| • Science | • People | • Locations | • Timeline |
| Coast Redwood
Lower Risk
| ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
A Coast Redwood in Redwood National and State Parks | ||||||||||||||
| Scientific classification | ||||||||||||||
| ||||||||||||||
| Binomial name | ||||||||||||||
| Sequoia sempervirens ( D. Don ) Endl. |
The Coast Redwood or California Redwood (Sequoia sempervirens) is an evergreen, long-lived, monoecious tree in the family Cupressaceae. It is the tallest tree in the world, reaching up to 112 m in height, and 7 m diameter at the base. The oldest known Coast Redwood is about 2200 years old; many others in the wild exceed 600 years of age. It is one of three species of trees known as redwoods.
Trees over 60 m (200 feet) are common, and many are over 90 m (300 feet).
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.
Among current living trees only 15 Giant Sequoias are larger; these are less tall, but have thicker trunks. The largest living redwood has a volume of 1,037 cubic metres (36,621 cubic feet), compared to the largest Giant Sequoia with a volume of 1,487 cubic metres (52,513 cubic feet). A redwood cut down in 1926 had a claimed volume of 1,794 cubic metres (63,354 cubic feet), but this is not verified.
The Coast Redwood root system is composed of deep, widespreading lateral roots with no taproot. The bark is up to 30 cm (12 inches) thick and quite fibrous. This 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.
Coast Redwood reproduces both sexually and asexually. Seed production begins at 10-15 years of age, and large seed crops occur frequently, but viability of the seed is low. The low viability may be an adaptation to discourage seed predators, which do not want to waste time sorting chaff (empty seeds) from edible seeds. The winged seeds are small and light, averaging 265,000 seeds/kg (120,000 seeds per pound). The wings are not effective for wide dispersal, and seeds are dispersed by wind an average of only 60-120 m (200-400 feet) from the parent tree. Coast Redwoods can reproduce asexually by layering or sprouting from the root crown or stump. Sprouts orginate from dormant or adventitious buds at or under the surface of the bark. They develop all round the circumference of a cut stump, but tend to be most numerous on the downhill side of the stump. 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. Sprouts can achieve heights of 2.3m (8 feet) in a single growing season.