Science Spotlight

Lassics lupine grows under protective cages.


Richard Macedo, Habitat Conservation Planning Branch Chief constructs a cage to protect rare, endangered Lassics lupine.


Lassics lupine grows under protective cages.

Biologists from three government natural resource agencies banded together this summer in an unusual effort to help preserve a species under threat of extinction. They lugged materials to build wire cages into the rough terrain of the remote Lassics mountains near the border of Humboldt and Trinity counties in an effort to protect their target. However, these cages were not built to trap animals; they were constructed to keep animals out.

The barren, green serpentine slopes of Mount Lassic, located in a seldom-visited part of Six Rivers National Forest, are home to one of California’s rarest plants: the Lassics lupine (Lupinus constancei). Lassics lupine is a short plant in the pea family that has bright rose-pink flowers. Only approximately 450 adult Lassics lupine plants were observed during 2017 monitoring of the species conducted by the U.S. Forest Service and the U.S. Fish and Wildlife Service, with assistance from CDFW.

Rodents such as deer mice, squirrels and chipmunks have been eating so many Lassics lupine seeds from the plants that, absent intervention, the species appears to be on the path to extinction within the next 50 years (Kurkjian et al. 2016).

Biologists believe that historical suppression of fires in Six Rivers National Forest beginning in the early 1900s may be indirectly responsible for the encroachment of forest and chaparral into Lassics lupine habitat. Fires that were put out quickly did not grow large enough to reduce encroaching forest, and therefore the forest expanded. With the encroaching vegetation came more seed-eating rodents that depend on vegetation cover for protection from predators.

In 2003, the U.S. Forest Service, U.S. Fish and Wildlife Service and other researchers began an emergency attempt to halt Lassics lupine’s trend towards extinction. Each summer, biologists set off on the laborious hike up Mount Lassic to place cylindrical wire cages over as many flowering Lassics lupine plants as possible. Each cage is anchored to the ground to prevent rodents from squeezing underneath.

The cages are remarkably effective at stopping rodents when properly installed, and they remain on the plants for the duration of the growing season. After Lassics lupine fruits have matured, they often split open suddenly and send seeds flying through the air up to 13 feet away. The cages are then removed each year before the onset of winter snow.

“Protecting endangered species is California’s policy and plants like the Lassics lupine could disappear within our lifetimes,” explained Jeb Bjerke, a biologist with CDFW’s Native Plant Program. “We should do what we can to save these unique plants for the future.”

In 2015, in the midst of an historic drought, an 18,200-acre fire spread through the Lassics, killing many Lassics lupine plants and charring the chaparral vegetation nearby. The fire had little effect on the forest that encroaches into Lassics lupine habitat, but preliminary studies suggest that the fire may have reduced rodent density in the burned chaparral. Despite the apparent reduction in rodent density following the fire, the impact from rodents eating Lassics lupine seeds remains high. Continued caging of Lassics lupine plants therefore remains critical for preventing extinction of the species until a more permanent solution can be implemented, such as significant reduction of encroaching forest. However, such efforts are expensive to plan and implement. As the primary land manager, the U.S. Forest Service would likely be the lead agency in future protective actions.

In 2016, the California Fish and Game Commission received a petition to list Lassics lupine as an endangered species under the California Endangered Species Act and the species was designated a candidate species earlier this year. CDFW is in the process of producing a status review for Lassics lupine that will include a recommendation to the California Fish and Game Commission on whether listing the species is warranted. The legislature directs all state agencies, including CDFW, to seek the conservation of endangered and threatened species.

“I hope that CDFW can continue to partner with the U.S. Forest Service and U.S. Fish and Wildlife Service to protect the Lassics lupine from extinction,” Bjerke said.

For additional information on this subject, please see:

• Report to the Fish and Game Commission, Evaluation of the Petition from Mr. David Imper and Ms. Cynthia Elkins to List the Lassics Lupine (Lupinus constancei) as an Endangered Species under the California Endangered Species Act (PDF).
• Kurkjian, H.M., S.K. Carothers, and E.S. Jules. 2016. Seed predation has the potential to drive a rare plant to extinction. Journal of Applied Ecology 54:862–871.

California Department of Fish and Wildlife photos by Jeb Bjerke

California hosts approximately 6,500 different kinds of plants that occur naturally in the state, and many of these are found nowhere else in the world. Some of these plants are so rare or have been so impacted by human influence that they are at risk of permanent extinction from the wild and have been protected by state and federal laws. The California Department of Fish and Wildlife’s (CDFW) Native Plant Program is developing and implementing standardized and repeatable monitoring plans for ten state and federally listed plant species on nine CDFW Ecological Reserves throughout the state. This work is funded by a federal grant awarded in 2015.

One of the plants being monitored is Butte County meadowfoam (Limnanthes floccosa ssp. californica), which occurs at North Table Mountain Ecological Reserve, north of Oroville in Butte County. The reserve is on an elevated basalt mesa that was created by ancient lava flows and supports a rare type of vernal pool called Northern Basalt Flow Vernal Pools. There were only 498 Butte County meadowfoam plants found on the reserve this spring. The reserve also supports a high diversity of other plant species that erupt with bright colors in the spring and attract hordes of visitors.

Another plant being monitored is the endangered Slender-petaled thelypodium (Thelypodium stenopetalum) that occurs at Baldwin Lake Ecological Reserve, in the San Bernardino Mountains near Big Bear. The reserve is in a unique environment known as the pebble plains, which only occur in Big Bear Valley and nearby Holcomb Valley. The pebble plains were formed when glaciers receded during the Pleistocene age and mainly consist of clay soils overlain by a layer of orange and white quartzite pebbles. Slender-petaled thelypodium only grows in this rare pebble plain habitat, and only 15 plants were found on the reserve last spring. Other rare plant species such as the endangered bird-foot checkerbloom (Sidalcea pedata) are found on the reserve and in the surrounding pebble plain habitat.

The monitoring project also includes plants at Little Red Mountain, Boggs Lake, Loch Lomond, Stone Ridge, Phoenix Field, Pine Hill and Apricum Hill Ecological Reserves. The grant is funded through January 2018 and the Native Plant Program has applied for another grant to continue this project.