Trees are extremely important. Trees,prevent other plants/smaller trees /animals from strong wind and rain. They are also large carbon dioxide suckers, replacing it with ample and lost of oxygen. They also provide shade from the sweltering sub. To be honest, I reccomend everyone buy a tree and plant one in there and have less carbon-dioxide. Trees are also important because if you think about it in a physcat way trees guard you from the wild parts of mother nature.