The National Park Service says that exotic plants are the most wide-spread threat to the natural resources of the parks. Park Service rangers have ranked exotic plants ahead of other problems such as wildfires, overcrowding, pollution, vandalism, oil drilling and off-road vehicles. Aggressive exotic plants endanger native wildlife just as much as the bulldozer, plow and dredge. Exotic plants are often hardier than local native plants because they have no predators in their new environment. Because they can take over huge areas, they create monocultures and severely impact biodiversity, destroying the ancient relationships between plants and animal life.
Many native insects require specific plants for survival.
Without these insects other animals won't have the variety of protein-rich food that they need. Invasive plants which displace native trees and shrubs can eliminate habitat for birds such as the quail and Wrentit and provide a poor source of food and shelter. As each level of the food chain grows weaker, larger animals find it harder to meet their survival needs. Native Intelligence Luckily you can help wildlife starting right in your own yard. Instead of manicuring your lawn, provide a place for animals to forage and hide.