Expert: Thick forests aren't natural

Most people escape to forests to enjoy the natural landscape. But Thomas Bonnicksen, professor emeritus of forest science at Texas A&M University, said the woods have become increasingly unnatural.

Bonnicksen, a forest historian, said most people believe that thick forests are natural, old-growth forests, when the opposite is true. A century ago, forests contained approximately 66 trees per acre. Today's forests average 460 trees per acre, with some parts of the Sierra Nevada exceeding 1,200 per acre.

"They are overcrowded with trees and unnatural," Bonnicksen said during a presentation at Wednesday's meeting of the Tahoe Regional Planning Agency Governing Board. "Unnatural forests burn in unnatural ways."

Bonnicksen warned that it's only a matter of time before a catastrophic forest fire hits the Tahoe Basin, which will destroy property, sterilize soils - making them impervious to rain and causing more erosion - kill wildlife, and destroy the largest and oldest trees.

"The fires are getting bigger and more destructive," he said.

Since 1980, firefighting costs have risen 21 times, and forest fires are getting bigger. Last year, California fires damaged 750,000 acres of land. In the past three years, 24 million acres of land have burned across the nation - costing $5 billion to fight the fires.

Approximately 80 percent of the Tahoe Basin is under U.S. Forest Service management, and Bonnicksen said much of that land is highly susceptible to wildfires. He said it's essential for agencies to form partnerships with private companies to help fund forest-thinning programs.

"I believe the forests we use to have is the best model," Bonnicksen said. "You're not supposed to duplicate the historic forest; you're supposed to use it as a guide."

Although some members of the public are opposed to forest-thinning plans that bring in private logging companies, Bonnicksen said foresters remove trees with "near surgical precision," and that restoration plans are often unfeasible without money from the private sector.

Thinning programs that protect forests and the communities "embedded" in them will also protect the lake, he said.

"As a forester, 'saving Tahoe' means to me, you cannot save the lake without saving the forest. They are absolutely interrelated," Bonnicksen said. "You could spend tens of millions of dollars to keep that lake clean, and one fire will wipe that out."