Fremontodendron californicum , California flannelbush

California flannelbush, Fremontodendron californicum , is a shrub or small tree that occurs in California, central Arizona, and northern Baja California, Mexico. It is most common on dry sites in mountainous areas and is commonly associated with nutrient poor, rocky, or coarse soils. California flannelbush occurs mainly in chaparral and woodland communities and may be dominant in desert chaparral. California flannelbush reproduces by seed and by root sprouting, and it can sprout from roots and root crowns after top-kill from fire or other disturbances. Seeds may be produced on plants as young as 2 years old. Seeds fall from capsules and are likely dispersed by ants over short distances. Seeds are dormant and must be scarified in order to germinate. High temperatures stimulate germination. No information on California flannelbush seed banks was available; however, observations of seedling establishment after fire indicate that seeds persist in the soil for at least short periods. California flannelbush is adapted to survive, regenerate, and establish from seed after fire in chaparral and woodland environments. It is considered “fire dependent” and a “fire-recruiter” because seedling establishment is largely restricted to the first rainy season after fire and because it sprouts after it is top-killed by fire. California flannelbush is typically most abundant in early postfire environments in both chaparral and pinyon-juniper woodlands. While it can persist in late-successional chaparral (~100 years after fire), it is rarely observed in late postfire succession (>80 years after fire) in singleleaf pinyon ( Pinus monophyla ) woodlands. Fire regimes in California chaparral are typically characterized by intense, stand-replacing crown fires. Historical fire intervals vary depending on location, but typically range from about 35 to 115 years. Fires have become more frequent in the late 20th and early 21st centuries on some southern California sites, resulting in conversions from native chaparral to communities dominated by nonnative, annual forbs and grasses. Repeated fires at short intervals may reduce California flannelbush occurrence in favor of herbaceous species; however, its response to frequent fires has not been studied.