Volunteers help return San Francisco's Presidio to its more natural setting
San Francisco is one of the most densely populated urban environments in the nation. And yet, in the midst of it are natural ecosystems struggling to survive. On Saturday, in one of those areas--the Presidio--volunteers pitched in to remove the hand of man and return the land to a more natural setting.
The annual Presidio Planting Day began with the removal of a stand of towering trees that used to occupy the hillside overlooking Baker Beach.
When the Army established the Presidio more than 200 years ago, they purposely began changing the natural environment, planting Monterey Pines. Now, with the trees coming to the end of their lifespans anyway, the park decided to change the area back to the huge rolling sand dune that it once was.
"When you have a bunch of trees in here, it kind of locks the dune sand into one place because of the really intense root structures," said Kristen Jones, the Presidio's Ecological Horticulture Project Manager. And so, it doesn't allow for the native species that would normally grow here to grow here, because they require the sand to have more movement and more light than it would under the shade of those trees."
With the trees now removed, about 100 volunteers fanned out over the 4-acre site, removing unwanted soil-locking species, like oxalis and ice plants, and replacing them with native plants that prefer the shifting sands of a dune.
Nine-year-old volunteer Oliver Murray said it was pretty fun once you get the plant out of its container.
"Sometimes it can be difficult because the plant is stuck in there," he said, banging his trowel against the seedling container. "It's important to restore the dune because some of these plants are, like, endangered. And the animals too...some animals might come back."
A lot of animals disappeared when the land changed, but at least one of them couldn't come back.
The Xerxes Blue butterfly went extinct in the 1940s right there in the Presidio, becoming an international symbol of the sometimes irreversible damage of habitat loss.
But Dr. Durrell Kapan, a senior researcher at the California Academy of Sciences, has been leading an effort to introduce into the ecosystem a replacement for the Xerxes, a close genetic cousin called the Silvery Blue butterfly.
"The main reason for loss of biodiversity is the transformation of habitat, so we can put those habitats back," said Dr. Kapan. "And in some cases, the butterflies are gone, so we have to move in an alternative. But in many cases, the animals will come back on their own."
That's what they're hoping will happen once the dune is restored. And volunteer planter Alberto Rodriquez was more than happy to lend a hand.
"It's a personal area for me," he said. "I walk through here a lot and I wanted to help make it closer to what it might have been like hundreds of years ago. We've come here and sort of imposed ourselves upon the land, and I think it's important to respect the land as much as possible. And that includes allowing it to be what it's meant to be and it's naturally supposed to be. And so, it's important to me to help get it to that point as much as possible."
From a distance, the hillside looks barren, like all life has been removed. But a closer look reveals the tiny new plants, waiting for the winter rains that will begin a whole new lifecycle for the Presidio, with an understanding that there is a place in nature for all creatures, great and small.
Saturday was the big annual Presidio Planting Day, but they also host volunteer events every Saturday and every other Wednesday throughout the park. Anyone interested in helping out can find more information at www.presidio.gov.
