-young-trees-in-order-to-enhance-green-infrastructure-of-valuable-trees
A monolith seems to be a somewhat controversial British term (because of its ambiguity) for "managed standing deadwood". My impression as a Midwesterner was that a "snag" was the term for the natural occurrence of a standing dead trunk but it seems that it also can be used for a managed one.
https://www.trees.org.uk/News-Blog/Latest-News/Monoliths-A-layman%E2%80%99s-view
Thank you Alexander! I've incorporated that link into the main body of the post. :-)
DeleteSeems kinda related:
ReplyDeletehttps://knowablemagazine.org/content/article/living-world/2025/rotting-logs-mini-ecosystems-habitat-and-food The teeming life of dead trees - Rotting logs turn out to be vital to forest biodiversity and recycling organic matter