Why can't my huge trees be chopped down?

Question

In my world there is a forest of huge trees which people can't or won't chop down. The trees are similar to redwood trees but they have a large crown and no lower branches. The forest is quite dark because the trees block out most of the sun. Due to the low light-levels, barely anything grows on the forest floor.

People are scared of the dark forest so it has become a refuge for bandits and other criminals. The forest is habitable but growing food that requires sunlight is impossible.

There is no cultural reason the trees are unable to be harvested, people have tried for a very long time. There is clear motivation to harvest the trees as the wood is highly valuable.

My world is inhabited by humans with roughly 11th to 15th century technology but no gunpowder.

The older trees are the size of the trees in the picture and the forest floor looks similar to the picture.

Answer 1

The most likely reason would be that they simply don't have anything that can cut them in your scenario.

You say that the trees are highly valuable, so there's a high motivation to cut them down. This suggests that no matter how difficult it is, the reward is worth it. So, the only other possible reason to not be able to cut them down is going to be technology.

In the 11th to 15th centuries, metallurgy was nowhere near as advanced today. Your best bet would be to make it so that their metallurgy is on the much lower end of what we could do during the same timeframe. Namely, that they cannot produce a steel hard enough, yet flexible enough, to cut the trees without breaking their teeth. You could make the problem even more difficult for them by assuming that the wood of these particular trees is extremely hard and dense, something like teakwood in our world, but of an even higher level. If you want to get very fantastical, you could even say the trees' wood is a form of carbon that is like diamond (or is diamond itself), and thus extremely hard.

So here is a possible scenario for you:

• The trees are extremely hard and dense. This is because they need to be to support their immense height and mass. The locals have taken to calling them "diamondwood" because they're "hard as diamonds." This makes their wood highly valuable for all sorts of construction.
• Unfortunately, the trees are hardest when they're alive, and the poor knowledge of how to make good steel means your civilization is limited to either very soft or very brittle iron products.
• Many have tried to cut the trees, but their diamond skin either immediately bends the teeth of their saws (for soft steels), or strips them off completely (for hard steels).
• Because of this, the only way they've been able to harvest diamondwood is to wait for a tree to fall naturally and dry for several months. This makes the wood soft enough to cut, but still strong enough to be valuable.
• The wood-hunters who look for these trees often have valuables on them that the bandits want to rob them of, so they're forced to hire bodyguards for protection.

Answer 2

Underneath the outer cork-like layer of bark, the trees have a second foam-like layer. The cells of this layer are filled with a volatile liquid (in the chemistry sense - meaning it evaporates easily) which the tree uses to help boost water and nutrients up to the crown.

Unfortunately for your would-be loggers, this liquid, once it evaporates into a gas, has some interesting side effects. Hallucinations, et cetera. Combined with the slight hiss of the outgassing liquid, this convinces everyone near a damaged (i.e. cut) tree that they are under attack by snake demons, and run away in fear!

The tree is then free to heal its small nick in peace.

Answer 3

People get the wood. The trees are cut. They are just not cut down. There is no need to cut them down.

Your forest is a pollard forest.

https://en.wikipedia.org/wiki/Pollarding

Pollarding, a pruning system involving the removal of the upper branches of a tree, promotes a dense head of foliage and branches. In ancient Rome, Propertius mentioned pollarding during the 1st century BCE.[1] The practice occurred commonly in Europe since medieval times, and takes place today in urban areas worldwide, primarily to maintain trees at a determined height.[2]

Traditionally, people pollarded trees for one of two reasons: for fodder to feed livestock or for wood...

The trunks of these trees are huge and very difficult to handle with the tech available. But upper branches are the size of normal trees and can be dealt with. Woodcutters ascend to the crown and cut tree sized branches, which fall to earth and are hauled away: pollarding. The loss of some branches is not a big deal to a tree this size. Some trees have ladders installed on them to facilitate repeat collection of branches from the same tree.

Plus, as with pollard forests, branches are a sustainable resource. The tree will grow them back.

Answer 4

Diseases or toxins

Maybe the forest is a hazardous place due to various diseases thriving in local flora or fauna for example Malaria mosquitos. Bandits would not be immune, but well maybe they have little other choice than to soldier on.

Or the trees are dangerous. Perhaps there's no problem if you leave the trees alone, but if you start chopping them down they release various toxins that kill people. Similar to how bronze smiths in ancient Egypt would often die due to arsenic poisoning (they inhaled the fumes). That way whilst the wood might be very valuable, it would also be a pretty big health risk for the woodchoppers and carpenters. The end users would probably be safe as they wouldn't inhale any saw dust.

That said this would make the trees known as the trees that kill people. Perhaps people will even think of them as cursed.

Answer 5

Cutting a tree down is just the first step, then you need to remove the wood from the cutting place and move it to somewhere else, be it the place where it will be used or a place where it can be disposed of.

Already cutting down such a large tree is challenging for the tech period you have specified, then, once it is on the ground, you need to cut it in smaller pieces and transport it. It is a logistic nightmare if you don't have roads and means of transportation.

Long story short, there is not advantage in cutting them down: smaller trees are easier to handle.

Answer 6

Lack of industrialisation

The trees are too big to be handled without a large team of people and draft animals. There's no river nearby to float them down. The tools required to efficiently cut one down are too expensive for your average woodcutter. The wood is too hard to be valuable for day to day use and it doesn't burn well. They're not blocking the route between important locations. The land they're on is not particularly good for farming. There's no task that requires a tree of that size.

There's just no good reason to try cutting them down and no way of handling them once cut. In fact they'd be more of a problem once down than they are up.

Answer 7

Dangerous animals live in the tree canopy. They won't bother humans if the tree is left alone, but if they sense their home is being threatened, they will attack. If their home is destroyed, the homeless ones will go berserk and go on a killing rampage until they are put down. These animals could be anything. Tree-dwelling grizzly bears. Giant killer owls. Extremely venomous wasps. But if dozens of humans get mauled/pecked/poisoned to death every time a tree gets cut down, that's not going to be worth it despite the value of the wood.

Answer 8

Similar to @Chronocidal's answer, but instead of volatile liquid enclosed in cork-like outer layer, make the tree's interior high pressure near the base because of the weight of the tree pressing down upon it. Now make the outer layer brittle and prone to shatter into sharp aerodynamic splinters. First touch of a sawtooth to that brittle bark and the whole tree goes off like a 360 degree claymore mine.

The villagers tried to cut down a tree once... exactly once.

Answer 9

There is clear motivation to harvest the trees as the wood is highly valuable.

I assume then, that some of these trees have been and can be harvested, so.

The trees are sticky.

These massive trees contain an equally massive amount of exceptionally viscous, extremely sticky sap, which oozes out after you break through the hard bark. The sap is tougher and thicker than tar, and once it sticks to something, it's stronger than super glue. Trying your saw or axe on one of these trees is as good as throwing it off a cliff: you'll never get it back, no matter how hard you yank on it. It's dangerous to even attempt to harvest one, lest your arm or leg get caught up in the sap, leaving you an amputee.

This also makes for a really cool visual, with broken axe heads, saw blades, and human bones protruding from the bottoms of trees at odd angles.

No known solvents or substances seem to be able to dissolve any substantial amount of the sap, leaving only one option for harvest.

When an ancient one of these trees finally dies and falls, it remains unharvestable for a year or so. The wood only becomes safe to cut once all the sap hardens into a rosin-like substance, which can be chipped away with pickaxes. This natural scarcity, combined with the hardness, supple texture, and rich color of the wood makes it highly sought-after by nobles the world over (and drives many a young woodsman to forfeit his first axe, dreaming of riches). It also serves to explain the roving bandits, who patrol their territory of the woods, waiting for new trees to fall, guarding their claims and even fighting over trees that haven't quite dried out yet...

Answer 10

The trees have guardians.

The forest is inhabited by 9ft. tall (~3 meters) primates, much stronger and tougher than humans. There are large numbers of them. Those beings are herbivores, and will leave humans to their own devices most of the time.

It just happens that the tree sap smells exactly like the pheromone the females release when they are in heat. That drives the males into a mating frenzy. They can smell it from miles away.

When a female releases the pheromone, the males will turn the attention to that particular female, which will be both:

• accepting;
• able to withstand the male's hard... er, love.

When the smell is coming from the tree sap, though, it is because an oblivious human has driven a axe into the trunk of a tree, and the human is usually neither accepting the giant primate males' love, nor tenacious enough to receive it unharmed.

Anyway, the mating frenzy of the males makes it impossible to cut a tree. Every other generation there is an idiot who doesn't heed the warnings and tries to take down a tree. They become "those who can never sit again", serving as living warnings to the rest of the tribe.

Answer 11

Toxins, a different approach:

When cut the trees release a slow toxin. This manifests as homicidal madness after a while. Given the lag between exposure and insanity it isn't realize it's a toxin and thus they don't even try to block it. (Which doesn't work very well, anyway, as it's gaseous and works through skin contact. You need chemical warfare gear to survive it, something that doesn't exist at your tech level.)

Answer 12

The trees are alive and conscious. Think Narnia trees that are awake.

Humans walking around are just like ants on their toes. They ignore them.

But as soon as humans start a nick in the skin of the tree, they become quite vicious, (like humans once they detect a mosquito). They could use their roots or branches.

Every time humans tried to cut a tree, no one returned. Even the bandits inside the forest died because the trees are quite paranoid. So now, the bandits protect the trees fiercely.

Answer 13

The wood is only valuable if the tree dies of natural causes.

At the end of the life of the tree, some chemical process makes the wood extra strong. If you cut it down earlier, you get only normal wood.
So there is no incentive to cut the trees early because you risk that the wood becomes worthless and you also don't want to cut them down for space because then you wouldn't get the expensive wood later.

Answer 14

It just isn't economical

The trees have a very expansive branch network, and the branches of nearby trees are interwoven. Since those interwoven branches are also very strong, they are able to support the weight of the tree even if the base is removed.

If someone wants to cut down such a tree, they have to, after cutting it down at its base, go along the upper half of its trunk and cut down the branches that are now keeping the tree upright. If you have a team of experienced loggers that are also experienced alpinists, this process still takes multiple days, and is filled with casualties. And you have to pay a lot of money to get a team of professionals to do something that will kill at least a few of them in the timespan of a few days.

Furthermore, the expensive equipment used for climbing the trees, and the expensive lumber that is up for grabs at the end of the process attracts all kinds of bandits, so you have to pay through the nose for security too.

When getting it out of the forest, you can't even rotate the trunk because other giant trees would get in the way, so you'd have to drag something that weighs a few hundred tons in the direction that it fell, even if the terrain in that direction isn't favorable. So you have to cut it up into smaller pieces, which reduces its value. That also requires labour, and the labour has to be at least somewhat qualified, to prevent ruining the wood.

After all that is taken care of, you have a sizeable workforce of at least a few dozen people, most likely more, that still needs to be fed, and the encampment isn't anywhere where food can be grown (it's dark in the forest). So you also have to import food (and other things required for living) for them, and the caravan also needs protection because of bandits.

Answer 15

They can't be cut down because they're bottle rockets writ large. Their core is a form of solid rocket fuel. As long as an unripened tree is safely encased in their stony bark they're 99.99999% proof against being touched off unintentionally - even a direct lightning strike is unlikely to affect them - and if it does it'll most likely cause them to "blow up on the pad", leaving a huge clearing in the forest. But when one gets fully ripe and the right conditions occur the tree will self-ignite, rise to great altitude, and then explode, scattering its seeds to the winds - and in the case of exceptionally large trees, to the stars.

However, if one dies and falls naturally, after a few years the volatile components of the fuel will evaporate or be chemically neutralized, rendering them (relatively) safe to handle and hardening the "wood".

Naturally, in the past the unknowing and the foolhardy have attempted to harvest the standing trees. They've generally died in a large explosion or, in rare cases, by being baked in the exhaust of a successful launch. After a while the standing trees are seen as "cursed" by the natives, who avoid them like a flaming plague from hell (which, in a way, they are).

See Larry Niven's classic story "A Relic of the Empire".

Answer 16

Gain to effort ratio is very low.
You would need to cut those trees. We know from historic videos like This recording of cutting down trees in 1940 it was a large logistic setup before. And from old photos we know it took dozens of men to cut those gigantic ones tree with "analog" equipment.

Using same equipment a "triad" of workers could cut in one day a truckload of trees. As shown in this video Logging in 1950s Georgia . Which produced much more workable wood. Easier to cut into planks, fire wood, building materials. Also because of the size it's easier to use smaller tools to work with them. Smaller axes, smaller saws. And that means those tools could be used in much more occasions. Cutting axe could be also used to split firewood. Handsaw could be use to cut planks to desired size.
Which means there was less resources wasted.

Also if you look into Europe almost every big tree is equalled to old one and old big tree usually have some legend behind them to why they are so old and big. And that legend itself prevent people from cutting them down.

Answer 17

BAD things happen to anyone who threatens these trees!

Upon examination, it's clear from scars and regrowth that there have been attempts to cut down a few of these trees, over the years. Less clear is who made those attempts and whether any of the gruesome stories or songs have any factual basis. If you're foolish enough to bring an axe near these trees, you'd better have everything you need to survive until you're well clear of the forest -- and excellent defensive skills.

Although there's not, in fact, much honor among thieves, there is a ruthless pragmatism to their actions. In this forest, if you're seen to threaten a tree with axe or fire, you're bringing a painful, remorseless death on yourself and anybody near you. And if you're lucky, the human residents of the forest will kill you relatively quickly.

If you're still foolish enough to persist, study parasitic wasps from Old Earth and see the Earther flat-film called "Alien." Trust me, you really don't want to meet the special seeds these trees can produce when they feel they need to; it's a long and agonizing final career to be 'volunteered' to be a host of a new tree.

Enjoy your stay in the forest.

Answer 18

I remember a story in Analog years ago about a colony on a planet with huge trees of beautiful, very strong wood. The only practical way (in theory) to cut down the trees was with lasers (because they were so large -- saws were not practical), but the smoke produced when these tools were used was enough to block the laser beam almost immediately, so the trees, given the manufacturing capabilities of the colony, were effectively unfellable.

Answer 19

You pose an interesting question with a few intricacies as far as I can tell they are:

• Big Trees, that can't/shouldn't be cut down
• Dark scary forest where less reputable people has come to inhabit
• The people living there

THE TREES

In my world there is a forest of huge trees which people can't or won't chop down. The trees are similar to redwood trees but they have a large crown and no lower branches... People are scared of the dark forest...There is no cultural reason the trees are unable to be harvested, people have tried for a very long time. There is clear motivation to harvest the trees as the wood is highly valuable. My world is inhabited by humans with roughly 11th to 15th century technology but no gunpowder.

I take a few things from this, the trees are large and valuable, ok. What makes them valuable - in order to create the logistics to harvest them there would need to be an economic cause to do so. This leads into why they can't be harvest - if they were incredibly dense (like an Ironwood) they would be great for building large buildings (beams and the like) as well as furniture. Smaller pieces would be more easily managed even with the tech your world has readily available. However, they (without great effort) can't do so as it would take teams of workers to make it possible to man the tools, fell the trees and then subsequently delimb and transport them.

This leads into the next problem

Dark Scary Forest & The People Living There

...The trees are similar to redwood trees but they have a large crown and no lower branches. The forest is quite dark because the trees block out most of the sun... People are scared of the dark forest so it has become a refuge for bandits and other criminals. There is no cultural reason the trees are unable to be harvested, people have tried for a very long time...

You say there is no cultural reason that the trees cannot be harvested. It sounds like you have a blank canvas to create a cool sub-culture (see Robin Hood with Kevin Costner). This subculture could potentially create a small tree city and make it so the "outsiders" have cause to not come in asides from "that's where those scary people hide".

Additionally, if the trees are quite dense and strong, with some hard work these bandits could come together and make a city in the trees - cut the tops off the tress and have sunlight and suspended gardens (a landbased system based loosely from the Aztec people). This takes care of sustaining the "bad guys", culture and provides your reader with an understanding of why this wood is so valuable.

Taking into account all these things the economic need and demand for these trees should be too large to motivate some Lord or something to start trying to harvest them. This could be why, the can't be cut down not cultural but economic barriers.

Answer 20

Cones

Make your giant trees produce giant cones.

Anyone standing below the tree is prone to be hit by big, heavy and hard piece of its reproductive organ.

In addition, make in a way a heavy bang from an ax or the vibration from a saw makes dozens of those things fall at once making the lumberjack working area a very hazardous one.

Imagine the scene: A few lumberjacks are sawing the tree while observes are alert for fallen cones. One shouts "Incoming!" and the lumberjacks run for their lives while 50lbs pieces of hardwood fall like a deadly rain around the trunk.

Of course, they can send prisoners/slaves to try to hit the tree to deplete it from ammo but they can quickly run out of manpower making possible to just cut down one every few months/years. Quickly enough to keep the wood as a commodity but not fast enough to threaten the forest.

Scene: A few lumberjacks are using a lengthy saw and axes to try to cut down the immense trunk when an alert observer shouts "incoming!". In an instant dozen, men are running while a deadly rain of heavy hardwood fall around the trunk

Answer 21

Those aren't ordinary trees

As an alternate version of Chris Happy's answer, the trees are intelligent and powerfully telepathic. They don't mind when a human carts off a fallen tree or cuts down a standing dead one, but people who attempt to cut down a live tree are never heard from again.

Answer 22

Superstition is superstition. Culture is culture. Because there are many people that are superstitious of the number 13, or believe ghosts are haunting their pantry doesn't mean those beliefs are cultural values of a society. Culture is learned. Superstition is born of ignorance.

Who says the disease has to be non-existent? There could be a very real disease that the bandits have developed an immunity to. Since we are talking 11th-15th centuries, most disease was attributed to demons and such.

Answer 23

Or the trees fight back. Whomping willows come to mind...

Answer 24

Like the Acacia cornigera, your trees might have symbiotic relations with agressive, eusocial, territorial animals, like the acacia ants. These animals feed on the sap or some other product the trees make readily avaiable to them. In return, these animals, which we might call gardeners, protect the trees from herbivores and lumberjacks, vines and mistletoes, and destructively scour the surrounding ground for seedlings that could come to compete with their host trees if they were allowed to grow. The survival of the host trees is just about the same as the survival of the colony so these gardners will go to extreme lengths to protect their trees, sometimes even sacrificing themselves.