Coast redwoods: Majestic giants benefit all humankind
Ancient trees suck moisture out of fog and support minivan-sized ecosystems. They deserve our respect and protection.
Thu, Jun 10, 2010 at 07:59 AM
AMONG THE KINGS: Redwoods stretch hundreds of feet above some the trails of the old growth forest in Redwood National Park in Prairie Creek, Calif. (Photo: ZUMA Press/ Jacqueline Lovato)
Imagine the most perfect tree on Earth: one that outdoes all others in magnificence, size, height, productivity, architecture and ability to draw thousands of gallons of water, yet marvelously resists drought, fire, insects, disease, mudslides, flooding and wind; and it possesses exquisite biodiversity in its crown. Then, and only then, as naturalist and Sierra Club founder John Muir put it, you'd know the "Kings of the forest, the noblest of a noble race" — the immortal Sequoia sempervirens, otherwise known as the coast redwood.
Coast redwoods’ direct lineage can be traced back to 144 million years ago to the beginning of the Cretaceous period. At the time Tyrannosaurus rex was beginning to rule for over 40 million years as no reptile or animal has achieved since. Redwoods belong to the plant group known as Taxodaciae, and they were the most widespread of all conifers inhabiting planet Earth.
Redwoods are considered unique for many reasons. They are able to reproduce from both seed and a lignotuberous organ at the base of the tree just beneath the soil. No other conifer possesses this dual mechanism — shooting roots from its base. It is a trait that is widespread amongst the more advanced race of trees called angiosperms or broadleaf trees that evolved about 80 million years after redwoods were born. The angiosperms owe their existence to pollinators — like bees, moths, bats and birds.
The tallest living tree on Earth is a 379.3-foot coast redwood. That's taller than the Statue of Liberty or the equivalent of a 38-story skyscraper. That tree was probably born at the time Jesus Christ walked the Earth. It carries well over 1 billion needles, enough to cover a football field.
Redwoods store thousands of gallons of water, so in the dry summer months they never run out, and consequently probably grow 12 months of the year. The wood doesn't contain gooey pitch like pines, firs, spruces and larches and thus doesn't burn easily. The 20-inch or thicker bark is an excellent insulator — in the north of its range, fire frequencies are in the order of 600- to 800-year events. The bark is high in tannic acid and the wood is filled with volatile essential oils which make it very rot resistant. Though insects do infest redwoods none can singularly kill mature trees.
Coast redwoods have survived climate changes, geologic upheavals and ice ages. Today they exist only along a narrow strip of land about 435 miles long reaching from southwest Oregon to the Big Sur. There are three distinct populations: northern, central and southerly.
They have adaptations which enable them to live at least a couple thousand years. Redwoods have the ability to suck water out of fog so that during summer dry periods they can continue to grow. Like all trees, their roots have a partnership with a soil fungus called mycorrhizae whereby the fungus feeds on the tree roots’ sugar and in return provides additional moisture and nutrients for the roots. The particular mycorrhizae associated with redwoods also confer drought resistance to redwood roots, just in case an unforeseen prolonged dry spell sets in.
The real story occurs way up in the treetops. Redwoods can sprout a forest above a forest — scientists think that this is in response to mechanical damage and to seek more available light needed to be captured to make more food.
Branch to branch, branch to trunk and trunk to trunk fusions are common in many of the ancient northerly trees. These become sources to store and share water and nutrients and stabilize the crown during winter storms. These forests above forests promote biodiversity.
In the treetops, there are 500-year-old saturated fern mats (small lakes) the size of large minivans weighing over 551 pounds. Banff and Los Angeles-based conservation institute Global Forest Science have found aquatic copepods (miniature freshwater critters) 230 feet above the Earth living in the moss fern-mat lakes. Prior to their discovery these critters were known to live only in streambeds on the forest floor. Scientists believe they crawled 230 feet up the rain-drenched trunks during the winter months — the human equivalent would be to crawl up Mount Everest!
These ancient redwood forests and their treetops support myriad lichens, bryophytes and mosses as well as other vascular plants like salmonberry, huckleberry and Rhamnus trees growing 240 feet above the Earth.
These canopies or treetops are also home to endangered animals like spotted owls — each breeding pair requires at least 2,476 acres of undisturbed forest to successfully breed, and they are being dislodged by baird owls. The endangered marbles murrelet, which was discovered only in 1974, can fly at speeds in excess of 85 mph and lives at sea for up to nine months. It comes ashore only to breed on moss draped branches in the ancient redwood forests.
Redwoods are quite simply the most productive ecosystems on Earth, producing a staggering 4,500 cubic meters of wood per acre.
Only .007 percent of huge ancient redwood ecosystems remain. The world is a very different place today from when the Taxodiacea were one of the most broadly distributed group of plants on Earth. Tyrannosaurus is gone, but the redwoods remain. Barely.
Although the extinction of the coast redwood species in the near future is doubtful, the sensitivity of the redwood ecosystem is undeniable. Climate change is beginning to bite into these forests too; it’s reducing the number of hours of fog by three hours a day, and in the hot, dry summer, missing fog has a significant effect on tree health and longevity.
Conservation biologists must be given the opportunity to study and understand these magnificent forests. Their health and longevity will undoubtedly benefit all humankind. A moratorium on all logging in any ancient remaining redwoods is of paramount importance.
Dr. Reese Halter is a conservation biologist at Cal Lutheran University, public speaker and founder of the international conservation institute Global Forest Science. Follow him @ twitter.com/DrReeseHalter.
Thumbnail photo: richardmasoner/Flickr