Presidio habitat restoration effort plants seeds of hope

El Polin Spring was bubbling last Saturday with 133 volunteers ready to participate in the 13th annual Presidio Planting Day.

The Presidio Trust, which manages the park, set a goal to plant over 1,000 native plants in the Tennessee Hollow Watershed. Volunteers planted 2,800.

Winter rains will help them grow, further transforming the former military base into a vibrant habitat for San Francisco’s native flora and fauna.

“The hard facts, whether about climate change or the loss of biodiversity, have been streaming in at a higher decibel lately,” Lew Stringer, associate director of natural resources, said to the crowd. “For me, this day is all about people gathering in communities to bring back the wild things. The great hope is there are many communities like us.”

It isn’t always easy to maintain hope. Climate change is only one of the global environmental crises we’re facing. Scientists also say we’re living through the sixth mass extinction. Once plentiful birds, lizards, frogs and other animals are disappearing. Drops in insect populations, which many only recognize by their cleaner-than-usual car windshields, are particularly concerning. Small arthropods help keep our agriculture and ecosystems healthy.

Addressing insects’ decreasing numbers is tricky. Bugs, a description scientists only use for large insects with piercing or sucking mouths, are incredibly diverse. Insects are also not well understood and are confronted with a variety of threats, such as climate change, pesticides and habitat loss.

But the Presidio’s efforts provide insight into the power of native-habitat restoration.

On Saturday, volunteers began planting a half-acre muddy slope at Inspiration Point. Two months ago, acacia trees grew on the small plot. The park removed the fast-growing, non-native species in September and ground the stumps to discourage re-sprouting. No pesticides were used.

Now, after the Presidio Planting Day, the site is covered with over 40 species of native grass and wildflowers. Soon seeds from the endangered Presidio clarkia wildflower will be spread across the soil. Next month, volunteers will plant the Franciscan manzanita, which hasn’t grown wild in San Francisco in decades. If all goes as planned, more of Inspiration Point will be filled with thick grasses, wildflowers and manzanitas next winter.

“We think this work is important because grasslands are a disappearing habitat and host an incredible amount of biodiversity,” Brian Hildebidle, supervising natural resource management specialist, told me. “The amount of insects and birds that use grasslands is incredibly diverse.”

While the Presidio typically monitors birds on restored sites, it hasn’t delved deeply into studying insect populations. But metrics should be coming soon.

According to Stringer, researchers at San Francisco State University will begin an inventory of bee species in the Presidio early next year. The study will build on information collected about 10 years ago, which identified 60 different bee species in the park. If the number has increased or remained steady, it could underline the importance of habitat restoration.

In addition, the Presidio also plans to compare insect use of native and ornamental plants, which decorate some San Franciscans’ front and backyards, early next year.

“We’re hoping to gather some information on the relative value of native and ornamental plants,” Stringer told me, who estimates that both studies will be completed in 2020.

Both studies are important as policymakers seek to addressing significant losses of biodiversity.

At the Convention on Biological Convention in Egypt last month, global leaders noted that data on the status and trends of wild pollinators is limited. The Presidio’s studies will help to fill these gaps of information.

For this, and many other reasons, it’s difficult to overstate the importance of volunteers’ workin the Presidio. As they dug in the dirt and chatted with each other on Saturday, they were lowering the wall between humans and wildlife. After another year of historic fires and fear-inducing environmental news, watching the wild spaces grow inspired a lot of hope.

For Owen, 9, and Phoebe Anair, 6, who were participating in their third annual Presidio Planting Day, the value of the day was simple.

“It’s fun,” the brother and sister grinned before happily sitting down in the mud.

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Robyn Purchia is an environmental attorney, environmental blogger and environmental activist who hikes, gardens and tree hugs in her spare time. She is a guest columnist. Check her out at

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