Without a central nervous system our human idea of pain makes no sense. Plants can no more experience pain than you or I can photosynthesize.
That's not to say I don't understand your thought process here. It's easy to project those feelings of empathy onto just about anything if it's subject to enough violence. I have definitely cried over a broken mug before.
Plants don't have the nervous system required to feel pain and thus cannot and do not feel pain
If you define pain as pain nerve receptors reacting to stimuli, then yes, but is that a good definition of pain? Is a headache pain by that definition? What about phantom pain in humans?
What about animals like arthropods, who shouldn't feel pain, but studies on crabs and lobsters have shown that they react avoidantly to negative, painful stimuli. Does it need to be a pain receptor to cause pain? I don't know how the brain of a lobster or cuttlefish or salmon or dog or spider or dog or cow interprets external stimuli.
Snails seem to have chemoreceptors - are there certain chemicals that they touch that produce painful sensations in their brains? They certainly seem to avoid copper and sharp objects.
Does one even need a brain to experience negative stimulus? I don't know. I am not confident enough to answer that trees don't experience pain. Plants respond to good and bad growth conditions. They scar when cut. They produce toxins and chemicals to inhibit things from damaging them and encourage things that are good. To me there's very little difference from those responses to our responses to pain, except with different time scales. We can move fast and so react quickly to stimuli. Trees and plants move slowly with growth -- but quickly with hormone production.
Anyway, I don't know. I think about this a lot.
If you define pain as pain nerve receptors reacting to stimuli,
But I don't. Pain is the subjective experience created in your brain that you know as pain. Plants don't have any reasonable way to produce such an experience and thus (since I'm not in the habit of entertaining hypotheses with no logical or evidential backing) plants don't feel pain.
Glad you read at least my first sentence. I'm just thinking about stuff. I see a lot of people very fast to dismiss possible suffering in living things that aren't us or that we don't understand.
Heck, we don't even really understand the mammalian brain let alone that of other families of creatures.
It is just reminiscent to me of the "facts" that people used to believe that animals don't feel pain, or animals don't have feelings, or whatever, to justify factory farming. I'm not saying it's the same, just a similar idea that since we can't talk to snails it's easy to assume they aren't hurt by stuff. Or with plants, too, sure, they don't have an animal brain, but their cells still coordinate to grow and live - it's something we don't understand too well.
:shrug-outta-hecks: Show me evidence that a plant can have subjective experiences and I'll take it seriously. Just reacting to something isn't enough. When I touch something hot, my body reacts to the negative stimulus long before I feel the subjective experience of pain. The negative stimulus on its own is unpleasant only to the unconscious, automatic parts of my body the opinions of which I frankly do not care about. It is when the subjective experience of pain is formed that something bad has actually happened. Since plants act entirely through these unconscious systems (as there is no consciousness) it is impossible to inflict pain on them.
Interesting, although if you want evidence-based studies about plants feeling pain, I mean you know that doesn't exist and can't since we can't communicate with them. Similarly, we actually don't have that kind of evidence for any animals other than humans.
We have visual evidence of dogs, eg, crying out when getting hurt, but are they having a subjective experience? We can't know.
I would say that the only way we are other animals having pain is through avoidant reactions (running away, fighting back, etc), which you are saying are really just caused by unconscious behaviors. We know in humans that these are associated with pain, so we canmproject that onto other animals (which I think is correct), but in terms of validated science saying animals have subjective pain it doesn't exist for dogs, it doesn't exist for snails, and it doesn't exist for non-animals either, of course.
I have no way of knowing what another animal or plant feels when exposed to negative stimulus. I know that humans have pain, and i can infer that other animals probably do as well, but if animals avoiding negative stimuli suggests that they feel something like pain, who am I to deny (without evidence) that plants don't have some kind of unpleasant "feeling" associated with their avoidant behavior reactions to negative stimuli.
Overall, we can't know - but if you believe that having a brain is the threshold to experiencing something unpleasant that is like pain, I can be on board with that. I don't want to deny that there might be other unpleasant interpretations of negative stimuli that humans don't know about.
The problem is that by this logic, maybe rocks feel pain. Maybe the atmosphere feels pain when we pollute it. Maybe the ghost of Jimmy Johnson who lives in my attic feels the pain of loneliness. "Maybe it feels pain but we don't know about it" is a completely meaningless and unactionable observation. Without evidence that it feels pain, we can only assume that it does not.
No, because plants and trees respond to negative stimuli. Do rocks? Are ghosts real? These aren't real equivalencies and you know it
One of the primary evidences that something feels pain is a reflex. When I slap a tree, it doesn't try to run away.
When you cut a tree it starts making different chemicals to fight you off
Plants and trees definitely react to negative stimuli - producing protective hormones and chemicals and releasing them into the air -- saying that, what part of hydroponics do you rip plants out of the ground?
I grow seedlings in small containers and then transplant -- there shouldn't be damage to the root system or any system - or if you're worried about it plant the seed directly in the hydroponic system. It will take extra care but can be done.
With a well-maintained hydroponic system the plants are getting all of the nutrients they need so should be quite happy there, actually.