Sequoia (California)

The name Sequoia is also used as a general term for the subfamily Sequoioideae in which this genus is classified together with Sequoiadendron (Giant Sequoia) and Metasequoia (Dawn Redwood). The leaves are variable, being 15-25 mm long and flat on young trees and shaded shoots in the lower crown of old trees, and scale-like, 5-10 mm long on shoots in full sun in the upper crown of older trees;

Range and ecology

Coast Redwoods occupy a narrow strip of land approximately 750 km (470 miles) in length and 8-75 km (5-47 miles) in width along the Pacific coast; the elevation range is mostly from 30-750 m, occasionally down to sea level and up to 920 m (Farjon 2005). The trees above the fog layer, above about 700 m, are shorter and smaller due to the drier, windier, and colder conditions. In addition, tanoak, pine and Douglas-fir often crowd out redwoods at these elevations. Few redwoods also grow close to the ocean due to intense salt spray, sand and wind. The largest populations are in Jedediah Smith Redwoods State Park (Del Norte County), Redwood National Park and Humboldt Redwoods State Park (Humboldt County).

This native area provides a unique environment with heavy seasonal rains (2500 mm or 100 in annually), cool coastal air and fog keeping this forest constantly damp year round. This forest community includes Douglas-fir, Western Hemlock, Tanoak, Madrone, and other trees along with a wide variety of ferns, Redwood sorrel, mosses and mushrooms. Redwood forests provide habitat for a variety of mammals, birds, reptiles, and amphibians. Remnant old growth redwood stands provide habitat for the federally threatened Spotted Owl and the California-endangered Marbled Murrelet.

The thick, tannin-rich bark, combined with foliage that starts high above the ground provides good protection from both fire and insect damage, contributing to the Coast Redwood's longevity. The oldest known Coast Redwood is about 2200 years old;

Statistics

Trees over 60 m (200 feet) are common, and many are over 90 m (300 feet). The tree was discovered in Redwood National Park during Summer 2006 by Chris Atkins and Michael Taylor and has been measured as the world's tallest living thing. The previous record holder was the Stratosphere Giant in the Humboldt Redwoods State Park, at 112.83 m, last measured in 2004 (was 112.34 m in Aug 2000 and 112.56 m in 2002). It too stood in Humboldt Redwoods State Park; There are 15 known living trees more than 110 m (361 feet) tall. There are 47 trees that are more than 105 m (344.5 feet) tall.

In 2004, an article in Nature reported that the theoretical maximum potential height of Coast Redwoods (or any other tree) is limited to between 122-130 m (400-425 feet), due to gravity and the friction between water and the vessels through which it flows. A redwood cut down in 1926 had a claimed volume of 1,794 cubic metres (63,350 cubic feet), but this is not verified.

Reproduction

Coast Redwood reproduces both sexually and asexually.

Growth of seedlings is very fast, with young trees known to reach 20 m tall in 20 years. Coast Redwoods can also reproduce asexually by layering or sprouting from the root crown, stump, or even fallen branches; Within a short period after sprouting, each sprout will develop its own root system, with the dominant sprouts forming a ring of trees around the parent root crown or stump.

Redwoods may also reproduce using burls. A burl is a woody lignotuber that commonly appears on a redwood tree below the soil line, though when above, usually within 3m of the soil.

Cultivation and uses

Coast Redwood is one of the most valuable timber species in California, with 364,000 ha of redwood forest, all second growth, managed for timber production . Coast Redwood lumber is highly valued for its beauty, light weight, and resistance to decay. Shaughnessy, Chief Engineer of the San Francisco Fire Department wrote:

Redwood burls are used in the production of table tops, veneers, and turned goods. The phenolics and tannins present in old growth redwood stock affords excellent termite and water damage protection. Old growth redwood construction is highly prized as a result. Only 3 percent of the present redwood forest is old growth, but not all of it is protected from further exploitation. The Pacific Lumber Company, a subsidiary of the Maxxam Corporation, continues to log old growth Redwoods despite decades of public protest. Examples of this are the Big Basin State Park and the recently acquired San Lorenzo River Redwoods. Some of the remaining forest consists of redwood plantations grown on a short (40-70 years) rotation.

The Coast Redwood is locally naturalized in New Zealand, notably at Rotorua. The Redwood Forest: history, ecology and conservation of the Coast Redwood. "Climbing the Redwoods" - 2/14-21/2005 New Yorker article with detailed insights into intricate upper canopy biology.