Layne's Butterweed - Lane Blankenship

LAYNE’S BUTTERWEED -  Senecio layneae

Listing: Federally Threatened; California Rare

Description and Ecology -  

Layne’s Butterweed is a yellow flowering perennial herb that blooms from April to June.  It is a California native, and endemic to gabbro and occasionally serpentine soils in the Pine Hill region of the Central Sierra Nevada foothills. The reproductive cycle uses outcrossing - each individual reproduces with members of its community outside its own genetic line.  It is an secondary succession chaparral plant.  The population’s life cycle is linked to a fire cycle of between 60 and 80 years between burns. (2)

Gabbro soils are specific, and fairly rare in California. They have an average of ten inches of topsoil with about thirty percent granular igneous rocks meaning quick drainage and nutrient loss. They are rich in iron and magnesium, and the plant life in these areas has adapted to use these surpluses. (1)

(3)
Geographic and Population Changes -

Geographic changes started with the development of the gabbro soils area for access to the American River Canyon water. Water flumes were constructed, and this began the fragmentation of populations. Next was mining roads for gold and semi precious stone miners. Fragmentation of the gabbro soils communities continued, and the edge effect started to take its toll. Chaparral cutback as a fire prevention method around residential and commercial structures contributed to overall habitat loss, and interfered with fire succession patterns.

Soil seed bank loss mixed with excess carbohydrate storage was devastating to population reproduction, and drastically impaired reproductive patterns. When fires finally came, they were too hot due to excess fuel, and burned what was left of the seed banks. This all happened from 1970-1980. The human community took notice and in October 1996 Layne’s Butterweed was placed on the federally threatened list, and five other plants were placed on the federally endangered list.  While this was caught before unrecoverable, it was not until populations were severely impacted. (1)

Cause of Listing and Continued Threats-

The cause of listing is low population numbers based on the plant’s inability to reproduce efficiently and the fragmentation of populations into very small sections.

Continued threats are always evolving. One of the largest threats are fires. While needed for reproduction and recruitment, a fire too hot can wipe out an entire population. Lack of fire, because it is an intermediate succession plant, it can be shaded out as old growth settles in and possibly even wiped out from an entire area.Another threat is road widening, this cause the edge effect to take an increasing toll on the already small suitable growth areas. (1)

Recovery Plan -

The recovery plan is a long term multi-species approach.  Its main goals are habitat protection and management; surveying and monitoring; research; and public participation, outreach, and education. The US Fish and Wildlife Service recommended the areas shown on the map below as the Pine Hill Preserve. (1)

What Can You Do?

Currently the Pine Hill Preserve can use volunteer builders and maintenance workers to create and upkeep the Pine Hill Preserve.  There is also a need for educated nature leaders to educate the public through nature walks, museum showcases, and advertisement.  It is also underfunded and could use donations of land and capital to the cause.

Resources -

1. U. (2002, August 30). RECOVERY PLAN FOR GABBRO SOIL PLANTS OF THE CENTRAL SIERRA NEVADA FOOTHILLS [PDF]. Portland, Oregon: U.S. Fish and Wildlife Service.
2. Brink, C. (2016). Pine Hill Preserve - Rare Plants. Retrieved November 29, 2016, from http://www.pinehillpreserve.org/rare_plants/
3. W. (n.d.). Threatened, Endangered, and Proposed (TEP) Plant Profile. Retrieved November 29, 2016, from http://www.fs.fed.us/wildflowers/Rare_Plants/profiles/TEP/packera_layneae/index.shtml