Floating forests: how realistic is this?

[Inevitability]

I felt like adding a rarely-seen biome to my world, and eventually arrived at the idea of massive, intertwined networks of plants floating high above the earth, each with its own complex ecosystem.

Of course, I need to justify such an otherworldly thing, and would like the Playground's feedback on my current explanation.

1. Hundreds of millions of years ago, a pitcher plant in a dry, nutrient-poor environment developed a symbiotic relationship with one or more species of acetic acid bacteria. The bacteria would feed on the sugars present in caught prey (which the plant cannot use themselves) and the produced CO₂ would be used by the plant for photosynthetic purposes (thereby reducing the amount of time the plant's stomata would have to be opened, and minimalizing the amount of water evaporated).

2. The plant, already evolved to produce hollow, cupped leaves, and incentivized to collect the gases the bacteria produce eventually mutates in a way that causes the created hydrogen to stay trapped within the leaves.

3. Over time, natural selection favors the plants with more and more holding space for gases. Eventually these plants become able to contain sufficient gas to completely support their own weight.

4. At the same time, the plants develop in an aerophytic organism that can get its water from the rain: they no longer need their roots for any purpose now. This allows it to focus on developing even larger air sacs and even bigger leaf surfaces.

5. Finally, the atrophied root-systems and lighter-than-air contents cause a number of plants to detach from the ground. Their new, skybound position, makes them more noticeable to insects, increasing the rate of nutrient absorption and hydrogen synthesis. Natural selection applies once more, preventing the plants from floating so high or low that it becomes detrimental.

6. The plants continue growing, and a soil-like material starts forming on their giant leaves, rife with insect waste, decaying matter, and rain water.

7. Another mutation, this one allowing the plants to seed their own dirt-plateaus. After all, there's less seed-eating creatures than on the surface. The newly grown plants also produce hydrogen, further increasing the size of the plant-networks. Networks composed of thousands of organisms begin to form, supporting great amounts of soil.

8. Eventually, the plants start developing in various separate species, and animals begin to inhabit the floating forests as well. They're mostly birdlike and insectoid, though there's a few bats that migrate to the new biomes as well. From there, a truly varied ecosystem begins to form, especially when their tendency to drift to places with varying temperatures and weather patterns is considered.


So, are there parts here that don't make sense? I don't care if it's unlikely, I'm trying to find out if it's possible.

[Mechalich]

Well, you have a giant organism floating on bags of hydrogen that is not, in any way, shielded/grounded. So, um, it gets struck by lightning and explodes.

Also, the reality of load-bearing using hydrogen in organic bags is going to be rather limited. Based on some zeppelin statistics, my back-of-the-envelop guess is that you need a cubic meter worth of gas storage for every kilogram of material you're lifting. Herbaceous plants are mostly water, which is fairly hefty. So for every cubic meter of volume you can only have around a liter's worth of plant matter, which lends the image of a giant gas-bag set of organisms that are mostly membrane and a bunch of vine-like connective tissue, sort of like a giant plant-jellyfish creation. Soil is even heavier, and would be a huge drain on lift resources, as would any woody material, which is much heavier and mostly not living.

There's also probably a stability issue. This organism or mix of organisms (again a large colonial jellyfish comes to mind) can probably only be so big before wind gusts overcome its ability to remain together. Zeppelin size seems reasonable, but the size of an entire landform is pushing it unless the bonds between the gasbags are somehow super-strong.

So, rather than soil, I'd probably keep your plants carnivorous or put them in a symbiotic relationship with floating filter-feeders that acquire organic matter from the air much like actual jellyfish - which would make them kind of like floating soft corals - in order to acquire essential nutrients. It wouldn't amount to a massive ecosystem on its own, but if these things existed in sufficient density, or moved about on the prevailing winds in pods of some kind they would certainly be a significant influence on ecosystems. The idea that they would support large numbers of arthropods and other animals (don't forget gastropods, flatworms, and the rest of the undergrowth assemblage) is quite reasonable but all such creatures would have to be very light. That doesn't mean they couldn't be massive - just very low density. However, because weight is at a premium, there's probably going to need to be some sort of active mechanism to slough off/consume waste rather than allowing it to accumulate, since that would bring your structure down.

[Nifft]

The incremental evolution seems unnecessarily convoluted.

Instead, have them evolve from seaweed, which IRL has already evolved sealed pods of lighter-than-water gas specifically for the purpose of flotation.

Now they don't need soil either: part of their migration path can travel over an ocean, and at various times of day / year / whatever they dip long roots into the ocean and extract whatever it is they want.

[denthor]

As a player do I care how it got there? NO!!!!


Can I adventure in kill loot make magic items? Yes. I am in let's go. Can I save someone? I am in. Is that where the adventures go ? I'm in. I do not care. Let us play and roll dice it is,a dice game.

Many DM lament that there players do not appreciate the time and effort that goes into the world. Some investigate till it is no fun have a little this is enough and then let your players decide how much they want to know

Now I have heard tale of players who want to know exactly where the nets are in the store, spoons plates vegetables are. So they can say I go to the southern part of store middle and grab and purchase from Gregson the merchant mean while I ask him if the chickens I ordered for the church have come in yet and I noticed you are out of beer in eastern corner when you next shipments due

Not me

[the_david]

As a player do I care how it got there? NO!!!!


Can I adventure in kill loot make magic items? Yes. I am in let's go. Can I save someone? I am in. Is that where the adventures go ? I'm in. I do not care. Let us play and roll dice it is,a dice game.

Many DM lament that there players do not appreciate the time and effort that goes into the world. Some investigate till it is no fun have a little this is enough and then let your players decide how much they want to know

Now I have heard tale of players who want to know exactly where the nets are in the store, spoons plates vegetables are. So they can say I go to the southern part of store middle and grab and purchase from Gregson the merchant mean while I ask him if the chickens I ordered for the church have come in yet and I noticed you are out of beer in eastern corner when you next shipments due

Not me

As player I'd like the DM to tell me what kind of wildlife lives in the region so I can select an appropriate animal companion. I'd like to know what kind of creatures are in the region so I can select a favored enemy that makes sense. I don't like my character to wield a meteor hammer if it's not a kind of weapon that is known in the region. When I play a cleric, I want him to have some support from a local church.

In other words, I do pay attention to the fluff. I find that it enhances roleplay.

But the floating forest may as well be created by some wizard. It's actually the foundation of the wizard's tower and the dungeon underneath it. The forest just sprouted up around the tower and once the wizard died there was nobody left to keep the wildlife in order. Harpies and other flying creatures have taken up residence in the forest and the dungeon.

Now I want to have a flying forest...

[khadgar567]

okay can some one dumb it out why setting has natural flying threes and no one put 2 and two together and invent the airships and all this evolutionary stuff feels unbaked so can you throw few monsters adapted to our flying islands so we can have background for islands

[sktarq]

Well I could see a few issues.

Firstly-if they rely on insects for nutrients to this extent these plants have to stay near large supplies of insects that fly high enough for them to eat. Which begs the question of how they manage to not blow away to areas that are not insect rich (like the ocean)

There seems to be a vulnerability for even minor browsing damage (from birds or tunneling insects) to cause gas leaks (either by hitting a big gas chamber or by basically fracking weakening the more diffuse structures)

You lightning issues. With explosives on board

There is also the practical issue of what happens when a plate clad, hobnail booted, sword swinging paladin steps onto the forest floor. At around 1kg/m^2 I would deem it likely that said paladin would rip his or her way right through the forest floor and fall out the bottom unless supermaterials are being widely used (which would be great reason to go) (gas bag walls repurposed as sailcloth for example)

[Yora]

The only realistic problem I see is floating in air. Which is probably going to be physically impossible. A little dose of magic should solve all problems here.

From a botanical perspective this all seems completely sound. If it were floating in water it would all work. Things like these actually exist in reality.

The incremental evolution seems unnecessarily convoluted.

Instead, have them evolve from seaweed, which IRL has already evolved sealed pods of lighter-than-water gas specifically for the purpose of flotation.

As a professional (apprentice) gardener (first year) that was also my first thought. Having a floating plant take off from water is evolutionary the much simpler and faster route.
Reproduction is also very easy. Most plants have highly decentralized organs that make it very easy to simply cut one in half and both halves continue living and growing without much complications. If you take a plant and "split it down in the middle" so to speak, With each half having all the parts that constitute a plant it's the easiest. But many times a leaf with a bit of stem can regrow new roots at the point where it was cut. That's how we produce almost all our plants at work. And there are cases where it only takes a piece of root or scrap of a leaf to grow a new plant.
The only downside to this is that the plants are genetically identical and there is no genetic exchange happening. However, this can easily be adressed by making the floating islands colonies of symbiotic plants, similar to lichens. When the constituent plants release spores they can land on other islands and germinate there, resulting in each island being actually made up of many different species. And then you can have seeds from regular terrestial plants being carried up on the islands by birds and then start growing there.

Moors actually don't have any earth anywhere near the surface. The entire soil is nothing but dead and simi-decayed moss. Not many plants can survive on such ground, but there's still a good number that have adapted to such conditions.

[Trekkin]

As an alternative to evolving from seaweed, you could always start with dandelions or other seeds scattered by wind. Gas cells on their seeds could increase their range without needing to be lighter than air or perfectly sealed; from there, incrementally better seals and bigger cells mean more spreading. At some point, that means carrying the bacteria themselves onboard. Then, since they're flying anyway, they might need to collect water in flight to stop them and their bacteria from drying out, and that starts them down the path to growing ever-larger in flight and therefore having a better chance of surviving wherever they land. Eventually these seeds, having evolved to grow in flight, just get better and better at flying until they can themselves spread seeds while airborne, at which point you have your floating forests.

That's how I would go about it, anyway; it involves fewer individual pressures and a more gradual change in selective pressure, so it'd sound more probable to me as a player. (You might also want to make the atmosphere much, much denser to make it possible for less balloon-shaped plants to float.)

[Admiral Squish]

While it's important to figure out the mechanism by which a floating forest would float, and put some cursory thought into how it got to be like that, I'd say you're probably overthinking it. If you show players a floating forest, they are likely not going to ask for the evolutionary progression of the flying plants.
That said, you're probably not going to make such a forest work via logical, scientific means, at least, not with existing science. Your best bet to justify it is some sort of unobtanium, be it a natural magic of the plants, some super-light gas, magnetic wood... Something.

I do think you should put some serious thought into what you want the forest to actually be like on the 'ground level'. It it just, like, a floating island you can walk on, so it's basically just a regular forest, but with a better view? Is it more like a network of trees connected by vines? Are there woody plants at all, or just leaves and fleshy vines?
One thing to consider is, the top of the floating forest is the most valuable real estate for photosynthesis, so you'll be looking at something like a rainforest's vertical biomes, with a dense canopy and shadowy lower layers.

[FreddyNoNose]

Obviously this is where Liftwood comes from!

https://en.wikipedia.org/wiki/Space:_1889

[denthor]

As player I'd like the DM to tell me what kind of wildlife lives in the region so I can select an appropriate animal companion. I'd like to know what kind of creatures are in the region so I can select a favored enemy that makes sense. I don't like my character to wield a meteor hammer if it's not a kind of weapon that is known in the region. When I play a cleric, I want him to have some support from a local church.

In other words, I do pay attention to the fluff. I find that it enhances roleplay.

But the floating forest may as well be created by some wizard. It's actually the foundation of the wizard's tower and the dungeon underneath it. The forest just sprouted up around the tower and once the wizard died there was nobody left to keep the wildlife in order. Harpies and other flying creatures have taken up residence in the forest and the dungeon.

Now I want to have a flying forest...

If you have animal companion already then go into the floating forest do dismiss and get another make them disposable?

You have a favorite enemy goldfish at 1st level you get to the forest one level before you select another. You get to pick when you are in the forest humming bird you go to the dessert you can not get another.

You have the wrong weapons make it work retreat and restock.

That being said nice easy description you gave I need no more

[Pux]

I think the timeline for evolution is off. If they are carniverous plants they couldn't have evolved any earlier than their food source and now we are talking about a long string of evolution with no major extinctions mentioned. I guess maybe intelligent creatures may not have evolved very quickly here or something like that. But carniverous plants in and of themselves didn't evolve on Earth till about 60 - 125 million years ago. These evolved and became flying forests before the characters arrive? Did intelligent life evolve and later leave the planet?

If they evolved floating they may have actually gained their evolutionary advantage after a meteor strike where they floated above the ash clouds. And as it settled came lower to the ground. And formed these massive colonies.

I am not sure that animals create the sugars you mention as being used to create the hydrogen. I think sugars were a result of a photosynthetic process. Feeding off of other plants might actually work better on an evolutionary scale.

Personally I prefer my floating forests to be the work of aliens. A space ship crashes that uses a gravity drive so both propel itself and power itself. They are only meant to be used in deep space because of the damage they can do to matter over time and proximity. They destroy it's ability to be affected by gravity. The crashed space ship drive kept operating until it ran out of juice and everything in the forest area was effectively weightless. Plants continued to use the same molecules and poof they can float.or blame a wizard pretty much the same thing. In fact maybe the wizard is why the matter didn't fly off into space as gravity in the area failed and now it is aliens and wizards.

[Nifft]

or blame a wizard pretty much the same thing. In fact maybe the wizard is why the matter didn't fly off into space as gravity in the area failed and now it is aliens and wizards.

Spoiler

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There are aesthetic advantages for aliens rather than wizards, especially if you're playing in a swords-and-sorcery setting like Lankhmar, or the world of Nifft the Lean (of which I personally recommend both, because they're both quite good series).

There's also a major functional advantage of aliens -- which is that Wizard is a class available to PCs in many games, but Alien is not. So you get to have a mysterious forest which cannot be re-created using the magic available to PCs.

[sktarq]

Actually since the evolutionary parts seem to troublesome and this may still be a D&D world, have you considered divine intervention? The gift of a forest God to the sky God. Either to say sorry, to get one to marry the other, as a show of friendship when the other get married to third party...whatever works in the setting.

That way it can be something weird even to the point of ill-logic. It would also help give you a theme and feel of the place even if you have it corrupted or "fallen" in some way.

[Potato_Priest]

I'd be very worried about things falling on me when these passed over head. As giant masses of decaying plant material, it's easy to imagine sticks, showers of dirt, and logs falling from the sky. Also, they'd get really heavy and probably land when it rained.

Also note that there should be no rocks in the sky forest. A player who tries to find one will fail.

[tantric]

you can relax, i'm a trained ecologist. your world is safe in my hands

let's start with the basic problem - the upper atmosphere, like the midocean, is a desert, devoid of nutrients. we change this by brining in some volcanoes, not earthlike, but ones the smoke and belch continually but never really erupt. add a continent that is undergoing long irreversible desertification and blowing huge amounts of top soil away.

there exists on this dying land a fungus distantly related to puffballs, though also similar to tumbleweeds. These tumblepuffs, rather than sprouting and dying in a few days spend the cool winter growing their cubic meter fruiting bodies, protected my a noxious reek of hydrogen sulphide. Inside are hundreds of tiny spheres filled with aerogel. Symbiotic methanogenic fungi and algae convert sugars to CH4, which is locked in the aerogel pores. Tiny webflies spin slik around the puffweeds, sealing in the methane and lighter than air aerogel along with their eggs.

that was five million years ago. now tumblepuffs are now fully obligate aerials. now they are spheres with lighter than air aerogels inside. they reproduce by exploding into more balls. this happens in the troposphere, in/on one of the mirkmists (solid clouds via fungal aerogel). The newborns need water for the algal symbiont iridescence on their skins. when a baby ball is born, it sucks up water, which is dissociated into h2 and o2 by uv and enzyme catalyst. they gulp down the hydrogen ravenously and veriy shoot up out of their clouds into the stratosphere, which is about 1/1000 the pressure of the surface. quickly thier hydrogen is sucked out and the pressure equalized. then, just as they reach the top of the stratosphere, the outer wall of their aerogel cores hardens. why? because now all the bubbles are full of near nothing and our baby tumblepuff is a vacuum balloon

more later.

[Trekkin]

One problem with an organism relying on a vacuum balloon, the same as has been the problem for manmade attempts at one: most things are generally permeable by light gases, and that goes double for flexible things and triple for biological flexible things. It's not as much of a problem when you have continual production of the gas you want and an overpressure to bias diffusion outwards, but if you want to seal a vacuum against everything you're going to need some really specialized membranes to do it and a means of continuing to remove errant gas molecules that leak through anyway.

If you can think of a way for an organism to evolve to coat their vacuum chambers in perfect graphene sheets, then maybe. Otherwise the vacuum will become contaminated immediately.

Incidentally, tantric, I've seen you refer to having done work in several fields in various posts on here. If you wouldn't mind saying, I'd be curious to know what your graduate degree(s) is/are in; it sounds like you've had an interesting career path.

[tantric]

One problem with an organism relying on a vacuum balloon, the same as has been the problem for manmade attempts at one: most things are generally permeable by light gases, and that goes double for flexible things and triple for biological flexible things. It's not as much of a problem when you have continual production of the gas you want and an overpressure to bias diffusion outwards, but if you want to seal a vacuum against everything you're going to need some really specialized membranes to do it and a means of continuing to remove errant gas molecules that leak through anyway.

If you can think of a way for an organism to evolve to coat their vacuum chambers in perfect graphene sheets, then maybe. Otherwise the vacuum will become contaminated immediately.

Incidentally, tantric, I've seen you refer to having done work in several fields in various posts on here. If you wouldn't mind saying, I'd be curious to know what your graduate degree(s) is/are in; it sounds like you've had an interesting career path.

yes, i''m cheating outrageously. it is fantasy, afterall. my real goal is to develop a stable ecosystem. given the paucity of nutrients, i'm going to make it completely mutualistic and interdependent.

i have a BA in japanese and asian lit. i got a job building a database in a wildlife epidemiology lab, took some classes then the PI encouraged me to take the GRE. i spent two weeks learning how to take the GRE and became an honory asian. i scored 1540/1600, second highest in the school of ecology. i got an award that gave me free tuition and a $1200/mon stipend for two years.

i found in this that i have a gift for calculus. i *loathed* trigonometry so i never explored calc. ah, the math of infinity! i worked with mathematical modeling ecosystems and epidemics. my dissertation would have been on modeling different parasites interactions in deer using ecological models.

but three years in my ferret got cancer and died and i burned out....which somehow resulted in me being sent to a maximum security prison for 2 years. now i'm a felon, unemployed and seriously considering having another go at clandestine chemistry.

[Trekkin]

yes, i''m cheating outrageously. it is fantasy, afterall. my real goal is to develop a stable ecosystem. given the paucity of nutrients, i'm going to make it completely mutualistic and interdependent.

i have a BA in japanese and asian lit. i got a job building a database in a wildlife epidemiology lab, took some classes then the PI encouraged me to take the GRE. i spent two weeks learning how to take the GRE and became an honory asian. i scored 1540/1600, second highest in the school of ecology. i got an award that gave me free tuition and a $1200/mon stipend for two years.

i found in this that i have a gift for calculus. i *loathed* trigonometry so i never explored calc. ah, the math of infinity! i worked with mathematical modeling ecosystems and epidemics. my dissertation would have been on modeling different parasites interactions in deer using ecological models.

but three years in my ferret got cancer and died and i burned out....which somehow resulted in me being sent to a maximum security prison for 2 years.

I...see. My apologies for bringing up what I can only assume was an unpleasant memory.

At any rate, my objection to the vacuum balloons has nothing to do with mutualism and everything to do with physics. It is simply not possible to make a biological membrane impermeable to all gases, so those aerogels are going to be filled with rarefied air that's going to increase in density rapidly, which means those balloons are going to fill up and return to earth. Hydrogen balloons can last indefinitely, perhaps, given a hydrogen source, but you cannot maintain a vacuum with turgor pressure.

[Carl]

One relatively simple thing that might help here if you don't mind some other serious evolutionary questions, make sea level air pressure higher. it's the difference in absolute density that produces lift. I also wouldn't rule out life being able to isolate helium, despite it's general rarity. The biggest issue is that there is a practical limit to how high you can raise the atmosphere pressure before oxygen toxicity becomes an issue even if you dial down the partial oxygen pressure It's still several dozen atmosphere afaik. But your probably limited to no more than 30-40kg's of lift per cubic m of gas. So it probably can't be done practically speaking without some serious fudging, but i wouldn't rule it out as completely impossible on a physics level, just so improbable and requiring such specific circumstances it would be unsuited to D&D adventuring.