Tall trees

 I am writing a science fiction story, where the trees can grow as tall as 244 meters tall which makes them almost three times as tall as the tallest tree on Earth.  The gravity and atmosphere is about the same.  The climate is about the same.    My question is; What kind of structure would the tree have to have in order to reach that height.   What would the width of a tree like that be.   They reach the end of their lives at 244 to 250 meters then slowly die out.  The wood of the tree is very expensive and only one tree a year can be cut down, and only if there is a tree that has reached its turning point.  So all the trees that are eligible are marked  for cutting with a maturity date.   The first rule of writing is "Don't insult the reader."  Okay the average person would say "Okay its an 800 foot tall tree."  however, there are those out there that will say, "impossible"  So I'm going to ask the botanist in here to think outside of the box.  My explorer botanist is saying "Impossible."  while the obvious is pointed out.  "Yet there they stand."  So what would you look for in a tree that tall?  What would you expect to find if you encountered a three that is 244 meters tall?   If you think I am asking you the impossible just wait until I start bugging limber jacks about how to cut down a tree that size without damaging it.  

I'd be asking myself how the tree got water up to the top leaves.  I think it's generally considered that the mechanisms currently used can only raise it to a max height of around 120 metres.

This article summarises it quite nicely - water rising.

This video summarises the 'what' but not the 'how', despite the title.  It might inspire you though.




This video has a bit more of the science.




This explains the problems pretty well too.



That should give you some food for thought.  Enjoy!

As an aside, if I saw a tree that tall, I'd also be asking myself

'Why does it need to be that tall?  
What possible benefit could there be to the tree that would make it worth all the extra work of getting that big?'
Is it something to do with spreading seeds or pollen?  Or attracting pollinators?
Or have they been artificially selected, which would mean I'm almost literally barking up the wrong tree?

This is actually a very interesting topic and incidentally I am a logger (not really called lumberjacks anymore, but I am hardly offended by the term).

The first thing to know is that trees are roughly made of thirds, so its crown will be about 1/3 (leaves or boughs) will be about 1/3 its height, so in your case about 250 feet wide. From ground to the crown, the trunk (also called the bole) semi-self-prunes on bigger trees as the crown shades out the light and so you get the main part of the tree free of branches. The last third part of the tree is the root system and is about as big as the crown, you just cannot see the vast network of roots. However, the roots may, or may not go deep, it all depends upon what they have for soil, and what kind of tree it is. It does not matter if it is a softwood or hardwood, some are easily to stump like apple trees which have such shallow roots a person can practically push them over. That is not going to happen with an Ash though which puts a tap root into hades that lucifer grips ahold of when I push on them with my bulldozer! White pine are very similar, but an eastern hemlock 3 feet through will push out easier then a ten inch White Pine. Regardless, the roots are in a diameter under the tree about the same diameter as the crown. They call this the "dripline" which is readily seen on a misty day. The circle where the dry area under the tree starts is about where the tree roots start, so again, about 250 feet in your tree.

Now on to the fun stuff like dropping a massive tree without ruining it. This depends on how you want to fell the tree. You could write about a massive machine that fells the and delimbs the tree called a Feller-Buncher, but honestly they are more suited for numerous, but smaller trees. In the logging business, the big trees are still hand felled by chainsaw. Because of your selective thinning requirement, I assume you are talking about hand felling trees with chainsaw.

For this we have to go back in history on how that very thing was done! Obviously you can go with handsaw and axe, or a very big chainsaw. For a massive chainsaw, you would only need the saw to be a two person saw with one guy holding the bar end of the sawblade, and the other guy holding the engine. Old chainsaws were two person saws!

Chainsaw or with axe and crosscut saw, the tree first must have a pie shaped cut in it in the direction it will fall towards. In the old days this was a flat bottom cut with a 45 degree top cut, made about 1/3 of the way through the tree. Today we do it a bit different and make a 20 degree bottom cut sloping upwards, and then a top cut going down at a 70 degree angle. This is called the open faced notch and a lot id on the web about it as it is much safer for loggers to employee.

With either type of notch, a level backcut is made on the back of the tree with a saw, a small wedge tapped in, then it forces the tree to fall in the direction of the notch. Keep in mind, an inch of lift by a wedge at the bottom of the tree, would pitch a 800 foot tree by fifty feet or more at the top. As soon as the center of gravity of a tree is changed enough, it starts falling by itself.

But how would a logger keep the tree from shattering after falling so far and with so much kinetic energy (about 120 mph from 800 ft)? Easily, by doing what they did back in the 1600-1700's here in Maine when ships masts were cut for the Kings Navy. Loggers would cut all matter of smaller trees, make cribbing and would pile it all in front of where the big tree was to land. Basically it was a big brushy, cushion of inferior trees that would absorb the impact when the tree landed.

Here is one part of your book though that you may not have thought of. Beyond the requirement of using massive equipment/or hundreds of oxen to move the massive tree to a river where it could be floated to a sawmill, an 800 foot tree will take a wide swing on any turn. Today in Maine, many towns that were close to rivers or shipbuilding ports like the town of Union Maine, or Gardner, Maine, had town centers. These were not parks, they were devoid of any trees or buildings so that as the masts came through town, they can be swung around corners. Today trees have grown up and gazebos put in, but that is why these triangular parks are there.

Now this has been a ton of writing so I will stop here, but I look forward to answering any other questions you may have.

Oh, do not forget about the water table.

When I clear forest into fields on my farm, automatically the water table rises. Why? because trees are mostly made out of water and are sucking up a lot of it. It is no different then watering a garden. It takes a lot less water to get crops in the garden to grow when they are seedlings then when they are fully grown. Now think about an acre of forest with a hundred trees 60 feet tall, that is a lot of stored water. A lot of water pulled from the ground to keep those leaves and boughs green. That is why redwoods are growing in the wet Northwest, and why White Pine in Maine on grows on the most fertile soil.

How about this scenario:

The trees require higher levels of UV radiation to grow, UV increases by 4% for every 300 metres in altitude.

Buttress roots help support its mass, and pendulous leaves on the upper branches don't act like a sail, so they are also somewhat wind resistant.

The trees are not deciduous as energy expenditure would be too high. Perhaps it sheds its bark like some eucalypts to aid growth, prevent disease, add photosynthesis and to feed the forest below.

I would suggest some sybiotic fungal relationship(s).

Perhaps a fungus, or a complex of interacting fungi, inhabit the bark layers of the tree, recycling the nutrients of the constantly decaying outer layers of bark for the tree, perhaps interacting with and supporting species of moss where it's humid enough, and lichen higher up, where it isn't, that do things for the tree like photosynthesize sunlight into food.

The maximum height to which the tree can pump water is also an issue. Perhaps the lichens in the crown could collect moisture from the air, or perhaps they and the fungi could act as living wicking membranes within the bark.

Perhaps these trees are actually giant fruiting bodies of an enormous subterranean fungus. Or are these tree-borgs (cybernetic trees, technologically enhanced after germination with, I don't know, semi-sentient nanobot colonies or something, acting as another cognitive/neural layer)?

Great ideas so far. Keep them coming.

-CK

Science fiction gives us tremendous latitude. On our planet it is fairly clear that plants evolved in a specific way. Though if you go back to unicellular plants there are some motile algaes which transcend the differences between what is plant and animal. So on earth immobile creatures ultimately became multicellular plants without any muscles or moving parts such as we know in animals. So as someone explained our plants use mechanisms to transport water that use largely the physics of small tubes, though some may have active transport workarounds of some kind. Our plants are subject to such things as catastrophic cavitation of the phloem.

An alien plant on another planet might not have the same limitations. Evolution of plants on the alien world may have gone differently. So an alien plant might have a moving pump, or pumps. What we think of as hearts in animals. These plants with pumps need not be much different from ours, but imagine if the phloem were more like blood vessels than straight tubes and a network of tiny pumps were interconnected to it. Imagine if the liquid inside was more like blood than sap and had platelets to clot wound and white blood cells to attack pathogens.

Genetic engineering has some potential to rewrite evolution as well. At the current time we are transitioning from the ability to transfer a few genes crudely to the ability to rewrite genes. These transfers and rewrites have the potential to transcend all evolutionary history. Artificial chromosomes and entirely artificial organisms have been proposed. So in science fiction these possibilities can be massively advanced from anthing we do now. So we could with future technology perhaps give a tree a water transport system derived from animal systems.

What structural elements allow a building or monument to stand taller than the tallest trees? Evolution has been pretty good at developing some amazing architectural structures like bird bones and bamboo. As long as physics allows it, it seems to me that a taller tree could be possible, and if possible, assuming there is alien life, might be found somewhere.

So I would check heights on tallest buildings vs. Tallest trees. Research what tall buildings have that trees dont. Then I would pick a back story as to what alternate mechanism these trees had to transport water and where that mechanism came from- alien lineage or engineered lineage though these two possibilities are not incompatible as an alien society might have advanced engineering capabilities.

Also, living things as we know them might be quite different on another planet or in another time. Technology and life might be combinable. Think nanobots meshed with living cells. Does the tree have DNA as we know it? Or could its genetic information be silicon in nature? Blood cells or nanobots? Does a tree have to be made of cellulose or could its trunk be made of silica and steel? What is the density and structure of the wood? Think of how different a hollow elderberry stem, a bamboo stem, a tree cactus stem, and a oak or pine stem are. A tree size plant might have some unexplored structural options. A extraordinarily tall tree might have some structures we don't find in our current tall trees.

To address the water problem, the leaves could be tattered and shredded by wind (which would reduce wind resistance); this increases surface area so the leaves collect water from fog/mists. There is a beach/desert plant that does this, but my Google-fu fails me right now.

For strength, the trees could grow as colonies with connected roots.

I wonder if it's a species like the strangler fig which starts life in another tree and then grows both up and down.  Maybe it even grows with a symbiotic species (I'm thinking shelf fungus forming shallow basins) that helps catch and store water where special roots can gather it for the upper reaches of the canopy.

Since a wooden building  could  theoretically be even taller, it's the why of it and the how of nutrient/water movement that needs to be answered.
Plants can be bred to do things they otherwise would not, so sentient interference is an option.
Perhaps there are nutrients 244 meters up that are not available lower down.
Perhaps the tree aspirates moisture and collects other nutrients via a fine sieve of leaf, or leaf like structures.
They might be filter feeders.
Check out Larry Niven's Integral Trees.

Are these proper trees,  or do they just look like trees?
Are they fungus,  or maybe a hybrid organism?

What is the planet like? Is the gravity the same as the Earth? What about wind speeds? Storms like ours or more massive? Rainfall?

Slow growing trees tend to have stronger wood. Maybe these trees are extremely ancient.

If they need to get that tall for some reason, you might need to explain how they survive until they get tall, unless the height is just for pollination or seed dispersal.

Paring down the alien origin idea, it is even possible that trees from Earth grown out to evolve on a superearth, as in similar environmental conditions, but with greater gravity, might evolve to adapt to their new environment.

Potentially, by the time those genes have evolved to grow to their Earth height under increased gravity, seeds from those trees might gain adaptations that cause them to surpass the species' original limitations when returned to Earth.

When is this story being told?

I don't see a fixed limit.
As far as water transportation is concerned, at the cellular scale, the physical laws for water as we know it are not quite applicable any more. Effects that are irrelevant at our scale become effective: electrostatic force, friction…
Why would a tree not have a series of pumps? It could also be hollow, evaporate water at the bottom and collect the condensate at the top …

And why would the tree grow that tall?

I think you are going to want to research coast Redwoods and Douglas fir morphology, as these are the tallest species we have records for. The tallest living tree, a 379ft Redwood, is less than ten miles from my house. The tallest tree ever felled and fairly reliably measured was 426ft, in western Washington during the logging boom. We have evidence of coast Redwoods twice the volume of the largest current coast redwood trees, which would make it half again larger than the Sherman tree (a sequoia).

Coast Redwoods trees are generally at their tallest relatively early in life (300-500yrs), as they shoot up to join the canopy around them and compete for light, and as the go above the canopy of older, weathered trees around them their tops get shorn off by wind, lightning or dessicate in the wind. “He who sticks his head up above the crowd will be the first to be decapitated” (old Norwegian saying). So generally the largest trees are of similar heights in a given grove. Where the worlds tallest tree lives, the canopy averages 325ft. A good question was raised in “why would trees need to get so tall?” (800ft) In the case of Redwoods, they grow around several of the other tallest species on earth: Doug fir (1st-3rd depending on how you measure and consider old logging accounts); Sitka Spruce (4th); western hemlock (7th). If it were college football, Redwoods would be like Alabama in the SEC, competing with the best in an environment that is ideal for growing conifers. For non US folk, coastal Northern California is the Champions League of tall trees. Western hemlocks can reach 270ft tall but have to be the most shade tolerant tree in North America to grow as midstory tree here. So your biggest trees are going to need light competition to drive them to adapt and evolve into the absurd obelisks of your imagination. Another thing to consider is that the tallest and oldest trees are all perfectly straight up and down. Any lean gets impossible to hold up with such height and mass. So your super tall trees would benefit from an evolved self balancing strategy.

Also, cork screwing of wood makes trees stronger in the wind and spiraling cambium/xylem eases the strain of siphoning upwards of 4000lbs/500gal of water up 350+ft.

Another factor in height of all the tallest trees is that they all tend to grow in places where ridgelines run perpendicular to prevailing windstorms. The largest trees in the Redwoods and Olympics mostly grow in valleys that run perpendicular to the Southwesterly storms.

They also grow on 1000yr+ terraces, where only once in a millennia floods barely reach, but in doing so drop immense volumes of sediment to fertilize their growth.  They are close enough to constant water flow for their furthest roots (75-200ft from trunk) to reach the water table. The largest redwoods also tend to be surrounded by three sides by a stream, safely up on a terrace on a peninsula at a river bend that drops silt or a between two streams at a confluence.

I hypothesize a positive feedback loop occurs in these places supporting the largest, longest lived trees. Over millenia, these largest trees are especially effective in stabilizing their environment, even the geology and climate around them. In the case of extensive tracts of old coast Redwoods, they even make the area invulnerable to catastrophic fire.

This place also has the highest biomass/acre on earth (on land at least).  And these trees are growing faster now than at any point in their lives. Redwood trunks only die “of old age” when their heartwood overtakes the cambium layer. This happens because heartwood increases at a slightly higher exponential rate than the sapwood and cambium. This limits a single trunk’s lifespan to 2000-2500yrs, but the root system of coast Redwoods survive indefinitely and reiterate new trunks from roots, burls and even branches of the fallen trunk. If in a redwood forest, look for trees of similar size/age in lines and circles, as these are likely all the same tree. Like fingers on a giant giant’s hand, and you are standing in the palm.

The redwood forest’s limiting growth factor is  nitrogen fixated mostly by fungus, so nitrogen and carbon cycling is also at peak efficiency with the extremely slow decomposition of redwood. A loss of salmon nutrients has also likely slowed their growth rates. I would bet your 800ft trees would also have to get some anadromous fish feeding them ocean-based nutrients.

As much as the biology and morphology will be interesting to make sense of, I think your outlines forestry model would bring up fascinating socio-economic-political dynamics. It is hard for people who move here to the Redwoods because of the forests' beauty and benefits to understand how our predecessors rationalized the plundering and bargain basement sell off of the most productive and abundant ecosystem on earth to bring us to our current economically depressed state. The Talowa and Yurok lived here for upwards of ten thousand years at a higher population density than we have currently. They left us the world's greatest forests and immense salmon runs. How and why did our predecessors destroy it so quickly? How would they answer their grandchildren’s questions and complaints about the economic and ecological mess left behind? How would a society like that you describe for your book which has figured out that cutting too many trees is a bad idea rationalize cutting one of the lost magnificent living things on earth, and for whose benefit? Would it be tied to hospital and school funding like it is now?

Great idea for a book, good luck!

Wow a lot of good feed back.  I wasn't expecting so much.  I especially like the lesson on how to cut a tree down.   He brought up points that I never even considered.  It is not just a matter of cutting the tree down but once it is cut down then there is the problem of moving it.  So I have that figured out.  I'll just fly it out of there with a series of rotor blades attached to the tree itself.  Then remotely guided.  As for the cradle instead of cutting down a bunch of trees it could be an erected cradle that would catch the tree as it fell. As for the location it is a rain forest and the reason it grows so tall is competition.  The water supply is a problem but I think I have a way around it.  Catch basins that catch and collect water.   Either through condensation or rainfall.  The larger the tree the bigger the catch basin.  That also gives me some other ideas about the life forms that live in and around the trees.   Thanks for all the great feed back this really will help.  Still when it actually comes to cutting this thing down I'm going to have to do some homework.  

Someone ask what the planet was like.  One of the reasons the planet was picked for colonization was because the planets environment is almost identical to Earths.   Colonization was limited to only a half a million people.  Because the environment is so much like earth it was perfect for transplanting earth species that were on the verge going extinct.  Both plant and animal.  The tree is not a transplant but a native species indigenous to the planet.  Even the animals on the planet while odd are not all that exotic.  It even has an equivalent of a humanoid.  Slightly smaller, with pointed ears and longer canines to tear at roots and fruit rinds.   Thus the rub.  

 I also understand that being science fiction there is some leeway what I can or can't get away with.  Still I would like my planet to be as realistic as possible as well as not insult the reader botanist. and the people who cut down trees for a living.    

Ok I know I am resurrecting a three year old thread about a fictional topic, but it is a neat thread, and I am curious how this book went, and I also have some ideas about theoretical limits of tree growth.

Some of the world's largest organisms are fungi. The so-called "Humongous Fungus" Armillaria ostoyae in the Malheur National Forest in Oregon is well over 2000 acres in size, and possibly much bigger. It is thousands of years old, and is slowly growing and slowly surrounding and digesting entire forests. In the Upper Peninsula of Michigan there is an Armillaria gallica fungus that is pretty big as well. These fungi require skilled and educated experts to identify and locate. It is well within reason that other bigger ones could easily exist in other humid, wooded, remote environments in Canada, Siberia, Brazil, and other such places. Possibly magnitudes bigger.

In the plant kingdom there is the Pando, an enormous Aspen colony in Utah that is over 100 acres and is considered to be the heaviest living thing in the world and also the oldest. Again, it is not hard to imagine a bigger one somewhere else in the world that hasn't been formally identified yet.

Using these strange kinds of organisms as a foundation, I am imagining the sci-fi trees to be a combination of tree and hill, and not ordinary trees.

I have Tulip trees Liriodendron tulipifera in my woods. They are the tallest east coast trees in the USA, and they are known to suck up lots of minerals into their trunks. They run straight up quickly and draw enough minerals to stain the wood and dull my chainsaw prematurely.

So imagine a plant like the Pando Aspen Colony growing on an enormous fungus that is itself bedded into a geological formation that mixes sandstone and clay over a solid granite bedrock. The fungus slowly grows over the centuries, and since it cannot grow any deeper than the granite bedrock, it slowly bulges upwards, creating a rising mound. This fungus is symbiotic with the tree's biology, and slowly feeds it a mixture of sandstone and clay, which the tree pulls upwards, giving it a nearly concrete hardness, especially at its base. (Try mixing sand into heavy clay soil and see what happens). So the tree is growing upwards and pulling sand and clay into its trunk, giving it a kind of concrete foundation from which to grow, like a skyscraper. Meanwhile the fungus is slowly thrusting upwards while also fertilizing the tree.

Fungi are naturally aggressive towards wood, so this tree must continuously be growing at a faster rate than the fungus can digest. It is a symbiotic competitive relationship. The more the tree roots grow, the more the fungus consumes, the more the tree must grow, etc...

So the tree is continuously stretching its roots to stay ahead of the fungus, and the roots are continuously feeding the tree more and more. It has nowhere to go but up. It is not racing for sun dominance like an ordinary tree, but racing for its life. Meanwhile the fungus is slowly pushing up around its trunk. After several centuries of this race the trunk might be buried in a few hundred feet of fungal soil, but since it is solid, healthy, and growing this part of the trunk still counts as a trunk, and it is a solid half concrete, half wood foundation for a tree that is continuously being challenged to grow. Basically a living and growing petrified tree. The vigorous roots are constantly stressed and growing, always pulling more and more nutrients upwards, forcing the tree to stretch higher and higher. The rising base of fungal soil around the trunk makes it easier for the tree to draw water higher, and the constant flow of minerals into the wood hardens the trunk against the fungus.

Felling a tree under these circumstances would require excavation work, since the base of the trunk is actually underground, but the benefit of it is that the top of the tree, when it is felled, does not actually have to fall the entire distance down, because even though it may be a thousand feet tall, it might be only 600 feet above the ground level, and the excavators can pile the remaining fungal soil in a kind of ramp to catch the falling treetop.

To cut a tree that is half petrified would require a different kind of chainsaw, perhaps something more like a concrete saw, or a controlled dynamite ring at the base.

Ok, I know there is no point to this, and the book is probably written by now. But reading the thread got me thinking and I couldn't help myself.  OP, if you are still out there, did you ever finish the book? Is it available anywhere? Did you utilize any of the ideas here?

Sources of imagination:
Humongous Fungus in Oregon - https://www.scientificamerican.com/article/strange-but-true-largest-organism-is-fungus/
Very Big But Not Humongous Fungus in Upper Peninsula - https://www.livescience.com/64343-humongous-fungus-in-michigan.html
Pando Aspen Colony (with beautiful pictures)- https://thetreeographer.com/2017/11/22/pando-aspen/
Trees in Yellowstone that suck up silica/sand through their trunks https://onlinelibrary.wiley.com/doi/full/10.1111/pala.12480