Answer: Too many deer in a given area results in overgrazing and the eventual loss of brush and shrubs in forested areas. Loss of undergrowth means no place for small animals and birds to shelter and nest. The result is the disappearance of many native species that no longer have access to the habitat they need.
I think its because so the plants can absorb more nutrients from the soil while being sturdy and wide so when the plant gets snowed on it doesn't break<span />