Incident raises awareness about the plight of rare species in the Santa Monica Mountains.
The Los Angeles County Department of Public Works is under investigation for mowing down an endangered plant in Topanga State Parks as part of a wildfire prevention project. The incident, first reported on by the Los Angeles Times on August 1, highlights the increasing conflict between conservation and human infrastructure needs.
Braunton’s milkvetch, Astragalus brauntonii, is a short-lived perennial member of the pea family that has purple flowers and gray foliage. It’s endemic to just three mountain ranges in Southern California, with the largest surviving population in the Santa Monica Mountains and is found nowhere else on Earth. At the time the plant was listed as a federally endangered species in 1998, it was estimated that there were just 3000 plants left in 18 locations. More than half of the population was in Topanga State Park.
The plant has a global conservation status of G2, which is defined as “Imperiled—at high risk of extinction due to very restricted range, very few populations (often 20 or fewer), steep declines, or other factors.”
Braunton’s milkvetch only grows in soil where carbonate—limestone—is present, and it is usually only abundant after a fire, although its seeds can also germinate without fire, or after manmade—mechanical—soil disturbances like brush clearance. This makes fire roads an ideal place for the plant to thrive, but it also puts it at risk for destruction.
The DPW incident took place in July, and involved bulldozing several acres of milkvetch habitat along a fireroad near the Pacific Palisades side of the park. This incident isn’t the first time this endangered species has been seriously impacted by a fireroad clearing project. A major population of the plant was accidentally destroyed following the 1993 Old Topanga fire. A second colony of the plant on the Ventura County side of the Santa Monica Mountains was deliberately bulldozed during negotiations to protect the site in August 1998, completely extirpating the plant from that area.
The recovery plan developed for this plant by the Department of Fish and Wildlife cautions that this species is so limited that a random incident that destroys a large enough population could trigger the species’ local extinction. It also states that, at the time of listing “the primary threats to Astragalus brauntonii included direct loss of plants and habitat from urban development and fire suppression. Since the plant is well documented at the site where it was destroyed by the DPW in July, it’s unclear why the July DWP project was allowed to proceed once the presence of the plant was known, and without input from a biologist or a monitor on site.
The LA Times reports that the Topanga State Park milkvetch incident is being investigated by California State Parks and the California Coastal Commission to determine if the DWP was negligent or simply careless. The California Native Plant Society is also involved in assessing the damage. How much harm was done will depend on whether the vegetation was bulldozed before or after the plants set seed.
Conservation advocates hope the high profile news story will help increase awareness, but this incident isn’t the only one in recent months to highlight the vulnerability of local endangered or threatened species in the aftermath of the Woolsey Fire.
The same Los Angeles Times article reported on an incident during the winter, when an LA County DPW road crew accidentally poured concrete into a creek culvert that was habitat for a population of endangered red-legged frogs. The culvert was damaged during the wildfire. The work crew was unaware that the creek contained critical habitat. By the time the damage was discovered it was impossible to determine if any frogs were harmed, but the discovery was a blow for the National Park Service biologists working to reestablish the locally extinct species in the Santa Monica Mountains. The fire and subsequent flooding had already taken a major toll on the frogs, before the concrete mishap was discovered.
The Woolsey Fire, itself a manmade disaster, impacted every kind of rare, threatened or endangered species in the Santa Monica Mountains. National Park Service documents list 23 federally listed plant and animal species with potential to occur within the Santa Monica Mountains National Recreation Area, and three state-listed species. There are an additional 46 animal and 12 plant species in the area that are federal or state species of concern. In addition, a number of other plant and animal species are considered rare or are species of concern specifically within the recreation area. Nearly half of the park was burned in the Woolsey Fire, and nearly 90 percent of National Park lands were impacted.
The milkvetch and red-legged frog incidents are reminders that disasters like wildfires aren’t the only threat endangered, rare and threatened species face, and that even populations located in areas set aside for conservation, like state and national parkland, are not immune to environmental damage.