The landscape of Channel Islands National Park is so interesting in large part because it is characterized by so many different habitats, all strongly influenced by the area’s Mediterranean and maritime climates. Nearly all the habitats within the park have also been influenced by how people have used the land in the past. Non-native animals such as sheep, cattle, deer, elk, pigs, and rabbits were introduced onto the various islands beginning in the mid-1800s as ranches and other businesses were established on the islands. Non-native plants were also introduced to the park either intentionally or accidentally. Almost one quarter of the park’s 800 known plant varieties are considered non-native.
Each park island supports its own unique combination of habitats. The differences can be subtle, and are due to different microclimates, topography, geology, soils, plant colonization histories, and particular land use histories. Size is also a factor. The larger islands have larger elevation changes and more complex geologic features resulting in more microclimates and a greater variety of habitats.