"When you talk about expanding a botanical garden, you don't necessarily think about bringing the natural landscape back," Brown said, invoking the idea of gardens as showcases for exotic and rare species. "But now, it's the native habitat that is exotic, because it's been mucked up, it's been changed, altered by human interests."
Five years ago, Brown and former head horticulturalist Brian Sullivan came up with the idea to return the land to a much earlier iteration of the L.A .basin, before Spanish missionaries hit California's shores in the late 1700s, bringing with them agriculture, hungry livestock and stowaway seeds tucked into clothes, cargo and animal hides.
Those three influences nearly obliterated the pristine prairie ecosystem, home to a rich biodiversity of plant and animal species. Only recently have naturalists shown an interest in reviving native landscapes for the enjoyment and edification of the public.
Brown said he and Sullivan made several trips to the Santa Rosa Plateau Ecological Reserve in Riverside County, one of the few remaining natural prairies in Southern California, for inspiration and research.
The project, estimated at $1.2 million, was completed using funds from Proposition A, committed by Los Angeles County Board of Supervisor's District 5 under Mike Antonovich and awarded to the nonprofit L.A. Conservation Corps, which provides job training and work experience to at-risk youth.
Together with staff, corps members hand-weeded the parcel, sparing native plants while transplanting another 30,000 cuttings and seedlings grown specifically for the area. An equal number are scheduled for planting in the near future. But the coast live oaks (Quercus agrifolia) were always intended to be the main attraction, according to Rachel Young, Descanso's director of horticulture and garden operations.
"Oaks are the architecture under which the garden thrives," Young said, adding that most Descanso oaks must compete with camellias and other thirsty species for vital water. "We wanted to create a place where there were oaks and they could just be."
On Saturday at 9 a.m., garden officials will share the new space with the visiting public in an unveiling celebration featuring guided walks, woodland crafting and a special display of a Mars rover model, on loan from NASA's Jet Propulsion Laboratory.
Although the new space has been outfitted with modern contrivances, like ADA-compliant pathways and temporary irrigation hoses to help tender buds take root, its look and feel evoke a more primitive landscape, one Brown said humans find intrinsically appealing.
"The first experience you have when you come here for the first time is that it's so open. I think when you're out in a space like this, you instantly get an intuitive comfort from being able to see what the big macro habitat consists of," he added.
And people aren't the only ones who appreciate the restored habitat — staff say cameras installed in the woodland have already captured several curious animals. In addition to rabbits and coyotes, bobcats and bears, rarer species like the gray squirrel and Mandarin duck have been recently spotted.
Julianne Rook, Descanso's chief operating officer, said as amazing as the new addition is, it's far from finished.
"Oak trees live 500 years, so I don't know that this project will ever be done," she said. "I think after two years, you're going to see a much different place. But it's beautiful now."
For more pictures and videos from the cameras, see the Camera Trap.