SLD? Rapid expansion due to gasses?

[JoshR]

Is that discoloration heart wood or incipient decay?

I think it was a pocket of decay. And just so you know, It’s been a long time since I took those pictures so, I may not have very good answers to questions about it BUT, This was a pretty small limb. Maybe 5-6” in diameter. I remember looking for a starting point of the decay and I looked for an old lateral that was broken or cut off close to that dark spot in the middle and I didn’t find one. So, it was a mystery to me how that dark pocket of dead came to be. Normal heartwood on these pecans are not that dark. Look at the discoloration of the sapwood in the tension wood area. It’s not as light as the sapwood on the bottom where it peeled

 

[Treeaddict]

I’d buy the ethylene gas participation. Further reading indicates that it’s a hormone. It can cause leaves to drop. It seems to be particularly active in times of stress.

I don’t like that the information can induce fear. A branch could kill you at anytime so let’s cut em all off. Mitigate the hazards! The odds of that happening (killed by a sld) have to be close to getting struck by lightning in your home. I know of 2 cases where falling limbs killed people on quite windless days but not sure if sld was a factor.

 

[moss]

Your last paragraph defines SLD and seems to contradict your first statement, no?

Living trees are constantly changing and reacting to environmental conditions. Sometimes, conditions cause changes in living trees that create loads that exceed structural capacity, with or without an obvious structural flaw.

I wasn’t clear enough, there is typically a structural flaw. Yes a tree (an apple tree is the classic example) can overload a limb with foliage and/or fruit. But that is not heat related.
-AJ

 

[Birdyman88]

I don’t like that the information can induce fear. A branch could kill you at anytime so let’s cut em all off. Mitigate the hazards!

I think the intent of the magazine article was to just to rehash that the park rangers were just getting people to keep their wits about them. This is Yosemite, and California does see more intense drought conditions than most states. Maybe SLD is more common there, IDK. As far as mitigating the hazards, that's sort of the dilemma with SLD that it's really not obvious which limbs are gonna fail, so not obvious which ones to prune. My point of posting was really just to highlight the supposed Ethylene role in weakening the cellulose. This is the first time I've seen it mentioned in SLD.

I gotta tell you though, the Buzz is getting to be a strange place to hang out.

 

[Tom Dunlap]

Is SLD an acronym for sudden limb drop?

Yes

 

[JD3000]

Same here. And I’d like to be corrected if wrong, that’s the whole point of the post I want to be updated if anything has changed in the past 10-15 years I’m not privy to.
One of the common thoughts is the water column in trees is under negative pressure. Without looking it up, my thoughts is pressure dramatically effects the boiling point, not sure what negative pressure does.

https://dr282zn36sxxg.cloudfront.net/datastreams/f-d%3Aa5600a373274ec8c91953c143b3c93b4305221cbec4ec8e7d62f3cb3%2BIMAGE_THUMB_POSTCARD_TINY%2BIMAGE_THUMB_POSTCARD_TINY.1

So could there be some truth?

Just spit-balling but yes, let's say the water column is broken which causes a strength loss in live sapwood which then allows compromised rotten wood to do its thing.


Seem logical? As I've said, my observations have been oaks with good looking limbs dropping that all had internal decay bit good looking recent wood

 

[Treeaddict]

Birdyman88, I really appreciate you sharing that article. I think everyone did. It made me aware that trees produce ethylene as a hormone. New to me! I thinks its the way the writer portrayed the situation.

You know how paranoid many people are regarding trees.

Again, thank you for the information. Sorry if I made you think otherwise with my comments.

 

[Basswood]

Huh?

Sorry, a few drinks last night and definitely should have avoided response.

My point is a lot of tree work is either sold on fear or based on unnecessary fear. While I’ve anecdotally seen a fair amount of sudden limb drop I don’t think it’s common enough, or predictable enough to warrant special precautions that may lead to unnecessary work or removals. I would hate to see this added to the growing list of “this tree should be removed because…” or “that whole limb needs to be pruned because….”

 

[Birdyman88]

Birdyman88, I really appreciate you sharing that article.

Sorry, a few drinks last night and definitely should have avoided response.

Lol. When you get to be my age and read an article like that all I see is "blah blah blah ... ethylene concentrations increase ... blah blah blah". I just naturally filter out everything else, lol. I guess it never occurred to me that any of the rest of it was that important. Age does have its perks.

Add: I used to teach MCAT test prep, and that's the way we used to teach the reading comprehension section. I imagine I adapted the method over time.

 

[Winchman]

I worry more about being hit by a falling green longleaf pine cone.

 

[chipper1]

Last week this cherry limb came down while I was working on the barn out front.
The tree it came out of can be seen behind it, it flipped over on the way down, that had me confused as I saw it hit the ground and couldn't think of a "tree" that size coming from that direction. The tree it came from is about 28+ across.