There is something invading California estuaries and it is not Sparta, the powerful ancient city-state. Rather, this invader takes its form as the coastal plant Spartina commonly known as cordgrass. Various characteristics of the Spartina make its territorial conquests quite aggressive. Possibly its most stealthy tactic for invading is its interaction with the native California cordgrass, Spartina foliosa. The nonnative forms of Spartina are able to form hybrid species with native forms and further expand their range.
Once the invasive forms have spread to new territory, the establishment of the invasive Spartina can have major consequences for native habitat. Their presence often results in the loss of native biodiversity by out-competing native vegetation, reducing mudflat and channel habitat by clogging flood channels, and increasing sedimentation rates. Furthermore this invasive species impacts foraging and nesting habitat for numerous shorebirds, including the endangered Clapper Rail.
However, it is not all doom and gloom in the realm of nonnative species. This October, the San Francisco Estuary Invasive Spartina Project received the organization of the Year award from the California Invasive Plant Council for the project’s success reducing the range of the hybrid Spartina since 2005. Many dedicated individuals are continuing to work on both eradication and restoration efforts in the Bay Area. Congratulations!
Invasive species are often associated with causing local extinctions and changing ecosystem processes. For this reason, The Watershed Project incorporates nonnative plant removal as an important part of creek restoration days. If you want to learn more about the importance of protecting native habitat and how to get involved in removing invasive plants, contact Martha Berthelsen at martha@thewatershedproject.org to learn more about our upcoming restoration workdays.
Top photo: Spartina densiflora, dense-flowered cordgrass, invasive species of spartina found in Humboldt Bay National Wildlife Refuge.
Middle photo:Spartina densiflora, dense-flowered cordgrass, invasive species of spartina found in Humboldt Bay.
Bottom photo: Spartina alteniflora, hybrid species established in native Spartina foliosa habitat.