On a damp-again, dry-again day with white clouds racing overhead and turkey vultures flying in circles, Sandy DeSimone stood on a hillside, smiling broadly, holding a branch of black sage.
The hillside at the Audubon Starr Ranch Sanctuary was dense with native shrubs — California sage, white sage, laurel sumac — and looked like a prime stretch of Orange County’s vanishing native plant community, coastal sage scrub.
DeSimone’s “before” pictures show a sterile-looking slope of dry, straw-colored stalks, the familiar aftermath of a thistle invasion. (First photo shows thistle, second photo, same hillside after restoration; all photos courtesy Scott Gibson, Starr Ranch.)
“All our restoration work — native grasslands, coastal sage scrub — begins with artichoke thistle,” DeSimone said on a recent visit to one of her restoration sites. “We began with five years of research on its biology and ecology.”
Reviving Orange County’s native scrub habitat is a complex, difficult task. Removing invasive plants like artichoke thistle is even worse.
But Sandy DeSimone, a plant ecologist who is also the sanctuary’s director of research and education and the wife of its manager, Pete DeSimone, proved it is possible — even for a non-profit institution that must watch every penny of its modest funding. (Sandy DeSimone with black sage, left).
“There were enough red flags from them (herbicides) for environmental and human health that I decided to go non-chemical,” she said.
All that is needed, it appears from her work, is an intimate familiarity with every detail of growing preferences for both native and invasive plants, a few low-tech tools, and a small army of young biologists and biology students eager to take their hoes to the ecologically damaged portions of the 4,000-acre nature reserve.
Starr Ranch is a place of mountain lions that roam at will, barn owls that lay eggs and raise young live on camera, mule deer that feed on shoots in the scrub hills or wooded streams.
It’s also an outdoor laboratory.
For years, Sandy DeSimone has tinkered with the landscape like a cook trying different recipes — that is, if the cook kept meticulously plotted charts and graphs of her and her team’s every move.
She tracks rainfall, soil type, seed mix, growing seasons. She knows the best times for native plants to bloom; she knows when the thistle is most vulnerable, the prime moment to strike.
And when the moment comes, the thistle plant’s leaves are cut away.
The cutting must be done several times a year, at precisely timed moments during a season. Spreading of native seeds, too, must be exact, at the times and locations established through years of research.
It is a war of attrition, with thistle reluctantly giving way and the natives gradually reclaiming the land they’d lost. The key, DeSimone says, is relentless attacks on the thistle — and persistence.
“It was reduced by 95 percent after one to two years, per site, using repeated brush cutting,” she said as she conjured graphs to prove it on her computer at the ranch’s rustic headquarters.
The thistle, which escaped cultivation for food and reverted to its wild from, is no longer edible — and is a formidable enemy.
“It’s really spiny,” DeSimone said. “It has a tap root that goes six to nine feet into the soil.”
Her restoration work has brought some fascinating surprises. At the foot of the restored slope shown above, tiny California sage plants are colonizing what’s left of the once-disturbed area — all on their own (sage hand-planted from seed shown below).
And small mammals — rodents, rabbits — that take shelter in the mature coastal sage venture by night into the disturbed regions to dine. Their nibblings, though indiscriminate, appear to help the native plants recolonize the soil.
DeSimone has so far restored about 75 acres on the ranch out of 250 targeted for coastal sage replanting that were severely disrupted by thistle. Her other restoration plots include native grasslands, where she’s reclaimed 286 out of 450 disturbed acres, and tree-lined, streamside corridors.
She’s begun to draw the attention of other restoration biologists trying to reassemble native landscapes that have been wrecked by invasives.
And she hopes some of the techniques she’s pioneered can be used by other land managers to bring back lost landscapes — along with the many wild animal species that inhabit them.
“We modify our approach based on experience,” she said. “All these experiments are finding dramatic results.”
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