Oldest Muir Woods redwood is only half its estimated age

Muir Woods
CC BY 2.0 Jason Toff/Flickr

At 777 years old, Tree 76 is just a babe in the woods.

California is home to many exquisite things, but the state’s trees – those majestic, glorious, ancient humble trees – are truly one if its most extraordinary gifts. They are a superlative bunch that includes the tallest tree, the largest tree by volume, and the oldest living tree known to man. We’re talking some tremendous trees.

One spot well-known for its collection of trees – for its old-growth coast redwoods – is Muir Woods National Monument just north of San Francisco; it was designated the country’s 10th national monument by Teddy Roosevelt in 1908. It plays host to a wonderful array of giant old gals and guys, but until now, nobody had ever officially calculated the age of these treasures. Scientists' best guesses had the trees in the 1,200- to 1,500-year-old range.

Bu lo and behold, a new study by a Humboldt State University tree-ring specialist, Allyson Carroll, has found that possibly the oldest tree in the bunch, the lacklusterly-named Tree 76, is but a youth. The 249-foot-tall beauty is not some 1,500 years old as assumed, but a mere 777.

“It’s one of the largest redwoods in Muir Woods, so it probably represents one of the oldest,” said Emily Burns, science director for San Francisco’s Save the Redwoods League, which is documenting the specifics of the trees as part a California-wide project called the Redwoods and Climate Change Initiative.

Carroll determined Tree 76’s age by comparing its rings to a database of core samples taken from redwoods across the state. The samples were taken in March of 2014 and, surprisingly, represent the first significant scientific study of the tree canopy at Muir Woods.

The plan over time is to identify tree-ring patterns that are consistent throughout the coast redwood range and figure out how the trees react to climate change. As of now, the collective redwood tree-ring record in California can reliably be traced back to the year 328, revealing drought years and other major weather events, writes SFGAte.

Besides Tree 76, Carroll has worked on the ages of two fallen trees in the area; the Vortex Tree was 693 years old, according to her report, and the Solstice Tree, was 536 years old, she concluded. This leads to the theory that the entire grove is probably younger than previously thought.

The trees can tell stories, and have so much history to share that we may not have access to otherwise.

Burns suggests that some catastrophe likely struck the area; a fire or flood perhaps, forcing the forest to start again from scratch. “We know redwoods can get older than this, and some redwoods in the Bay Area were logged. But we don't see any evidence of logging,” she said. “That leads me to believe that there may have been some sort of disturbance.”

Oldest Muir Woods redwood is only half its estimated age
At 777 years old, Tree 76 is just a babe in the woods.

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