USA — As wildfires continue to blaze across California, one UC Davis group is aiming to learn more about the fires’ potential effects on the ecosystem of the Lake Tahoe basin.
The UC Davis Tahoe Environmental Research Center, a group of professors, researchers and graduate students studying sustainable use of the lake, recently installed a fourth air sampler designed to provide detailed analyses of the compounds and toxic materials resulting from forest wildfires.
“The new sampler is designed to collect organic fallout from the small particles in smoke,” said Charles R. Goldman, professor of limnology and director of the Tahoe Research Group. “We expect to determine more precisely the nutrient and light-altering impact that these fires are having on Tahoe lake water quality.”
One such effect could be on the water clarity of the lake, which has seen improvement in recent years. In results published from 2007 clarity tests, researchers found that for the first time since they began measuring Lake Tahoe’s water clarity over 40 years ago, the rate of decline in the lake’s clarity has begun to slow, according to the center’s website.
“From 1968 to 2000 there was a near-continuous decline in lake clarity,” said Geoffrey Schladow, director of the Tahoe Research Center. “But since 2001, we have had seven years in which the clarity has consistently been better than the long-term trend would have predicted. This is unprecedented.”
Lake clarity is determined by a number of factors, including runoff from nearby roads, climate change and forest wildfires similar to the recent ones this summer, all of which have adverse effects on water clarity.
Fallout from the wildfires also appears to have a fertilizing impact on the lake, Goldman said.
“[The Tahoe Research Group] started sampling air quality and especially fallout over a decade ago,” he said. “It was then that we discovered that most of the nitrogen loading of the lake, a potent fertilizer, was coming from atmospheric fallout. For example, the 1985 hot brush fires in California contributed significant fertilization to the lake from nutrients contained in the small particles of ash transported to the basin as smoke.”
The new air sampler could also help researchers learn more about the effects of different types of forest wildfires.
“In the past we learned the great impact that the hot brush fires from Southern California were having, but also found that the coniferous pine forest fires did not appear to be as fertilizing to the lake as the brush fires from the south,” Goldman said. “This work needs further verification and the new sampling of the current smoky situation should bring further clarity to the question.”