After millions of years, why are carnivorous plants still so small?
smithsonianmag.com
smithsonianmag.com
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.
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.
I'll raise you this:
“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.