PALLID MANZANITA } Arctostaphylos pallida
HABITAT: The manzanita grows only on rocky ridges and outcrops in maritime chaparral or coastal scrub habitats in the East Bay hills, primarily on thin, low-nutrient soils composed of chert and shale.
RANGE: The pallid manzanita lives in Alameda and Contra Costa counties in California’s eastern San Francisco Bay Area.
LIFE CYCLE: The pallid manzanita is an obligate seeder, reproducing sexually only from seed. Bees appear to be important in pollination. The species primarily requires fire for reproduction, needing fire-sterilized soil and scarification of seeds to germinate. Plants can occasionally reproduce asexually by layering, when branches from the plant’s base come into contact with deep leaf litter and produce roots.
THREATS: Urban development, improper vegetation-management activities, shading and competition by native and nonnative trees, the effects of fire suppression, herbicide spraying, hybridization, and habitat loss and fragmentation are hurting the manzanita.
POPULATION TREND: There are only 13 known occurrences of pallid manzanita. The total population in 2006 numbered about 1,200 plants — only 25 percent of the estimated numbers reported in 2002. Over the past two decades, the Oakland Hills population has been reduced by almost half, to approximately 125 plants.