Yosemite rim blaze good for nature.

• Position: Wildfires

With the close of yet another active fire season, the debate over how to live with fire in California rages on. Wildfires often are described as "catastrophic" and "devastating," and this is true when human life and property are lost. However, for many birds, wildlife, and plants, wildfire is a vital part of the ecosystem in the Sierra Nevada.

The Yosemite Rim Fire burned some 402 square miles of forest and meadows in and around Yosemite National Park over two months. "Strict adherence to Smokey Bear's motto of 'only you can prevent forest fires' has compromised the health of our forests," maintains Ryan Burnett, lead Sierra Nevada researcher of Point Blue Conservation Science. "Smokey's goal of preventing human-caused wildfire has led to a gross misunderstanding of the role wildfire plays in forests. We now know that wildfires are critical to sustaining forests and wildlife populations."

As a result of fire-suppression policies over the past century, many Sierra Nevada forests now are filled with far more trees--especially small ones--that are more susceptible to fire. This build-up of fuels, combined with longer, drier summers--possibly the result of global warming--means that, when fires occur, they burn...