6 to 249 km2. During the Last Glacial Maximum and up to about 10,000 years ago, the four northern Channel Islands (San Miguel, Santa Rosa, Santa Cruz, and Anacapa) were connected into a single landmass known as Santarosae Island, separated from the mainland by a watergap of about 7–8 km (Erlandson et al., 2011b). This separation from the mainland led to distinct island ecosystems and numerous endemic and relict species. In general, the biodiversity of terrestrial plants and animals is reduced compared to the mainland, with the largest post-Pleistocene land mammals being the

diminutive island fox (Urocyon littoralis) found on six islands and the island spotted skunk (Spilogale gracilis) found on two islands. Only Peromyscus maniculatus (island deer mouse) is found on all eight of the Channel Selleckchem Venetoclax Islands. Deer, elk, and large to medium sized predators common on the mainland were all absent from the islands, until some were introduced during the historic period. Terrestrial plants were also less diverse than the mainland, with a Selleck LY294002 smaller amount of oak woodland and other plant communities. Freshwater was limited on some of the islands, but the large islands of Santa Cruz, Santa Rosa, Santa Catalina, and San Miguel are all relatively well watered. Our perspective of both island

plant communities and freshwater availability, however, is changing as the islands recover from more than a century of overgrazing from introduced livestock and both freshwater and terrestrial plants appear to have been more

productive than once presumed. Although ethnobotanical research has been limited on the islands, recent research demonstrates the exploitation of blue dick corms and other plant foods throughout the Holocene ( Reddy and Erlandson, 2012 and Gill, 2013). Humans colonized the northern islands by at least 11,000 B.C., while the northern islands Phosphatidylethanolamine N-methyltransferase were still one landmass and there were more conifers and other trees scattered around the islands. Native Americans appear to have lived on the islands more or less continuously until about A.D. 1820, when they were removed to mainland missions. Following Native American occupation, the islands were occupied sporadically by Chinese abalone fishermen with the ranching period beginning in the mid-19th century. Today, the northern Channel Islands and Santa Barbara Island comprise Channel Islands National Park, while San Nicolas and San Clemente have naval installations, and Santa Catalina is privately owned with the only formal city (Avalon) on the islands. Each of these human occupations had different influences on island ecosystems, with distinct signatures that help inform contemporary environmental issues, conservation, and restoration. Population growth is one of the key factors related to increased human impacts on ecosystems.