They haven’t transferred the money to anyone else. An ethical investment fund just selects businesses that meet certain criteria, e.g. no weapons manufacturers or tabacco companies. They haven’t given a penny back to anyone, not even made a donation to e.g. a non-royal family charity or good cause, as far as I’m aware. They’ve just changed the source of funds for the renovations that this particular income was reported to being used for.

You can get tree protection orders for single or groups of trees. I have a feeling you can make an application to get them protected without them being on your land.