Coastal Strand Restoration: Protecting a Fragile Ecosystem on the Bayside
The bayside of Silver Strand State Beach (SSSB) is home to a fragile ecosystem that includes rare plants and ground nesting birds. A research study, and the low fence that visitors see, are part of the continuing story of SSSB's efforts to balance conservation and recreation in this area. You can read more of the story below.
A rare plant emerges on the bayside
By the 1990's, much of the bayside at SSSB was covered with thick mats of invasive sea fig (Carpobrotus edulis), a succulent plant native to South Africa. After the sea fig was pulled in the early 2000's, seeds of native dune plants began growing in the sand, after years spent dormant underneath the sea fig. Since then, a flora rich in sensitive plant species has emerged. One such discovery was Brand's phacelia (Phacelia stellaris), an annual plant in the borage family with deeply lobed leaves and bell-shaped pale violet flowers that often grows to be a few centimeters tall. This was an exciting find because Brand's phacelia is rare, currently located in just twelve occurrences (seven in the United States and five in Mexico). The species is categorized by the California Native Plant Society as 1.B.1 or rare, threatened, or endangered in California and elsewhere, and seriously endangered in California.
A charge to protect a tiny plant in a busy place
California State Parks is charged with the long-term protection of its natural resources, including rare plants and sensitive habitats, in fulfillment of its mission to help preserve the State's extraordinary biological diversity. The discovery of Brand's phacelia over a decade ago has emphasized the importance of maintaining a balance between recreation and natural resource conservation on the bayside at SSSB. This is a popular destination for bicyclists, walkers, picnickers, campers, kayakers (at the aquatic center), and college classes. In addition to Brand's phacelia, dozens of animal species stop by or live here, including migratory killdeer, resident horned larks, rabbits, and fence lizards. To better inform management decisions and sustain a native coastal strand ecosystem within the State Beach, California State Parks initiated a research study in 20121. The goal is to experimentally evaluate how rare dune plants, particularly Brand's phacelia, respond to human disturbance and other habitat conditions.
Focusing in on the research study
Experiments evaluate: a) the effects of annual raking, biennial raking, and weed removal on the abundance of Brand's phacelia; b) the response of Brand's phacelia to reduced or eliminated recreational use of some areas; c) the response of Brand's phacelia to soil-texture; and d) the abundance of Brand's phacelia relative to the abundance of invasive non-native plants. To accomplish this, 45 total 3 meter squared blocks are surveyed each year: 21 unfenced blocks in a campground/recreational use area, and 24 fenced blocks in a protected area. The fenced blocks contain 1 meter squared subplots randomly assigned a disturbance treatment (annual raking, biennial raking, weeding, control/no treatment). To survey each block, a biologist counts the number of Brand's phacelia and estimates the cover of all plant species, bare ground, and dead plant material. Baseline survey data was collected in spring 2012. Weeding and raking treatments began in 2013. Post-treatment surveys were completed in 2013, 2014, and 2015. Results indicate that fencing supports native species richness (number of native species present) and Brand's phacelia abundance. There were fewer native species and Brand's phacelia found in unfenced areas. So far, the data has not demonstrated a significant relationship between raking or weeding and rare dune plant abundance.
Working together and looking toward the future
In September 2013, California State Parks and other landowners2 responsible for managing Brand's phacelia populations entered into a Candidate Conservation Agreement with the U.S. Fish and Wildlife Service to assist in the long-term conservation of this species. Each landowner has specific responsibilities in pursuing this agreement. California State Parks committed to controlling invasive species within areas that support Brand's phacelia, monitoring Brand's phacelia populations every year, installing fence around sensitive areas that support Brand's phacelia, and managing large, off pavement special events on the bayside at SSSB. The findings of the research study are shared with the other landowners on an annual basis. This work helps rare plants and humans coexist at SSSB, today and into the future. The story of SSSB's efforts to balance conservation and recreation continues.
1 With support from the following partners: U.S. Fish and Wildlife Service, Southwest Wetlands Interpretive Association, and Tijuana River National Estuarine Research Reserve
2 Naval Base Coronado, U.S. Marine Corps Base Camp Pendleton, Department of Homeland Security