Besides these attempts at tree farming, the principal economic uses for giant sequoia today are tourism and horticulture.Metasequoia, or dawn redwoods, is a genus of fast-growing deciduous trees, one of three species of conifers known as redwoods. In the northwest United States, some entrepreneurs have also begun growing giant sequoias for Christmas trees. This is resulting in some interest in cultivating giant sequoia as a very high-yielding timber crop tree, both in California and also in parts of western Europe, where it may grow more efficiently than coast redwoods. The wood from immature trees is less brittle, with recent tests on young plantation-grown trees showing it similar to coast redwood wood in quality. As late as the 1980s, some immature trees were logged in Sequoia National Forest, publicity of which helped lead to the creation of Giant Sequoia National Monument. The public can visit an example of 1880s clear-cutting at Big Stump Grove near General Grant Grove. Pictures of the once majestic trees broken and abandoned in formerly pristine groves, and the thought of the giants put to such modest use, spurred the public outcry that caused most of the groves to be preserved as protected land. The wood was used mainly for shingles and fence posts, or even for matchsticks. Still, as little as 50% of the timber is estimated to have made it from groves to the mill. Loggers attempted to cushion the impact by digging trenches and filling them with branches. Due to their weight and brittleness, trees would often shatter when they hit the ground, wasting much of the wood. The Hume-Bennett Lumber Company was the last to harvest giant sequoia, going out of business in 1924. From the 1880s through the 1920s, logging took place in many groves in spite of marginal commercial returns. Wood from mature giant sequoias is highly resistant to decay, but due to being fibrous and brittle, it is generally unsuitable for construction. The sap containsВ tannic acid, which provides significant protection from fire damage.The leaves areВ evergreen, awl-shaped,В 3вЂ“6В mm ( 1вЃ„ 8вЂ“ 1вЃ„ 4В in) long, and arranged spirally on the shoots. Giant sequoia bark is fibrous, furrowed, and may be 90В cm (3В ft) thick at the base of the columnar trunk. The oldest known giant sequoia is 3,200вЂ“3,266 years old based onВ dendrochronology.В Giant sequoias are amongВ the oldest living organismsВ on Earth. The trunks of coast redwoods taper at lower heights than those of giant sequoias which have more columnar trunks that maintain larger diameters to greater heights. Between 20, it is claimed that specimens of coast redwood were found to have greater trunk diameters than all known giant sequoias - though this has not been independently verified or affirmed in any academic literature. The specimen known to have the greatest diameter at breast height is the General Grant tree at 8.8 m (28.9 ft). Trunk diameters of 17 m (56 ft) have been claimed via research figures taken out of context. Record trees have been measured at 94.8 m (311 ft) tall. They grow to an average height of 50вЂ“85 m (164вЂ“279 ft) with trunk diameters ranging from 6вЂ“8 m (20вЂ“26 ft). Giant sequoia specimens are the most massive individual trees in the world. The common use of the name sequoia usually refers to Sequoiadendron giganteum, which occurs naturally only in groves on the western slopes of theВ Sierra Nevada mountain range of California. Giant sequoia specimens are the most massive trees on Earth. SubfamilyВ Sequoioideae, together with Sequoia sempervirens (coast redwood) and Metasequoia glyptostroboides (dawn redwood).

Metasequoia giganteum