HANC Presents a Slideshow on San Francisco's Natural History.

HANCs January meeting is a wrkshop co-planned with Nature in the City. Greg Gaar will be presenting his popular slideshow on SF's Natural History. He will show more than 100 historic images documenting the evolution of San Francisco's landscape over the last 150 years. The presentation will display San Francisco's diverse native plant communities--sand dunes, coastal prairie and scrub, the trees, the creeks, lakes and the bayshore. Greg will discuss the efforts of government agencies, non-profits and volunteers to preserve and restore our natural heritage.

Native Plant Communities
Native plants are the foundation of all the Earth's ecosystems.

Sand dunes originally spread from the ocean to the bay consisting of deep rooted native plants adapted to drifting sand such as lupine, dune tansy and seaside daisy (Ft. Funston, western Presidio, Grandview Park).

Coastal prairies are grassland communities engulfed by multicolored perennial and annual wildflowers growing on a thin layer of soil on top of chert or serpentine bedrock (Twin Peaks, McLaren Park, Bayview Hill).

Fresh water or riparian habitats have plants that grow in moist valleys and gullies adjacent to creeks and lakes such as rushes and sedges (Lake Merced, Mountain Lake, Islais Creek and Lobos Creek).

Along the bayshore, salt water tidal marshes dominated by pickleweed filtered the bay and were rich habitat for mollusks and crustaceans offering food for numerous species of shorebirds. All of San Francisco's original tidal marshes were eliminated, but nature and humans have re-created new ones (Heron's Head Park and Crissy Field).

San Francisco's indigenous trees grew in sheltered valleys including Coast live oak, buckeye and Arroyo willow (Oak woodlands survive in Golden Gate Park and Buena Vista Park).

Wildlife
Mountain lions, antelope, deer, herds of elk and troops of the now extinct California grizzly bear were common here prior to the arrival of the Europeans and Yankee settlers. Great flocks of geese and pelicans darkened the sky while hundreds of species of butterflies and thousands of other insect species took nectar or laid eggs on specific native plants.

Indigenous People
For over 5000 years, native people hunted, fished, managed and worshiped the land. A diversity of tribes with different languages and cultures would vary from valley to valley. In 1770, the Ohlone population from San Francisco to Santa Cruz numbered between 15-20,000. Under the Mission system, European diseases such as smallpox, measles and venereal disease wiped-out most of the indigenous inhabitants.

Preserving Our Natural Heritage
Over 95% of San Francisco's indigenous landscape has been eliminated in a mere 240 years. The greatest threat to the planet's diversity of life (biodiversity) is the destruction of habitat by human encroachment through development or the spread of invasive exotic plants and animals. San Francisco is a microcosm of what is occurring to the entire planet. People are engaging in habitat restoration to preserve and restore the Earth's ecological health. Habitat restoration offers great rewards to the planet and to the people who participate. An easy first step is planting native plants in your garden. The birds, bees and butterflies will return. Volunteer with the National Park Service in the Presidio, Lands End or Ft. Funston to remove weeds and to plant appropriate natives.

Volunteer with the Natural Areas Program of the Recreation and Park Department. NAP manages 31 natural areas (1100 acres) or remnants of the original landscape with seven staff and scores of volunteers. Nearby natural areas include Corona Heights, Tank Hill, Twin Peaks and the oak woodlands in Buena Vista Park and Golden Gate Park.

Special projects for volunteers include the Mt. Sutro Stewards, the Green Hairstreak Butterfly Corridor and of course the HANC Native Plant Nursery and Gardens. Check out the websites of Nature in the City, Native Plant Society (Yerba Buena Chapter), the Natural Areas Program and the National Park Service. And check out the Garden for the Environment workshop on "Landscaping with Native Plants" coming up on January 15. See page 3 or the GFE website for more info.