Distribution dynamics and environmental factors associated with recruitment of valley oak (Quercus lobata Née.) in the Santa Monica Mountains

Valley oak (Quercus lobata Neé), California's largest endemic oak, is facing a well-documented regeneration problem in that aging adult trees are not being replaced by saplings at a sufficient rate. This study aims to use a combination of landscape mapping and dendrochronology to document the spatial and temporal dynamics of two sites within the southernmost population of this species in the Santa Monica Mountains, Los Angeles County, CA. The two sites, Paramount Ranch and Cheeseboro Canyon, exhibited varying amounts of recruitment, despite being located relatively near one another. Adult and juvenile trees at Paramount Ranch were dispersed throughout multiple types of topography, while recruitment mainly occurred at Cheeseboro Canyon along a riparian floodplain. With each site possessing unique land use histories and hydrological characteristics, management of valley oak recruitment must be tailored to fit the individual ecological context of each site.