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An introduction to the central valley farming community in the united states

The Great Central Valley Starthistles: It is about miles long and about 75 miles wide. At its extreme northern and southern ends, the elevation is about feet. At its center, east of San Francisco Bay, it is slightly below sea level. The Great Central Valley is actually two large valleys lying end to end, each drained by a major river.

The confluence of these two rivers occurs east of San Francisco Bay. This area, the Sacramento-San Joaquin Delta, was formerly a massive wetland.

This geomorphic province has more than any other been altered by activities of humans. It its pristine state, it contained three primary communities of plants and animals: As such, it shares many characteristics with the desert provinces. Climate The climate of the Great Central Valley promotes widespread grasslands.

Precipitation occurs during winter months, but it is reduced because of the rain shadow of the Coast Ranges. To the north, in the Sacramento River Valley, average annual precipitation is moderate. To the south it is reduced to desert proportions. Geology The Great Central Valley is a huge basin filled with sediments. Sands and gravel over 30, feet deep lie upon Sierran basement rocks that extend downward at an angle from the western slope of the Sierra Nevada.

During the last 5 million years, sediments accumulated as alluvial deposits washed out of the mountains. These deposits are only a few thousand feet deep over most of the valley floor. Depths up to 10, feet occur in some places, indicating that the valley floor was not always as monotonous as it is today.

Unfortunately, San Joaquin Valley crude oil is very thick, making it a high-cost, low-price product. When oil prices drop, it is not economically feasible to pump oil in the San Joaquin Valley. Pristine grasslands also contained annual grasses and herbs, although the annual grasses were not as abundant as the perennial forms. Some of the wildflowers produced displays of color that are legendary. Among these wildflowers were numerous annual species of geophytes. Other carpets of wildflowers may include various members of the sunflower family.

Among these are small species such as Goldfields that occur in untold millions. Tarweeds and thistles bloom long after the grassland becomes dry. By blooming during summer, they capitalize on a lack of competition for pollinators. Common Tarweed stands about 2 feet high. These plants have glandular hairs that produce a tarlike substance. This resinous material helps to retard water loss during the long, hot summer.

Thistles are prickly plants that usually have purple flowers. It first appeared near Benicia in the inner Coast Ranges and has spread into overgrazed areas of the western Great Central Valley. If harvested in the bud stage, this plant provides an edible artichoke. Cattle and sheep avoid it, so one it becomes established, it spreads rapidly to infest entire pastures.

Its beauty is the only redeeming feature of overgrazing. It contains native Valley Grassland in a relatively undisturbed condition. Nature Conservancy and are working to restoring it to its original condition. The Corral Hollow, another valley southwest of Tracy, has been used for grazing sheep and cattle and a motorcycle playground.

Death of the Central Valley

A portion has also been the site of nuclear testing. Now it is a acre ecological reserve. It is home to many reptiles and amphibians.

The Corral Hollow also has serpentine soil and the endemic plants associated with the soil type. It is also host to the Large Flowered Fiddleneck, a state and federally listed endangered plant. Vernal Pools Vernal pools or "hogwallows" occur where the hardpan is close to the surface. In the Central Valley there are three types of vernal pools: Merlin's Grass, a spore-bearing plant is abundant in vernal pools.

It is an aquatic plant that uses crassulacean acid metabolism, a photosynthesis typically associated with drought-adapted succulents.

It helps to conserve CO2. Valley pools are common in the basins or valleys of low-lying areas of saline or alkaline soils. Volcanic pools are similar to terrace pools in flora.

They occur throughout the state. Terrace pools occur on ancient flooded terraces on higher ground. Rainwater accumulates because it cannot absorb into the ground.

  • They resemble willows but are in the Sunflower family;
  • Other carpets of wildflowers may include various members of the sunflower family;
  • Nature Conservancy and are working to restoring it to its original condition.

It is surrounded by wildflowers in the spring as it recedes in the spring. Because they are ecological islands there is a great deal of endemism.

They are mounds of up to 6 feet and in the low spots are vernal pools. Wind deflation of old stream channels and soil build up around shrub fields are believed to be the contributing factors.

There has been a significant decline in the number of vernal pools in California.

An introduction to the central valley farming community in the united states

Freshwater Marshes The Great Central Valley had many wetland habitats that were created from mountain runoff. Wetlands are characterized by a mixture of water and emergent vegetation.

They are termed swamps, marshes, and bogs. Swamps have the most open water and plants located in swamps are able to withstand submergence of their roots by water.

Swamps do not occur in California. Bogs have the least amount of water. They are soggy or supersaturated substrates. They are very acidic and the plants in bogs are nutrient deficient. They water in these locations is often brown because of decay. Freshwater marshes are the result of the accumulation of water in the shallow depressions of flatlands.

They are no longer common in California. Before the ecologic disruption of draining and damming, there were three large lakes in the Central Valley: Covering more than square miles, Tule Lake was the largest freshwater lake west of the Mississippi.

Freshwater marshes throughout the state were similar. As a reserve, the Creighton Ranch Reserve demonstrates what a marsh system was like. Vegetation is distributed in bands. Plant species occur in single-species zones as bands on the edge of water. Macrophytes "large plants" float in the water and closer to the shoreline are rooted macrophytes and then rooted plants occur in shallow water and on land. Freshwater marshes are dominated by reeds that grow in water-saturated soils.

They fall into 4 categories: Rushes, Bulrushes, Sedges, and Cattails. They are all similar in their grasslike appearance.

  • Irrigation of big tracts of land, using water subsidized by public funds has helped large agribusiness to lean towards immediate profit;
  • Rainwater accumulates because it cannot absorb into the ground;
  • Various members of the geranium family, Red Stem filaree and Storksbill, were also introduced;
  • They water in these locations is often brown because of decay.

Cattails cannot tolerate deep water so they occur on the outer edge of marshes. Sedges and rushes are different in that sedges have triangular stems and rushes that round stems.

Bulrushes "tules" are related to sedges. Water loving trees such as willows occur farther away from the water than the previously mentioned plants.

Some willows resemble large shrubs. Seeds are dispersed by wind. Shrubs, such as mule fat occur on higher ground where water is more alkaline. They resemble willows but are in the Sunflower family. Their flowers are small and white and there seeds are dispersed by the wind.

  • Merlin's Grass, a spore-bearing plant is abundant in vernal pools;
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  • The Water-fern Azolla filiculoides also grows on the water it is a mosslike fern;
  • Unfortunately, San Joaquin Valley crude oil is very thick, making it a high-cost, low-price product.

Plants that grow within the marshes are Watercress, a low-growing aquatic plant that emerges slightly above the water. Floating plants include the Water-fern and duckweeds. Water-fern contain a blue-green alga, which is important in nitrogen fixation and enriches the marsh environment. Duckweeds appear as floating leaflike structures that cover the water. It contributes to the supply of detritus. Non-native floating plants like Water hyacinth also occur.

It remains afloat due to their inflated leaves. When in bloom, blue flowers are displayed. These non-native plants are renowned for their rapid growth and rapid rate of absorption of dissolved nutrients.