Tree mortality an increasing concern in Lake Tahoe Basin

STATELINE — An increase in tree mortality in the Lake Tahoe Basin due to drought conditions and growing bark beetle populations has local experts teaming up to figure out a course of action.

Forest service and fire management officials presented the facts and outlined an action plan at the Tahoe Regional Planning Agency (TRPA) governing board meeting on Aug. 24.

“Presently there are more than 66 million dead trees in the state of California,” said Mike Vollmer, environmental improvement program manager at TRPA. “Even though the hardest hit areas in the Sierra are to our south, you can see how the outbreak has been moving north — and it now poses a threat to the forests here in Lake Tahoe.”

The issue? Drought conditions that are providing an ideal environment for the increased propagation of bark beetles.

“These guys actually carry biological warfare along with them. When they attack a tree they not only send out a pheromone signal to signal other beetles also to attack the tree, but they are also carrying a fungus that infects the tree and helps to overwhelm the tree,” explained Vollmer.

“The beetles in our forest right now are native species and they do play an important role in forest dynamics and nutrient cycling and a lot of different things, and under normal conditions they attack sick, old and weakened trees.

“But under conditions that are favorable for increasing bark beetle populations such as five years of drought and forests that are overly dense — if that sounds familiar, it’s because those are the exact conditions we have here in Lake Tahoe — these beetles can actually have a profound destructive effect on a landscape level.”

As a result, the U.S. Forest Service, TRPA and the Tahoe Fire and Fuels Team teamed up to create a Lake Tahoe Basin Tree Mortality Task Force Incident Action Plan with the goal of proactively working against the outbreak in conjunction with other tree mortality task forces on the county and state levels in California and Nevada.

Removal of the dead trees not only helps to curtail the spread of the bark beetle populations, it also reduces the fuel for potential forest fires — but that type of work takes funding.

“We used to have places to take the [timber] and have it be used in a merchantable way, and what that does is simply offset the cost. We don’t have the kind of infrastructure now so the math is a lot different with having to look at various forms of subsidy for transportation,” explained Jeff Marsolais, Lake Tahoe Basin Management Unit forest supervisor, comparing this bark beetle outbreak to the last that spanned from 1991-1997.

“What do you do with the material once it’s on the ground? How do you remove the bark from the trees so that we reduce the galleries that are going to continue to hatch the next round of bark beetles? These are all very tough questions.”

Despite these challenges, Marsolais said that forest thinning and dead tree removal work will continue to increase in pace and scale.

“Since the beginning of the field season more than 250 individual trees that have been affected by bark beetle have been removed from our high priority sites — things like our recreational sites on the South Shore and East Shore.”

More than 10,000 acres are now under contract for federal lands, said Marsolais, and $1 million has been provided to local jurisdictions for land treatment as well.

But the issue goes back much further than to 2012, when pockets of tree mortality began popping up in the southern Sierras. Marsolais pointed to the legacy of the Comstock logging era as an ongoing issue for the health of forests in the area.

“We have an even-aged timber stand. It’s roughly 80 to 100 years old. It doesn’t have the species composition that we would expect. It doesn’t have the diversity and stand structure we need.

“So that’s what all this work that’s been ongoing in Lake Tahoe for so many years has been trying to do — reduce the overstock stands, create stand structure, and replant species of trees that would normally exist on these landscapes.”

NATIONAL ATTENTION

What started as a State of Emergency proclamation on Oct. 30, 2015 by Governor Brown has escalated to the point that it may receive national attention.

“This emergency is really getting to the point that it is exceeding local and state resources,” said Chris Anthony, Cal Fire Chief and Deputy of the Tree Mortality Task Force.

Part of the task force’s work is seeking a presidential disaster declaration, which would open up new funding opportunities, he added.

The statewide tree mortality task force now monitors 10 counties, including El Dorado and Placer counties — but as Marsolais mentioned, there are issues with what to do with the removed timber.

“Bioenergy markets are very important because they provide an outlet for a lot of this material, much of which isn’t good as saw logs,” Anthony said.

“The saw-milling capacity is pretty much at capacity anyway due to the massive wildfires that we’ve had over the last several years. So we’re working to identify and promote other wood markets throughout the state.”

The growing issues of tree mortality and the outbreak of bark beetles is expected to be a key topic at the Lake Tahoe Summit on Wednesday, Aug. 31. President Barack Obama will deliver a speech at the event, which will take place at Harveys Outdoor Arena in Stateline, Nevada.