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.
NegativeLatency 11 days ago [-]
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.
tetha 10 days ago [-]
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.
ge96 11 days ago [-]
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"
thatcat 11 days ago [-]
Try adding some natto innoculant to the seed
tmoertel 10 days ago [-]
For the Bacillus subtilis?
thatcat 9 days ago [-]
yes, b. subtilis produces exogenous anti-fungal peptides and VOCs. Additionally, sterilizing the seed before inoculation using sodium hypochlorite or h2o2 would help.
pantalaimon 10 days ago [-]
Same with Lychee, after a bit the leaves all start getting brown from the tip and die off.
Avocado on the other hand grows like a charm.
kakapo5672 10 days ago [-]
Weird. We just planted a madrone too.
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.
khafra 11 days ago [-]
I hope there's a mad scientist somewhere, making a cross-genetic venus flytrap that also produces capsaicin and nicotine.
dyauspitr 10 days ago [-]
And is also selecting for size. If other plants are anything to go by we can probably increase the size three fold.
dylan604 10 days ago [-]
Wait, I've seen this movie. I'd suggest not trying this if your name is Seymour
konfusinomicon 10 days ago [-]
throw thc in and that will make one hell of a hot tamale
IAmBroom 10 days ago [-]
Genius!
Terr_ 10 days ago [-]
So it draws people in with the promise of a nicotine fix, and then sprays them with mace to stop them from struggling free...
kragen 10 days ago [-]
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?)
flir 10 days ago [-]
Hm. What about hydroponics? Lower risk of fungal infections there.
belval 10 days ago [-]
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.
Falling coconuts can not only kill people, but probably kill far more small animals, again benefiting from them as fertilizer,
ethbr1 11 days ago [-]
Came to HN for tech news, left with a disturbing realization that coconut trees might be low-key carnivorous.
__MatrixMan__ 10 days ago [-]
If it's a fun kind of disturbing, and you like SciFi, you might enjoy Semiosis.
username135 11 days ago [-]
Right?!
aaron695 11 days ago [-]
[dead]
yesbabyyes 10 days ago [-]
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.
doesnt_know 11 days ago [-]
Going down that line of thought... Cocunuts naturally selected for harder shells because those killed, creating more fertilizer ...
kragen 10 days ago [-]
Coconut husks are fairly soft. About like a pumpkin. They're only dangerous because they're so large and heavy.
trgn 10 days ago [-]
Dont they clank!
Affric 11 days ago [-]
If plants moved faster we would be absolutely terrified of them.
signalToNose 10 days ago [-]
The Day of the Triffids
loa_in_ 10 days ago [-]
Attack of the killer Tomatoes!
bregma 10 days ago [-]
He means fruits.
rcarmo 10 days ago [-]
Came here for this comment.
athenot 11 days ago [-]
Let's not be too hasty...
pauldraper 10 days ago [-]
The kill rate of coconuts cannot be high.
zimpenfish 10 days ago [-]
[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.
dyauspitr 10 days ago [-]
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.
imoreno 10 days ago [-]
Wouldn't animal scavengers pick the carcass clean long before it rots?
kragen 10 days ago [-]
That still counts if the scavengers poop nearby.
imoreno 10 days ago [-]
Usually, animals move around while digesting. They don't just eat the food, immediately digest it, and poop on the spot like a cartoon.
“None of you seem to understand. I’m not locked in here with you. You’re locked in here with me!”
gbraad 10 days ago [-]
The size of insects has decreased over time, correlating with a drop in atmospheric oxygen levels. Maybe this has also happened to carnivorous plants?
moate 10 days ago [-]
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.
ahartmetz 9 days ago [-]
One can imagine some pretty twisted stuff, but anyway large mammals tend to have enough brains to learn to recognize dangers without, or failing that, with evolution (think innate fear of snakes).
HelloNurse 5 days ago [-]
Consider plausible interactions, like cow vs. sundew. The sundew's only hope for survival is looking inedible and repelling the cow, capturing the cow is completely out of the question.
knowitnone 10 days ago [-]
this is a secondary mechanism. Falling branches kill and therefor get fertilizer.
10 days ago [-]
lambdasquirrel 10 days ago [-]
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.
jcalx 10 days ago [-]
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.
If you liked this you should watch the animated series Scavengers Reign.
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.
TheOtherHobbes 10 days ago [-]
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.
freedomben 8 days ago [-]
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
beAbU 10 days ago [-]
So what you are saying is that a Venus fly trap can actually make a fly problem worse, by attracting more than it can eat?
bell-cot 11 days ago [-]
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.
hirvi74 11 days ago [-]
Some carnivorous plants do eat mammals. Though not primarily, some pitcher plant species have been known to eat mice, for example.
Nevermark 11 days ago [-]
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.
adrian_b 11 days ago [-]
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.
Nevermark 10 days ago [-]
> 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.
BartjeD 10 days ago [-]
Rent seeking economy = parasitism
olau 11 days ago [-]
I think the problem is that then you need two energy harvesting systems, and there's not just that much to eat nearby.
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.
IAmBroom 10 days ago [-]
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.
almosthere 11 days ago [-]
We haven't had an unscheduled total eclipse of the sun with people singing in the background yet.
colecut 11 days ago [-]
have they tried feeding them alllll niiight loooong
leoedin 11 days ago [-]
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.
HelloNurse 11 days ago [-]
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.
IAmBroom 11 days ago [-]
Counterpoint: mice and at least one monkey baby have died in pitcher plants in the wild.
jonplackett 11 days ago [-]
Isn’t this still just the original point though, mice ain’t that big!
IAmBroom 10 days ago [-]
We're using different criteria for "big".
imtringued 11 days ago [-]
A lot of pitcher plants evolved to be a toilet for shrews.
cyberax 11 days ago [-]
OK, let's see. You're a plant, so you have photosynthesis. It allows you to tap around 5W (averaged out) per square meter of foliage by just AFK-ing. Your major need: water, you have to evaporate it for the photosynthesis to work. But it's not a problem in your habitat, there's plenty of water available.
You also need nitrogen, phosphorus, and other nutrients, but comparatively little of them. Nitrogen is the toughest one. This is the one that you can easily get from animals, though. So you can evolve a complicated mechanism to trap small animals and digest them for nutrients. It also provides you with a bit of energy, but it's completely immaterial compared to photosynthesis, so you don't even bother evolving all the complicated protein-to-glucose pathways.
Now, you want to grow bigger. How would you do it? Energy is not an issue, the photosynthesis provides plenty of it. But you need to trap more or bigger animals, and that's an issue. There just aren't that many of them, and you can't just get away with simple traps anymore.
jijijijij 10 days ago [-]
Is nitrogen really the bounty, not phosphor? I imagine nitrogen fixation is basically the same problem everywhere, equally distributed through air, but phosphor depends on geological processes, depends on the mineral make of the soil. If phosphor gets depleted, you have two options: Wait for mountains to grow and shed some, or indulge in someone else’s DNA and ATP. Maybe the acidic soil makes uptake harder, or aids wind and water erosion?
Looking at my spotted windowsill, if I was a plant on an evolutionary adventure, I‘d befriend some spiders and turn my crown into a cotton candy guano cloud. I‘d rather have the animal predators do the work and then have them shit in my yard for the nitrogen and phosphor. You only need twigs and then some bioluminescence or stink to help those spiders fill their nets.
Have a fungus rot my legacy core wood so an owl can defecate a hectare of mice and squirrels right into my tummy. Or you look all mighty and judgmental so these funny naked apes drench your soil in the blood of goats and their youths. Is that still a thing?! What about instagramable forest cemeteries? Heard about the tree toilet TikTok challenge? So fun! Super healthy and natural too.
Now thinking of it, I wonder how many plants encourage animals shitting and dying in their yards. Maybe it’s not deterrent, but enterotoxic payment options?
I guess, unless your objective is to grow impractically large fruits, because your human creator couldn’t keep it in their pants, for most plants in most places, neither phosphor nor nitrogen side hustles are really worth the effort.
cyberax 10 days ago [-]
Yep, nitrogen is the limiting nutrient in swamps. It can be fixated only through biological means, while phosphorus is produced by weathering rocks. Nitrogen fixation is suppressed in swamps, while phosphorus is typically still available from the inflowing streams.
I don't think this is very correct, but why do these biological means fail in bogs/swamps? Kinda my point: Other plants and ecosystems figured out the nitrogen problem all over the world. It's more or less the same everywhere, since nitrogen naturally comes from the atmosphere. AFAIK, there are more or less three ways to have nitrogen input into an ecosystem: Lightning, biological fixation in plants/microbes and artificial synthesis/fertilization.
I suspect the swamp ecosystem has something going which makes nitrogen fixation difficult. All other plants in the swamp need nitrogen to grow, too, how are they doing? Maybe it is the (often) low pH, maybe it's a lack of trace metals for certain enzymes. Maybe the anaerobic conditions favor inaccessible conversion of nitrogen in decay.
Nitrogen can't be completely exhausted, because you have (low) constant influx from the atmosphere everywhere on Earth's surface, even without biological fixation. Phosphorus, on the other hand, can be effectively depleted. The "cycling" of phosphorus happens on geological timescales. A low soil pH may leech out the phosphorus from minerals and have it carried away by wind and water.
I still don't think plants would go the carnivorous route just for the nitrogen. If anything, I suspect they recycle the "nitrogen" as amino acids to save on synthesis. Some carnivorous plants apparently secrete phosphatase into their prey. That's a lot of evolutionary effort...
cyberax 9 days ago [-]
Carnivorous plants certainly don't mind extra phosphorus, but it's usually not limiting.
> I don't think this is very correct, but why do these biological means fail in bogs/swamps?
They don't. Moreover, the anoxic environment of swamps actually promotes the nitrogenase activity. However, the constant presence of water also diffuses the nutrients, and denitrifying bacteria use ammonia as an energy source. In oxygenated environments, they are typically outcompeted by regular air-breathing bacteria.
This happens in regular soil, but it's normally not saturated with water, so nutrients are not constantly washed out.
> All other plants in the swamp need nitrogen to grow, too, how are they doing?
Not very well. Swamps are not very productive biologically. There is _some_ nitrogen available, it's just that its equilibrium concentration is much lower.
IAmBroom 10 days ago [-]
Thank you. TIL.
IAmBroom 10 days ago [-]
> Now thinking of it, I wonder how many plants encourage animals shitting and dying in their yards.
All it takes is to make your forest more attractive to bears than the Vatican City is.
Bears are notoriously suspicious of ritualized worship, so... low-entropy solution achieved.
hinkley 10 days ago [-]
They don’t fit into the pews. Humans design them to be inaccessible to bears. It’s discriminatory. The cats stay away because they get bored easily by people talking about themselves or other people instead of about cats.
zimpenfish 10 days ago [-]
> then have them shit in my yard for the nitrogen and phosphor.
Nepenthes Lowii says hi.
"However, pitchers produced by mature N. lowii plants lack the features associated with carnivory and are instead visited by tree shrews, which defaecate into them after feeding on exudates that accumulate on the pitcher lid."
Still, I kinda want to see a tree's light faintly glowing through their guano cloud of horrors. You could plant them next to lakes and such to get rid of mosquitos! But mostly for the eerie atmosphere, to make man afraid of the night again. Whispers of ten thousand feet, be wary of the lantern trees!
imoreno 10 days ago [-]
>Most of this carnivorous botany is small, but the diversity of different trapping mechanisms raises an evolutionary question.
Isn't the obvious conclusion that:
1. There are many peaks in the fitness hypersurface for plants that correspond to meat eating
2. The peaks have smooth gradients at the outskirts
3. All peaks are minor local maxima
1 is because low nitrogen alone is not enough to make carnivory a net positive contributor to fitness. You need additional factors to make the gradient positive to begin with. That means the peaks (niches) are random and narrow.
3 is because carnivory implies an arms race against prey defenses, competing scavengers, and competing predators. Specialist animals are at a large advantage against plants, especially if meat is still a side dish to sunlight.
To me the interesting question is 2 - most plants don't digest animals at all, so how does this begin to evolve?
I.e., because they got their nutrients from animals they didn't need chloroplasts and the chloroplasts 'broke' over time. Chances are minimal to zero that carnivorous plants will regain chloroplasts. In a way, carnivory in plants is an evolutionary 'dead end' similar to parasitism, which is also often linked to chloroplast loss. Where could the plants evolve 'to' if they have no chance of getting energy from alternative (chloroplast) sources?
chrisco255 11 days ago [-]
> Some large carnivorous plants are alive out there, but none is big enough to make a meal out of you.
Clearly these researchers have never been to the Mushroom Kingdom.
signalToNose 10 days ago [-]
Mushrooms technically are not plants
jijijijij 10 days ago [-]
„Technically“… talking kingdoms :D
Like, an orca is more fish, you are more fish (or fungus for that matter), than a mushroom is a plant.
How about: larger animals can learn from seeing others eaten, so they won't fall for the trap.
moate 10 days ago [-]
I mean, that's a weak evolutionary argument against all forms of predation/prey. It assumes a level of cultural/shared knowledge that doesn't typically exist. Also, size =\= intelligence/problem solving. Chimps and humans are both smarter than gorillas.
Yes, troop 1 of monkeys have learned about the monkey-eating plants that have evolved overnight, but troops 2-10 haven't. Eventually troop 1 leaves the deadly forest, and troop 2 comes in. After a few seasons, they notice these fucking plants keep eating their babies (again, most predators go after babies for the reason you mentioned, they haven't learned how to avoid death yet) and then they move on. Repeat for several centuries. Behold nature in all its splendor.
I like the article's ideas: If you can grow large enough to eat a person, you're getting enough nutrition that you don't need to eat a person.
11 days ago [-]
bilsbie 11 days ago [-]
A related question is why plants in general can thrive on such tiny amounts of protein. (Nitrogen)
IAmBroom 10 days ago [-]
Simple. They don't need that much nitrogen.
I'd be surprised if your tomato plant "ate" a whole teaspoon of fertilizer in its entire growing season.
10 days ago [-]
Sevii 11 days ago [-]
Plants not being able to chew or tear their prey is a big disadvantage.
mlinhares 11 days ago [-]
Not if you're prey. i'd rather not have more stuff trying to eat me :P
IAmBroom 10 days ago [-]
Baleen whales seem to do just fine without it.
musicale 11 days ago [-]
I guess there are still some things that we can be grateful for.
mmsc 9 days ago [-]
One day it'll The Day of the Triffids
MisterBastahrd 10 days ago [-]
Because a fly can spit on your food, but a mouse can eat a hole in your baseboards.
Noelia- 10 days ago [-]
I used to think carnivorous plants would someday grow huge and eat people like in the movies. Turns out they have always stayed small and just got really clever instead.
This piece made me see it differently. Not growing big is not a flaw. In a place with barely any nutrients, surviving with just a bit of strategy is actually kind of amazing.
nyeah 11 days ago [-]
tl;dr Basically a lot of sorry excuses.
If you're a plant, don't buy into the negativity. Work your way up the food chain. If you eat it, then it's your food.
AStonesThrow 11 days ago [-]
[dead]
curtisszmania 11 days ago [-]
[dead]
Rendered at 21:23:22 GMT+0000 (Coordinated Universal Time) with Vercel.
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.
Avocado on the other hand grows like a charm.
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,
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
I'll raise you this:
https://www.bbc.com/news/world-europe-66429342
“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.
> 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.
You also need nitrogen, phosphorus, and other nutrients, but comparatively little of them. Nitrogen is the toughest one. This is the one that you can easily get from animals, though. So you can evolve a complicated mechanism to trap small animals and digest them for nutrients. It also provides you with a bit of energy, but it's completely immaterial compared to photosynthesis, so you don't even bother evolving all the complicated protein-to-glucose pathways.
Now, you want to grow bigger. How would you do it? Energy is not an issue, the photosynthesis provides plenty of it. But you need to trap more or bigger animals, and that's an issue. There just aren't that many of them, and you can't just get away with simple traps anymore.
Looking at my spotted windowsill, if I was a plant on an evolutionary adventure, I‘d befriend some spiders and turn my crown into a cotton candy guano cloud. I‘d rather have the animal predators do the work and then have them shit in my yard for the nitrogen and phosphor. You only need twigs and then some bioluminescence or stink to help those spiders fill their nets.
Have a fungus rot my legacy core wood so an owl can defecate a hectare of mice and squirrels right into my tummy. Or you look all mighty and judgmental so these funny naked apes drench your soil in the blood of goats and their youths. Is that still a thing?! What about instagramable forest cemeteries? Heard about the tree toilet TikTok challenge? So fun! Super healthy and natural too.
Now thinking of it, I wonder how many plants encourage animals shitting and dying in their yards. Maybe it’s not deterrent, but enterotoxic payment options?
I guess, unless your objective is to grow impractically large fruits, because your human creator couldn’t keep it in their pants, for most plants in most places, neither phosphor nor nitrogen side hustles are really worth the effort.
> It can be fixated only through biological means
I don't think this is very correct, but why do these biological means fail in bogs/swamps? Kinda my point: Other plants and ecosystems figured out the nitrogen problem all over the world. It's more or less the same everywhere, since nitrogen naturally comes from the atmosphere. AFAIK, there are more or less three ways to have nitrogen input into an ecosystem: Lightning, biological fixation in plants/microbes and artificial synthesis/fertilization.
I suspect the swamp ecosystem has something going which makes nitrogen fixation difficult. All other plants in the swamp need nitrogen to grow, too, how are they doing? Maybe it is the (often) low pH, maybe it's a lack of trace metals for certain enzymes. Maybe the anaerobic conditions favor inaccessible conversion of nitrogen in decay.
Nitrogen can't be completely exhausted, because you have (low) constant influx from the atmosphere everywhere on Earth's surface, even without biological fixation. Phosphorus, on the other hand, can be effectively depleted. The "cycling" of phosphorus happens on geological timescales. A low soil pH may leech out the phosphorus from minerals and have it carried away by wind and water.
I still don't think plants would go the carnivorous route just for the nitrogen. If anything, I suspect they recycle the "nitrogen" as amino acids to save on synthesis. Some carnivorous plants apparently secrete phosphatase into their prey. That's a lot of evolutionary effort...
> I don't think this is very correct, but why do these biological means fail in bogs/swamps?
They don't. Moreover, the anoxic environment of swamps actually promotes the nitrogenase activity. However, the constant presence of water also diffuses the nutrients, and denitrifying bacteria use ammonia as an energy source. In oxygenated environments, they are typically outcompeted by regular air-breathing bacteria.
This happens in regular soil, but it's normally not saturated with water, so nutrients are not constantly washed out.
> All other plants in the swamp need nitrogen to grow, too, how are they doing?
Not very well. Swamps are not very productive biologically. There is _some_ nitrogen available, it's just that its equilibrium concentration is much lower.
All it takes is to make your forest more attractive to bears than the Vatican City is.
Bears are notoriously suspicious of ritualized worship, so... low-entropy solution achieved.
Nepenthes Lowii says hi.
"However, pitchers produced by mature N. lowii plants lack the features associated with carnivory and are instead visited by tree shrews, which defaecate into them after feeding on exudates that accumulate on the pitcher lid."
[0] https://royalsocietypublishing.org/doi/abs/10.1098/rsbl.2009...
Still, I kinda want to see a tree's light faintly glowing through their guano cloud of horrors. You could plant them next to lakes and such to get rid of mosquitos! But mostly for the eerie atmosphere, to make man afraid of the night again. Whispers of ten thousand feet, be wary of the lantern trees!
Isn't the obvious conclusion that: 1. There are many peaks in the fitness hypersurface for plants that correspond to meat eating 2. The peaks have smooth gradients at the outskirts 3. All peaks are minor local maxima
1 is because low nitrogen alone is not enough to make carnivory a net positive contributor to fitness. You need additional factors to make the gradient positive to begin with. That means the peaks (niches) are random and narrow.
3 is because carnivory implies an arms race against prey defenses, competing scavengers, and competing predators. Specialist animals are at a large advantage against plants, especially if meat is still a side dish to sunlight.
To me the interesting question is 2 - most plants don't digest animals at all, so how does this begin to evolve?
I.e., because they got their nutrients from animals they didn't need chloroplasts and the chloroplasts 'broke' over time. Chances are minimal to zero that carnivorous plants will regain chloroplasts. In a way, carnivory in plants is an evolutionary 'dead end' similar to parasitism, which is also often linked to chloroplast loss. Where could the plants evolve 'to' if they have no chance of getting energy from alternative (chloroplast) sources?
Clearly these researchers have never been to the Mushroom Kingdom.
Like, an orca is more fish, you are more fish (or fungus for that matter), than a mushroom is a plant.
Yes, troop 1 of monkeys have learned about the monkey-eating plants that have evolved overnight, but troops 2-10 haven't. Eventually troop 1 leaves the deadly forest, and troop 2 comes in. After a few seasons, they notice these fucking plants keep eating their babies (again, most predators go after babies for the reason you mentioned, they haven't learned how to avoid death yet) and then they move on. Repeat for several centuries. Behold nature in all its splendor.
I like the article's ideas: If you can grow large enough to eat a person, you're getting enough nutrition that you don't need to eat a person.
I'd be surprised if your tomato plant "ate" a whole teaspoon of fertilizer in its entire growing season.
This piece made me see it differently. Not growing big is not a flaw. In a place with barely any nutrients, surviving with just a bit of strategy is actually kind of amazing.
If you're a plant, don't buy into the negativity. Work your way up the food chain. If you eat it, then it's your food.