Cosumnes River Preserve
Encyclopedia
The Cosumnes River Preserve is a nature preserve of 46000 acres (186.2 km²) located 20 miles (30 km) south of Sacramento
, in the US state of California
. The preserve protects a Central Valley remnant that once contained one of the largest expanses of oak tree savanna, riparian oak forest
and wetland
habitat in North America. Agricultural development has changed the landscape from groves of oaks and tule marshes to productive farmlands.
The Cosumnes River
is the last remaining free-flowing river in California's Central Valley, with the preserve located on the river's lower reach where it joins the Sacramento-San Joaquin Delta tidelands. The area supports a diverse range of plant and animal life, including three species of oak as well as rare plants like the endemic northern California black walnut (Juglans californica var. hindsii). Notable features include the sandhill crane
fall migration and the Tall Forest in Wood Duck Slough. More than 250 bird species, more than 40 fish species, and some 230 plant species have been identified here.
Located on the bird migration route, the Pacific Flyway
, the preserve is designated an Important Bird Area by the American Bird Conservancy
and National Audubon Society
. Several rare birds, such as the Tri-colored Blackbird and the Greater Sandhill Crane, have been identified. Many bird species that have been extirpated
from most of the Central Valley are returning to the area.
The preserve is between two growing urban centers, Sacramento
in the north, and Stockton
to the south, which threaten to constrict the protected areas to a narrow corridor extending from the Sierra foothills to the Sacramento River Delta.
The National Park Service
has been protecting the area since 1976 when the agency added the Cosumnes River environment to the National Natural Landmark
Program as the Cosumnes River Riparian Woodlands. This program conserves examples of the country's natural history and is the only natural areas program of national scope that identifies and recognizes the best representations of biological and geological features in both public and private ownership.
of 1200 square miles (3,108 km²) in size.
Some partners in the cooperative agreement include: US Bureau of Land Management
, California Department of Water Resources
, California State Lands Commission
, Sacramento County Department of Regional Parks, California Department of Fish and Game
, Wildlife Conservation Board, Ducks Unlimited
, Inc. and private landowners.
In 1998, the Howard Ranch, located within the watershed area, was put up for sale. The ranch contains important wetlands, including vernal pool
s, and the conservancy purchased the property of 13000 acres (52.6 km²) property using a combination of grants and loans. The loans included funds from the federal Clean Water Act
's State Revolving Fund. This was the first time these funds had been used to purchase and protect wetlands.
Currently, the preserve is more than 46000 acres (186.2 km²) with educational and scientific studies being conducted in one of the largest conservation efforts begun on a watershed-sized scale. Collectively known as the Cosumnes River Project, it is a broad-based work to restore and protect the integrity of the river and associated landscapes including Central Valley habitats and wildlife.
Notable trees in the preserve include valley oak and blue oak. The valley oak was once common in central California, forming large groves along rivers and streams. In grasslands, they form open savannas along with blue oaks. The valley oak
is the largest of the native California oak trees and can live to be 600 years old. With a vertical root system as deep as 80 feet, it can reach groundwater levels. The blue oak
tolerates dry soil and can have a root system 30 feet deep. It has a distinctive blue tint in the green leaf color that can best be seen when compared to another nearby oak of a different type. The blue oak can live to be 400 years old and provides critical winter range for deer and other wildlife.
The oaks provide several hundred pounds of nuts yearly, and at least 35 mammals and around 100 birds include oak acorn
s in their diet. Especially mule deer and western gray squirrel, who rely so much on the acorn crop that a poorly-producing year can limit their populations.
Threats to the trees include land-clearing, rodents and exotic grasses. The non-native grasses are more aggressive and produce more seed than the native perennials, which attracts seed-eaters like Botta's Pocket Gopher that also feed on acorns and oak seedlings. Restoration includes breaching the levees, allowing floodwaters to scour out the non-native grasses, reduce rodent populations and deposit sediment. With the buildup of sand and sediments in the flooded areas, studies have shown an increase growth of cottonwoods and willows, which in turn trap more sediments during the next flood cycles.
The vegetation of oak, willow, alder, elderberry, cattails, and many other plants provide food, shelter and nesting sites for a wide range of wildlife, including migrating birds on the Pacific Flyway
. The river is part of a dynamic balance of natural processes that sustain the plant and animal life that depend upon it.
"Every time a levee is repaired, the river is prevented from establishing a healthy floodplain, and every time river water is stored in a reservoir, the flow pulses essential for ecologic processes are eliminated."
-Philip B. Williams, Ph.D., Reno, NV. August, 2001 (from his speech River Engineering Versus River Restoration given at a ASCE conference)
Recreation uses include wildlife-viewing, paddling, photography, nature study and limited fishing. The launch site for paddling is near the visitor center and a self-guided trip brochure with map is available. Tidal influence from the ocean is evident here with water levels changing several feet each day, exposing mudflat
s and sandbars. There are several named slough
s both east and west of the visitor center. Wood Duck Slough is the easternmost slough and has views of the Tall Forest, with large valley oaks overhanging the water and providing deep shade. "The scene is reminiscent of Bogart and Hepburn on the African Queen", writes author Charlie Pike in his book, Paddling Northern California.
Hiking trails include short "walks" that showcase wetland plants and animals, to longer trails, such as the 7 miles (11 km) roundtrip Howard Ranch trail that has vernal pools, riparian habitat and views of oak woodland and the Sierra Nevada Mountains.
There is also a driving tour which allows visitors to see the scope of the conservation project, showing properties that are closed to the public.
Sacramento, California
Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...
, in the US state of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. The preserve protects a Central Valley remnant that once contained one of the largest expanses of oak tree savanna, riparian oak forest
Riparian forest
A riparian forest is a forested area of land adjacent to a body of water such as a river, stream, pond, lake, marshland, estuary, canal, sink or reservoir. -Etymology:...
and wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
habitat in North America. Agricultural development has changed the landscape from groves of oaks and tule marshes to productive farmlands.
The Cosumnes River
Cosumnes River
The Cosumnes River is a river in northern California in the United States. It rises on the western slope of the Sierra Nevada and flows approximately into the Central Valley, emptying into the Mokelumne River in the Sacramento-San Joaquin Delta.-Name:...
is the last remaining free-flowing river in California's Central Valley, with the preserve located on the river's lower reach where it joins the Sacramento-San Joaquin Delta tidelands. The area supports a diverse range of plant and animal life, including three species of oak as well as rare plants like the endemic northern California black walnut (Juglans californica var. hindsii). Notable features include the sandhill crane
Sandhill Crane
The Sandhill Crane is a large crane of North America and extreme northeastern Siberia. The common name of this bird references habitat like that at the Platte River, on the edge of Nebraska's Sandhills in the American Midwest...
fall migration and the Tall Forest in Wood Duck Slough. More than 250 bird species, more than 40 fish species, and some 230 plant species have been identified here.
Located on the bird migration route, the Pacific Flyway
Pacific Flyway
The Pacific Flyway is a major north-south route of travel for migratory birds in America, extending from Alaska to Patagonia. Every year, migratory birds travel some or all of this distance both in spring and in fall, following food sources, heading to breeding grounds, or travelling to...
, the preserve is designated an Important Bird Area by the American Bird Conservancy
American Bird Conservancy
American Bird Conservancy is a non-profit membership organization with the mission of conserving native birds and their habitats throughout the Americas...
and National Audubon Society
National Audubon Society
The National Audubon Society is an American non-profit environmental organization dedicated to conservation. Incorporated in 1905, Audubon is one of the oldest of such organizations in the world and uses science, education and grassroots advocacy to advance its conservation mission...
. Several rare birds, such as the Tri-colored Blackbird and the Greater Sandhill Crane, have been identified. Many bird species that have been extirpated
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...
from most of the Central Valley are returning to the area.
The preserve is between two growing urban centers, Sacramento
Sacramento, California
Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...
in the north, and Stockton
Stockton, California
Stockton, California, the seat of San Joaquin County, is the fourth-largest city in the Central Valley of the U.S. state of California. With a population of 291,707 at the 2010 census, Stockton ranks as this state's 13th largest city...
to the south, which threaten to constrict the protected areas to a narrow corridor extending from the Sierra foothills to the Sacramento River Delta.
The National Park Service
National Park Service
The National Park Service is the U.S. federal agency that manages all national parks, many national monuments, and other conservation and historical properties with various title designations...
has been protecting the area since 1976 when the agency added the Cosumnes River environment to the National Natural Landmark
National Natural Landmark
The National Natural Landmark program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only natural areas program of national scope that identifies and recognizes the best examples of biological and geological features in...
Program as the Cosumnes River Riparian Woodlands. This program conserves examples of the country's natural history and is the only natural areas program of national scope that identifies and recognizes the best representations of biological and geological features in both public and private ownership.
History of the preserve
The fast-disappearing valley oak (Quercus lobata) tree of California's Central Valley prompted The Nature Conservancy, a nonprofit conservation organization, to find and protect these trees from the rapid urban growth in the 1980s. After surveying the entire valley, the best stands were found on the lower Cosumnes River and a preserve of 800 acres (3.2 km²) was established in 1987. With further study, scientists better understood the river-oak forest relationship; the "swamp oak" is another name for the valley oak because it thrives on deep, alluvial soils (which also makes good farmland) that the river deposits with seasonal flooding. The Conservancy realized that it needed a larger, broader view that included the river, floodplains, the whole watershed. As a result, in 1993, the conservancy moved beyond its hallmark of outright land purchases and into cooperative agreements with farmers, water-and flood control agencies, and shared in management responsibility with federal, state and local land agencies toward the goal of protecting a watershedDrainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
of 1200 square miles (3,108 km²) in size.
Some partners in the cooperative agreement include: US Bureau of Land Management
Bureau of Land Management
The Bureau of Land Management is an agency within the United States Department of the Interior which administers America's public lands, totaling approximately , or one-eighth of the landmass of the country. The BLM also manages of subsurface mineral estate underlying federal, state and private...
, California Department of Water Resources
California Department of Water Resources
The California Department of Water Resources , is a department within the California Natural Resources Agency. The Department of Water Resources is responsible for the State of California's management and regulation of water usage...
, California State Lands Commission
California State Lands Commission
The California State Lands Commission is a unit of state government that is responsible for management and protection of natural and cultural resources, as well as public access rights, on some of California's publicly owned lands....
, Sacramento County Department of Regional Parks, California Department of Fish and Game
California Department of Fish and Game
The California Department of Fish and Game is a department within the government of California, falling under its parent California Natural Resources Agency. The Department of Fish and Game manages and protects the state's diverse fish, wildlife, plant resources, and native habitats...
, Wildlife Conservation Board, Ducks Unlimited
Ducks Unlimited
Ducks Unlimited is an international non-profit organization dedicated to the conservation of wetlands and associated upland habitats for waterfowl, other wildlife, and people. It currently has approximately 780,000 members, mostly in the United States and Canada.-Introduction:Ducks Unlimited was...
, Inc. and private landowners.
In 1998, the Howard Ranch, located within the watershed area, was put up for sale. The ranch contains important wetlands, including vernal pool
Vernal pool
Vernal pools, also called vernal ponds or ephemeral pools, are temporary pools of water. They are usually devoid of fish, and thus allow the safe development of natal amphibian and insect species...
s, and the conservancy purchased the property of 13000 acres (52.6 km²) property using a combination of grants and loans. The loans included funds from the federal Clean Water Act
Clean Water Act
The Clean Water Act is the primary federal law in the United States governing water pollution. Commonly abbreviated as the CWA, the act established the goals of eliminating releases of high amounts of toxic substances into water, eliminating additional water pollution by 1985, and ensuring that...
's State Revolving Fund. This was the first time these funds had been used to purchase and protect wetlands.
Currently, the preserve is more than 46000 acres (186.2 km²) with educational and scientific studies being conducted in one of the largest conservation efforts begun on a watershed-sized scale. Collectively known as the Cosumnes River Project, it is a broad-based work to restore and protect the integrity of the river and associated landscapes including Central Valley habitats and wildlife.
River and forest relationship
The Cosumnes River has no major dams on its course of 80 miles (128.7 km) and floods after heavy rains bringing in sediments that provide nutrients for the vegetation, as well as recharging groundwater levels. In addition, removal of the man-made levees allows more innudation of floodwaters and is what ecologist Rich Reiner terms " natural process restoration".Notable trees in the preserve include valley oak and blue oak. The valley oak was once common in central California, forming large groves along rivers and streams. In grasslands, they form open savannas along with blue oaks. The valley oak
Valley Oak
Quercus lobata, commonly called the Valley oak, grows into the largest of North American oaks. It is endemic to California, growing in the interior valleys and foothills. Mature specimens may attain an age of up to 600 years. This deciduous oak requires year-round access to groundwater.Its thick,...
is the largest of the native California oak trees and can live to be 600 years old. With a vertical root system as deep as 80 feet, it can reach groundwater levels. The blue oak
Blue Oak
Quercus douglasii, the Blue Oak, is an oak in the white oak section of the genus, Quercus sect. Quercus. It is endemic to California and is found in foothills surrounding the Central Valley of California and certain locations in the California Coast Ranges, USA...
tolerates dry soil and can have a root system 30 feet deep. It has a distinctive blue tint in the green leaf color that can best be seen when compared to another nearby oak of a different type. The blue oak can live to be 400 years old and provides critical winter range for deer and other wildlife.
The oaks provide several hundred pounds of nuts yearly, and at least 35 mammals and around 100 birds include oak acorn
Acorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...
s in their diet. Especially mule deer and western gray squirrel, who rely so much on the acorn crop that a poorly-producing year can limit their populations.
Threats to the trees include land-clearing, rodents and exotic grasses. The non-native grasses are more aggressive and produce more seed than the native perennials, which attracts seed-eaters like Botta's Pocket Gopher that also feed on acorns and oak seedlings. Restoration includes breaching the levees, allowing floodwaters to scour out the non-native grasses, reduce rodent populations and deposit sediment. With the buildup of sand and sediments in the flooded areas, studies have shown an increase growth of cottonwoods and willows, which in turn trap more sediments during the next flood cycles.
The vegetation of oak, willow, alder, elderberry, cattails, and many other plants provide food, shelter and nesting sites for a wide range of wildlife, including migrating birds on the Pacific Flyway
Pacific Flyway
The Pacific Flyway is a major north-south route of travel for migratory birds in America, extending from Alaska to Patagonia. Every year, migratory birds travel some or all of this distance both in spring and in fall, following food sources, heading to breeding grounds, or travelling to...
. The river is part of a dynamic balance of natural processes that sustain the plant and animal life that depend upon it.
"Every time a levee is repaired, the river is prevented from establishing a healthy floodplain, and every time river water is stored in a reservoir, the flow pulses essential for ecologic processes are eliminated."
-Philip B. Williams, Ph.D., Reno, NV. August, 2001 (from his speech River Engineering Versus River Restoration given at a ASCE conference)
Public access and education
The Cosumnes River Preserve Visitor Center is the hub for all activities concerning the preserve. Educational workshops, field trips and activity packets for teachers and students are provided through the visitor center.Recreation uses include wildlife-viewing, paddling, photography, nature study and limited fishing. The launch site for paddling is near the visitor center and a self-guided trip brochure with map is available. Tidal influence from the ocean is evident here with water levels changing several feet each day, exposing mudflat
Mudflat
Mudflats or mud flats, also known as tidal flats, are coastal wetlands that form when mud is deposited by tides or rivers. They are found in sheltered areas such as bays, bayous, lagoons, and estuaries. Mudflats may be viewed geologically as exposed layers of bay mud, resulting from deposition of...
s and sandbars. There are several named slough
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...
s both east and west of the visitor center. Wood Duck Slough is the easternmost slough and has views of the Tall Forest, with large valley oaks overhanging the water and providing deep shade. "The scene is reminiscent of Bogart and Hepburn on the African Queen", writes author Charlie Pike in his book, Paddling Northern California.
Hiking trails include short "walks" that showcase wetland plants and animals, to longer trails, such as the 7 miles (11 km) roundtrip Howard Ranch trail that has vernal pools, riparian habitat and views of oak woodland and the Sierra Nevada Mountains.
There is also a driving tour which allows visitors to see the scope of the conservation project, showing properties that are closed to the public.