How are the trees useful for mankind?

The trees are very useful for mankind. They have various uses. They fulfil the needs of all forms of life on the earth. Birds take their food and shelter from the trees and so many animals also do the same. As far as the human beings are concerned, for human beings trees are a major source of life sustenance on the planet. Trees give us fruits, shade, timber, medicines and various other such elements for the use of human beings. Trees are also a source of entertainment. Children love to play around the trees. Trees provide relief and also work as subjects that could be painted by those, who have leisurely time.