Creeks, Oaks & Roosters

The Natural History of Cotati, CA


Cotati: The Heart of Sonoma County

Cotati, California is situated in the heart of Sonoma County. Its population of 7,000 is diverse, active in civic participation and environmentally-minded. While Cotati is Sonoma County’s smallest incorporated town, it makes up for its diminutive physical size by having an outsized cultural and environmental presence.  

Cotati's citizens have a deep pride over its cultural and natural heritage, including of the city's trees, waterways, wildlife and agriculture development through time. Today, a dense urban core hosts a multitude of vibrant community festivals, parks, community gardens, and many lovely pedestrian paths along creeks and other natural assets.

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A Place of Creeks & Oaks

The Laguna de Santa Rosa and its People

Cotati was and still is a place of creeks and oaks, and a place of great bounty. In fact, Cotati is located at the southern headwaters of the Laguna de Santa Rosa, the largest wetlands complex in Northern California. Before these wildlands were transformed into agricultural and urban uses, the Laguna de Santa Rosa consisted of vast oak woodlands, dense riparian forests, lakes, and both perennial and seasonal freshwater wetlands.

A rich abundance of migratory birds, insects, mammals, reptiles and amphibians depended on the Laguna for sustenance, shelter and habitat during breeding and nesting season. Elk, pronghorn antelope, mountain lions, grizzly bears and a multitude of other animals called the region home.

Indigenous communities, including Pomo, Wappo and Miwok peoples, have lived in the Laguna watershed for more than 10,000 years. The Coast Miwok tribe in particular called the place that is now Cotati home.

This community of nomadic seasonal gatherers' culinary culture depended on the natural resources found in the area: acorns, roots, seeds, berries, fish, coastal shellfish, waterfowl, and a variety of game animals including elk and pronghorn antelope. The plants harvested from the forests of the area, which the communities actively tended, also provided more than just food. Materials for clothing, dyes, and medicines were all found right here. Canoes were a transportation mode in the often-flooded lands of the area. Shelter and rope from tule, watertight baskets from willow and sedge, and countless other essentials were expertly manufactured right in the community.

The prevailing order of life which existed for thousands of years came to an abrupt and violent end in the 1800's. The Coast Miwok peoples were enslaved, forcibly moved, killed or died from exposure to diseases introduced by settlers during this brutal period, bringing an end to the Coast Miwok's longstanding control over their territory. This very important history is recounted by historian Gaye LeBaron in the video included here. Additional resources are below.

In present times, Coast Miwok and Southern Pomo people are citizens of the Federated Indians of Graton Rancheria tribe. The tribe is an integral part of Sonoma County's culture and leads the stewardship of the environment within the region.

Today, spanning over 30,000 acres, the Laguna de Santa Rosa Wetland Complex sustains many different types of ecosystems, including seasonal and perennial freshwater wetlands such as creeks, ponds, marshes, vernal pools, swales, floodplains, riparian forest and grassland. The Laguna serves as a sponge that soaks up and holds water in times of high rain and provides sustenance during drought years. Its banks act as a filter for pollution and sediment. In short, the Laguna de Santa Rosa is arguably the most important ecological feature of the city and the region, and one that is important to learn more about.

The Oaks and the Mycorrhizae 

The oak species you might see in Cotati. Illustrations by Obi Kauffman,  The Forests of California 

While the Cotati section of the Laguna de Santa Rosa might be the ecological power behind the scenes, the oak trees are the powerful reminder of the woodlands that once stood in the region. These oaks were the centerpiece of an intricate and fascinating plant community. The Sonoma County oak woodlands continue to be uniquely adapted to the fire-prone  Mediterranean climate  of the region, serving as the habitat for thousands of types of wildlife and insect species.

One can easily find evidence of the  symbiotic relationship  oak trees have with other species in the form of an oak gall. The tiny gall wasp lays its eggs in the twigs of oak trees. The larvae that hatch release a chemical compound that mimics the tree's own hormones, resulting in a perfectly sized woody "home" for the wasps to grow on the branches. These apple-shaped woody growths are called galls. The insects inside the galls are hunted by birds, including the California scrub jay and woodpeckers. The galls become food for other insects and even mammals like the adorable native dusky-footed woodrat and California ground squirrel. Check out this informative webinar to learn about this ecosystem and the efforts to protect it.

Oak gall.  Secrets of the Oak Woodland , by Kate Marianchild. Illustration by Ann Meyer Maglinte.

Historic Cotati valley oak, felled by a 2024 storm.

Beneath the ground, the oaks develop a critical symbiotic partnership with fungi called mycorrhizae. Mycorrhizae appear like white filaments that spread out like roots themselves, with oaks retaining more of these relationships than any other broad-leaved tree. These mycorrhizal fungi transport essential nutrients to the trees, carry chemical messages between plants to warn each other of impending dangers like infestations, and "send" nutrients to a struggling plant of another species.

Knowledge of the importance of mycorrhizae has existed for years before becoming the subject of Netflix documentaries. Ethnoecologist Kat Anderson reported, "Miwok grandmothers instruct their grandchildren that the fine threads under the ground, know to mycologists as mycelia, must not be disturbed, to ensure future abundance; in addition, some mushrooms must be spared."

The oaks' relationship to other forms of life in our ecosystems is absolutely fascinating, and worthy of exploration. The  Secrets of the Oak Woodlands  by Kate Marianchild expands on the subject and presents one special chapter after another describing our native oak habitat.

Oak & Mycorrhizae  Secrets of the Oak Woodland , by Kate Marianchild. Illustration by Ann Meyer Maglinte.


Transformation: Oak Woodlands to City of Roosters

Between 1953 and 2020, agricultural land has given away to urban development in Cotati's center. But, many little slivers of Cotati's natural assets, including historic farms and trails can still be visited and appreciated! Source:  Sonoma County Library  

European colonization and settlement of Sonoma County, including Cotati, resulted in a seismic transformation of the landscape. The first efforts by the new arrivals including altering the movement of water to support the burgeoning settlements. Wetlands were drained to create agricultural land. Channels were constructed to encourage water runoff into the Laguna de Santa Rosa. This effort had the effect of mitigating the naturally-occurring flooding on many areas, but encouraged downstream flooding and prevented rainwater from soaking into aquifers.

Cotati's farms further transformed the land through the introduction of poultry farms, which left an indelible mark on the city's culture and the environment. For years, residents encountered this heritage in the form of neighborhood roosters who called the local Peet's Coffee Shop their home.

Besides the re-engineering of our waterways, agriculture and urban development triggered another irreversible alteration to the native ecosystem in the form of invasive plants that are outcompeting native plant species which in turn support many other forms life. The result is a reduction of biodiversity in Sonoma County. Painstaking work is currently underway to remove the worst offenders like the notorious "French broom" (pictured).

Thankfully, agricultural and land development practices have advanced over the years with Sonoma County at the forefront of sustainability. Cotati continues to slowly and steadily develop to accommodate our growing population. Much of the development is concentrated to a defined urban boundary line, with the areas outside of that line retaining much if its agricultural and environmental heritage (see map). This is intentional.

As noted by the  City of Cotati , "Throughout the 1990's, Cotati has faced this challenge by effectively encouraging growth within strict limitations. In 1990 the citizens of Cotati overwhelmingly voted to curtail the growth of the city by forbidding any annexation of land beyond a fixed urban boundary line. This highly popular self-imposed limit on annexation turned the focus on development inwards."

Despite this growth, Cotati's urban areas are home to many beautiful natural features. Vernal pools might be the rarest. Vernal pools are temporary wetlands that are critical habitat for many endangered plant and animal species. There is currently only one vernal pool in Cotati's center (pictured) on land owned by the City of Cotati, and a few more on the outskirts of the city under private ownership. This is a special natural asset that is best observed from a distance to minimize the impact of foot-traffic.


A Glimpse of Nature & Farming in Cotati!

1

Veronda-Falletti Ranch

A historic urban ranch owned by the  City of Cotati  and protected by a conservation easement once served as a poultry farm. Today, the site acts as a demonstration farm and community center, and is managed by  Sandy Loam  and  Phoenix Farm Concepts .

2

Delano Park & Cotati Creek

A neighborhood park is tucked away just a couple blocks from the town plaza. The adjacent Cotati Creek is partially channelized (paved) in some areas. But, there are many areas in which water can pool and infiltrate into the ground.

3

Headwaters of the Laguna de Santa Rosa

A lovely trail runs along the headwaters of the Laguna de Santa Rosa. This area was restored by the  Cotati Creek Critters , a group of local volunteers. Invasive species were hand removed, and native vegetation was introduced.

4

Cotati Pocket Park Food Forest

An urban food forest was installed by a local non-profit,  Daily Acts, in 2009 . The park demonstrates how small neighborhood spaces can serve as a functional (food creation) and an aesthetic (beautiful neighborhood gathering space) asset.


If you're interested in learning about the cultural history of Cotati, check out this virtual tour hosted by the Cotati Historical Society!

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Between 1953 and 2020, agricultural land has given away to urban development in Cotati's center. But, many little slivers of Cotati's natural assets, including historic farms and trails can still be visited and appreciated! Source:  Sonoma County Library  

Oak gall.  Secrets of the Oak Woodland , by Kate Marianchild. Illustration by Ann Meyer Maglinte.

Oak & Mycorrhizae  Secrets of the Oak Woodland , by Kate Marianchild. Illustration by Ann Meyer Maglinte.