“Redwoods” first made their appearance in the Lower (or Early) Cretaceous between 146 and 100 million years ago. Of over 80 “redwood” species that have been described, all are extinct except three. The coast redwood (Sequoia sempervirens) inhabits the north coast ranges of Northern California and Southern Oregon (see “Coast Redwood” on 10-13-18). Dawn redwood (Metasequoia glyptostroboides) survives only in south-central China. It is only in my wildest imagination that I would ever see a dawn redwood in its native environment. The third “redwood”, the giant sequoia (Sequoiadendron gigantea), only grows between 4,000 and 8,000 feet on the western slopes of the Sierra Nevada in California, chiefly in isolated groves. Leonard and I hiked to the Merced Grove in Yosemite National Park to view these titans. The Merced Grove is a small grouping of giant sequoias. Although it is less visited and does not contain the massive, famous trees of the other giant sequoia groves, Leonard and I appreciated the opportunity to study and admire these awe-inspiring specimens without any other people around.
Giant sequoias are considered the “oldest and mightiest” of trees. Although they may not hold the record as the tallest trees (that honor goes to the Coast redwood), they are the greatest in girth. Some giant sequoias have measured over 330 feet in height. Although mature living trees are usually between 18 and 25 feet in diameter, prone trees exist that measure over 30 feet in diameter. There are many estimates as to the longevity of giant sequoias, however, most now living are around 3,000 years of age. Old, fallen trees have been estimated at 4,000 to 5,000 years.
These giants grow where the summers are dry and the snowy winters can drop up to 30 feet of snow. Young giant sequoias have trunks with short, slender branches that reach to the ground giving a pyramid aspect. This form helps protect the young trees from heavy snows. After about 200 to 300 years the lower branches begin to thin out and by maturity, giant sequoia trunks are clear of branches for a long way up the trunk (except for a few “stragglers”). Gone are the drooping, slender branches of youth, replaced by a high-peaked crown.
The yellow wood of young giant sequoia trees is supple to bear the weight of Sierran snows. In the second century of life dark, rose hardwood forms while the wood at the top of the tree is pinkish. Giant sequoia wood was marketed as “redwood” for shakes, shingles, fence stakes and poles. The wood, although very durable and resistant to rot, is more brittle and less heavy than coast redwood lumber . A large portion of giant sequoia trees cut were eventually never utilized because the trees were too big or costly to handle or because the brittle wood smashed to bits when the massive trees fell. Also the base of a giant sequoia, because of the great strain of the tree’s size, is buttressed with convoluted and tough wood, unfit for commercial use. Sadly, unlike the coast redwood, giant sequoias do not sprout from cut or injured stumps after about 20 years of age.
In my next post, more about giant sequoias. . . .