Sequoia sempervirensCoast Redwood
Sequoia sempervirens. Photo by Kathryn Rummel
The tallest of all living conifers, the coast redwood can reach up to 369 feet in height, and live up to 2200 years! They are native to the protected coastal valleys from Big Sur in central California to southwest Oregon, just over the border. The natural range of redwood is limited to areas of heavy summer fog.
The frequent occurrence of fog that blankets the redwood region is more significant to the redwood than the amount of precipitation it receives. Fog moisture is collected by its needles and branches, some of which is directly absorbed by the foliage while much of what remains drips to the ground, where significant amounts are absorbed by the tree's shallow root system. Without summer fog our coastal redwoods could not grow to be the tallest conifers in the world.
The common name of "redwood" refers to the reddish-brown heartwood and fibrous bark that can be up to 12 inches thick. The thickness of the bark combined with a lack of resin helps protect the redwood from fire damage. The bark gets its red color from tannins, or bitter chemicals that make the wood difficult to digest for microbes and burrowing insects. The wood is valued for its beauty, light weight, and resistance to decay. It is used in many different applications from building construction to furniture. Due to extensive historic timber harvests, only one to six percent of old growth coast redwood forests remains today.
The coast redwood is unique among all conifers in its ability to reproduce asexually from sprouts and burls. Sprouts arise from dormant buds that grow commonly from the roots of a mature tree. One peculiar outcome is the occurrence of white redwoods, or "ghost trees", originating as root sprouts that have genetically mutated and are completely non-photosynthetic. They derive all of their nutrients from the roots of their host. White redwoods are found only in old-growth forests, where the overstory biomass of photosynthetic redwoods is great. SFBG has one albino redwood at the west end of the Redwood Grove along the paved path. Cuttings of the albino redwood taken at SFBG have grown into typical trees with green foliage. There is still a lot that is not understood about this unique and rare phenomenon.
Burls are masses of buds that arise at base of trunks within the first year. Occasionally burls are found higher up where limbs emerge from trunk. These buds will sprout in case of injury or if the top of tree is damaged. As the tree grows the burl continues to add dormant buds. The burl results in 'birds-eye'-grained wood popular in veneers, clocks, tables, other woodworks.
The giant redwood has two closely related cousins: the giant sequoia (Sequoiadendron giganteum), native to the Sierra Nevada region in California; and the dawn redwood (Metasequoia glyptostroboides), native to China. Prehistorically the coast redwood and its relatives covered much of the northern hemisphere.
||Moist, often found in valleys. The coastal fog provides a lot of the moisture from leaf drip during the California dry season
||Small cones appear on branch tips after about 10-15 years
||Valued as timber, needs a large park or garden due to its size; also used in bonsai
||Of all the world's vegetation types, mature redwood forests produce the greatest amount of biomass per unit area – far more than tropical rain forests.
There is a lot of debate on which tree is the actually the tallest in the world. Eucalyptus regans from Australia reaches up to 375'
IN BLOOM CONTRIBUTORS:
Text by David Kruse-Pickler and Mona Bourell. Photos by Joanne Taylor and Kathryn Rummel.