Often referred to as the blue whales of the plant world, coastal redwoods are the tallest trees in the world, able to exceed more than 100m in height. Equally impressive is their longevity, with many trees reaching their 1,000th birthday. The oldest known redwood is thought to be an eye-popping 2,200 years old.
The tallest redwood, a roughly 600-year-old specimen known as Hyperion, is located in Redwood National and State Parks, Humboldt County (a UNESCO World Heritage site). Located on a steep, remote slope, it commands the landscape from a height of nearly 116m.
This lofty spectacle draws millions of campers and day-trippers every year, as does the Pacific forest wildlife. Mountain lions leave tantalising clues, though these notoriously shy creatures are seldom encountered. Smaller mammals that live among the trees include ground squirrels, racoons, woodrats, muskrats and several varieties of vole and chipmunks, to name but a few. Many are nocturnal and difficult to spot, but their existence is given away by the turkey vultures circling overhead.
Birdwatchers are frequently drawn to the coastal cliffs, populated with guillemots, grebes, California brown pelicans, cormorants and Caspian terns. In the campgrounds, Steller’s jays squawk noisily at humans invading their space, though flycatchers, warblers, owls and woodpeckers have their feathers less ruffled by human presence. In the heart of the forests, bald eagles, peregrine falcons and rare marbled murrelets nest in tree hollows.
“Coastal redwoods provoke the human spirit,” says Candace Tinkler, chief of education and interpretation at Redwood National and State Parks. “People are naturally curious about the superlatives and broader ecological questions, but for many the experience goes beyond science and can be reflective, even restorative.”
What are redwoods?
Redwoods are the survivors of the plant kingdom and their ability to withstand drought, floods, fire and pestilence is key to their longevity. They have evolved several unique traits to ensure a long and healthy life. Redwoods are able to absorb moisture from the air, with 40 per cent of their needs supplied by the dense fog that blankets the Pacific Northwest. In addition, these are sprouting trees, with new growth generating from the ‘crown’ of a single organism. Even if an entire forest burns down, redwood stumps are able to regenerate – and with gusto. Studying a single old-growth tree in Redwood National and State Parks, scientists discovered that no less than 148 trunks had resprouted from the main bole. Five of these had diameters of over a metre; the largest was more than 40m tall.
Yet another adaptation lies in the redwood’s bark. A mature tree’s bark often exceeds 30cm in thickness and protects the core of the tree. Tannin in the bark helps to repel insects such as termites, as well as fight fungal pathogens including oak blight.
Despite their armoury of survival tools, coastal redwoods are in peril. Climate change, drought and non-sustainable commercial practices are all impacting the health of these iconic giants. Though only 4 per cent of old-growth forests remain, these trees are still being harvested. Logging is the single most damaging practice responsible for the trees’ demise, triggering an unprecedented loss that brings with it a fundamental change in the diversity of coastal forests.