California’s Channel Islands

The California Channel Islands are situated along the west coast of southern California.  They are oceanic islands because, in spite of their proximity to the mainland, they were never connected to it.  Although difficult to date with precision, they likely range from 0.6 to about 5.0 my, the same age range as most other oceanic islands.  In spite of their relatively small size and proximity to the mainland, the proportion of native species that are insular endemics is greater than 15%, much higher than documented for other islands of similar size and isolation.

Conservation Genetics

Many of the endemic plant taxa are rare simply by virtue of their narrow geographic range.  However, the introduction of grazing mammals (cattle, sheep, goats, and pigs) and weedy competitors over the last 150 years have decimated many native species.  Additionally, increased fire frequency, erosion and habitat loss from human activity have further endangered plant taxa.  Our research on the genetics and ecology of these rare species will help guide management efforts to ensure their continued survival.

Island Evolution

The California Channel Islands have been little studied in terms of plant evolution and phylogeography.  However, their proximity to each other and to a mainland source of colonists offers an opportunity to study insular evolution in a situation where dispersal rates are considerably higher than on isolated islands.  Understanding the balance between connectivity and isolation of populations that allows divergence of unique evolutionary entities is a goal of our research program.