OK, I wrote my theory, and then read the article: same.
But I will add that a commercial grower of venus flytraps once got curious, and took a few thousand cloned plantings, growing them in a variety of conditions. As soon as the soil became nourishing, the plants would die. Post mortem seemed to indicate their roots were fungally attacked.
So: plant adapts to living in a food desert (not an actual one, of course; it has to be wet for the carnivory to work, as the article points out). Plant gains weirdo digestion abilities, but at the same time, it no longer needs expensive anti-fungal defences - because the ground isn't rich enough to support parasitic fungi.
Then: human adds the nutrients back in. Boom! The ordinary fungus in the air, which has a tough time invading grass or tree or tobacco or pepper roots (because they have extensive defences, like capsaicin), lands in the rich soil of pretty-much helpless flytrap roots, and has a buffet.
Sorta similar with a lot of plants I imagine, we planted a Madrone tree and it's very tempting to want to water a small & new tree but they can also get root issues if the ground is too wet or doesn't drain well enough. They're highly adapted to living on the sides of cliffs.
We recently had this discussion about house plants as well. The unexpected part is: Too much watering hurts more than too little watering. Especially with bad drainage.
If the watering is on the too-little side for the evaporation and plant size going on, well, the plant will look a little sad for a bit. Then you water it, and it goes back up and looks happy again. This is a situation plants regularly deal with in the wild - drought - and they have adapted to it.
If you water too much, especially with bad drainage, there will be stagnant water in the pot, roots rot and the plant dies with little recourse.
So now I make sure my pots can drain, take my plants outside once or twice a week, absolutely drown their soil and let that drain for an hour or two. This way, the soil becomes saturated without stagnant water and... some of these plants are reproducing and growing at unreasonable rates for the amount of effort placed into them.
I've been trying to grow a mango from a seed for so long. The roots always get hit by black fungus and it dies off. Tallest I got one to grow was about 10"
Labor of love (beautiful trees), but they are very iffy trees to get going. I did attempt to help things along by putting lots of madrone duff with it, so as to try to get the right biota.
98% of grass or tree or tobacco or pepper roots are invaded by fungus, and cannot survive in soil if they are not invaded by fungus. Rice is one of the rare exceptions. Having their roots invaded by fungus is probably what enabled plants to colonize land in the first place.
I think that's a double whammy, not only are the fungi ready and willing to use those extra nutrients in the soil, the carnivorous plants have in many cases lost most of their unneeded-in-poor-soils ability to absorb the nutrients. That's why you can feed your flytrap tiny bits of hamburger (or maybe tofu, not sure if the amino balance matters unless that's all they're getting?)
In a clean room maybe, but honestly hydroponics usually makes things like that worse, not better and I say that as someone who's had a set up for over ~5 years at this point.
At the end of the day it's a pit of water with nutrient that is usually somewhat warm. You can control algae with hydrogen peroxide but there is always some water that will stagnate somewhere and lead to some mold level. It's really best to grow plants with a clear growth => harvest cycle so that you can periodically re-sanitize everything.
I've visited Lady Musgrave Island in the Great Barrier Reef. It is covered with trees called "the grand devil's-claws", the seeds of which are barbed and sticky. The seeds stick to the wings of birds eating seeds, and so they can spread across islands.
However, a visitor to the island will soon notice lots of dead birds on the ground. There are no predators or scavengers, so the birds lay there decomposing.
Thus, the trees use the birds not only for reproduction, but also for food. It's a carnivorous forest out there on the reef.
[0] lists 28 documented cases - if we ignore the 5 before 1943 (probably not reliable records), that gives 23 in just over 80 years or roughly one every 3.5 years (although you'd expect that to have increased over time as more people live or tourist near the trees)
Of those 23, 5 were infants (<3y), 1 was killed by 4 coconuts, 1 was killed by a bunch of 57 coconuts(!), and 2 were accidentally killed by their harvesting monkeys.
Killing an animal on their way to the beach is a free bonus for coconuts: they necessarily drop from the top of the tree and they need a high quality shell in any case for their primary job of floating on water and dispersing.
I was in south India for about a month and I heard of 1 person dying from a coconut during that time period and heard it wasn’t unheard of. Not a lot of people die but plenty of folks get injured.
As the article points out: If conditions exist for "high-quality plant growth" (correct light, soil, moisture, etc) then plants don't make weird adaptations like eating things/water-conservation methods.
However, if those conditions DON'T exist, then it's hard for plants to get very big.
There's also this: the larger a moving creature you're trying to capture, the more resources you need to invest in the trap. Bladderwort exists everywhere because it's easy to trap small/microscopic things. Giant bear-eating plants exist nowhere because consistently trapping a bear with just leaves, sap, and stems is really fucking hard.
At a certain point, the plants reach an equilibrium where the effort is worth the end result, but diminishing returns if they got larger.
If you want to speculate about that, then how about the bamboo die-off cycle? Imagine if you lived in the PNW or Appalachia, and every 120 years the entire side of a mountain launched an army of hungry rats at you. Starves all those cute smug “panda” gluttons too.
Reminds me of a semi-plausible mechanism for carnivorous flora from this [0] Worldbuilding Stack Exchange answer by ckersch:
> Bonegrass is a white fungus which grows in wheat fields. Most of the time, the bonegrass fields are normal wheat fields, indistinguishable from other wheat fields except for their exceptionally high yields and relatively low numbers of animal inhabitants. Of course, this entices lots of animals, large and small, to move into the area. Populations boom, fueled by the seemingly unnatural abundance of the wheat.
> And then the bonegrass blooms. Overnight, huge mycelial mats below the wheat fields become active, with white fungal growths growing up the stalks of the wheat plants, using their stalks for support. Then, simultaneously across hundreds of square miles, the bonegrass releases its paralytic spores. Within 12 hours, the wheat fields become pale, white places of death. The fungus then begins to grow over the paralyzed creatures, flooding their body with neurotoxins that keep them immobilized until they die from dehydration over the next few days.
> The dead animals quickly break down, broken apart by the fungus. As suddenly as the bonegrass grew, it will then die back, shrinking back beneath the earth, where it will slumber as the land above it slowly repopulates, drawn by the seeming gaia above the soil, and unaware of the horrors slumbering beneath...
Scary stuff. Symbiotic plant-fungi or plant-bacteria relationships seem like plausible mechanisms for "carnivorous" plants, even if it's not "plants directly eating people" a la Little Shop of Horrors. There are more good answers with a similar premise under the same SE question.
I bought a tiny Venus Fly Trap once, left it in the kitchen, and went away for a weekend.
When I came back the kitchen was buzzing with flies, and the plant had literally gorged itself to death.
This was extra impressive because none of the windows were open. It had somehow leaked attractant scent through gaps I didn't know existed and the flies - not exactly numerous where I was - must have been aware of it from hundreds of yards away.
Point being the plants may be small, but they can be very good at what they do.
I wouldn't think it gorged to death because the leaves close around the fly while digesting. I have a few small Venus fly traps as well and the greenhouse I bought them from said they are really easy to kill with too much or too little water, even just using basic fertilizer. Just speculating of course. These plants are cool but feel so alien.
But yeah they definitely can attract a lot more flies than they can eat and can make the fly problem way worse
As soon as a carnivorous plant gets big enough to be eating young mammals, it hits the Mama Bear barrier. With motivation, even a tiny mammal can do an enormous amount of damage to a plant.
I would have thought that plants which ate neighboring plants, for their easily accessed nutrients and to protect their own access to sunlight, water and forest nutrients, would be pervasive.
I have heard of chemical/strangling/parasitical type competition. The banyan tree is territorial, for instance.
But we would need another name, other than territorial, carnivorous or vegetarian, to describe plant predators which overtly, actively fed on the physical structure or leaves of fellow plants.
There are many parasitic plants, like the well-known mistletoe, which eat other plants. Unlike mistletoe, some of the other parasitic plants have given up completely on phototrophy, depending only on the nutrients sucked from the host plant.
It is likely that there are much more parasitic plants than carnivorous plants.
Plants that feed on other plants must do it similarly to a fungus, by penetrating them and growing into them a root-like organ, for sucking their fluids.
A plant could not bite and chew another plant, because, like the fungal cells, the plant cells have abandoned their ancestral animal-like mobility, by covering their cells with walls made of cellulose, which prevent cell mobility. While there are a few plants capable of infrequent fast movements, like the Venus flytrap, they use special tricks for creating tension in an elastic structure, like when drawing a bow, which would not be suitable for sustaining a sequence of movements.
> A plant could not bite and chew another plant, because, like the fungal cells, the plant cells have abandoned their ancestral animal-like mobility
I would think capabilities like that would be recoverable, if the biological economics worked.
But your point that parasitical plants continuously live off other plants, i.e. they essentially farm them, resolves that. Given victim plants can't run away, their metabolisms are worth far more than any one-time resource extraction.
Nah. Eating and reproducing lots, fast, is a viable means. See: much of the fungi kingdom.
I suppose you could view the passive offspring dispersal system (wind, current, animal digestive tract, raindrops, etc.) as a form of intergenerational movement.
Larger animals tend to more intelligent - presumably there’s a natural limit to the size of prey a carnivorous plant can reliably catch from a static location.
Larger animals are highly undesirable prey because they tend to be able to free themselves from a carnivorous plant (low value), with a high probability of severe damage to the plant in the attempt (high cost): they can just walk or climb away, but also involuntarily break a stalk with their weight, tear open a sac with talons, rip away slowly regenerated adhesive parts, eat something that should be dangerous, and so on.
Readit News
But I will add that a commercial grower of venus flytraps once got curious, and took a few thousand cloned plantings, growing them in a variety of conditions. As soon as the soil became nourishing, the plants would die. Post mortem seemed to indicate their roots were fungally attacked.
So: plant adapts to living in a food desert (not an actual one, of course; it has to be wet for the carnivory to work, as the article points out). Plant gains weirdo digestion abilities, but at the same time, it no longer needs expensive anti-fungal defences - because the ground isn't rich enough to support parasitic fungi.
Then: human adds the nutrients back in. Boom! The ordinary fungus in the air, which has a tough time invading grass or tree or tobacco or pepper roots (because they have extensive defences, like capsaicin), lands in the rich soil of pretty-much helpless flytrap roots, and has a buffet.
If the watering is on the too-little side for the evaporation and plant size going on, well, the plant will look a little sad for a bit. Then you water it, and it goes back up and looks happy again. This is a situation plants regularly deal with in the wild - drought - and they have adapted to it.
If you water too much, especially with bad drainage, there will be stagnant water in the pot, roots rot and the plant dies with little recourse.
So now I make sure my pots can drain, take my plants outside once or twice a week, absolutely drown their soil and let that drain for an hour or two. This way, the soil becomes saturated without stagnant water and... some of these plants are reproducing and growing at unreasonable rates for the amount of effort placed into them.
Labor of love (beautiful trees), but they are very iffy trees to get going. I did attempt to help things along by putting lots of madrone duff with it, so as to try to get the right biota.
https://en.wikipedia.org/wiki/Mycorrhiza
At the end of the day it's a pit of water with nutrient that is usually somewhat warm. You can control algae with hydrogen peroxide but there is always some water that will stagnate somewhere and lead to some mold level. It's really best to grow plants with a clear growth => harvest cycle so that you can periodically re-sanitize everything.
Brambles can trap sheep, benefiting from the sheep as fertilizer: https://www.youtube.com/watch?v=mrGobnZq83g
Falling coconuts can not only kill people, but probably kill far more small animals, again benefiting from them as fertilizer,
Dead Comment
However, a visitor to the island will soon notice lots of dead birds on the ground. There are no predators or scavengers, so the birds lay there decomposing.
Thus, the trees use the birds not only for reproduction, but also for food. It's a carnivorous forest out there on the reef.
Of those 23, 5 were infants (<3y), 1 was killed by 4 coconuts, 1 was killed by a bunch of 57 coconuts(!), and 2 were accidentally killed by their harvesting monkeys.
[0] https://en.wikipedia.org/wiki/Death_by_coconut
“None of you seem to understand. I’m not locked in here with you. You’re locked in here with me!”
However, if those conditions DON'T exist, then it's hard for plants to get very big.
There's also this: the larger a moving creature you're trying to capture, the more resources you need to invest in the trap. Bladderwort exists everywhere because it's easy to trap small/microscopic things. Giant bear-eating plants exist nowhere because consistently trapping a bear with just leaves, sap, and stems is really fucking hard.
At a certain point, the plants reach an equilibrium where the effort is worth the end result, but diminishing returns if they got larger.
Deleted Comment
> Bonegrass is a white fungus which grows in wheat fields. Most of the time, the bonegrass fields are normal wheat fields, indistinguishable from other wheat fields except for their exceptionally high yields and relatively low numbers of animal inhabitants. Of course, this entices lots of animals, large and small, to move into the area. Populations boom, fueled by the seemingly unnatural abundance of the wheat.
> And then the bonegrass blooms. Overnight, huge mycelial mats below the wheat fields become active, with white fungal growths growing up the stalks of the wheat plants, using their stalks for support. Then, simultaneously across hundreds of square miles, the bonegrass releases its paralytic spores. Within 12 hours, the wheat fields become pale, white places of death. The fungus then begins to grow over the paralyzed creatures, flooding their body with neurotoxins that keep them immobilized until they die from dehydration over the next few days.
> The dead animals quickly break down, broken apart by the fungus. As suddenly as the bonegrass grew, it will then die back, shrinking back beneath the earth, where it will slumber as the land above it slowly repopulates, drawn by the seeming gaia above the soil, and unaware of the horrors slumbering beneath...
Scary stuff. Symbiotic plant-fungi or plant-bacteria relationships seem like plausible mechanisms for "carnivorous" plants, even if it's not "plants directly eating people" a la Little Shop of Horrors. There are more good answers with a similar premise under the same SE question.
[0] https://worldbuilding.stackexchange.com/questions/38354/how-...
It’s about astronauts crash landing in an alien planet, where the flora and fauna have a symbiotic relationship, and what happens when humans appear.
Fantastic show.
When I came back the kitchen was buzzing with flies, and the plant had literally gorged itself to death.
This was extra impressive because none of the windows were open. It had somehow leaked attractant scent through gaps I didn't know existed and the flies - not exactly numerous where I was - must have been aware of it from hundreds of yards away.
Point being the plants may be small, but they can be very good at what they do.
But yeah they definitely can attract a lot more flies than they can eat and can make the fly problem way worse
I have heard of chemical/strangling/parasitical type competition. The banyan tree is territorial, for instance.
But we would need another name, other than territorial, carnivorous or vegetarian, to describe plant predators which overtly, actively fed on the physical structure or leaves of fellow plants.
It is likely that there are much more parasitic plants than carnivorous plants.
Plants that feed on other plants must do it similarly to a fungus, by penetrating them and growing into them a root-like organ, for sucking their fluids.
A plant could not bite and chew another plant, because, like the fungal cells, the plant cells have abandoned their ancestral animal-like mobility, by covering their cells with walls made of cellulose, which prevent cell mobility. While there are a few plants capable of infrequent fast movements, like the Venus flytrap, they use special tricks for creating tension in an elastic structure, like when drawing a bow, which would not be suitable for sustaining a sequence of movements.
I would think capabilities like that would be recoverable, if the biological economics worked.
But your point that parasitical plants continuously live off other plants, i.e. they essentially farm them, resolves that. Given victim plants can't run away, their metabolisms are worth far more than any one-time resource extraction.
I guess to effectively live a long life by eating other stuff, you need to be able to move, or what you eat need to be able to move to you.
I suppose you could view the passive offspring dispersal system (wind, current, animal digestive tract, raindrops, etc.) as a form of intergenerational movement.