There is a downside to having trees around in certain areas. When dead and if not disposed of properly, trees an become a fire hazard. They've also been known to fall on people, houses, across roads, and on power lines. So when they are in populated areas, trees do need to be maintained.
As far as spirituality is concerned, some people connect to a spiritual existence when surrounded by trees and other plant life. The sheer beauty of trees brings a sense of wonder to the admirer. It's believed that having trees nearby can help reduce stress. They even lend to the healing process.
Magickally speaking, trees have certain properties that can be used by those who recognize them. Here are some examples:
Alder confidence, strength Apple life, renewal, beauty Ash rebirth, peace, communication Aspen intuition, overcoming obstacles, sensitivity Birch beginnings, energy Blackthorn control, connected to the Dark Lady Elder change, life cycles Fir vigor, secrecy Oak truth, strength, endurance Rowan insight, premonition, creativity Willow intuition, enchantment, psychic ability