Plants feel a lot. I've worked with a European start up for a short while, they're making plant well being sensors for farmers. These sensors detect internal signals plants produce. Plants are capable of discerning animal touch from the wind, temperature changes, damage caused by insects, etc. They can feel everything, but can't react much.

Things get even more complex in the forests, where trees exchange resources with each other through underground fungi networks. Trees in the forest not only react to the environment, but also talk to each other and help each other. That's why replanting forests is very hard and takes a lot of time - creating this underground network is essential, but it's a very slow process.