Paleoethnobotany and Native Plant Use on California’s Northern Channel Islands

The abundance and diversity of terrestrial plant resources on the northern Channel Islands off the Santa Barbara coast vary in terms of island biogeographic distribution. These plant resources provided food, medicine, and raw materials for island populations. However, island plant resources have long been described in the literature as “depauperate,” an idea based largely on direct field observations of a flora decimated by historical overgrazing practices, yet one that has greatly influenced our interpretations of archaeological data. A growing body of recent paleoethnobotanical research focused on carbonized plant remains indicates that prehistoric island plant resources were more abundant and diverse than previously thought. A remarkably consistent use of plant foods at the Diablo Valdez site (SCRI-619/620) on Santa Cruz Island is evident, with no significant change in densities of various plant foods over nearly 6000 years of occupation. Furthermore, plant remains from grassland habitats dominate the island archaeobotanical assemblages, and may support ethnohistorically documented landscape management of grasslands using fire. I discuss paleoethnobotanical data from various island sites dated to between 10,500 years ago and the Historic Period, providing important information about human responses to terrestrial paleoenvironmental change. These data also have implications for modern restoration and land management decisions.