Celebrate California Native Oak Day by Joining the Effort to Protect Them

Take Part in a Community Science-Led Project

By Jose Esparza Aguierre

Did you know that California is home to more than 20 species of native oak (Quercus spp.)? From the tough and shrubby leather oak (Quercus durata) to the majestic canopy of coast live oak (Quercus agrifolia), native oaks once covered 1/3 of our state. The oldest oak leaves found in California date back at least 16 million years to the Miocene period. Rightly, we honor our native oaks on November 3rd with California Native Oak Day. 

Oaks are essential to life in California as we know it. A single oak can support hundreds of other species and even improve the health of the soil. In the face of climate and biodiversity crises, though, we must also remember that like all life, oaks are vulnerable. Globally, one-third of oaks are threatened by extinction—in California, that number jumps to nearly half. Changes in land use and climate contribute to reductions in oak populations. In many areas, the changing climate means that oaks struggle to reproduce. 

That’s why one critical way to learn about the state of our native oaks is by understanding where young seedlings and saplings are located. In this case, community science can do the work that no one else can!

The California OakWatch Project

Community science is a powerful tool for conservation because people from all over the state can create biodiversity data that it would take botanists years to collect. More importantly though, community science is characterized by people making observations in the areas they know or call home, leading to collective action and empowerment. Community science can give people the tools to negotiate, improve, and even transform governance for stewardship and social-ecological sustainability.

The CNPS California Oak Watch project focuses on collecting valuable data about oaks native to the California Floristic Province, with a particular emphasis on young oaks. To protect them, we need to know where they are, and with the help of people in our community, we can map them!  

Here’s how you can contribute to the conservation of California’s oaks through community science:  

1. Join the California OakWatch Project

Getting started is easy! Use the iNaturalist project to record your own observations, get help with identifications, collaborate with others to collect this kind of information for a common purpose, or access the observational data collected by iNaturalist users. 

iNaturalist connects people to nature, and in our case, we want to connect you to oaks!  

2. Learn about Native Oaks

Oaks are messy, but we love them. They hybridize, resprout, and change their leaves depending on herbivory or other stress–so it’s tough to identify them even with good photos! Thankfully, our project journal page offers some great resources to get started with oak identification, including our official oak guide and recorded oak identification webinars by local experts!

3. Encourage Others to Get Involved

Spread the word about the importance of California’s oak trees and the California OakWatch project. The foundation of community science is that it provides everyone—regardless of their background—with an opportunity to contribute meaningful data to further our scientific understanding of key issues. We encourage everyone to join! The California OakWatch project aims to engage all people in the outdoors — building connections and networks, as well as making science more equitable and accessible.   

As California Native Oak Day reminds us, let’s come together to celebrate the remarkable beauty and significance of our native oaks. By participating in the California OakWatch project and engaging in community science, we can help protect them. Happy California Native Oak Day! 

Jose Esparza Aguirre is a Community Science Coordinator at CNPS, where he leads the California OakWatch project.