Coastal Scrub & Chaparral
Coastal scrub and chaparral are the two most common shrublands found in coastal California. Shrub species that make up coastal scrub typically have bendable stems and soft leaves that generally shrivel up or fall off in the dry summer months. The leaves of many species also contain aromatic compounds that smell like kitchen herbs (e.g. sage or rosemary). In Golden Gate and Point Reyes, the coastal scrub is composed of species that are adapted to relatively wet and cool conditions and may not have characteristics typical of drier areas like that found at Pinnacles. For example, most of the coastal scrub in Point Reyes is composed of larger, less aromatic species and is sometimes referred to as “northern coastal scrub” as opposed to “coastal sage scrub” or simply “coastal scrub.”
Chaparral shrublands are made up of somewhat taller shrubs that have stiff, woody branches and thick leathery leaves that generally do not fall off or shrivel up during the dry summer months like those of coastal scrub plants. In the San Francisco Bay Area, chaparral can be found in very cool, moist conditions near the coast (e.g. maritime chaparral), on relatively dry and harsh serpentine soils (e.g. serpentine chaparral), and also on ridges or in dry interior canyons associated with a variety of soil types.
Fire is important to many of the vegetation types found throughout California, including coastal scrub and chaparral. Both habitats include species that are clearly adapted to wildfire and will resprout following fire or require fire to germinate from seed. All types of coastal scrub and chaparral are adapted to a particular fire regime, which is based on the fire return interval, intensity, seasonality, and other factors. In many cases, humans have altered fire regimes by making the fire return interval too short (frequent burning) or long (fire suppression). When fires are too frequent, shrublands can convert to other vegetation types, like grassland. In the case of the relatively cool, moist shrublands typical of Golden Gate and Point Reyes, the time between fires has been long enough that tree species like coast live oak (Quercus agrifolia) and Douglas-fir (Pseudotsuga menziesii) have colonized and shaded-out shrub species.