Coastal bluff vegetation dynamics, Fraser Pt, Santa Cruz Island, 1975-present

Distribution of coastal bluff vegetation has been monitored for over 35 years on Fraser Point on the west end of Santa Cruz Island. Introduced annual species (Mesembryanthemum crystallinum) were abundant after periods of disturbance and drought. Native annual species (Lasthenia californica) were abundant after periods of high late autumn and winter rainfall.Dudleya nesotica, a rare island endemic, persisted in the same section of the transect over the entire course of the study. Once a species occupied a site, it usually continued to occupy that site due to high levels of seed deposition or vegetative reproduction until unusual meteorological events triggered its replacement. Summer rainfall accompanied by high temperatures followed wy warm fall rains favored germination of Mesembryanthemun and simultaneously inhibited germination of Lasthenia. Rainless summers followed by cold fall rains favored Lastheina germination and inhibited Mesembryanthemum germination.