New Study Reveals Redwoods Contain Climate Data Over the Ages
Sonoma County Slowly Destroying Forests for Wineries
Seeing the forests for the trees depends upon how you view the whole situation. Take these two articles making the rounds in the news today, for example:
SEATTLE, WA– Many people use tree ring records to see into the past. But redwoods – the iconic trees that are the world’s tallest living things – have so far proven too erratic in their growth patterns to help with reconstructing historic climate.
A University of Washington researcher has developed a way to use the trees as a window into coastal conditions, using oxygen and carbon atoms in the wood to detect fog and rainfall in previous seasons.
“This is really the first time that climate reconstruction has ever been done with redwoods,” said Jim Johnstone, He is corresponding author of a study published online Oct. 24 in the Journal of Geophysical Research-Biogeosciences.
While coastal redwoods are not the longest-lived trees on the West Coast, they do contain unique information about their foggy surroundings. Coastal redwoods in Northern California use fog as a water source, incorporating the molecules in their trunks, Johnstone found.
“Redwoods are restricted to a very narrow strip along the coastline,” Johnstone said. “They’re tied to the coastline, and they’re sensitive to marine conditions, so they actually may tell you more about what’s happening over the ocean than they do about what’s happening over land.”
The new study used cores from Northern California coastal redwoods to trace climate back 50 years. Weather records from that period prove the method is accurate, suggesting it could be used to track conditions through the thousand or more years of the redwoods’ lifetime.
Tree-ring research, or dendrochronology, typically involves a detailed look at a cross-section of a tree trunk. But the rings of a redwood are uneven and don’t always fully encircle the tree, making it a poor candidate for anything except detecting historic fires.
The new paper uses a painstaking approach that’s more like processing ice cores. It uses the molecules captured in the wood to sample the atmosphere of the past.
Most oxygen in Earth’s atmosphere has an atomic mass of 16, making it O-16, but a small percentage of oxygen is the heavier O-18 isotope. When seawater evaporates off the ocean to form clouds, some drops fall as rain over the ocean, and more of the heavier O-18 molecules rain out. The remaining drops that fall on land thus have a higher proportion of the lighter O-16 molecules.
Fog, on the other hand, forms near shore and blows on land where it drips down through the branches until the trees use it like rainwater.
By looking at the proportion of O-16 and O-18 in the wood from each season, the team was able to measure the contribution of fog and rain.
“We actually have two indicators that we can use in combination to determine if a particular summer was foggy with a little rain, foggy with a lot of rain, and various combinations of the two,” Johnstone said.
Related research by Johnstone shows that the amount of West Coast fog is closely tied to the surface temperature of the ocean, so redwoods may be able to tell us something about the long-term patterns of ocean change, such as the Pacific Decadal Oscillation. Understanding the cycles could better distinguish natural and human-caused climate change.
“It’s possible that the redwoods could give us direct indication of how that’s worked over longer periods,” Johnstone said. “This is just a piece that contributes to that understanding in a pretty unique place.”
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SONOMA COUNTY, CA– Would you like a little whine to go along with that cheese?
A coalition of environmental groups in California is fighting to stop a Spanish-owned winery from chopping down 154 acres of redwood trees and Douglas firs to make room for yet more grapevines, NPR reports.
The fight, according to the report, is a global one, with a 2013 study finding climate change would profoundly impact ecosystems, with wine grape production being “a good test case for measuring indirect impacts by changes in agriculture.”
In the California case, the groups, which filed suit in 2012, are charging that state officials violated California’s environmental protection laws when they approved the plan to clear the area, which is in the wine mecca of Sonoma County.
According to the NPR report, Artesa Vineyards and Winery, owned by the Spanish Codomiu Group, will spare two old-growth redwoods on the property. According to a company spokesman, most of the trees at the site are less than 100 feet tall. ”There are no forests on this site,” spokesman Sam Singer told the station.
Redwoods are among the biggest trees on Earth, and can stand more than 350 feet high. Some are more than 2,000 years old.
The redwoods at the center of the controversy are not the old-growth trees. Thousands of trees slated for removal are between 50 and 80 feet high, according to Chris Poehlmann, president of a small organization called Friends of the Gualala River, one of the plaintiffs in the lawsuit. He says the trees provide important habitat to local wildlife and guard the soil against erosion, which has been a significant challenge for streams in the area that once harbored salmon as well as steelhead trout.
Dennis Hall, a higher official with CalFire, says his department’s approval of Artesa’s project in 2012 came only after a lengthy review process found that it would not significantly damage the environment.
Still, Poehlmann feels CalFire has been too lenient on proposals by developers to level trees. ”They are acting as if they are actually the ‘department of deforestation,’ ” he told the station.
“But at least we’ll have plenty of wine to drink,” he quipped, “while we bemoan the fact that our forests are all used up.”
Friends of the Gualala River and the Sierra Club’s Redwood Chapter, another plaintiff in the current Artesa lawsuit, have tried several times over the past 10 years to successfully stop ‘timberland conversion’ projects. Those projects, proposed by winery groups, were approved by the state.
But from 1979 to 2006, 25 conversions occurred in Sonoma County at an average rate of 21 acres per year– for a total loss of 560 acres of forest– according to county officials, NPR reported.
Articles via University of Washington, NPR News, and Inhabitat.com
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