Scarred for Life

Paul Hetzler, ISA Certified Arborist

It makes sense that dying trees have terminal bud scars. Sounds like an awful condition – my condolences. But the healthiest trees have them, too (terminal scars, not condolences). It’s a good thing, since terminal bud (aka bud-scale) scars provide an excellent way to leaf through a tree’s health records going back 5 to 10 years.

After a woody plant has its full complement of leaves, and they have hardened off, that tree or shrub makes both vegetative buds and flower buds for the following year. Inside each vegetative bud is an inchoate shoot tip, while the reproductive parts are in the flower buds (incidentally, trees have a secret stash of vegetative buds in case of spring frost damage, but no spare flower buds). At the tip of each twig, a woody plant makes a larger bud, the future leader of its respective leaf-dom. When a terminal bud starts to grow in springtime, it leaves behind a ridge of bark around the twig.

You can look down the twig toward its parent stem, and usually find at least five terminal bud scars, sometimes fewer, sometimes more. Reading glasses or a hand lens will help, because older scars are less distinct. The space between each scar is called a node, and it represents the growth from a particular year. It acts as a ruler for arborists and foresters, and it can be for you as well.

Certainly this varies by species, but one would expect to see four to six inches of new growth each year for a twig getting ample sunlight. Yet if you visit a college campus or walk down a busy village street, you’ll discover trees with only a fraction of an inch between terminal bud scars. It might be fair to consider those trees terminal cases.

This information will help you make good decisions about managing your landscape trees, sugar bush, or woodlot. If you notice a consistent lack of good growth, you’ll treat that tree or stand differently. Perhaps a soil test is in order to see if essential nutrients are missing. If you plan to prune a tree with scant growth between scars, prune lightly, no more than five to ten percent of leaf-bearing material. If you’re wondering how foresters collect twig samples from the upper canopy, one of their tools is a handy thing called a shotgun. You have to keep your work interesting.

Another helpful metric when evaluating young trees is something called a trunk flare. Examine the base of any tree. If there is an obvious flare, that’s as it should be. But if the trunk resembles a fence post at the soil surface, that tree’s rots are barely able to function. Occasionally a young tree will survive long enough to grow new (adventitious) roots up where they can get oxygen, but it generally won’t thrive the way it could have.

It also will be more likely to develop girdling roots, a condition which is exactly what it sounds like. These are roots which began growing in a circular pattern because the burlap was too difficult to penetrate in the first year or two. As the expanding trunk reaches this ring of death, the python-like girdling root (s) chokes the trunk. This happens when the trees are two to three decades old. Sidebar: always strip off the burlap once the tree is situated in the hole.

One can see the handiwork of girdling roots along major NYS roads between mid-August and mid-September. DOT-planted trees of that 25-35 age class begin to turn color before surrounding trees of the same type. Once you’re tuned in to this phenomenon, you will see it everywhere you go in late summer and early autumn.

The reason strangled or sick trees are early leaf-shedders has to do with their balance sheet. If a tree is being strangled by girdling roots, its sugar factory is less efficient than in other trees of its ilk. Root-girdled trees reach the break-even point earlier than robust trees, and hence they color first.

Now you have a few more ways to evaluate tree health. I hope they can help you keep a few trees from becoming terminal before their time.

Paul Hetzler has been an ISA-Certified Arborist since 1996, and is a member of ISA-Ontario and the Society of American Foresters. His book “Shady Characters: Plant Vampires, Caterpillar Soup, Leprechaun Trees and Other Hilarities of the Natural World,” is available on amazon.com

 

 

Views: 371

Comment

You need to be a member of CornellForestConnect to add comments!

Join CornellForestConnect

Forum

Deer stand damage help

Started by Joanne Vaughn in Woodlot Management. Last reply by Joanne Vaughn Dec 27, 2020. 1 Reply

My son left his deer stands up for 3 years and the screw in metal foot pegs have been partially encased in the bark. Has anyone advice about how to extricate them with minimal injury to the trees?Continue

Changes in Emeral Ash Borer Regs

Started by Brett Chedzoy in Woodlot Management Dec 16, 2020. 0 Replies

New year, new approach.  USDA ending quarantine efforts on EAB:https://www.morningagclips.com/aphis-changes-approach-to-fight-emerald-ash-borer-eab/  Continue

IPhone surveys

Started by Jim Martin in Woodlot Management. Last reply by John McNerney Dec 14, 2020. 8 Replies

Smart phones have GPS.  Has anyone figured out how to use them for mapping wooded land.  I am especially interested in a way to map  my logging trails. Jim MartinContinue

Striped maple control

Started by WJ Rodenhouse in Woodlot Management. Last reply by Gerry Hawkes Dec 13, 2020. 3 Replies

Looking for way to control large volume of striped maple and witch hazel. Both are interfering with growth of oak seedlings. Cut/treat stump? Hack and squirt? if so what chemical for either of these? Best time of year to treat?Best time of year to…Continue

How long do brush cutter blades work?

Started by Joanne Vaughn in Woodlot Management. Last reply by Gerry Hawkes Dec 11, 2020. 5 Replies

I dunno maybe it's because time flies when it's multiflora rose and buckthorns that are getting whacked. It seems that these blades are needing retirement after 8 or so hours.   Is this typical for this type of material. WIde range of material but…Continue

Tags: cutter, brush

Paulownia: Is this a tree for NYS?

Started by Joanne Vaughn in Agroforestry Dec 3, 2020. 0 Replies

I have stumbled across some descriptions of Paulownia trees (Empress, Princess).  It is described as marketable, fast growing (sequesters carbon quickly), not fussy about soils, relatively pest free. Does anyone here have first hand experience with…Continue

Saving the American Chestnut

Started by Stephen Kutney in Woodlot Management Aug 24, 2020. 0 Replies

Below is a message from the American Chestnut Foundation on the deregulation of the Darling 58 blight-resistant American chestnut.SteveThe 60-day public comment period is now open and will remain open until Monday, October 19, 2020. Here are two…Continue

Forester recommendations?

Started by Roger Rodriguez in Woodlot Management. Last reply by Kelly Nywening Jul 15, 2020. 1 Reply

We are new to forestry ownership and need some advice. We would like to be good stewards of the property and also provide occasional profit of some kind, especially to offset the taxes we pay on the property. I was thinking tree farming (?) as a…Continue

Badge

Loading…

© 2021   Created by Peter Smallidge.   Powered by

Badges  |  Report an Issue  |  Terms of Service