Coast Redwoods - World's Tallest Living Tree
by Mary Jasch
If any one plant says “Northern California” it is the coast redwood, Sequoia sempervirens.
As the tallest tree on the planet and one of the biggest with the most biomass, it’s been documented at 379 feet tall and 26 feet diameter breast height (dbh) and known to live at least 2,000 years.
Coast redwoods live in a 470-mile stretch from Oregon to Central California and inland to 50 miles between the Pacific Ocean and the Northern Coast Range.
These big trees each produce about 100,000 tiny seeds a year but germination is low because they sprout on mineral soil, not on moss-covered logs or forest duff.
Nevertheless, coast redwood is the perfect species matched to its environment and well-adapted. They reproduce largely from sprouting: from cut stumps, roots, trunks and branches. If a tree dies from surface burn or logging, new root sprouts will eventually appear up to 30 to 40 feet out from the stump. A circle of redwoods around a stump is known as a “fairy ring.”
Some root from branches that fall and if you come across a straight line of the trees, they most likely sprouted from the trunk of a fallen tree (unlike in East Coast forests where straight lines usually mean “planted”).
“Coast redwood is one of the few conifers that will do that,” says Dennis McKiver, Patrol Lieutenant, California’s Natural Resources Agency, Department of Fish and Wildlife. “A redwood can burn off all its branches and will sprout (from the trunk) and get new trees from roots. There are fewer old growth trees but tree for tree there is more redwood now than there’s ever been. For one tree cut down, there are 30 to 40 from the root mass that’s been cut.”
Their shallow root systems extend 100 feet in radius and intertwine with others, which stabilizes the trees and offers plenty of root space for sprouting. The sprouted trees on McKiver's property are over six feet dbh and over 100 years old.
Their red, fibrous, fire-resistant bark can be a foot thick! Its tannin makes them insect and disease resistant. Plus coast redwood tends to drop its lower branches, from either water weight or a slow fire, leaving a high crown which protects it further from fire. These days Fish and Wildlife are selectively thinning the coast redwoods to grow bigger trees.
Near the coast, they depend on winter rainfall and fog in summer. They also grow on mountainsides to catch the rain from the west but the largest ones grow in stream valleys with constant access to water. Some places have 100 inches/year rainfall that leaches nutrients from the soil, so the coast redwood depends on the recycling of mushrooms, ferns, herbaceous plants and other trees to fill its nutrient needs. Young sprouts utilize the mother plant for nutrients and water.
Fort Bragg, chartered 125 years ago, grew up as a logging town. McKiver’s property was logged 150 years ago when the government gave out land grants and the redwood stumps were burned to clear the land for farming. Usually, the burned-out stumps are the height where the tree trunks buttressed out. Loggers only wanted the straight trunks. Cutting with hand saws took weeks to cut one 10-foot diameter tree. They burned the bark off the stumps and made slots to set boards to support them as they worked. These cuts can still be seen today.
Redwood is not a strong wood for construction and, when being logged, if a tree hit the ground hard it often shattered. To cushion the fall, loggers often laid branches on the ground when felling a tree.
Dennis McKiver lives in a transition forest – from closed-cone Bishop pine to coast redwood as are other areas along the Mendocino coast. Bishop pines thrive with the summer fog, its substitute for rain. They grow in dense, even-aged stands produced from fire. Tanoak, coast live oak, huckleberry and salal live in the Bishop Pine forest Pinus muricata. The bishop pines have reached their 80-year lifespan and are dying off. Bishop pine requires fire to open its cones and reseed itself. There is no fire on the coast due to human habitation so there is little regeneration.
Now young Western hemlock, coast redwood and firs are marching into pine territory. Western hemlock, which grows out of the tops of old logs, are sprouting up in old logging areas, altering the forest tree species.
Coast redwoods do not like the ocean wind which dries the needles. When the pines started dying, they became exposed to the winds and salty air and their branches on the upwind side and tops began to die. Branches on the downwind side grow out horizontally and in winter become so heavy with water they break off. But these survivalist trees adapt with tightly bunched top growth and flat needles on lower branches to catch more light.
Right now an uncontrolled fire burns slowly in northern Mendocino County near Leggett, famous for the largest coast redwoods and its drive-thru tree. Though the wild fire is a sad situation and difficult to put out due to rugged terrain, some espouse the burning of underbrush, which is ultimately better in the long run for the trees to regenerate.
This long-lived, highly-adaptable plant of such a discreet ecology begs answers. Since an entire forest can be burned down and regenerate through stump, root, branch and trunk within a century, the question becomes: Can these trees live forever?
Says Chris Earle, consulting forest ecologist: “The oldest cell in a redwood is probably in the range of 150-200 years. Only the outer portions of the tree – the sapwood, the leaves, the generative tissues – are alive. The heartwood and the outer bark are dead.
“The oldest standing redwood tree has probably been growing on that spot for about 2,500 years. None have been found that are quite that old, but a number of dates come close. Maybe someday we'll even find a 3,000 year old one, but that would be extraordinary.
“Redwoods can resprout from cut stumps or roots, or from a fallen tree, or from a tree that has burned in a fire. The new trees are clones of the old ones. Nobody has any evidence about how old the oldest redwood clone is, but other plant clones have been estimated to be in the range of 10,000 to 40,000 years, so a guess (and only a guess) would be that redwood clones can attain similar ages.”
Related sequoias with one living species in each genus
Coast redwood Sequoia sempervirens
Giant redwood Sequoiadendron giganteum
Dawn redwood Metasequioa glyptostroboides
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published August 22, 2014