Have you noticed planting trees is slowly becoming a popular hobby? I am happy to see this, as tree planting is a passion of mine. The first thing I do when I buy a new property is to plant trees. Fruit trees for food, birches, willows, maples and populars for the bees, oaks for longevity, ashes because they are a nice wood for many things and they grow easily in my area. Evergreens such as pine and fir etc... As the trees grow, I notice more insects, birds and other critters appear.
I like to plant a variety of trees as they fulfill different functions for various critters. Each tree has numerous functions in the environment as well as things we can do with them. Some are edible or used as medicine, some for fire wood, or making furniture etc. The uses are endless for some of the trees. They all provide food for mycelium which make huge underground networks that are necessary to the health of the planet. If you don't know what I am talking about, check out a video or book by Paul Stamets.
All the trees use carbon dioxide and make oxygen. This is an important point which I think the world is catching onto. All of us critters like that oxygen and there is a lot of people concerned about too much CO2 and how to stop making it. When I hear folks worried about it, I tell them to plant trees and many of them think I am silly to present them with such a simplistic solution. However, if they took the time they spent complaining about CO2 and simply planted trees they could be helping the planet.
I hear many folks complain about too many slugs in their garden. I tell them their issue is not too many slugs, it is a lack of ducks. The same goes for folks who complain about too much CO2, I think we have a lack of trees.