BERKELEY, Calif., Feb. 16 (UPI) — A University of California-Berkeley study suggests foggy conditions have declined during the past century along California’s redwood coast.
The scientists, led by postdoctoral scholar James Johnstone, said the decline in fog potentially endangers coastal redwood trees that are dependent on cool, humid summers. The researchers said it is unclear whether the diminished foggy conditions are part of a natural cycle or the result of human activity.
“Since 1901, the average number of hours of fog along the coast in summer has dropped from 56 percent to 42 percent, which is a loss of about three hours per day,” Johnstone said. “A cool coast and warm interior is one of the defining characteristics of California’s coastal climate, but the temperature difference between the coast and interior has declined substantially in the last century, in step with the decline in summer fog.”
Professor Todd Dawson, the study’s co-author, said coastal redwoods and other ecosystems along the U.S. West Coast might be increasingly drought-stressed, with a summer climate of reduced fog frequency and greater evaporative demand.
“Fog prevents water loss from redwoods in summer, and is really important for both the tree and the forest,” said Dawson. “If the fog is gone, we might not have the redwood forests we do now.”
The study appears in the online early edition of the Proceedings of the National Academy of Sciences.
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