Study: Tallest tree in Muir Woods has mere 777 years

SAN FRANCISCO — An analysis has found that the tallest redwood tree in Muir Woods is 777 years old -- and not the much older 1,500 years once assumed.

The San Francisco Chronicle (http://bit.ly/1EOHn2F ) reports Sunday that the study out of Humboldt State University is the first determination of the age of trees in Muir Woods, north of San Francisco. The findings mean that a 249-foot-tall coast redwood named Tree 76 was born seven centuries later than originally believed, at the start of the Medieval Inquisition in the early 13th century.

This also means the oldest and biggest tree found in Muir Woods is just a baby compared with the huge old-growth trees farther north.

San Francisco's Save the Redwoods League is documenting the age, size, and tree-ring history of California's old-growth redwood groves as part a statewide project. The plan is to identify tree-ring patterns and figure out how trees react to climate change.

Tree rings are larger during wet years and smaller during dry years.

Tree-ring science was used to document a coast redwood near Crescent City that is 2,520 years old. The oldest giant sequoia, a redwood species that grows in the Sierra, is 3,240 years old.

Scientists have suggested that the tallest trees in Muir Woods were between 1,200 and 1,500 years old, but the Humboldt study compared the ring size of Tree 76 to a state database and concluded it is 777 years old.

Emily Burns, science director for Save the Redwoods League, told the newspaper that the relative youth of this tree and the newly documented ages of two other tall trees mean that the grove is probably younger than was believed.

She suggested a fire, flood or some other catastrophe might have struck the area, forcing the entire forest to regenerate.

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Information from: San Francisco Chronicle, http://www.sfgate.com