Turn­ing back time to re­new old habi­tat

Army post’s orig­i­nal ecosys­tem re­stored as ur­ban park

San Francisco Chronicle - - FRONT PAGE - By Peter Fim­rite

The wry look on Lew Stringer’s bearded face should have been a give­away, but there re­ally wasn’t any­thing about the in­con­spic­u­ous bush he was ges­tur­ing to­ward that seemed special.

“This is a Fran­cis­can man­zanita,” said Stringer, the as­so­ciate di­rec­tor of nat­u­ral re­sources for the Pre­sidio Trust, point­ing to a large, green, ground­hug­ging plant.

This par­tic­u­lar man­zanita species was thought to be ex­tinct out­side of nurs­eries un­til 2009, when one was dis­cov­ered grow­ing in the Pre­sidio of San Fran­cisco and later moved to a se­cret lo­ca­tion.

The care­ful nur­tur­ing of the last re­main­ing wild man­zanita of its kind is part of a wider ex­per­i­ment — one of the most am­bi­tious ever un­der­taken — to engi­neer and re­build a wild ecosys­tem in an ur­ban set­ting that over its 200 years as a mil­i­tary base had been paved over, pol­luted, pocked with land­fills and over­run by weeds.

Twenty­five years af­ter the U.S. Army turned the Pre­sidio over to the Na­tional Park Ser­vice, the 1,491­acre former mil­i­tary base has been largely trans­formed, ful­fill­ing a vi­sion that seemed, early on, to be lit­tle more than a fan­tas­ti­cal dream.

Many of the old mil­i­tary build­ings have been re­stored and rented out, mak­ing the Pre­sidio eco­nom­i­cally self­suffi

cient, but the most re­mark­able changes have been to the nat­u­ral land­scape.

Over the past three decades, a shore­line la­goon and a his­toric, nat­u­ral lake have been re­stored. Hun­dreds of thou­sands of na­tive plants — some of them en­dan­gered — have been planted. Indigenous wildlife has re­turned, and an an­cient creek ecosys­tem was freed from un­der­ground pipes, ex­pos­ing hid­den streams and ponds that once quenched the thirst of Amer­i­can In­di­ans.

“It is a place where you have this in­cred­i­ble evo­lu­tion of bi­o­log­i­cal di­ver­sity in the form of plant life,” said Stringer, as he took in the sweep­ing view from In­spi­ra­tion Point of the green hill­sides dot­ted with red­roofed build­ings slop­ing down to San Fran­cisco Bay. “We have the most di­verse plant com­mu­nity in all of San Fran­cisco of indigenous na­tive plants that still ex­ist — over 150 species of wild­flow­ers, grasses and small things.”

The grand plan be­gan in 1994 when the Park Ser­vice took over the land and, two years later, cre­ated the Pre­sidio Trust to pre­serve and enhance the in­te­rior 80% of the park, in­clud­ing 262 acres of his­toric for­est planted by the Army in the 1880s. The Park Ser­vice main­tains the re­main­ing 20%, mostly along the north­ern and west­ern edges that in­clude Crissy Field and Baker Beach.

The work re­quired an un­der­stand­ing of his­tory, in­clud­ing what the Pre­sidio was be­fore Euro­peans ar­rived, but also what it be­came in the more than 240 years since the Span­ish first erected adobes in the windswept dunes that cov­ered most of what would be­come the city.

The idea was to re­store the land where pos­si­ble while pre­serv­ing scat­tered patches of rem­nant na­tive land­scapes. So far about 100 acres have been re­stored, while an­other 23 rem­nant acres are un­der stew­ard­ship.

The Pre­sidio Trust, in col­lab­o­ra­tion with the Park Ser­vice and the Golden Gate Na­tional Parks Con­ser­vancy, be­gan by restor­ing 11 acres of coastal sand dunes in Lo­bos Creek Val­ley at the south­west­ern edge of the park. A board­walk was con­structed to open the site to the pub­lic.

Coastal habi­tat off Bat­tery Caulfield Road, near 15th Av­enue in the Rich­mond District, also was re­stored, as were dunes at Baker Beach, where in­va­sive Euro­pean dune grass and ice plant — in­tro­duced by the Army to sta­bi­lize coastal bluffs — were ripped out and re­placed with na­tives such as Amer­i­can dune grass, yel­low sand ver­bena and dune tansy.

The cre­ation of Crissy Field Marsh has been the big­gest pro­ject. It was also the start of an un­der­tak­ing still in progress al­most 20 years later.

The res­ur­rec­tion of the marsh, com­pleted in 2001, was an at­tempt to re­store a por­tion of what once was a 200­acre wet­land that ex­tended from the Golden Gate past what is now the Palace of Fine Arts. It was once a hunt­ing and fish­ing ground for the Ye­lamu tribe of Ohlone In­di­ans.

The orig­i­nal la­goons and marshes had been used as a dump and in 1915 were filled in to make room for the Panama­Pa­cific In­ter­na­tional Ex­po­si­tion. Crissy Field was later cov­ered with as­phalt and ware­houses and used as an Army air­field.

“This was 40 acres of as­phalt and chain­link fence. Now it’s tidal marsh and dune habi­tat,” said Michael Chassé, a nat­u­ral re­source man­age­ment spe­cial­ist for the Golden Gate Na­tional Recre­ation Area who has worked on the pro­ject since the be­gin­ning.

“Some of the plants you see here are from the orig­i­nal plant­ing, but a lot of these plants have just re­gen­er­ated on their own,” he said as he stood in the dunes re­cently ex­plain­ing to stu­dents how seeds, in­clud­ing in­va­sives like cord grass and Al­ge­rian sea laven­der, float in on the tides.

The marsh was the first piece in a com­pre­hen­sive ef­fort to day­light the 270­acre Ten­nessee Hol­low wa­ter­shed, three trib­u­taries that drain through a bowl­shaped val­ley into the marsh and out to the bay.

The wa­ter­shed, named by the U.S. Army af­ter a reg­i­ment of vol­un­teers from Ten­nessee that camped in the area in 1898, had been an im­por­tant source of fresh wa­ter for the 193 Span­ish res­i­dents who founded El Pre­sidio de San Fran­cisco on July 26, 1776.

The creeks, one of which is sea­sonal, start near the south­east cor­ner of the park and come to­gether at MacArthur Meadow, where restora­tion started in 2016. It runs un­der the Lovers’ Lane bridge, which marks the his­toric trail that once led from the Pre­sidio to Yerba Buena Cove, site of the fron­tier set­tle­ment that even­tu­ally be­came San Fran­cisco.

Af­ter run­ning through an­other re­stored area across the street and then dip­ping back un­der­ground be­low the Pre­sidio YMCA park­ing lot, the wa­ter­way reap­pears at Thomp­son Reach, named in honor of famed Army nurse Dora Thomp­son. In 2006, the creek, which was re­cently named Pet­lanuc af­ter the his­toric Ye­lamu vil­lage, was freed from un­der­ground pipes — 77,000 tons of land­fill de­bris had to be re­moved.

That com­pleted pro­ject was the first solid ev­i­dence that the am­bi­tious habi­tat restora­tion plans for the park could work.

“We were able to show that we were ac­tu­ally able to do this,” said Terri Thomas, the Pre­sidio Trust’s former di­rec­tor of con­ser­va­tion and re­search, who over­saw the pro­ject. “Peo­ple had day­lighted creeks, but no­body re­ally trusted that we could do it. At that time we were re­ally just a bunch of vol­un­teers.”

Six years later, El Polin Spring — the main, cen­tral trib­u­tary — was day­lighted and the area turned into a peo­ple­friendly wet­land, com­plete with ri­par­ian plants, ponds and pre­served his­toric cob­ble­stone chan­nels. A pedes­trian path and board­walk now loop around the whole ensem­ble.

El Polin, a drinking wa­ter source for Na­tive Amer­i­cans for thou­sands of years, is one of the most im­por­tant his­tor­i­cal lo­ca­tions in the Pre­sidio. It is where ar­chae­ol­o­gists dis­cov­ered the foun­da­tions of adobes dat­ing to 1810 and where the fam­ily of Mar­cos Bri­ones, a colo­nial sol­dier and a founder of El Pre­sidio de Mon­terey, is be­lieved to have lived.

The last piece of the Ten­nessee Hol­low pro­ject is planned within the next year, when an un­der­ground drain is re­moved, cre­at­ing a brack­ish, 6­acre wet­land known as Quar­ter­mas­ter Reach that will con­nect to Crissy Field Marsh. It will be the first time an en­tire ur­ban wa­ter­shed has been re­stored from its head­wa­ters to its mouth.

Large as it is, Ten­nessee Hol­low is just one of dozens of habi­tat restora­tion projects in the park un­der­taken by staff, con­trac­tors and vol­un­teers.

The re­ha­bil­i­ta­tion of Moun­tain Lake, which had be­come a filthy pond teem­ing with in­va­sive species, in­clud­ing thou­sands of dis­carded gold­fish that grew into 3­foot carp — reached its fi­nal stages the past few years. The spring­fed lake, where Span­ish ex­plor­ers camped in 1776, is now home to na­tives like the three­spined stick­le­back fish, west­ern pond tur­tles, freshwater mus­sels and cho­rus frogs that sing in the evening.

The lake was dredged and the wa­ter fil­tered and cleaned be­fore it was re­turned to the lake. Its north and east arms have been re­stored as wet­land habi­tat. It is the first time an an­cient lake ecosys­tem in an ur­ban area had been re­stored roughly to the way it was be­fore Euro­peans ar­rived.

On the west­ern side of the Pre­sidio, new dunes were cre­ated from an­cient sand ex­ca­vated from Golden Gate Park when the un­der­ground park­ing garage was built at the mu­seum con­course.

That new habi­tat, lo­cated be­hind what is now the Land­mark apart­ment build­ing, gave restora­tion man­agers space to help en­dan­gered species like San Fran­cisco Lessin­gia — a flow­er­ing plant down to about 300 in­di­vid­u­als in the 1980s — grow and re­cover their pop­u­la­tions. Lessin­gia now num­bers in the hun­dreds of thou­sands each season.

An­other large pro­ject is the re­place­ment of 60,000 Mon­terey pine, cy­press and eu­ca­lyp­tus trees planted by the Army. The plan is to re­move the trees as they reach the end of their lives and put in a canopy of dif­fer­ent­aged trees that is eas­ier to man­age. The flammable, in­va­sive blue gum eu­ca­lyp­tus trees that make up 42% of the park’s 300­acre his­toric for­est are be­ing re­placed by the less volatile moun­tain gum.

The trees and na­tive plants are nur­tured in the Pre­sidio Na­tive Plant Nurs­ery, near Fort Scott. But a large num­ber of new plants have sprouted on their own, as in­va­sive plants were re­moved and suit­able habi­tat re­stored.

Over­all, bi­ol­o­gists have re­ported a more than ten­fold in­crease in the num­ber of na­tive plants in the Pre­sidio, in­clud­ing at least six species that are en­dan­gered or threat­ened.

Those in­clude that well­hid­den Fran­cis­can man­zanita, which was pre­sumed ex­tinct in the wild un­til a motorist, who hap­pened to be a bi­ol­o­gist, spot­ted it in 2009 af­ter it was ex­posed dur­ing the Doyle Drive re­build pro­ject.

The rem­nant shrub was re­lo­cated, but is no longer alone. Many cut­tings have been planted in the rocky ser­pen­tine hills, and bi­ol­o­gists are try­ing to ex­pand the ge­netic di­ver­sity and re­vive the species us­ing sprouts from Fran­cis­can man­zan­i­tas col­lected decades ago at the old Lau­rel Hill ceme­tery and kept alive in botan­i­cal gar­dens.

Other rare plants mak­ing a come­back are the en­dan­gered Pre­sidio clarkia — also once thought to be ex­tinct — and the Raven’s man­zanita, which was re­dis­cov­ered in the 1950s af­ter be­ing gone for half a cen­tury.

With the plants come the wildlife — but­ter­flies, hum­ming­birds and a va­ri­ety of mi­gra­tory birds now fre­quent the park. Ear­lier this year, a colony of sil­ver dig­ger bees ap­peared in the west­ern dunes af­ter not be­ing seen for al­most a cen­tury. A nest­ing pair of West­ern blue­birds was spot­ted a few years ago at Lo­bos Creek Dunes shortly af­ter they were re­stored — the first sight­ing in 70 years. West­ern cho­rus frogs have set­tled in sev­eral lo­ca­tions af­ter be­ing gone for many years.

Coyotes were first spot­ted in the Pre­sidio in 2000, ap­par­ently af­ter cross­ing the Golden Gate Bridge. There are now so many of them that bi­ol­o­gists have be­gun fit­ting them with GPS track­ing col­lars. In 2017, 300 check­erspot but­ter­fly cater­pil­lars were re­leased near El Polin Spring, where they hadn’t been seen in nearly 40 years, and have spread across the park.

Stringer said the Pre­sidio is now a cli­mate­re­silient “botan­i­cal won­der­land of rare and en­dan­gered species” that is closer than ever be­fore to the coastal ecosys­tem that ex­isted be­fore San Fran­cisco emerged out of the wilder­ness.

“We found that if you get the in­gre­di­ents right, it’s not that hard,” he said. “It just takes en­ergy, re­sources and peo­ple will­ing to be there for a long time to tend it. We’re just cre­at­ing the ideas. Now peo­ple can ref­er­ence them and say, ‘Hey, this is work­ing.’ ”

Amy Os­borne / Special to The Chron­i­cle

S.F. State stu­dents work with Park Ser­vice bi­ol­o­gist Michael Chassé on dune plants at Crissy Field.

Amy Os­borne / Special to The Chron­i­cle

The Ten­nessee Hol­low wa­ter­shed in­cludes tidal wet­lands and coastal dunes, which have been re­stored to their orig­i­nal state.

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