Conserving Fog Bank Ecosystems: San Bruno Mountain State Park

        We are visiting the mountain on which the SOUTH SAN FRANCISCO sign stands? Really, it looks barren. I can’t image what we will see there, I thought to myself. In fact, San Bruno Mountain State Park is considered one of the most important, and threatened, biodiversity hotspots in the world. We are lucky it exists in our backyard.
This park captures 2,416 aces of the northernmost portion of the Santa Cruz Mountains. It is home to a variety of endangered butterflies, plants and one snake. The park is maintained both by the county of San Mateo and the state of California.
First settled by the Costonoan tribe, cattle and sheep grazed the land 1769. By the 1870s, various quarries littered the mountain. At the entrance to the park, such a quarry can be seen to the south. During the Cold War, a Nike Missile early warning radar was installed at the mountain summit. Evidently, remnants of this relic can be viewed today scattered among the numerous radio and cell towers.
By the mid 20th century this area became the garbage dump for the city of San Francisco. The smell was noticeable and kept urbanites from settling here. Some say garbage saved San Bruno Mountain. By 1976, San Mateo county purchased 80% of what now is the San Bruno Mountain State Park.
What makes San Bruno Mountain State Park so special it that it lies within the Franciscan Fog Zone created the San Francisco Bay and the Pacific Ocean on either side. Edward O. Wilson, known as the father of biodiversity and two-time winner of the Pulitzer Prize for general nonfiction, considers San Bruno Mountain as one of the most important, and threatened, biodiversity hotspots in the world due to the endangered species found there as well as encroaching development pressure. In his book, The Diversity of Life (1999), Owen makes this claim about three sites including San Bruno Mountain. The other sites include Usabara Mountain forests, Tanzania and Oases of the Dead Sea Depression, Israel and Jordan.
The fog bank found here creates a variety of microclimates and dramatically different weather patterns. Drip from the fog can provide significant moisture even when rain is rare. An important ecosystem found in San Bruno Mountain is the Coastal Prairie Grassland which is home to all of the endangered species found here.
Friction between conservationists vying to protect these habitats and developers led to the production of the first Habitat Conservation Plan (HCP) in the United States in 1983. This plan allowed for the development of some of the fragile habitat while assuring that other parts were restored and maintained. Thus, the San Bruno Mountain State Park. Many conservationists consider HCPs to be inadequate protection for endangered ecosystems. In 2010, a movie entitled Butterflies and Bulldozers documents the struggle to conserve the San Bruno Mountain ecosystems.

Gina Haney