Category: Forest health

Aerial forest surveys track continued spread of spruce beetles across Colorado forests

State, federal scientists track forest health

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Aerial survey results show how spruce beetles are taking a toll across Colorado’s forests, with new areas of infestation in the Sange de Cristo, the West Elks and even the northern mountains.
Spruce beetle populations are surging in the southern Rocky Mountains. bberwyn photo.
Spruce beetles are still spreading in the southern Rocky Mountains. @bberwyn photo.

By Bob Berwyn

The latest results from aerial surveys of Colorado forests shows that spruce beetles are doing the most damage, with infestations detected on 409,000 acres across the state, expanding onto 182,000 acres of previously unaffected forests. Since 1996, spruce beetle outbreaks have caused varying degrees of tree mortality on more than 1.5 million acres in Colorado.

The mapping shows spruce beetles spreading outward from the San Juans to the West Elk Mountains, the Sangre de Cristo Mountains and into the northern part of the state around Rocky Mountain National Park. See the full report here: http://www.fs.usda.gov/goto/USFSR2ForestHealth.

State forest experts said it was the fourth year in a row that spruce beetle outbreaks caused widespread tree mortality. As populations of spruce beetles expand, they are starting to affect higher-elevation stands of Engelmann spruce. The report says blowdown events, combined with long-term drought stress, warmer temperatures and extensive amounts of older, dense spruce, have all contributed to the ongoing spruce beetle outbreak. Continue reading “Aerial forest surveys track continued spread of spruce beetles across Colorado forests”

Wildfires burned across 10 million acres in 2015

Feds spend more than $2.6 billion on fire suppression

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Wildfire activity surged in 2015. Graph courtesy NIFC.

By Bob Berwyn

For the first time in the era of modern record-keeping, wildfires burned across more than 10 million acres in 2015, mainly due to a series of large fires in Alaska.

According to the U.S. Forest Service, there were more than 50 fires that exceeded 50,000 acres, and 20 fires exceeded more than 100,000 acres. The fires destroyed more than 4,500 homes and other structures and killed 13 wildland firefighters.

The big wildfire season came after two-year lull, when the total wildfire footprint stayed below 5 million acres. For the last years, the average now stands at about 6.6 million acres.

The uptick in fires is no surprise to experts, who have been warning that global warming will result in bigger burns. Alaska, for example, reported its second-warmest year on record in 2015. Since 2000, fire seasons have grown longer, and the frequency, size and severity of wildland fires has increased.

In 2013, scientists linked a spate of massive Siberian wildfires with a “stuck” weather pattern associated with global warming. Overall, scientists say, those links are becoming more clear. It’s also clear that forests will have a more difficult time rebounding from fires as temperatures warm. Continue reading “Wildfires burned across 10 million acres in 2015”

Can the Southwest’s forests survive global warming?

New study projects widespread forest mortality by 2100

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Vast swaths of spruce trees have died in southern Colorado during the past few years. Photo courtesy U.S. Forest Service.
Forest ecosystems around the world are under the gun from climate change, development, insect invasions and conversion to agriculture. This stand of lodgepoles in Colorado was clear cut after pine beetles killed most of the trees.
Forest ecosystems around the world are under the gun from climate change, development, insect invasions and conversion to agriculture. This stand of lodgepoles in Colorado was clear cut after pine beetles killed most of the trees. @bberwyn photo.

Staff Report

Unless deep greenhouse gas cuts happen soon, last month’s historic climate agreement may be too little, too late for some forests in the American Southwest, where scientists are projecting a widespread die-off of needleleaf evergreens — including pine, spruce, piñon and juniper trees — by 2100.

After combining data from field observations with climate model projections, the research team concluded that  72 percent of the region’s needleleaf evergreen forests will die by 2050, with nearly 100 percent mortality by 2100.

“No matter how we investigated the problem, we got the same result. This consensus gives us confidence in this projection of forest mortality,” said Sara Rauscher, assistant professor of geography in University of Delaware’s College of Earth, Ocean, and Environment.

It’s pretty clear that the die-off is already under way. Even drought-resistant species like piñon pines were hit hard by a drought in the early 2000s. A massive bark beetle infestation wiped out millions of acres of lodgepole pines in the southern Rockies, and spruce beetles have taken a big toll on once-lush spruce forests in southern Colorado. Continue reading “Can the Southwest’s forests survive global warming?”

President Obama highlights ‘moral obligation’ to future generations in sustainability memorandum

This was one of the Snake River shots that never made into a daily post.
A presidential memorandum could mean more institutional love for America’s natural resources. @berwyn photo.

Federal agencies must target ‘no net loss’ in new projects

By Bob Berwyn

Federal agencies will be expected to make natural resource sustainability a key focus under a new presidential memorandum released this week.

Outlining a moral obligation to future generations, President Barack Obama said Americans have the ingenuity and tools needed to “avoid damage to the most special places in our nation and to find new ways to restore areas that have been degraded. ” Continue reading “President Obama highlights ‘moral obligation’ to future generations in sustainability memorandum”

Forests: Study says spruce beetle not a big factor in recent southwest Colorado wildfires

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A major spruce beetle outbreak has been spreading across forests of southwest Colorado, but that hasn’t been a big factor in recent wildfires in the region, according to CU-Boulder research.

Climate, topography likely more significant, researchers say

Staff Report

Colorado researchers have added another chapter to the long-running debate over beetle-kill and wildfires, finding that spruce beetle infestations haven’t increased the severity of wildfires in southwestern Colorado.

Spruce bark beetles have affected roughly half a million acres of Engelmann spruce and subalpine fir forests across the state in recent years, with infestations documented across an additional 87,000 acres in 2014. Continue reading “Forests: Study says spruce beetle not a big factor in recent southwest Colorado wildfires”

Environment: More maple tree woes

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What’s up with maple trees?

Study documents widespread growth slowdown

Staff Report

An extensive tree-ring study in the Northeast suggests a widespread and steady decline in the health of sugar maples, one of most economically and ecologically important trees in the eastern United States and Canada.

The decline started showing up in the 1970s a decline in the growth rate of of sugar maple trees, but the reasons are still unclear, according to the State University of New York researchers who recently published their findings in the open-access journal “Ecosphere.” Continue reading “Environment: More maple tree woes”

Forests and CO2 — It’s complicated!

One of the few lodgepole seedlings to survive the industrial clearcutting on the north shore of the Frisco Peninsula.
Climate models may be overestimating the carbon-capturing capacity of forests. @bberwyn photo.

Loss of nitrogen a key factor in forest equation

Staff Report

Forests may grow faster as atmospheric CO2 increases, but that doesn’t mean they’ll absorb more of the heat-trapping gas. Instead, a shortage of nitrogen means plants won’t be able to fix as much carbon as projected by some climate models.

“Forests take up carbon from the atmosphere, but in order for the plants to fix the carbon, it requires a certain amount of nitrogen,” said researchers Prasanth  who took a close look at the chemistry of secondary forests that are regrowing after deforestation, wood harvest and fires.

“If that ratio of carbon to nitrogen isn’t right, even if you add many times more carbon than it gets currently, the forests cannot absorb the extra carbon,” Meiyappan said. Continue reading “Forests and CO2 — It’s complicated!”