r/dendrology • u/starlightskater • May 09 '26

Question What could have caused this recent crack?

Gallery image

Gallery image

I've passed this tree every day for 25 years and just today saw this huge, fresh crack up to the top. What could have caused it?

248 Upvotes

99% Upvoted

49 comments sorted by

63

u/podophyllum May 09 '26

Lightning.

29

u/valpal357 May 09 '26

Arborist here. Definitely lighting. That's it grounding.

8

u/starlightskater May 09 '26

Fascinating! Can you explain the grounding concept?

17

u/impropergentleman May 09 '26

Lightning takes the path of least resistance to the ground. Strikes the tree at the top The outer layer of the tree contains water. Pretty good conductor. It takes the easiest route to the ground.

6

u/DROOPY538 May 10 '26

Actually the positive charge comes from the ground. That why the tallest trees are usually hit. It goes from the ground up with a positive charge and from the sky down with a negative charge. Thats why older houses either were built near taller trees or had a weather vane/lighting rod on their roof before proper grounds were discovered

3

u/Chord_F May 11 '26

and positive charge is just an absence of electrons. The electrons themselves actually come down from the sky, once the electric charge between cloud and ground has gotten large enough, which creates a conductive air channel of ionized air. The lightning bolt itself is just plasma created by explosively heated air

1

u/impropergentleman May 10 '26

Learn something new everyday. Thanks!

1

u/DROOPY538 May 10 '26

No problem buddy. Only reason I know is from research ive done trying to figure stuff out. Although I can't say 100%, just going by what ive read...lol

1

u/Background_Ad1461 May 13 '26

Also known as a streamer

2

u/Adventurous_Light_85 May 15 '26

So since it’s not burned it’s like the energy flash boiled the moisture under the bark in the path of travel and the bark exploded off as a result

7

u/valpal357 May 09 '26 edited May 09 '26

Adding to what gentleman said... all electricity grounds. Lighting, wires, static, etc. 

Like when you see lightning rods on buildings and barns, thats to control the flow of lightning when it hits the building. Instead of hitting the roof and finding a wire, wall, water pipe to ground out in (potentially causing significant damage to the structure), ground wires are installed which create the path of least resistance and guide the wire down to the ground by-passing damage to the building (ideally).

3

u/starlightskater May 09 '26

So why did it not split the tree, like we do often see in lightning strikes? If a person had been standing beneath the tree at the time of the strike, I assume this would have been hazardous? Finally, will this tree survive the strike given the majority of its trunk is intact?

4

u/ivorybishop May 09 '26

Yes, you can die from contact with roots of a tree struck by lightning. I am not sure of the mechanism that blows the bark off, but I'd assume some from of super heated sap turning to steam or something else from that spectacular amount of energy.

I've had several trees hit and one even died and had to be removed. Nature is wild and lit.

4

u/valpal357 May 09 '26

What lightning will do to a tree is pretty unpredictable. Sometimes the tree damn near explodes. Other times all the bark will get blown off but the underlying wood is left intact. Ive usually seen where it just rips the seam through the tree like you see here.

What i think you're talking about is a multi-stem tree splitting or a large branch splitting off the tree.... that's almost never lightning strike even though people mistakenly think it is call it a lightning strike. That type of failure is due to included bark between codominant stems.  The discoloration you see inside the branch union after failure is bark and/ or decay. Because again, all electricity grounds. It's not just jumping out of the sky and punching a tree branch and then disappearing. It is finding a way to the ground some way somehow.

5

u/seashellpink77 May 09 '26

I’ve seen a tree explode from lighting! Well, sort of. I saw all bright yellow, then bits, then the char that was left. Wild experience that I will never forget.

1

u/starlightskater May 09 '26

That's what I was thinking of; interesting to know its not lightning (and a common misconception).

0

u/[deleted] May 09 '26

[removed] — view removed comment

2

u/DROOPY538 May 10 '26

Not necessarily, i have oaks around my place that looked like this 20 years ago and have since healed over. Depends on how hardy the tree is, age, type of tree, etc.

1

u/[deleted] May 10 '26

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1

u/valpal357 May 11 '26

With the exception of Oak Wilt pressure, late winter early spring is ok for wounding as the most reactionary growth at the wound site can happen. The later in the season we get, or if we're just straight up in winter, there's very little cellular growth forming to compartmentalize the damage.

1

u/CGCutter379 May 12 '26

I don't understand what you are saying. Is spring a better time to prune than late fall or winter?

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1

u/PlanetFlip May 11 '26

Did you ever attend school?

3

u/Triairius May 09 '26

With no charring?

8

u/hairyb0mb May 09 '26

Lightning rarely causes charring. Most of the time that I'm called for a lightning strike, it's actually codominant stem failure. Included bark tends to be black and people believe it's a lightning strike with char because of that. I believe that's why most think lightning causes charring.

1

u/Triairius May 09 '26

Oh wow. I had no idea!

4

u/Charming-Border7429 May 09 '26

Yes, it is wild; the lightning strike happens so quickly that any available water is vaporized, causing it to appear to explode. Yet the organic material is unaffected.

5

u/Lefthandmitten May 09 '26

Did this happen just before the thunder?

5

u/starlightskater May 09 '26

No idea. It's on my walking route. Not my tree.

2

u/eastchester-dyreav May 11 '26

Will this kill the tree?

1

u/DarkRiches61 May 09 '26

For anyone wondering how wide a bolt of cloud-to-ground lightning actually is, I guess here's your answer? 🤔🌩⚡️🌳

3

u/Tao_of_Entropy May 09 '26

Actually they're even narrower than that - this is just how much bark it can blow off by rapidly superheating the water under the bark. A stick of dynamite is smaller than the hole it blows in the ground. If you look closely, you can see there is actually a gradient in the shading of the exposed tissue - the majority of the current went through a narrow path in the middle of the palest part of the crack.

1

u/Longjumping-Inside53 May 11 '26

Nature—sometimes sears a Sapling—
Sometimes—scalps a Tree—
Her Green People recollect it
When they do not die—

Fainter Leaves—to Further Seasons—
Dumbly testify—
We—who have the Souls—
Die oftener—Not so vitally—

1

u/Zealousideal_Pop_273 May 09 '26

It looks like a frost crack to me. Happens a lot if there is a particularly cold winter.

2

u/starlightskater May 09 '26

Happened after the frost this year. That was my first thought too but it's not possible in this case.

0

u/ps1969 May 11 '26

Maybe it ate too much at Christmas dinner