I grew up on a farm in central Wisconsin. The Pigeon River provided our southern boundary. Steep banks led down to the water. In downpours some of the soil washed away, leaving deep gullies.
My father wanted to conserve the soil, so we planted trees - hundreds of pine trees on the river banks. One of the gullies was so deep that when I stood in it as a child I couldn't see out.
Years later when I had grown up and married, I wanted to show that gully to my wife. I searched and searched and couldn't find it! The trees were now 30 - 40 feet tall and covered the river bank. The trees had done a Tree-mendous job of healing the scarred earth.