Macrolichen Inventories in the Golden Gate National Recreation Area in San Mateo County

Carlberg, Tom

Baseline macrolichen inventories were carried out at Rancho Corral de Tierra and Mori Point, two units of the Golden Gate National Recreation Area in San Mateo County. A habitat-based analysis identified seven inventory areas deemed likely to result in high lichen species diversity, based on differences in vegetation, elevation, and geology. Intuitively-controlled surveys were conducted in mid-July and early August, targeting the Alta Vista Trail, Peak Mountain, Gregerson Road, Denniston and San Vicente Creeks, a riparian westside location, and Mori Point. Ninety-six lichen species were identified from 312 collections. Foliose lichens comprised 51% of species detected, while 33% were fruticose and 8% were squamulose. Cursory collections of crustose species accounted for 7% of total species richness. Hypogymnia schizidiata was found, a California Lichen Society-listed species of concern, and represents a 280-mile range extension and a new population of this potentially-extirpated species in the U.S. This report includes detailed discussions of other significant species and range extensions found during the course of the inventory, and recommendations for additional baseline data are suggested.