Serpentine Chaparral
Serpentine - California's State Rock!
The rich and highly endemic flora of California epitomizes the plant geographer's dictum: Floristic diversity is fashioned out of environmental diversity (Stebbbins and Major, 1965; Raven and Axelrod, 1978). A major component of California's ecological diversity stems from the working of a great array of geologic processes and products.
- Arthur R. Kruckeberg in California Serpentines (1984)
Serpentine soil, created when the metamorphic rock serpentine weathers, is filled with toxic levels of nickel, chromium, and cobalt, and low levels of nitrogen, an essential nutrient for plants. It is a tough environment for plants to grow in, but the condition also provides lots of opportunities for the chaparral ecosystem to create endemic species. It is not so much that chaparral plants are adapted to the soil, it's mostly about the fact that other species can not tolerate it. This is similar to the plants that inhabit vernal pools.
Serpentine is formed during the collison of tectonic plates when water is combined with the plutonic rock peridotite.
Serpentine road cut north of San Luis Obispo, Hwy 101.
Serpentine soils can create an interesting patchwork of chaparral plant communities. Dense populations of chamise (deep green center and to the right) are often punctuated with occassional ghost pines (Pinus sabiniana). Location: Hwy 130, California.
Ghost pines (Pinus sabiniana) have a special tolerance for serpentine soils. It is one of the few trees that can be closely associated with chaparral. Location: Hwy 49 near the Merced River.
Chamise and a manzanita species growing over a solid deposit of serpentine. Location: Mt. Tamalpais, near summit.
Manzanita species on the (serpentine) rocks. Location: Mt. Tamalpais, near summit.
The hat rests on a boulder from the southern most deposit of serpentine in California near Pleasant Peak in the Santa Ana Mountains. The formation is a minor one and is part of the Santiago Peak Volcanics of Cretaceous age. It is difficult to locate even though it is along the Main Divide road according to geologic maps.
Interesting papers on serpentine soils in chaparral plant communities
Kruckeberg, A.R. 1984. Serpentine Geology. Chapter 2 in California Serpentines: Flora, Vegetation, Geology, Soils, and Management Problems. UC Press.
Kruckeberg, A.R. 1984. Serpentine Chaparral. Chapter 5 in California Serpentines: Flora, Vegetation, Geology, Soils, and Management Problems. UC Press.
Parker, V.T. 2014. A newly described serpentine-endemic Ceanothus (Rhamnaceae) in coastal Marin County, California. Madroño 61: 399-406. Safford, H.D. and S. Harrison. 2004. Fire effects on plants diversity in serpentine vs. sandstone chaparral. Ecology 85: 539-548. Safford, H.D. et al. 2005. Serpentine endemism in the California flora: a database of serpentine affinity. Madrono 52: 222-257. Whittaker, R. H. 1954. The ecology of serpentine soils. Ecology 35: 258-288.
Parker, V.T. 2014. A newly described serpentine-endemic Ceanothus (Rhamnaceae) in coastal Marin County, California. Madroño 61: 399-406. Safford, H.D. and S. Harrison. 2004. Fire effects on plants diversity in serpentine vs. sandstone chaparral. Ecology 85: 539-548. Safford, H.D. et al. 2005. Serpentine endemism in the California flora: a database of serpentine affinity. Madrono 52: 222-257. Whittaker, R. H. 1954. The ecology of serpentine soils. Ecology 35: 258-288.