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The researchers warn that the history of the Lake Tahoe Basin is unique. Most of the forests were clear-cut in the 1870s to supply wood to the miners of the Comstock Lode. The Basin's aspen stands are mostly around 120 to 130 years old.

"If the young age of the stands is not a factor, then aspen persists very well in this area," says Taylor. "The different behavior in different areas then makes this a much more complex problem."

To provide a glimpse at the complexities of forest behavior, especially in the light of clear cutting, fire suppression and other environmental changes, Taylor, who studies a variety of aspects of the Basin's forests, has produced an online exercise, "Lands in Transition, Complex Decisions in the Lake Tahoe Basin." This explains some of the complexity of the Lake Tahoe Basin forests and is supported by the U.S. Department of Agriculture's Forest Service, The program, which is an interactive learning program, was produced by Penn State's Gould Center for Geography Education and Outreach and is available online at http://www.gouldcenter.psu.edu/lit or on CD by contacting Mark Johnson at mgjohnson@fs.fed.us by email.

"Because aspen are clones and regenerate vegetatively, some of the groves are 8,000 years old," says Taylor. "Aspen have rarely been observed to regenerate from seed, however they did after the recent Yellowstone National Park fires."

The Penn State researchers suggest that it may take a major event, such as a massive fire, to force the trees to reproduce sexually. Also, because aspen are shade intolerant, they need open spaces to grow properly.

"Aspen may require fir
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Contact: A'ndrea Elyse Messer
aem1@psu.edu
814-865-9481
Penn State
7-Aug-2001