Native to western North America, redwood grows wild along a narrow coastal strip between California and Oregon. Most of the redwoods are located within Redwood National Park and Yosemite National Park. It is the tallest plant species in the world, and is also one of the longest-lived, being able to live over 2,000 years.
The plant prefers a type of temperate oceanic climate rich in humidity, but does not tolerate continental climates and temperatures that are too cold. It is widespread up to altitudes of 1,000 m above sea level, but generally grows at altitudes lower than 300 m. Sequoias prefer alluvial soils where they form pure or mixed forests with other local conifer species such as Pseudotsuga menziesii and Picea sitchensis.
Before the glaciations there were sequoias, or very similar trees, also in Europe. It was reintroduced to Europe in the first half of the 19th century for ornamental purposes, but in this short period of time the sequoias introduced into Europe, no more than 100-150 years old, reached a maximum height of 40-50 m.
Redwood National and the Yosemite Parks
The Redwood National Park is a United States national park, located along the Californian coast of the Pacific Ocean. It takes its name from the coast redwood sequoias, so named for the reddish color of the wood, which are the tallest trees in the world. With its 45,500 hectares the park protects 45% of the existing redwoods. The park also protects grasslands, cultural resources and 60 kilometers of pristine coastline.
In 1850, virgin redwood forest covered 810,000 acres of the northern California coast, an area inhabited by Native Americans for 3,000 years, when a small gold rush sparked logging. The National Park Service and the California Department of Parks and Recreation have jointly managed Redwood National Park and the three state parks since 1994, a collaboration that remains unique within the United States.
The park's ecosystem includes numerous endangered animal species such as brown pelicans, tidewater gobys, bald eagles, king salmon, American spotted owls and Steller sea lions. Recognizing its rare ecosystem and cultural history, UNESCO included the park in the list of world heritage sites on 5 September 1980, and among the biosphere reserves on 30 June 1983.
The Yosemite Park hosts one of the largest and least fragmented macro-habitats in the Sierra Nevada, both for plants and animals. The park has an elevation range of 648 to 3 997 m and contains five major vegetation belts: chaparral and oak woodlands, lower montane forest, montane forest, subalpine zone, and alpine tundra.
Of California's 7,000 plant species, approximately 50 percent are found in the Sierra Nevada and more than 20 percent are found in Yosemite. The park contains a suitable habitat for more than 160 rare plants, with rare local geological formations and soils with unique mineralogical compositions.
The local geology is characterized by granitic rocks and older lithological remains. About 10 million years ago, the Sierra Nevada rose and then tilted, giving rise to its relatively gentle western slopes and decidedly steeper eastern slopes.
The uplift increased the curve of streams and riverbeds, resulting in the formation of deep, narrow canyons. About a million years ago, snow and ice accumulated, forming glaciers in the higher alpine meadows that moved down river valleys. Ice thickness in Yosemite Valley may have reached 1,200 m during the first ice age. The downward movement of the ice masses dried and sculpted the U-shaped valley that today attracts so many visitors for its panoramic views.