I had a room mate once (who studied biology) that explained to me that the smell we smell when the grass is cut is actually a warning signal that grass expels when cockroaches or other bugs eat grass. It was always humorous because he would smoke a lot of weed and then tell me "The grass really lives man! Plants talk, plants communicate, we need to respect their feelings."
I guess from this article that him being stoned didn't deter him from telling the truth.
In many species, if the tree loses its leaves due to a pathogen or insects then it can still get nutrients from any tree (of any species) nearby, as long as both root systems are in symbiosis with a common fungus. The mycorrhizal net actually transports nutrients between trees. It's pretty cool.
I guess from this article that him being stoned didn't deter him from telling the truth.