Tijuana River Valley Invasive Plant Control Program

The Tijuana River Valley is in one of the most important biological sites in California. It includes

  • Prime riparian and salt march habitats within a county regional park, a state park, and a national wildlife refuge.
  • Critical habitat for the least Bell's vireo, southwestern willow flycatcher, salt march bird's beak, wandering skipper butterfly, light-footed clapper rail, and Belding's savannah sparrow.
  • A designation as a Biological Habitat of Special Significance in the San Diego Basin Plan.
  • Listing by the California Coastal Commission as one of California's Critical Coastal Areas.
  • Federal designation as a National Estuarine Research Reserve by NOAA.
  • International designation as a Wetland of International Importance by the Ramsar Convetion.

                JOHN M. BOLAND, Ph.D.

But the valley is being degraded by non-native invasive plants, particularly giant reed (Arundo donax), castor bean (Ricinus communis) and salt cedar (Tamarix spp.; SWIA 2002). These plants reduce the beneficial uses, alter vegetation structure, displace native plant species, and degrade habitats for native animal species. They also increase fire frequency, alter soil chemistry, reduce surface water availability, and alter rates of sedimentation and erosion.

The Tijuana River Valley Invasive Plant Control Program was started by SWIA in 2002 with funding from the California State Coastal Conservancy and the U.S. Fish & Wildlife Service. The purpose of the program was to obtain the support of the various public landowners in the valley and to start control activities on a small scale. During Phase 1 of the project, a Technical Advisory Group (TAG) was formed, the distributions of the target species were mapped, an control plan was developed, all the necessary environmental permits were obtained, and experimental treatments in small demonstration sites were conducted. In 2004, funding from the Proposition 13 Watershed Protection Grant Program, allowed for Phase 2 and a great expansion of the program. Phase 3 is now underway with additional funding provided by Proposition 40 through the Nonpoint Source Pollution Control Program and the State Water Resources Control Board.


  • Maintain a Technical Advisory Group (PDF 56.2KB)
  • Control the Three Worst Invasive Plants
  • Conduct Project Monitoring
  • Provide Public Education and Outreach


U.S. Fish & Wildlife Service

U.S. Navy

U.S. Border Patrol

U.S. Geological Survey

National Oceanic & Atmospheric Administration

U.S. Boundary & Water Commission

California Fish & Game

California State Parks

California State Coastal Conservancy

California Coastal Conservancy

San Diego County Department of Parks & Recreation

San Diego County Department of Agriculture

City of San Diego

City of Imperial Beach


Boland Ecological Services 3504 Louisiana Street San Diego, CA 92104 (619) 296-5061 JohnBoland@sbcglobal.net


Ph.D. (Ecology) – University of California, Los Angeles M.S. (Ecology) – San Diego State University B.Sc. (honours in Zoology) – University of Cape Town, South Africa


Boland, J.M. 2006. The importance of layering in the rapid spread of Arundo donax (giant reed). Madroño 53 (4): 303-312. Boland, J.M. Layering: a ‘new’ mode of spread in Arundo donax (giant reed). California Invasive Plant Council 15th Annual Symposium, Rohnert Park, CA. October 2006. http://www.cal-ipc.org/symposia/archive/pdf/2006/AquaticBoland.pdf