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 larger risk of a tree falling over onto your house during a storm
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 worked a hedge like this you'll quickly realise the topped stems are the platform to work off. These hedges can be maintained like this for years. For some reason, topped hedges are completely fine with being topped.
Two, it's either topping or removing. Arguably neither is ideal, but some retention is better than no retention. Topping puts the tree on senescence pathway and gives the ecology time to transition from alive to dead and dying. Whereas removal just makes the local fauna get confused about where the tree went.
Three, veteranisation in woodland settings. If there's a distinct lack of standing deadwood and age variation in a population of species in a given woodland NVC type, the topping and verteranising could be a positive management approach on a sample of trees.
This advice is very specific to the UK and especially on point three to the NVC woodland types. Generally though, prune properly at the correct locations, using proper technique being mindful of the structural loads and balancing of the tree. Topping generally, "because reasons" isn't an ideal approach at all.
The problem with number 2 is that it creates an allowance for people to plant the wrong tree in the wrong place and have fallback instead of being rewarded for their complete lack of forethought by having their tree summarily removed.
One of the cities on the east coast did a complete ban of planting anything but dwarf trees under utility lines. I don't know if you've ever seen an oak or a big leaf maple pruned to not tear down power lines but they look like something out of a Tim Burton movie.
Going forward, the answer should be removal, because otherwise the public will never learn, and you're enabling bad behavior, in the codependent sense of enabler.
> 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 roots. We've been puzzling over that for a week...
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...
Coppicing or pollarding are both well-historied techniques that can be used to keep trees growing short. They differ significantly from topping and require a lot of expertise. They also have to be started when the tree is young
This is often not useful advice, as it is common to acquire responsibility for a tree than has been badly managed. The GP's link actually gives a solution for this case: pruning more accurately over a slightly longer period.
More generally, I've found as the maintainer of a building that while mainstream practices (of property generally, not specifically trees) often undershoot good practice, heritage techniques are often impractically expensive, and function more as a status signalling mechanism than really as a way of doing better. Even more generally, economy-wide; there is a tendency to criticise the mainstream but then promote expensive, semi-artisanal products and services, which while better, simply offer an escape valve to pressure for reform. Better techniques can only benefit the populace as a whole if they are cost reduced under the discipline of serving the mass market, not just offered as a premium version for the well-to-do.
Well I agree it'd be ideal for our society would be organized in such a way that effective semi-artisanal trades are cheaper than practices that do more harm than good.
The real advice I should've given was to construct protection for a window or hire a certified arborist to do a proper thinning of the canopy. But I wanted to remain on the topic of interest dendrology info
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.
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 than they are worth in the sugar they make. The lower their wind profile, the lower the risk of the whole tree being uprooted during a storm.
When humans cut the wrong branches, it throws everything off balance.
I'd like to grow bonzai. I have zero prior knowledge. I suppose what you mention applies. Would you happen to have any good resource that applies to bonzai science please?
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!
Yes, the science has moved to "drink when you're thirsty" a long time ago and it's annoying how many people believe drinking 3 liters of water per day is a key tenant of human health.
(most of) Our bodies are quite good at telling us when we should drink more water. You should never be forcing yourself to drink
All that being said, I'm not sure GP was necessarily endorsing the idea that you should drink a certain amount of water a day. I read it as a suggestion to pull away from the screen and listen to your body
But why? unless it’s a copious amount of water like a gallon or more in an hour or two or something insane like that what is the problem with drinking water? I would assume it would just have positive effects.
> "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
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").
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 larger risk of a tree falling over onto your house during a storm
It's called cladoptosis (basically self-pruning) https://en.wikipedia.org/wiki/Cladoptosis
EDIT: since I'm on the topic of bad tree trimming, NEVER TOP YOUR TREES https://www.arborday.org/tree-resources/dont-top-trees
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 worked a hedge like this you'll quickly realise the topped stems are the platform to work off. These hedges can be maintained like this for years. For some reason, topped hedges are completely fine with being topped.
Two, it's either topping or removing. Arguably neither is ideal, but some retention is better than no retention. Topping puts the tree on senescence pathway and gives the ecology time to transition from alive to dead and dying. Whereas removal just makes the local fauna get confused about where the tree went.
Three, veteranisation in woodland settings. If there's a distinct lack of standing deadwood and age variation in a population of species in a given woodland NVC type, the topping and verteranising could be a positive management approach on a sample of trees.
This advice is very specific to the UK and especially on point three to the NVC woodland types. Generally though, prune properly at the correct locations, using proper technique being mindful of the structural loads and balancing of the tree. Topping generally, "because reasons" isn't an ideal approach at all.
The problem with number 2 is that it creates an allowance for people to plant the wrong tree in the wrong place and have fallback instead of being rewarded for their complete lack of forethought by having their tree summarily removed.
One of the cities on the east coast did a complete ban of planting anything but dwarf trees under utility lines. I don't know if you've ever seen an oak or a big leaf maple pruned to not tear down power lines but they look like something out of a Tim Burton movie.
Going forward, the answer should be removal, because otherwise the public will never learn, and you're enabling bad behavior, in the codependent sense of enabler.
> 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 roots. We've been puzzling over that for a week...
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...
>NEVER TOP YOUR TREES
they do it where I live because the branches bang against apartments' windows when it's windy. I don't think there's another low-maintenance solution.
Coppicing or pollarding are both well-historied techniques that can be used to keep trees growing short. They differ significantly from topping and require a lot of expertise. They also have to be started when the tree is young
This is often not useful advice, as it is common to acquire responsibility for a tree than has been badly managed. The GP's link actually gives a solution for this case: pruning more accurately over a slightly longer period.
More generally, I've found as the maintainer of a building that while mainstream practices (of property generally, not specifically trees) often undershoot good practice, heritage techniques are often impractically expensive, and function more as a status signalling mechanism than really as a way of doing better. Even more generally, economy-wide; there is a tendency to criticise the mainstream but then promote expensive, semi-artisanal products and services, which while better, simply offer an escape valve to pressure for reform. Better techniques can only benefit the populace as a whole if they are cost reduced under the discipline of serving the mass market, not just offered as a premium version for the well-to-do.
Well I agree it'd be ideal for our society would be organized in such a way that effective semi-artisanal trades are cheaper than practices that do more harm than good.
The real advice I should've given was to construct protection for a window or hire a certified arborist to do a proper thinning of the canopy. But I wanted to remain on the topic of interest dendrology info
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...
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 than they are worth in the sugar they make. The lower their wind profile, the lower the risk of the whole tree being uprooted during a storm.
When humans cut the wrong branches, it throws everything off balance.
Fascinating stuff. Reawakening my interest in arborist stuff ("arborism"?). Thank you for posting.
Because they B-Trees?
>NEVER TOP YOUR TREES
Kind of annoying when all the fruit is several meters out of reach
I'd like to grow bonzai. I have zero prior knowledge. I suppose what you mention applies. Would you happen to have any good resource that applies to bonzai science please?
https://www.reddit.com/r/Bonsai/wiki/walkthrough/
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.
Does this mean trees can actually “sense” when they're growing in the wrong direction?
https://news.ycombinator.com/item?id=49586189
Let me take this opportunity to remind HN readers - Posture & Hydration Check!
You are reminding to this very community the notion of cybernetics.
Or: drink when you feel thirsty and change your position when your back gets tired.
Yes, the science has moved to "drink when you're thirsty" a long time ago and it's annoying how many people believe drinking 3 liters of water per day is a key tenant of human health.
(most of) Our bodies are quite good at telling us when we should drink more water. You should never be forcing yourself to drink
https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-mi...
https://www.medicalnewstoday.com/articles/313389
All that being said, I'm not sure GP was necessarily endorsing the idea that you should drink a certain amount of water a day. I read it as a suggestion to pull away from the screen and listen to your body
But why? unless it’s a copious amount of water like a gallon or more in an hour or two or something insane like that what is the problem with drinking water? I would assume it would just have positive effects.
> "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
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").