Found on an elm

[Chris_Robinson]

I was sent to check out a declining elm this morning. Not having very much experience with elms, and not knowing a whole lot about them except for their susceptibility to Dutch elm disease, I was excited to check it out. The tree wasn't very big: 8 in DBH and about 20 feet tall. Definitely beginning to decline and had bark flaking off in large sections around the base of the trunk. Under the bark there appeared to be a white fungus growing and at the very base, under a piece of bark I found what looked like a bunch of eggs. Not sure what to make of all of it, except that, whether these egg looking things and the fungus are the primary or secondary stressors, the tree is definitely stressed and is starting to show clear signs of it in the canopy. Could it simply be Dutch elm disease and these eggs are the beetle eggs?

 

[nuthin_special]

Those look like mealybugs from where I'm standing. Could be overwintering in a bark crevice? From the picture, it looks like there is callus growth at the margins, not very dedish. Not that I'm too familiar with ded having seen it here once over the last decade.

Any potential root damage or trauma to the trunk during construction?

V

 

[guymayor]

Agree w Vince re scavengers--could be mechanical damage--, and check the roots, starting with the flare.

 

[guymayor]

" Not sure what to make of all of it, except that, whether these egg looking things and the fungus are the primary or secondary stressors, the tree is definitely stressed and is starting to show clear signs of it in the canopy. "

I wish I knew what folks mean when they say a tree is 'stressed'.

It's good you located this area of concern. Job #1 is to clear away the dead stuff from that area, so you can see what's going on. Expose the woundwood all the way around and you will see that's an old abiotic wound. Then find the flare; with a tree that young you gotta suspect root/planting/nursery issues.

Facts before theories.

 

[Chris_Robinson]

After getting rid of some of the dead stuff, it became pretty clear there is an old mechanical wound all the way around the base of the trunk. Probably from the tractor mower...I think it's killed more young trees in our town than anything else.

Do you think whatever the white fungus under the bark is, as well as the bugs, could be directly linked to this abiotic wound?

 

[guymayor]

All the way around like 100% circumference?

90%?

Fungus and bugs linked sure if the damage gives them habitat.

But they don't matter; roots do.

 

[Chris_Robinson]

Sorry, the wound or wounds spread around the entire circumference. Presumably from repeated wounding from the mower in different spots over time. But there isn't a total cut off of the vascular system. There are still patches of callous growth within the wounded area which I assume are what's keeping the tree alive, albeit barely.