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Tension wood: A 'muscle' that can both bend and straighten plants

phys.org

31–40 of 48 posts

Re: Tension wood: A 'muscle' that can both bend and straighten plants

#31

Earlier quoted context omitted.

I'm an arborist since 2022 in the UK and yes, never top trees. But... There's three scenarios that come to mind in which it's somewhere between "acceptable" and "totally fine for some reason". One, it's conifer hedge (the types popular in the UK) as these typically respond very well to being topped. It's what makes them a nice tidy hedge. I'm specifically referring to hedges above 3 meters in height. If you ever work…

> Topping puts the tree on senescence pathway and gives the ecology time to transition from alive to dead and dying. Is this why the council recently topped a tree on my road that's been breaking up the pavement? We thought they were cutting it down since they dug up all the tarmac around it, but they just knocked the top off, taking something like 98% of the leaves with it, and then put fresh tarmac over the exposed…

Hard to know with council works. Sometimes the work is great, sometimes it is a horror show. This sounds like more of a mis-managed tree that got too big, created too much liability in terms of legal risk and had to go. Rather than remove it from the landscape, leaving the stems does actually provide some green infrastructure benefit.

Re: Tension wood: A 'muscle' that can both bend and straighten plants

#32
post #4

Imo the title here buries the lede: we've known that trees form tension wood in response to external stress. This study claims to find that trees will form it in response only to their own curvature, independent of external factors even including gravity. They compare it to proprioception. That's neat!

I thought ‘interoception’ might also be appropriate in this context.

And just one letter away, "enteroception" sounds like a concept from the Alien films.

Re: Tension wood: A 'muscle' that can both bend and straighten plants

#33
post #27

Earlier quoted context omitted.

Fascinating! Where is this data stored? I love the idea of a Tree DB queried via TreeSQL.

It's basically a decentralized algorithm involving sugar defecits, auxin signalling, calcium flooding whenever cells stretch (due to gravity or wind), and ethylene release. Trees can use all these signals to know which branches are being shaded or dealing with a lot of wind, which side it's being pulled towards more, etc. Trees also optimize for their overall wind profile. Dropping branches that cause it more drag th…

Fascinating stuff. Reawakening my interest in arborist stuff ("arborism"?). Thank you for posting.

Re: Tension wood: A 'muscle' that can both bend and straighten plants

#34

Earlier quoted context omitted.

> Topping puts the tree on senescence pathway and gives the ecology time to transition from alive to dead and dying. Is this why the council recently topped a tree on my road that's been breaking up the pavement? We thought they were cutting it down since they dug up all the tarmac around it, but they just knocked the top off, taking something like 98% of the leaves with it, and then put fresh tarmac over the exposed…

Hard to know with council works. Sometimes the work is great, sometimes it is a horror show. This sounds like more of a mis-managed tree that got too big, created too much liability in terms of legal risk and had to go. Rather than remove it from the landscape, leaving the stems does actually provide some green infrastructure benefit.

Isn't a more proper treatment (assuming the tree itself is healthy) to bump up the pavement target height like a foot or thereabouts and put down some slope smoothing ramps to limit how much it acts as a speed bump? I'd assume it would involve hydrovac digging down between the roots a foot or two deeper than the sub base the roots appeared to believe in, to guide future growth of those roots down (by making that direction easier than to break the asphalt again).

Or perhaps literally just grinding (or otherwise prepping/cleaning by however is suitable given the presence of these roots) the fractured asphalt to improve bonding, and following with a good layer of fresh asphalt over top thick enough to keep the roots deep/the pavement surface resilient against the next decade of the root's growth? Ofc. including start&end ramps to not make an excessive speed bump.

If it's thick enough future crack fixing should probably only require a prius-parking-spot-sized heat lamp/"grill" placed over the cracked asphalt until it's soft throughout the full depth of the cracks, and then run a compactor/stomper over it to smash the malleable asphalt smooth. If needed that's the perfect time to spread a wheelbarrow of fresh hot asphalt in the heated cracks to restore decent coverage thickness over top of the roots. Maybe first grind it down an inch or two to get rid of the weathered topmost bit, but otherwise asphalt is pretty much unlimited recycling suitable, or at least we haven't yet really run out of demand for fresh asphalt to get rid of the used asphalt we're digging up by cleaning it a bit before mixing with new ingredients to dial in target softening temperatures and gravel composition...

Re: Tension wood: A 'muscle' that can both bend and straighten plants

#37
post #5

Trees "calculate" which branches to drop based on data they gather as they grow. A competent and experienced arborist knows how to read the tree and simply safely cut off the branches that the tree was already intending to drop so that it doesn't fall on your house or whatever. Inexperienced arborists often ignore this key dendrology fact and may totally butcher your tree. In the process they can create an even large…

Fascinating! Where is this data stored? I love the idea of a Tree DB queried via TreeSQL.

Reminds me how we have a local database from our city government with the exact location, what type of tree it is and more, updated relatively often: https://opendata-ajuntament.barcelona.cat/data/en/dataset/ar...

Different level of "Tree DB", I know, was still reminded that I at one point did something that required us to have a pipeline for downloading these trees location.

Apparently our city as 1/4 million trees and over 500 different species! https://ajuntament.barcelona.cat/espaisverds/en/management-a...

Re: Tension wood: A 'muscle' that can both bend and straighten plants

#38
post #14

Earlier quoted context omitted.

> "You can become dehydrated if you take in too little. And you can actually cause problems, such as exercise-induced low sodium or hyponatremia, if you take in too much," says Dr. Sara Filmalter, a Mayo Clinic family physician. "So the general rule of thumb at this point among physicians is to drink to thirst."

I've often read (sorry, no citations handy) that by the time you notice / feel thirst, you've already been dehydrated for some time. And chronic (mild) dehydration is much more common than hyponatremia. I'll always err on the side of drinking water whenever it occurs to me (and deliberately starting my morning with 16-20oz on waking) instead of waiting to feel thirsty.

That's more for the intrusive thought aspects of "being thirsty", which get you to stop "sitting by the campfire" and "walk over the 5 minutes to the stream, to shovel a few handfuls of water into your mouth".

Or these days tell your zoom meeting you'll be right back, muting, and walking over to the water cooler.

Or at home pause the family movie night to get up and refill the water pitcher from the tap (or walk to the pantry and fetch a new "bottled water").

If you're trying you should be able to perceive a difference between when drinking half of this 400ml cup/glass of non-sparkling non-cold (at least nowhere near ice cold) water is something you predict to leave you feeling "more comfy" as soon asyou're "done swallowing" and "have gotten about 2 breaths finished counting from when you have successfully re-assumed your comfy sitting position", vs. "less comfy".

Don't drink the water if you're feeling like you ought to regret it if going by hour-scale average comfy-ness.

To tune your perception make sure to give yourself enough headspace to allow the feeling pre-drinking to temporarily burn into memory ready for later retrieval when you'll reflect back on your hydration actions of the past 2~5 hours. Then you either drink or not drink (usually you'll soft-force by picking whether to go up and fetch a full cup or do nothing (I.e., just keep doing whatever you're engrossed in right then) until next time you remember the idea of hydrating). A few hours later when you remember you burned that feeling into same-day-only/wipe-at-sleep memory you recall what you did/didn't do about hydrating. And now you have the ground truth about if you feel better or worse hydrated than those hours ago.

And you burn in that you either "should go drink some water when you spare a thought about it and feel like this again" or "should refrain from gulping down [more] water when you're considering whether to and you feel like that".

Note that you're not putting your feeling into words for this! You're just focusing "on the moment" for a bit, long enough to make it a moment you'll remember (lack of specialty will make you forget it by the next morning or at least within a few days if nothing special happens). Because you literally don't _know_ how to express it into words: that's literally what you're learning with this entire process.

Note that drinking the water when you feel low key thirsty but don't get (nearly as much) hydration-feel-good out of it by the 30~60 minute mark (depending on how much you just stuffed your gut with food that's kinda in the way of the hydration getting absorbed) as you thought you should have, then you may be suffering from some acute lack of salt/electrolytes.

If it feels bad, like hangover/heartburn and/or substantial headache, take a pile of salt that looks about a third of an inch cubed (60% of a cubed centimeter volume) (technically this is "1/8th US Teaspoon (tsp)"), lick-pour it from your palm onto your tongue or pour the spoon you have it on onto your tongue or whatever, followed by washing it off your tongue and into your belly with about 300~500 ml (10~17 US fl oz) of water ideally not colder than half way between fridge and room temperature (closer to room temperature should help!). Unless you stuffed yourself with more than about 5 bites of food in the past hour, you should feel much relieved after 20~40 minutes. It will take time, usually more than 15 minutes!

In less severe cases you may try to mix a stick/pouch of hydration/"oral rehydration solution" mix with the ideally about 200~250ml (6.8~8.5 fl oz) but make sure to mix to the concentration the instructions tell you (drink only about that much if the pouch had powder for 350 ml (12 fl oz) or more, and drink the reminder an hour later (if less than that; else portion it hourly into this much each; for many hours duration put it in the fridge)). Otherwise you basically do as for plain water hydration perception training detailed above. Learn if that feeling is an acute electrolyte deficiency dehydration. Because beyond the very initial instant satisfaction of the water running down your throat and coating your mouth you pretty much only make it worse from drinking salt-free water :D

Re: Tension wood: A 'muscle' that can both bend and straighten plants

#39

Earlier quoted context omitted.

Some folks' interrupts are buggy, so they resort to polling.

ADHD hyperfocus disables most interrupts.. very task efficient, at the expense of all else :/

Yeah but you can train to perceive the threshold of impending over-hydration and adjust your behavior trigger thresholds to bump up against that more than you bump up against clearly perceived acute dehydration ("very much obviously clearly thirsty").
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