A healthy, native vegetative community is an important factor in watershed health. Grasslands and riparian vegetation provide a pathway for precipitation to infiltrate and can prevent soil erosion and the development of gullies. Removing undesirable noxious and invasive plant species in riparian areas, such as tamarisk (salt cedar) and Russian Olive, and planting native willow and cottonwood can help establish a more balanced riparian community. Similarly, selective thinning or removal of undesirable monotypic stands of sagebrush, cholla cactus, and piñon-juniper can allow the re-establishment of healthy grasslands. Seeding areas and fencing out grazing animals may help restore these desirable conditions.