Rating Hazard Trees

[kruege84]

Hey guys,

In one of my classes, I have to do defect/hazard ratings on trees around campus. I've run into a bit of a snag on this one and would really appreciate some input from the pros.

The tree looks like Quercus alba, about 42" DBH, on the campus of Michigan State University. The branch unions all look ok, no included bark. No cracks in the trunk. However, as you should be able to see, the tree has had most of its top removed. I can't get up to the cut to check for decay or how well the tree is coping with the injury. The branching is quite a bit heavier on the east side of the tree and it also leaning slightly in this direction. The soil is undisturbed, no heaving or visible roots. If it falls in any direction, it will hit at least a sidewalk on a busy college campus, so there is a target in all directions. Also, I noticed a hole in the bark (there is a pic.) Possibly some sort of borer?

We have to recommend a course of action for the tree. I'm thinking some light pruning may in order, mainly of any dead branches. At the same time, I'm thinking that the pruning of any live wood may be too much stress on this tree.

Thanks for your input, and I will try to respond quickly to any questions.

 

[kennertree]

You would need to get up there to visually inspect the top to make an evaluation. Check for decay with a rubber mallet around the base and the root flare.

 

[treeseer]

I can't get up to the cut to check for decay or how well the tree is coping with the injury. I'm thinking some light pruning may in order, mainly of any dead branches. At the same time, I'm thinking that the pruning of any live wood may be too much stress on this tree.

Good to keep living buds on a tree that old, but if the topping wound is heavily rotted (I do not like the looks of it from here), the branches coming off of it will need the sprawl reduced, retaining the upright, most productive laterals.

I agree with kenner, that defect must be aerially assessed. why cant someone climb it?

 

[treedoc1]

Has your class been introduced to the resistograph tool. That would allow you to examine the extent of decay coming down the trunk column.
Minor MP1" pruning on the canopy
Radial Mulching of the CRZ with an air spade followed with a mulch 4" deep under the CRZ will be the most beneficial to alleviate all the compaction. If that isn't feasible at least fracture the soil with the air spade in a grid pattern under the CRZ. We apply compost tea as a hydraulic application (deep root feeding) from 3-9" under the turf in a grid pattern. Stay away from a heavy N source, no reason to upset any growth balance between the crown and root system.

First alleviate any hazards from dead branches to pedestrian traffic, second, improve the CRZ.

Quit looking for zebras in regards to the borer hole. Insect activity will be attracted to weakened trees. You probably have more secondary insect activity up in that large cut than you will ever have from a Twolined chestnut borer larvae. They will be more active up in the crown than in the bottom of the trunk.

 

[tomtrees58]

the tree is a white oak to bad it was top i removed one here on LI NY it was 440 years old tom trees

 

[lxt]

440 yrs old?? are you sure about that? why did it need removed? I would think that would be a historic tree worthy of other than removal!!

440yrs old................did you do the counting?

LXT................

 

[farmer]

It was probably dead from old age.

 

[Dadatwins]

Good to keep living buds on a tree that old, but if the topping wound is heavily rotted (I do not like the looks of it from here), the branches coming off of it will need the sprawl reduced, retaining the upright, most productive laterals.

I agree with kenner, that defect must be aerially assessed. why cant someone climb it?

Also agree, I would guess some sort of storm damage took out the top years ago. Oak is not the best at closing large wounds, so I would guess there is some decay up there. Someone will need to get up there to evalute it properly.

 

[D Mc]

Hey guys,

In one of my classes, I have to do defect/hazard ratings on trees around campus....We have to recommend a course of action for the tree.

If they said "open book" does that include "laptop"? I'm telling!

Seriously, we agree with Treeseer on shortening the branches if possible. For the tree to survive safely for an extended period of time, it would be better to have the branches reduced in length. NO THINNING. This tree looks like it has already been overthinned to us. We, too, thought it looked like the top had come out in a storm but hard to tell...there was another across the street that looks just the same. Curious. Hmmmmmmm

We are also big mulch fans, keep the lawn away from the base (out to the dripline if possible) and apply mulch. We prefer whole tree mulch (disease-free) (that means with leaves and everything).

You noted that the tree has no limbs on the west side and has an inclination to the east. From where are the prevailing winds? More specifically the strongest storms.

Getting up there to check the condition of the top is imperative in a full risk assessment. We would also check the condition of the roots with a gentle hand excavation. The rubber mallot test is also great. We are not fans of drilling unless other indicators warrant it.

Good luck, and let us all know how we did on your assignment!

D and S Mc

 

[treeseer]

Oak is not the best at closing large wounds, so I would guess there is some decay up there.

Oak is not the worst at codit, by a long shot. But taht specimen looks low in vitality. yes decay in the top is evident in the picture. just go up there and stick your hand in!

At NCSU I took a plant physiology course where we were assigned to climb a baldcypress. At UW-Madison we climbed a bur oak in an ecology course. Maybe MSU in 2008 is a little more hinky about liability...

 

[capetrees]

I'm going to guess they just started offering this class because someone has been whaling on these trees for some time now. I doubt they would do it with an arbor class on camopus. From the first picture, you can see in the background someone else did the same to another tree. These are some fuggly trees. I would think a tree this large would seem secure and safe but I would try to investigate the core to inspect any rot. Too many times I've taken down white oaks to find the core was rotted away already.

 

[John Paul Sanborn]

The topping could well be from storm damage 20-30 years ago.

Vitality does look low, but the basal area looks rather good, no elephants footing of the root flair.

though that one looks like there is decline in the root too.

Soil remediation is a good idea in any turfed setting, but this is eval not curative reportage.

If aerial examination is out of the question, then throwline in the top and a pull test may be helpfull.

I would like a pull test to see how the but moves also. I've seen whites and burs in that condition with a very stable cylinder.