The Jasper Ridge Biological Preserve is a nature preserve and biological field station formally established as a reserve in 1973. The biological preserve is owned by

Stanford University Stanford University, officially Leland Stanford Junior University, is a private research university in Stanford, California. The campus occupies , among the largest in the United States, and enrolls over 17,000 students. Stanford is consider ...

, and is located at south of Sand Hill Road and west of Interstate 280 in Portola Valley, San Mateo County, California. It is used by students, researchers, and docents to conduct biology research, and teach the community about the importance of that research. The preserve encompasses Jasper Ridge and

Searsville Lake Searsville Dam is a masonry dam in San Mateo County, California that was completed in 1892, one year after the founding of Stanford University, and impounds Corte Madera Creek (San Mateo County, California), Corte Madera Creek (in the San Francisq ...

(actually a reservoir) and the upper reaches of

San Francisquito Creek San Francisquito Creek (Spanish for "Little San Francisco" - the "little" referring to size of the settlement compared to Mission San Francisco de Asís) is a creek that flows into southwest San Francisco Bay in California, United States. Histo ...

, along with the latter's Corte Madera Creek and Bear Creek tributaries.

Geology

Jasper Ridge is part of the foothills northeast of the

Santa Cruz Mountains The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central and Northern California, United States. They form a ridge down the San Francisco Peninsula, south of San Francisco. They separate the Pacific Ocean from ...

and is bounded by

, Corte Madera Creek and

Los Trancos Creek Los Trancos Creek (meaning "barriers" or "cattle guards" from the Spanish "Las Trancas") is a stream, creek that flows northerly from Monte Bello Ridge on the northeast slope of the Santa Cruz Mountains to its confluence with San Francisquito Creek ...

, although the preserve occupies only the northwestern half of the ridge. The hilly mass runs about ten kilometers from northwest to southeast and about half that in width. Serpentine (

Serpentinite Serpentinite is a rock composed predominantly of one or more serpentine group minerals, the name originating from the similarity of the texture of the rock to that of the skin of a snake. Serpentinite has been called ''serpentine'' or ''ser ...

) is the California State Rock. It was formed from deep sea or mantle rocks. This rock was squeezed toward the surface by tectonic plate movement, and thus feels greasy, as it has been polished over millions of years. Graywacke Sandstone after crossing Leonard's Bridge. This sandstone was part of the Franciscan formation 138 million years ago. Some rocks found at the preserve include: Greenstone, Chert, Serpentinite, Sandstone.

Ecology

In 1922, Cooper asserted that Jasper Ridge was historically chaparral, and cleared in the nineteenth century to open grasslands, primarily Eurasian wild oats (

Avena fatua ''Avena'' is a genus of Eurasian and African plants in the Poaceae, grass family. Collectively known as the oats, they include some species which have been cultivated for thousands of years as a food source for humans and livestock. They are w ...

and

Avena barbata ''Avena barbata'' is a species of wild oat known by the common name slender wild oat. It has edible seeds. It is a diploidized autotetraploid grass (2n=4x=28). Its diploid ancestors are ''A. hirtula'' Lag. and ''A. wiestii'' Steud (2n=2x=14), whi ...

). However much of the grassland has been replaced by various oaks, especially

Coast Live Oak ''Quercus agrifolia'', the California live oak, or coast live oak, is a highly variable, often evergreen oak tree, a type of live oak, native to the California Floristic Province. It may be shrubby, depending on age and growing location, but is g ...

(''Quercus agrifolia''), and

Pacific Madrone ''Arbutus menziesii'' or Pacific madrone (commonly madrone or madrona in the United States and arbutus in Canada), is a species of broadleaf evergreen tree in the family Ericaceae, native to the western coastal areas of North America, from Bri ...

(''Arbutus menziesii''). More recently, the oak/madrone forest is being succeeded by specimens of large

Douglas fir The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three va ...

(''Pseudotsuga menziesii'') as in the image above. In addition there are several groves of second growth

Coast Redwood ''Sequoia sempervirens'' ()''Sunset Western Garden Book,'' 1995:606–607 is the sole living species of the genus '' Sequoia'' in the cypress family Cupressaceae (formerly treated in Taxodiaceae). Common names include coast redwood, coastal ...

s (''Sequoia sempervirens'') in the preserve, some in large "fairy rings" indicating that trees of immense girth were cut down in the nineteenth century.

Academic studies

Numerous academic studies and ecological experiments are conducted at Jasper Ridge.

Global change experiment

The Global Change Experiment studies the response of California annual grassland to global change, including elevated atmospheric CO₂, temperature, altered precipitation, and increased nitrogen deposition.

Argentine ant invasion

This project studies and tracks the

Argentine ant The Argentine ant (''Linepithema humile''), formerly ''Iridomyrmex humilis'', is an ant native to northern Argentina, Uruguay, Paraguay, Bolivia and southern Brazil. It is an invasive species that has been established in many Mediterranean clim ...

s, an invasive species.

Bat monitoring

A station near the lake monitors bats at night, by converting and recording bat sounds (ultrasonic echolocation).

References

External links

Official Jasper Ridge websiteOrganization of Biological Field Stations
{{authority control Stanford University Nature reserves in California Ecological restoration Ecology organizations Ecological experiments Biological stations Protected areas of San Mateo County, California