As horseback riders, hikers and dog walkers passed on trails among rolling patches of purple, yellow and green wildflowers at the Santa Monica Mountains National Recreation Area on a recent Saturday morning, a team of volunteers was ready for battle.
The enemy was a long green weed with tiny flowers known as carnation spurge – a toxic relative of the holiday poinsettia plant and one of the “evil 25” nonnative species officials have identified as plaguing the Santa Monica Mountains by posing a threat to wildlife and a fire hazard to the park.
“They displace our native species,” said Joey Algiers, restoration ecologist with the National Park Service, which manages the park.
Carnation spurge, in particular, has toxins that can cause temporary blindness, skin irritation and digestive tract issues in wild animals, he said.
Nonnative plant species have invaded in full force this spring along with the colorful super bloom of native wildflowers blanketing Southern California due to the rainiest winter in years. Ecologists, park rangers and botanists across the region are mobilizing to confront and pull these pesky invaders from parks and trails.
“Rain was really great for the nonnative grasses also,” said Ramona Robison, science program manager with the California Invasive Plant Council, a nonprofit dedicated to protecting the state’s lands and waters through research, restoration and education. “Basically, you just got a lot of growth everywhere.”
In the Santa Monica Mountains, Algiers is leading a series of volunteer days on alternating Saturdays in May and June to help restore the park by pulling weeds.
“This is a pretty big push for us,” Algiers said. “You can’t have a successful restoration without continually controlling the invasive species.”
Rachel Capata of Los Angeles was among about 30 volunteers, armed with blue plastic gloves, who pulled weeds at Zuma Canyon during the first Saturday in May.
“I generally find that volunteerism is the best way to overcome personal frustrations,” said Capata, who is concerned that national monuments, designated as federally protected land by previous presidents, are under review by the Interior Department. “I’m a big believer in doing something about it rather than talking about it. Really, this is our backyard.”
The other volunteers were grateful when Capata, a former Girl Scout troop leader, spotted an idle rattlesnake coiled near the weeds. She alerted Algiers and other park staff, who soon contained the area that the snake did not want to leave.
Grey Wears and Stephanie Daniels of North Hollywood also wanted to do their part.
“I love to hike, and I love the Santa Monica Mountains,” Wears said. “It sounded like a way to help out, get exercise and be outdoors.”
The Santa Monica Mountains National Recreation Area spans more than 150,000 acres in Los Angeles and Ventura counties, making it the nation’s largest urban national park. The remaining volunteer days will run from 9 a.m. to noon Saturday, and also on June 3 and June 17.
Further south, at Anza-Borrego Desert State Park, which surrounds Borrego Springs, volunteers in February and March focused on pulling a newer weed called Volutaria, which was discovered in areas around the flower fields in recent years but multiplied this year, said Gina Moran, the park’s senior environmental scientist.
Volutaria is native to North Africa and has also invaded Chile.
The aim is “to eradicate it from the park, not just to control it,” Moran said. “That’s our challenge to try to get out there early.”
Staff trained volunteers to find Volutaria and, while they were out there, to also look for Sahara mustard, which is more widespread and has been at the park longer.
The long-term goal is to preserve the native plant and animal life at the park.
“The big challenge is if the weeds are here, they will out-compete the native flowers and shrubs,” Moran said. “Once we lose that diversity of plant life, we will lose that diversity of wildlife.”
Volunteer efforts help people learn more about their environment and the importance of preserving the health of the ecosystem, said Robison, from the California Invasive Plant Council.
“It’s very important for people to get out and experience the place they live,” she said.
Journalist Marisa Agha is based in Southern California.