Speaking as someone who has planted hundreds of trees, and carefully observed which lived, which didn't and why, I'm not convinced that the average person "planting trees because it's a good thing" does anything other than waste their time.
I believe botanist are the best at what ways and soil is best for a tree special and the best care that could be given to it and you might be a botanist yourself, I don't know that so I won't want to comment on that either but then, I don't so much agree with the idea that an average person planting trees is just a waste of time.
If it is about the fact that, planting non native species or invasive species could be harmful to the vegetation of that environment and in turn the environment itself, that I would understand but then, should native species be planted, even if it didn't get to grow to its full potential, for the years it did grew and persisted, it surely helped as cover crop, air cycles (Carbon, nitrogen etc) and shelter for aboral and terrestrial animals including the microbes so, it did help and it isn't a total waste of time.
A botanist really would be an expert, but you won't expect them to plant as many trees for the environment itself, they are busy doing their researches about plants, discovering something, and many more. A lot of documents and articles can be easily found in the internet, and you don't need a degree for that.
What I am going through with this is that anyone can plant trees and make it work for the environment, it is just that if they really care about the planting itself, they would go through the ways on how to nurture it, how to plant it, the distance needed between them.
But aside that, I agree that trees are really helpful, if that is what just this thread is asking.
