For the humans, trees are green gold on the earth as they provide clean and fresh air, reduce pollution, provide food, shelters, fruits, vegetables and fresh oxygen. They are considered to be the outside air conditioners as they cool the atmosphere and absorb the carbon dioxide which maintains the temperature.
Not only humans but for many animals. Animals live their complete life in the surrounding of trees.
It is fine to cut and use the trees as needed by the human beings, but it is not fine to not grow and care for the trees because eventually the effects will directly harm the living creatures. If we cut one tree then it also comes under our responsibility to grow as many trees as possible.