Mapping the historical dynamics of coastal sage scrub on the Palos Verdes Peninsula

California sage scrub (CSS) and adjacent vegetation communities have experienced significant declines due to numerous anthropogenic disturbances. A number of areas have been set aside on the Palos Verdes Peninsula to preserve open spaces and protect at-risk species. An analysis of the vegetation dynamics in the Portuguese Bend area of the Peninsula was performed using historical aerial imagery and derived land-cover classifications. Image data was classified using an object-based segmentation method combined with a ground-based classification. The land-cover layers were derived for six separate time periods, covering fifty years, and the layers were compared to determine what types of changes had occurred within the study area. The changes observed in this study are discussed using four hypothesized models as recovery determinants. While challenges were encountered due the chaotic nature of disturbance in the area, the aerial photos and land-cover layers provide an invaluable record of change within the Portuguese Bend Reserve.