Botanical Evidence of Paleodietary and Environmental Change: Drought on the Channel Islands, California

Abstract

AbstractFluctuations in climatic regimes and biodiversity through time are linked in complex ways to human behavior and socioeconomic processes. We use macrobotanical evidence from Chumash village sites on California’s Channel Islands to investigate the relationship between late Holocene climatic perturbations and one region of the larger Chumash world. Carbonized plant remains provide evidence of the shifting availability of native plants during the Transitional period (A.D. 1150–1300), when droughts impacted island floral diversity and the Chumash had to cope with changes in vegetation regimes that likely curtailed food availability. We find that drought-resistant plant resources appear in higher relative frequencies in proveniences dating to the Transitional era, and at least one food resource was first imported from the mainland around that time. These findings support the proposition that the Chumash intensified cross-channel trade in part to respond to dietary needs during episodic resource stress. This is also the time when several economic specializations blossomed, including intensive shell bead making. These specializations persisted for six centuries and were central to the development of institutionalized leadership and political complexity in the region ca. A.D. 1200. Various strategies to preserve stability in the plant diet were important elements in the broader reorganization of labor in coastal southern California.