The area was dramatically altered by a flood in 1965, which buried native vegetation under rock, gravel, and silt, leaving it slow to regenerate. More aggressive non-native plants can quickly colonize disturbed ground, depriving native species of the moisture and nutrients needed to re-establish themselves. As native plant species are lost, mammals, birds, amphibians, and insects that depend on them can also disappear. Native species form an interdependent community adapted over time to specific soil, moisture, and temperature conditions, and by interacting in a balanced manner they provide stability, diversity, and resilience to an ecosystem. Non-native plants, sometimes called weeds, produce abundant seeds, spread swiftly across disturbed areas, may release chemicals toxic to native plants, may introduce unwanted insects, and can grow so thick that they become a fire hazard. The National Park Service, with the help of volunteers, is working to recreate the natural ecosystem by removing exotic plants and planting native species.