By Maggie Chen
So you’ve been indoors the whole day and decided to go out to get some fresh air. The coast is on one side of you and along the trail you see a beautiful evergreen oak, extremely twisted, enormous, and gnarled. If the leaves are dark green and spiny-toothed along the edge, then it’s likely a Coast Live Oak! This native evergreen tree is one of the only California oak trees that flourishes near the coast, though you actually wouldn’t often find it right next to the shore. It can grow up to 100 feet tall and typically has a short trunk and enormous crooked branches that spread out and exceed its height.
This tree enjoys mild winters and the summer weather found near the ocean and is tolerant up to a certain degree to the aerosol-borne sea salt. In the bay area, the fog (affectionately called Karl the Fog) provides relief from the dry California summers. You can likely find them along well-drained soils of coastal hills and plains close to year round or perennial streams and they flower in the spring and winter.
The younger trees are often shrubby, older Coast Live Oaks get twisted and massive, and some specimens may live longer than 250 years old! They are pretty easy to grow and they get to the water they need by stretching their roots out to saturated soil. The oak’s fruit is a slender reddish brown acorn and attracts various birds and butterflies. This tree is one of the most integral wildlife plants utilized by a plethora of birds, mammals, reptiles, and invertebrates. And not only do wildlife use parts of the oak, but the acorn has been used as a staple food by several native bay area tribes. The acorns can be dried and ground into a powder and used as a thickening agent while cooking stews or mixed with the cereals when baking bread. This seed contains bitter tannins that can be leached out by running the seed through water, which could take several days or even weeks. Ruth Orta, a Him*re-n Ohlone, Bay Miwok, Plains Miwok elder, speaks about past and contemporary ways of processing acorns here.
Coast Live Oaks don’t need to be fertilized; they amend the soil over time with their own foliage and make the mycorrhizal fungus that they need to thrive. Additionally, the presence of this tree increases soil moisture and nitrogen availability in soil. Nitrogen plays a crucial role for vegetation, ensuring that energy is available for optimal yield. Its presence in the roots in the form of proteins and enzymes aids in regulating water and nutrient intake. Over time, these trees become islands of natural fertility that uplift and improve the health of surrounding vegetation. And as research suggests, being around trees and nature is beneficial for our mental and social well-being, so if you ever find yourself in need of a refresher then go for a walk and see if you can spot this native Californian oak along the way!
References:
California Native Plant Society. (2010). Coast Live Oak – Quercus agrifolia. California Native
Plant Society – Calscape: Restore Nature One Garden at a Time. Retrieved 6 March, 2022 from https://calscape.org/Quercus-agrifolia-(Coast-Live-Oak)
Golden Gate National Parks Conservancy. (2022). Coast Live Oak (Quercus agrifolia). Golden
Gate National Parks Conservancy. Retrieved 6 March, 2022 from https://www.parksconservancy.org/conservation/coast-live-oak
KOCH Agronomic Services. (2022). The Role of Nitrogen in Crop Production and How to
Protect It. KOCH Agronomic Services. Retrieved 6 March 2022, from https://kochagronomicservices.com/knowledge-center/The-Role-of-Nitrogen-in-Crop-Production-and-How-to-Protect-It_2288.aspx#:~:text=Nitrogen%20plays%20a%20critical%20role,regulate%20water%20and%20nutrient%20uptake
Marañón, Teodoro & Bartolome, James W. (1994). Coast Live Oak (Quercus Agrifolia) Effects
on Grassland Biomass and Diversity. JSTOR. California Botanical Society, Vol. 41, No. 1 (January – March 1994), pp. 39-52 (14 pages). Retrieved 6 March 2022, from https://www.jstor.org/stable/41426237
Weir, Kirsten. (2020). Nurtured by Nature: Psychological research is advancing our
understanding of how time in nature can improve our mental health and sharpen our cognition. American Psychological Association. Monitor on Psychology, Vol. 51, No. 3. Retrieved 6 March, 2022 from https://www.apa.org/monitor/2020/04/nurtured-nature#:~:text=From%20a%20stroll%20through%20a,upticks%20in%20empathy%20and%20cooperation
