By Jeff DeLong

RENO, Nev. — How the Sierra’s largest wildfire affected Lake Tahoe and several other mountain lakes is the focus of a new study by scientists.

Researchers based at UC Davis’ Tahoe Environmental Research Center, the University of Nevada, Reno, and three other universities began working as the Rim Fire was still smoldering last summer.

The effort was to gauge how the massive blaze affected water clarity, algae nutrients, light transmission and the aquatic food web at lakes close to the flames and others downwind that were smoked out for weeks.

“The Rim Fire, obviously, had such a big impact in the Sierra,” John Reuter, associate director for the Tahoe research center, told the Reno Gazette-Journal. “What we’re looking for are the impacts on aquatic ecosystems that this fire had. How does this affect lake ecology?”

Started by a hunter’s illegal campfire on Aug. 17 and not declared fully contained until Oct. 24, the Rim Fire charred more than 400 square miles, including parts of Yosemite National Park, destroyed 11 homes and caused about $70 million in damage.

Smoke from the fire wafted north, clouding the skies of the Reno-Tahoe area for weeks on end. Another fire west of Lake Tahoe that burned during much of the same period also hazed the region’s skies at times.

Scientists were quick to realize opportunity presented by studying a wildfire of such magnitude.

They obtained a so-called “rapid response grant” offered by the National Science Foundation, a program designed to bypass the typical and often lengthy grant application and peer review process and allow quick study of major ecological events such a wildfire, hurricane or big oil spill.

Two lakes located within the core of the fire area, Cherry Lake and Lake Eleanor, are being examined in the research. Lake Tahoe and nearby Cascade Lake, more than 100 miles away but heavily affected by smoke, are also under the microscope.

Two other lakes south of the Mammoth area — not affected by the fire — will be studied for comparison.

Teams that hit the lakes during and shortly after the fire will return after the first big storm event, when those lakes in the fire area are expected to be dramatically affected.

“We’re expecting there will be a lot of erosion and a lot of ash and material to be washed in,” said Geoffrey Schladow, director of the Tahoe research center.

Central to the research will be studies into how organic carbon compounds contained in ash — whether it washed directly into the closest lakes or was deposited from smoke in the air far away — affect zooplankton and other components of the aquatic food web.

Previous studies gauged the impacts of previous fires, including Lake Tahoe’s largest and most destructive: the Angora Fire of 2007.

Additional research focused on impacts to Tahoe after a barrage of lightning storms lit fires that burned more than 1 million acres of Northern California during the summer of 2008.

Both events had some impact on Tahoe’s clarity but in both cases, the lake got off relatively easy, scientists said. In the case of the Angora Fire in particular, “the lake was lucky” in part because a mild spring runoff period kept ash and other pollutants out of its waters, Schladow said.

The Rim Fire, the largest ever recorded in the Sierra, could offer a different story for the lakes it affected.

“The Angora Fire was put out fairly fast,” Reuter said. “When you’re talking about the Rim Fire, these lakes may have been engulfed in smoke for two or three weeks. That may have a very different effect.”

Studies of this type are increasingly important because wildfires of the magnitude of the Rim Fire are expected to be increasingly common due to a warming climate, scientists said.

“Wildfires have increased in frequency and intensity with climate change and that’s a trend that’s expected to continue,” Schladow said.

tahoe rim fireW

FILE – In this undated file photo provided by the U.S. Forest Service, the Rim Fire burns near Yosemite National Park, Calif. Researchers based at UC Davis’ Tahoe Environmental Research Center, the University of Nevada, Reno and three other universities began working as the Rim Fire was still smoldering last summer. The effort was to gauge how the massive blaze affected water clarity, algae nutrients, light transmission and the aquatic food web at lakes close to the flames and others downwind that were smoked out for weeks. Photo: U.S. Forest Service, AP

Comments

comments