Shrub Once Thought Extinct Gets Critical Habitat In San Francisco

Franciscan manzanita in bloom | Photo: USFWS/Flickr/Creative Commons License

A rare native shrub that botanists considered extinct for decades now has about a third of a square mile of habitat that's been deemed crucial for the species' survival. The Franciscan manzanita, rediscovered by fluke in 2009, is the beneficiary of a critical habitat designation Friday by the U.S. Fish and Wildlife Service that declares 230 acres of open space in San Francisco as necessary for protection and recovery of the shrub species.

The designation has been controversial, as San Francisco residents have worried that a formal designation of Critical Habitat for the manzanita could restrict what they can do with their land or bar visitors from public parks. (Those fears have been more or less groundless, as Critical Habitat designation changes virtually nothing for most private and municipal landowners.)

The species, Arctostaphylos franciscana, was thought to have been driven to extinction in 1947, when the last known population in San Francisco's Laurel Hill Cemetery was destroyed as the site was converted to housing. But in 2009, ecologist Daniel Gluesenkamp spotted a suspicious shrub in an area being cleared of vegetation for a road-widening project in San Francisco's Presidio. To the delight of botanists worldwide, the shrub turned out to be a Franciscan manzanita, still surviving in the wild.

The Franciscan manzanita is one of 119 species or subspecies of manzanita native to California. Manzanitas are one of California's signature shrubs, with their characteristic reddish bark and evergreen leaves sprinkled with white-to-pink urn shaped flowers during winter and early spring. The Franciscan isn't the only "extinct" manzanita that's been rediscovered in San Francisco: the Presidio manzanita, once found throughout the city, was rediscovered as a single plant in an undisclosed location in the Presidio by botanist Peter Raven in 1952.

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Both the Presidio and Franciscan manzanitas are relics of what was once a distinct but limited habitat, the Franciscan biome, that occupied the city and a few surrounding areas. That biome is almost as extinct as the manzanitas were once thought to be. Aside from San Bruno Mountain, a large open area just south of the city, almost all the original Franciscan biome has been crammed full of development.

Before its rediscovery, the Franciscan manzanita was considered to be extinct in the wild. Like zoo animals considered extinct in the wild, a few survived in the botanical equivalent of captivity. Botanist James Roof had salvaged two of the shrubs from the Laurel Hill Cemetery in 1947 and transplanted them to the Tilden Botanic Garden across the Bay in the Berkeley Hills. Seedlings were propagated from those plants, and you can now find their descendants in specialty nurseries through the state.

But the species' nursery stock has been hybridized with other manzanita species, and is now significantly different in a genetic sense from the wild individual discovered in 2009.

The shrub was transplanted out of the path of the road widening project to a protected area elsewhere in the Presidio. After a petition and a 2011 lawsuit by the Wild Equity Institute to force the listing of the rediscovered species under the Endangered Species Act, USFWS listed the manzanita as Endangered in 2012. Friday's Critical Habitat designation, a result of that listing, has been in the works since 2012.

The designation covers 230 acres split into 12 parcels on open land throughout the central hills of San Francisco. Some of the parcels are not known to have held populations of the species, which sparked some controversy among locals fearful of federal intrusion into city land management. What the parcels have in common are soils derived from the local complex of geological formations known as "Franciscan," exposure to marine layer fogs, suitable drainage and lack of development.

In its formal designation of Critical Habitat, published Friday in the Federal Register, USFWS spends more effort than usual correcting misapprehensions about the nature of the designation. Despite rumors to the contrary, Critical Habitat designation restricts only those development activities conducted, authorized, or funded by Federal agencies. That restriction consists only of a requirement to consult with USFWS so as to avoid damage to the species.

Nonetheless, public comment on the proposed designation over the last year has included significant concern that the designation would close parks to recreational use, keep homeowners from performing landscaping and retrofitting tasks, or otherwise inconvenience San Franciscans. USFWS says it received 4,801 form letters "that did not provide substantial information," mainly opposed to designation of Critical Habitat in city parks out of fear of Federal government control of those parks.

The agency identified one project in a local park that could conceivably be affected by the designation: a trail project in McLaren Park that may qualify for Federal funding.

As an example of the misinformation surrounding the designation, USFWS quoted one commenter as saying:

The mission blue, listed as Endangered since 1976, actually has no designated Critical Habitat.

Conservation of native wildlife has long been a complex and contentious issue in San Francisco, a place where one might expect broad public support for threatened species. Attempts to protect the Threatened snowy plover's habitat on local beaches has stirred opposition from dog owners since the 1990s, in response to enforcement of leash laws on that habitat. The city's Natural Areas Program has taken serious heat for its removal of invasive trees in some areas.

It's an indication that opposition to endangered species protection doesn't map strictly along liberal-conservative lines. And it's yet another example of public overreaction to an essentially benign designation of Critical Habitat for a species we nearly elbowed off the planet.

For ongoing environmental coverage in March 2017 and afterward, please visit our show Earth Focus, or browse Redefine for historic material.
KCET's award-winning environment news project Redefine ran from July 2012 through February 2017.

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