Aspens on the rebound

More than a century of fire-suppression efforts in the forests surrounding Lake Tahoe has left the basin's aspen trees fighting for survival.

"We've identified about 1,100 acres in the Basin where there's risk of stands disappearing," said Victor Lyon, project leader with the Lake Tahoe Basin Management Unit of the Forest Service.

The Forest Service has found about 2,600 acres of aspen total in the Tahoe Basin, he said.

What happens when fire is suppressed is fast-growing but vulnerable conifers aren't kept in check, and grow to overshadow sun-dependent aspen trees, he said.

"In stream environment zones we've had a lot of conifers " mostly lodgepole and white fir " choke out the riparian areas," said Tamara Sasaki, an environmental scientist with California State Parks.

Both California State Parks and the Forest Service will try to turn back the onslaught of conifers with crews thinning the competing trees as well as encouraging aspen growth.

"There is a constant balance between two hormones in aspens " one in the tips of branches, and the other in the roots," Lyon said. "If we tip the balance the roots will send up a whole bunch of shoots."

Mechanical thinning and aspen growth inducement could be followed by controlled burns to further thin out the conifers, Lyon said.

"We've all been doing aspen treatment in the Basin and already have a handle on what works and what doesn't," Lyon said.

State parks is further along in the process, Sasaki said, with plans to start work on 57 acres of aspen throughout five state parks this fall.

Lyon said the Forest Service is looking to finish environmental documentation by the new year, and field work would begin once snow melts in the spring.

And both agencies desire to maintain aspen in the Tahoe area is more than just aesthetic.

"Aspen stands are resistant to fire and don't carry fire well, so if you have a crown fire racing through the forest when it hits aspen it lays down and becomes a surface fire," Lyon said.

Ecologically, aspen riparian environments support biodiversity, he said.

"No species have been identified as entirely dependent on aspen, but many use aspen stands throughout their lives," Lyon said.