Monday, February 15th 2010 at 00:00 AM
Decline In Fog Threatens California's Redwoods
A surprising new study finds that during the past century the frequency of fog along California's coast has declined by approximately three hours a day. Published in the Proceedings of the National Academy of Sciences the researchers are concerned that this decrease in fog threatens California's giant redwoods and the unique ecosystem they inhabit.
"As fog decreases, the mature redwoods along the coast are not likely to die outright, but there may be less recruitment of new trees; they will look elsewhere for water, high humidity and cooler temperatures," explains coauthor Todd E. Dawson, professor of integrative biology and University of California, Berkeley professor of integrative biology with the Department of Environmental Science, Policy and Management (ESPM).
This drop in fog occurrence along with the change in temperature contrasts means that "coast redwood and other ecosystems along the U.S. West Coast may be increasingly drought-stressed, with a summer climate of reduced fog frequency and greater evaporative demand," adds Dawson. "Fog prevents water loss from redwoods in summer, and is really important for both the tree and the forest. If the fog is gone, we might not have the redwood forests we do now."
The authors are uncertain whether the temperature changes, and thereby the decline in fog, is apart of a natural cycle or linked to human impacts such as climate change. But in order to find the answer they plan to next look at redwood tree ring data and stable isotopes from redwood cellulose to construct the past climate of the coast.
Jeremy Hance
http://news.mongabay.com/2010/0215-hance_redwood.html
