North Richmond Urban Nature Loop Point of Interest #9
In the vacant lot across from you is a small stand of Coastal Live Oaks (scientific name: Quercus agrifolia) as well as a large Willow tree (scientific name: Salix glauca L.). These are ‘volunteer’ trees that grew naturally from seeds or acorns. If you stand still for a few moments, look and listen, you might observe some of the birds and other animals that live and rely on the habitat these oaks create.
Oaks hold immense significance to California, representing some of our most recognizable natural, cultural, and community aspects. Oaks are integral components of California’s diverse ecosystems. They provide vital habitat and food sources for numerous species, including birds, mammals, and insects. Oaks help preserve biodiversity by supporting a variety of plant species within their canopy and understory. They can live up to 250 years, and the width of some old oaks can exceed 10 feet!
Oak trees are incredibly resilient – they adapt to diverse climates and soil conditions and can cope with disturbances such as urbanization, pests and diseases, and even fires. They have deep root systems that let them access water and nutrients stored in deep soils during dry years. These root systems also provide stability and anchorage, allowing oaks to withstand strong winds, storms, and even flooding. The thick bark of oaks helps them cope with heat – they insulate the tree’s vital cambium layer (the living part of the trunk) from damage during the hot summer months and even during fires. Oak acorns are especially resistant to fires and can quickly sprout and establish new trees after a fire has passed, helping oak ecosystems to quickly rebound after fire. Oaks have a symbiotic relationship with mycorrhizal fungi, meaning both oaks and fungi benefit from this relationship: fungi collect water and nutrients from the soil and pass them to the tree, much more efficiently than tree roots. In exchange, the tree gives the fungi food, in the form of carbohydrates the tree has manufactured through photosynthesis.
Culturally, oaks hold deep roots in California’s heritage. They have been revered by indigenous communities for centuries, representing strength, longevity, and wisdom. Oaks have served as gathering places for tribal ceremonies, providing shade and shelter for important cultural events. The acorns produced by oaks have traditionally been a staple food source for Native American tribes, including the local Lisjan people.
Because they are so well adapted to our climate and natural ecosystems and because of their resilience, oaks are often planted in public parks, residential areas, and urban green spaces, providing shade and aesthetic beauty. Oaks create a welcoming environment for outdoor activities, such as picnics, gatherings, and recreational pursuits, fostering a sense of community connection and enjoyment of nature. The complete interview of Ruth Ortega can be viewed here.