Giant sequoias (Sequoiadendron gigantea), Calaveras Sequoia Grove, California, USA Photograph by David Olson   Western North America: Western United States Temperate Coniferous Forests   20,400 square miles (52,800 square kilometers) -- the size of Vermont and Maryland combined Critical/Endangered

· Majestic Mountains and Towering Trees
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
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Majestic Mountains and Towering Trees

From mountain peaks to steep canyons, the extraordinary range of habitat types within the Sierra Nevada support many unusual plant and animal communities. Half of all of California's vascular plants occur here, with 400 being endemic. Many other species, from chipmunks to salamanders, are also found nowhere else. Groves of giant sequoia trees that are more than 3,000 years old, alpine meadows filled with gentians and larkspurs, and rivers teeming with golden trout are just some of the habitats you can find in this ecoregion.

Special Features

In the Sierra Nevada Forests, 14,000-foot (4,200-m) mountain peaks tower over steep canyons, river valleys, several different forest types, extensive talus slopes, meadows, montane chaparral, lakes, and rock outcrops. The west slope of the mountain range supports forests conifers such as pine, fir, and incense cedar. On the drier eastern slope, pine and fir trees dominate. At lower levels are pinyon-juniper woodlands and sagebrush.

	Giant sequoias are the most massive trees on Earth, with some trees more than 260 feet (80 m) tall and more than 36 feet (11 m) in diameter.

Wild Side

From ponderosa pine forests to chaparral to woodlands, the forests of the Sierra Nevada are about as diverse as you can imagine. This diversity includes the biggest trees on Earth. Sugar pine is the world's tallest and largest pine species. And the giant sequoias that live here are the most massive. In the highest reaches above timberline, rocky outcrops give way to alpine meadows. Of the salamanders, frogs, fish and rodents found here, 13 species are endemic. These include the Yosemite toad, limestone salamander, alpine chipmunk, western heather vole, yellow-eared pocket mouse, and the golden trout. This is in addition to the abundant coyotes, cougars, ringtails, fishers, wolverines, and several large owls, hawks, and eagles that call this ecoregion home.

Cause for Concern

A century of intensive logging, mining, railroad building, development, fire suppression, and grazing by sheep and cattle have left only a quarter of the natural habitat in the Sierra Nevada intact. One-third of the giant sequoia trees have been cut, and the U.S. Forest Service was permitting the logging of these rare and unique trees as recently as the 1980s. While there are several large and well-protected national parks in this ecoregion, such as Yosemite and Sequoia, the vast majority of the native forests have been converted to tree plantations. Intensive forestry practices have not only taken much of the ancient forests, but they have dramatically simplified the structure of the forests today and made them much more prone to catastrophic fires. These forests are also more susceptible to outbreaks of fungal diseases and pests such as bark beetles. Outside the protection of national parks, most of the remaining fragments of original forest continue to face threats from logging, fire suppression, and grazing. Another alarming cause for concern in this ecoregion is the well-documented decline and disappearance of amphibians, which may be due to introduced fish, acid rain, and loss of habitat.

For more information on this ecoregion, go to the World Wildlife Fund Scientific Report.