Invasive plant species negatively affect park resources and visitor enjoyment by altering ecological processes, reducing native plant and animal habitat, blocking views, and increasing trail maintenance needs. Invasive species are the second greatest threat to global biodiversity, after habitat loss.
Given the extraordinary biodiversity of the San Francisco Bay Area and its urban development pressures, the San Francisco Bay Area Network (SFAN) parks serve as crucial habitat for native species. Over 100 rare plant species can be found in SFAN parks. Invasive plants threaten many of these rare species.
Discovering invasive plants before they become well-established is critical to reducing damage to ecosystem integrity, preventing the loss of habitat for rare plants and animals, and preventing costly natural resource management. Trails, roads, and waterways are the main routes of infestation of new exotic species. Monitoring these routes is the most effective way to prevent the spread of existing species and the infestation of new species.
Invasive plants are monitored in SFAN parks through partnerships between the National Park Service, Golden Gate National Parks Conservancy, and Point Reyes National Seashore Association, as well as by volunteers and students.