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Cotati Creek Critters Project Site ~ The Laguna de Santa Rosa ~ Why Plant Trees? ~ What About Flood Control? ~ Native and Invasive Plants ~ Why Plant Native Grasses? ~ Flora & Fauna ~ Revegetation Plant List

Cotati Creek Critters project site

Cotati Creek Critters current project site is a 1-mile reach of the main channel of the Laguna de Santa Rosa in Cotati and part of Rohnert Park – NOT Cotati Creek, which is a smaller tributary that flows into the Laguna channel from the west, under Old Redwood Highway close to downtown Cotati, and joins the Laguna de Santa Rosa near Marsh Way, just south of East Cotati Avenue.

The dotted line on the map above indicates the extent of the Cotati Creek Critters project site.

In Fall 2011, we will be starting restoration at a new project site, planting native trees and shrubs on the west bank of the Laguna channel from Gravenstein Way to Commerce Blvd.

Map of Gravenstein site

The Laguna de Santa Rosa

A watershed is an area of land that drains to a common creek, stream, or river.

The Laguna de Santa Rosa watershed covers a 250 square mile area. The Laguna waterway is the largest tributary to the Russian River. It runs northwest from Cotati/Rohnert Park to enter the Russian River north of Forestville. The Laguna watershed is made up of smaller watersheds - creeks such as Windsor Creek, Mark West Creek, Santa Rosa Creek, and Copeland Creek flow into the Laguna. The Laguna watershed in turn exists within the 1,485 square mile Russian River watershed.

Originally the Laguna was a vast mosaic of vernal pools, lakes, marshes, woodlands and grasslands. Many of the watercourses have been straightened or have filled with sediment, and many of the marshes and wetlands have been built on or drained for agriculture. Many species of birds, fish, mammals, and plants that used to be abundant have disappeared along with their diminishing habitat. As the areas of existing wetlands and waterways shrink, what is left becomes ever more valuable. The wetlands of the Laguna that remain act as a biological filter for water, provide storage capacity for floodwaters, provide valuable wildlife habitat, and important recreational opportunities for people.

Most of Cotati's creek channels have been channelized and the banks either denuded or overgrown with invasive species such as blackberry. The Cotati Creek Critters, working with the support of the Laguna de Santa Rosa Foundation, the City of Cotati and the Sonoma County Water Agency (SCWA), has been sponsoring volunteer creek restoration efforts since 1998, particularly since receiving an Urban Streams Restoration Grant from the California Department of Water Resources in 2005. This has allowed us to plant and maintain 2,000 native trees and shrubs along the Laguna in Cotati.  Since then hundreds of understory plants – native grasses, sedges, and rushes - have been planted as well.

 

The video above is a presentation on the Laguna de Santa Rosa: Past, Present and Future, by Denise Cadman, given in Cotati on January 12, 2012.

 

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Why Plant Trees?

Cotati Creek Critters has planted approximately a mile of native trees alongside the Laguna de Santa Rosa channel in Cotati and a section of Rohnert Park.

The benefits of planting trees include:

  • The trees will eventually form a leafy canopy over the channel, creating shade, which will discourage non-native plants such as Himalayan Blackberry and tall, invasive grasses that slow stormwater flows and trap debris.
  • Shade helps keep water cool, which is beneficial for aquatic life including salmonids downstream in the system.
  • Lower water temperatures keep bacteria levels low, which is important for clean drinking water and recreational uses downstream. The Russian River resort areas of Rio Nido, Guerneville and Monte Rio are on the receiving end of our stormwater runoff.
  • Tree roots will help to stabilize banks and prevent soil erosion, which causes sedimentation downstream in the Laguna. Sediment is considered a significant form of pollution.
  • Trees provide shelter, food and nesting sites for birds, beneficial insects, and other wildlife.
  • Healthy creeks and trees help to make Cotati a more beautiful and enjoyable place to be, improving our quality of life and providing valuable educational opportunities.

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What about flood control?

The Sonoma County Water Agency, which has jurisdiction over most of the creek channels in the area, balances responsibility for flood control with support of ecological values such as enhancing wildlife habitat. The banks of the Laguna channel in Cotati used to be mown once or twice a year. The resulting combination of water and sunlight in the creek channels created the perfect environment for water- and sun-loving plants, such as cattails and in some areas Himalayan blackberries, which filled the channel from side to side. The build up of vegetation in the channel caused concern from a flood control standpoint. The lack of shade also caused water temperatures to rise. Warm water temperatures are a major cause of the decline of salmonid species downstream in the system. The Water Agency periodically mechanically removed sediment from the channels to reduce risks of flooding and maintain flood water capacity.

By growing trees, in the long-term the trees will shade out the vegetation in the channel, helping to keep water cool.

Other measures are being taken to balance ecological and flood control needs. For example when the trees reach a certain height, the lower branches are trimmed to avoid the collection of storm debris in the channel. The plantings are in straight lines (rather than in more natural “clumps,”) to reduce obstruction for water flowing in the channel.

For further information on the Sonoma County Water Agency’s stream maintenance policies see http://www.scwa.ca.gov/about_your_water/stream_maintenance.php

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Native and Invasive Plants...

Q. What are "native" and "invasive" species and why does it matter?

A. Native species such as Valley Oak, California Buckeye, Big Leaf Maple, Box Elder, California Rose, Blue Elderberry, and Snowberry are ideally adapted to our unique environment, in which they and their ancestors have grown for thousands of years. They provide just the right kinds of food and shelter for the native birds, insects and mammals with which they have coevolved, mutually adapting to each others' needs.

Invasive species such as Himalayan blackberry, pampas grass, broom and periwinkle (vinca) have been introduced from other ecosystems and can outcompete native plants to the point of excluding them completely. They do not support the same diversity of wildlife as native plants do.

By selectively removing invasive exotics and replanting with natives we enhance the sources of food and shelter for wildlife.

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Why Plant Native Grasses?

Now that we have completed the planting of a mile of native trees and shrubs, Cotati Creek Critters is focusing on the planting of an understory of native grasses, sedges, and rushes. Here are some of the reasons why.

 

A few facts:

  • Most of the grasses we see around us are non-native annual grasses, introduced from Europe and other Mediterranean climatic regions during the past 200 years or so. (Annual grasses grow for a year or less, set seed, and die).
  • There are over 300 species of native grasses in California, most of which are perennial (meaning that they grow for more than a year).
  • Unlike non-native annual grasses, some native perennial bunch grasses can live for over 100 years.
  • 98% of California's native grasslands no longer exist, mainly due to usurpation by non-native species, conversion to agriculture, and urban development.

Understory plants in the nursery, ready to go ->

Non-native annual grasses have shallow roots that die with the plant, leaving the soil vulnerable to erosion, particularly during high water flows. During the growing season, grasses such as wild oats (Avena spp.) can grow to 5 ft. tall, then turn brown and dry during the summer, creating a fire hazard.

In contrast, native grasses have many beneficial characteristics.


click image for full sized diagram!

Root systems

Native perennial grasses are adapted to summer drought, with long roots which penetrate deep into the soil. This is important because:

  • They stabilize creek banks and reduce soil erosion.
  • They enable water and nutrients to infiltrate deep into the soil.
  • Approximately 1/3 of the root systems die each year, adding organic matter deep into the soil profile.

Growth Habit

  • Because the grasses grow in tufts or bunches rather than as a continuous layer of turf, spaces and tunnels are created between them which can allow small animals to find their way amongst them, and wildflower seeds, acorns etc. to fall into the gaps and take root, enhancing biodiversity.
  • On a larger scale, native grasslands support a wide variety of wildlife, from birds to foraging mammals. All grass seed is edible and is an important food source for many types of wildlife.
  • The species we are planting here in Cotati mainly grow 1 1/2 ft. to 2 ft. tall, so once established they will require minimal mowing.


Basket sedge, carex barbarae.
The long, horizontal roots of the sedge plant are a traditional basket-making material, now also used in riparian restoration projects.

There is much more to learn about native California grasses and grasslands. There are links to two informative articles at this website under Media.

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Changes Over Time

Click on the thumbnails below for maps and photos of the area over time.

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Flora and Fauna of the Laguna in Cotati

The Laguna de Santa Rosa is home to a wide variety of plants and animals. Click on the thumbnails below for larger images of some of these plants and animals, or click here to see a list of observed bird species.

(photos by Wade Belew unless otherwise noted)

Elder Flower

Elder Berries

Box Elder

Snowberry

Tule

Twinberry

Mulefat

Heron
(photo by Don Jackson)

Mallard Pair
(photo by Anne Leonard)


Ring-Necked Pheasant
(photo by Anne Leonard)
   

Birds Seen Around the Laguna in Cotati (provided by John A. Dell'Osso)

Browse our cumulative bird list below, or view a list of birds seen at specific outings and educational field trips in pdf format:

* = nesting species; w = winter resident

Black-crowned night heron
Green-backed heron
Snowy egret (w)
Great egret
Great blue heron
Mallard (*)
Killdeer
Long-billed curlew (w)
Common snipe (w)
Western gull
Ring-billed gull
California quail
Ring-necked pheasant
Turkey vulture
Black-shouldered kite
Red-shouldered hawk
Cooper’s hawk
Sharp-shinned hawk
Red-tailed hawk
Osprey
American kestrel
Merlin (w '03)
Rock dove (Pigeon) (*)
Barn owl
Anna’s hummingbird
Allen’s hummingbird
Belted kingfisher
Northern flicker (red-shafted)
Nuttall’s woodpecker
Hairy woodpecker
Western kingbird (*)
Say’s phoebe
Black phoebe

Cliff swallow (*)
Barn swallow
Western scrub jay
American crow (*)
Raven
Chestnut-backed chickadee
Bushtit
Western bluebird
American robin
Northern shrike (*) (extirpated since 1989)
Mockingbird (*)
Water pipit (w)
Cedar waxwing
European starling (*)
Yellow-rumped warbler (w) (ssp. Audubon’s)
Black-throated gray warbler
Common yellowthroat
California towhee
Dark-eyed junco (subspecies Oregon and Slate-colored (w))
Red-winged blackbird
Brewer’s blackbird
Northern oriole (Bullock’s) (*)
Hooded oriole (December 1998 only)
White-crowned sparrow (w)
Golden-crowned sparrow (w)
American goldfinch
Lesser goldfinch (*)
House finch
European house sparrow (*)

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Plant List for Revegetation of the Cotati Reach of the Laguna

The plants we have been planting along the Laguna include equal numbers of trees and shrubs/herbaceous plants. All these species are native to riparian plant communities of Sonoma County. It is probably a broader assemblage then what would have been present historically in Cotati. We’ve chosen to include as many different species as reasonable to maximize diversity for both wildlife habitat and human enjoyment. Many of these species have already become successfully established at our project site over the last several years. Many of these plants are great in a home or commercial landscape as well, and we can recommend a particular species depending on your needs. If you have any questions, contact Stewardship Coordinator Wade Belew.

Common Name Scientific Name

Box Elder

Acer negundo

Big Leaf Maple

Acer macrophyllium

Buckeye

Aesculus californica

White Alder

Alnus rhombifolia

Red Alder

Alnus rubra

Oregon Ash

Fraxinus latifolia

Black Walnut

Junglans californica

Western Sycamore

Plantanus racemosa

Fremont Cottonwood

Populus fremontii

Red Willow

Salix lutea

Yellow Willow

Salix lutea

Coast Live Oak

Quercus agrifolia

Valley Oak

Quercus lobata

Black Oak

Quercus kelloggii

California Bay

Umbellularia californica

Coyote bush

Baccharis pilularis

Mulefat

Baccharis salicifolia

Spice Bush

Calycanthus occidentalis

Basket sedge/White root

Carex barbarae

Redtwig dogwood

Cornus sericea

Hawthorne

Crataegus suksdorfii

Toyon

Heteromeles arbutifolia

Common Rush

Juncus effusus.

Ninebark

Physocarpus capitatus

Twinberry

Lonicera involucrata

Coffeeberry

Rhamnus californica

Pink flowering currant

Ribes sanguineum

California Blackberry

Rubus ursinus

Blue Elderberry

Sambucus mexicana

Snowberry

Symphoricarpos albus

 

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