Redwoods Faring Better than Humans in the Age of Global Warming

Friday, August 16, 2013

Few days seem to go by without some new measure surfacing of the terrible toll global warming is taking on the planet. Just a few days ago, a report (pdf) documented extensive damage already done to California and Californians.

But, apparently, the bad news does not extend to redwoods and giant sequoias.

The first results from a four-year study of California’s most impressive trees indicates they have thrived since the 1970s. The Redwoods & Climate Change Initiative—run by the Save the Redwoods League and scientists from the University of California, Berkeley, Humboldt State and the Marine Conservation Institute—found that changing environomental conditions were triggering growth spurts unequaled in their millennial  existences.

“We're not seeing any evidence of declining growth rates,” researcher and Humboldt State forestry professor Stephen Sillett told the San Jose Mercury News. “In fact, a lot of the sites are exhibiting increasing rates of growth over the last 100 years.”

As a bonus, the researchers also stumbled on the oldest known living redwood, a  2,520-year-old tree in Humboldt County that is 300 years older than the old record-holder.

The scientists sampled 78 old-growth redwoods and 44 sequoias with tree rings going back more than 1,600 years. Their research was centered on 16 sites—redwoods along the coast from Big Sur to Oregon and giant sequoias on the western side of the southern  Sierra Nevada Mountains.  

The study will continue for another 10 years, and no conclusions were reached about why the trees were faring so well. Longer growing seasons from higher temperatures may have helped the sequoias, and more sun from reduced fog might have aided the redwoods. A study three years ago found 33% less fog in redwood coastal areas than a century ago. But there are other factors to consider.

Years of human activities have helped reduce redwood forests to 5% of their ancient size. But Sillett told the Los Angeles Times that less Northern California air pollution could also be a factor. So could better ways of fighting and preventing forest fires. Or maybe the trees just like warmer temperatures and more carbon dioxide.

For whatever reason, they are putting on weight two to three times faster than other forests on the planet, while sucking up carbon dioxide like climate change champs. But Save the Redwoods League director of Science Emily Burns told the Marin Independent Journal that the improvement could be gone as quickly as it has appeared:

“There could be a tipping point where it becomes too warm or there isn't enough water for the redwoods.”     

–Ken Broder


To Learn More:

Surprise Findings: Climate Change Causes Marin Redwoods to Grow Bigger (by Mark Prado, Marin Independent Journal)

Global Warming May be Helping Redwoods and Sequoias Grow, New Study Shows (by Paul Rogers, San Jose Mercury News)

Climate Change May be Speeding Coast Redwood, Giant Sequoia Growth (by Bettina Boxall, Los Angeles Times)

California Documents the Damage Already Done by Global Warming (by Ken Broder, AllGov California)

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