Interestingly, I met coastal redwoods for the first time in the very same month as sequoias, during Thanksgiving weekend when me and some other international students left Davis for a much-needed break. We visited Armstrong Redwoods State Natural Reserve, where apparently some parts of Star Wars were filmed! And really, when you get there it feels so weird and alien, so wet and dark, and those incredibly tall trees looming over you. I also visited Muir Woods National Monument in Marin County, CA on the last day of 2011, and experience was very different as the day was sunny and bright and sun specks were playing between the trees. Either occasion, however, was incredible and made me appreciate those amazing trees and communities that they support even more.
Coastal redwoods are the tallest trees in the world: the highest one, named Hyperion, reaches a whooping 115.5 m. They tend to be shorter-lived than sequoias, the oldest known trees are about 2,200 years old. As their name indicates, redwoods grow along the coast of Pacific Ocean, with forests normally occupying a narrow stretch extending only up to 80 km inland. Trees also do not grow right next to the water as they don’t like the salt spray blown from the ocean. First redwood forest patches appear as far south as Santa Cruz, CA and stretches along the whole of Northern coast and as far as the border with Oregon.
Coast redwood forests are the fog countries. Trees require year-round moisture and they can get up to 50 percent of that from the air! This fog moisture collection is considered to be one of the reasons why trees are capable of growing so tall. Redwoods also are sensitive to great temperature fluctuations and can’t withstand temperatures as high or as low as those experienced by giant sequoias of Sierra Nevada.
As for fire, due to constant wetness fires are much rarer in redwood groves than in those of sequoias. However, redwoods have several adaptations to withstand fire, including thick, fire-resistant bark, little resin, and epicormic sprouting (i.e. from dormant buds in the bark). Seedlings require moist conditions while sunlight greatly accelerates growth, but overall they aren’t as picky as sequoia babies. Redwoods readily resprout when the crown is damaged or even from stumps; sometimes these interesting formations, Redwood fairy rings, can be observed where the parent tree has long died but the clones have sprouted in a circle around it. Redwoods have a surprisingly shallow root system for such tall trees – there’s no taproot! They literally hold onto other neighbouring redwoods, intertwining their root fingers. Redwoods, however, have a great capacity to develop new roots following large deposits of sediments by floods. These roots spread from the base of the tree which is now covered by silt into the new sediment.
Coastal redwood distribution is extremely limited by such factors as moisture, summer temperature, fire, and salt concentration gradients. Pollination and competition with Sitka spruce and Western hemlock are thought to be limiting their northern extent. There appears to be a genetic gradient in the species with most southern populations having greater drought tolerance, while those in the north are more frost-resistant.
Redwoods, unlike sequoias, can and do form pure stands. The understory is very rich in ferns and other moisture-loving plants; redwood sorrel, thimbleberry, salal, and salmonberry are among common ground vegetation.
Redwoods are amazing trees in many ways, and their highly valuable wood is one of the main reasons for inexplicable losses to the once great old-growth forests. Today barely 3-4 percent of these remain. The rest is all second-growth forests that have regenerated following the extensive logging of the 19th and 20th centuries. Large areas of these forests are now protected by the state or federal government but there’s still long way to go in redwood conservation.
- Growing is Forever by Jesse Rosten — a gorgeous and inspirational short film on redwoods in Northern California.
- The Super Trees by Joel Bourne from ‘National Geographic’ October, 2009 — on redwoods. Again wonderful photos and inspiring text about the issues with redwood forestry and conservation.