They are some of the most productive ecosystems in the West, with a great diversity of plant and wildlife species, Healthy riparian systems purify water by removing sediment as it moves through vegetation. Riparian vegetation absorbs and dissipates the energy of flood waters which cause stream bank erosion. They also provide critical habitat for wildlife and fish. I nvasive weed species, such as purple loosestrife, can be extremely competitive in a riparian setting. Invasive weeds crowd out valuable native species by forming solid stands.
Noxious weeds can alter the hydrologic cycles along riparian areas.
For example, saltcedar, which has invaded wetlands and areas along streams throughout the United States, uses large quantities of water and traps more sediment than native species. This weed lowers water tables and, in some areas, has eliminated surface water and native vegetation needed for wildlife. In addition, it has altered the shape, habitat, carrying capacity and flooding cycle along waterways.