Researchers are finding that plants commonly found in drier, southwestern climates are replacing vegetation burned in Lake Tahoe-area wildfires.
California’s drought and general warming trend are creating an environment well suited for fires to encroach upon higher-elevation forest environments, historically seldom burned, a new study reports.
The study, published by a UC Davis news service, asserts the changing ecosystem is putting the Sierra Nevada in particular danger, due in large part to climate change, forest-management practices and elements often associated with drought impact.
The resulting change may influence the rate at which the forests in the Sierra Nevada ecosystem are altered by the effects of climate change, the study suggests.
The changes may have larger implications for how forests are restored following future fires.
Though the study suggests implications for a change in forest management, here in the Tahoe region, local fire protection agency officials believe there are proactive methodologies already in place to effectively treat this growing phenomenon.
The strategy just may require increased routine treatment and changing public perception, said North Tahoe Fire spokesman Dave Zaski.
“Our philosophy is to try to get our forest back to the way Mother Nature had it before man moved into the basin, which involves prescribed fire into that 7,000- to 8,000-foot area that hasn’t seen it,” Zaski said.
Prescribed fires as a form of suppression, also known as controlled burns, require routine checkups, and in the higher elevations, Zaski explained that routine inspection could come every five years. The strategy also comes with a social stigma, he added.
“(Local residents) don’t want them,” Zaski said. “They don’t like the smoke and they’re concerned the fires could get out of hand.”
The other issues associated with prescribed fires are the uncontrollable elements such as weather, notably wind, Zaski said, meaning the controlled burns could only be conducted at certain points of the year.
“The fire threat is real, made worse by land management or mismanagement,” said Paul Spencer, spokesman for Truckee Fire Protection District. “Now it’s a matter not only to do fuel management, but to protect our communities and forest’s health.”
The study’s author, Mark Schwartz, explained Sierra Nevada forest fires rarely burned above 8,000 feet in the past. Fires primarily occurred at lower elevations, where forest fuel was drier and more abundant.
Over the past three decades, however, several fires each year have burned at or above the 8,000-foot level.
The drought cycles, Schwartz explained, are becoming more and more prevalent, increasing the amount of time these fuels stay dry.
Warming temperatures associated with climate change may be increasing tree density in the high, subalpine forests, building up the amount of fuel in those forests while also reducing moisture content, according to the report.
Reduced efforts in recent decades to extinguish fires at the upper elevations may be contributing to the trend, Schwartz added.
“There has been a change in practice, wherein firefighters are spending more to defend people’s personal space,” Schwartz said.
Like Zaski suggested, Schwartz believes the changing ecosystem will prompt a change in forest management practices at a state and federal level.
“Turning the tide on this is a question of values,” Schwartz said. “There is the argument that we ought to be having these types of fires.”
Because fire is a primary driver of forest change in the Sierra Nevada, the increase in wildfires at higher elevations may speed the impacts of changing climate on forest composition, structure and function, Schwartz noted.
“It’s not necessarily a problem we need to fix; however, there are other changes that give the opportunity for lower-elevation species (i.e., the types of trees), basically changing the ecosystems in the higher elevation,” he said.
More fires at the high elevations could accelerate shifts in vegetation, destroying existing growth and increasing opportunities for lower-level plant and tree species to migrate upward, according to the report.
“It demonstrates very well that a changing climate doesn’t automatically change the vegetation present,” said Forest Schafer, a forester with the North Lake Tahoe Fire Protection District.
The message over the past several years is forcing forest management and fire protection officials to change the way they think about the messages they relay throughout communities, Schafer said, a practice he believes has been received well within the Tahoe region.
“Our first prescribed fire burn (in the Tahoe region) was in the ’90s and it took the community a long time to get ready for that,” Schafer said. “Now there is acceptance and understanding within the community for (prescribed fires).
“That understanding is promoting that fires are a necessary tool to adapt that change.”
The vision moving forward isn’t singular, however, Schwartz said, and with a variety of opinions being offered, there’s no clear social direction within local, state and federal governments.
Schwartz also noted these restoration decisions include whether or not to seed locations that have burned and which species to seed in restoration efforts.
“We have been hit with change after change and it challenges us to look at resource management in the Sierra Nevada mountain range,” Schwartz said. “Now we have evidence to look at this at high elevation areas.”