Category: Forest health

Sunday set: Forests

Trees are our friends

Last week the UN celebrated the International Day of Forests as a way to acknowledge how important forests are to the world. To cynics, it may seem trite lip service by faceless bureaucrats. But in reality, it’s critical that everyone understands how important forests are for the planet. They cover about a  third of the Earth’s land mass and provide livelihoods, medicines, fuel, food and shelter for about 1.6 billion people – including more than 2,000 indigenous cultures. Forests are the most biologically-diverse ecosystems on land, home to more than 80 percent of the terrestrial species of animals, plants and insects. They may also be one of our last, best hopes for slowing climate change. Yet despite all of these priceless ecological, economic, social and health benefits, global deforestation continues at the rate of about 32 million acres per year, equivalent to 10-20 percent of global greenhouse gas emissions contributing to climate change. Check out my article and photo essay for Pacific Standard to learn more about forests, especially for ways you can get involved in helping to protect and restore them.

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Global warming hampers post-fire forest regrowth in Colorado

‘We are seeing the initiation of a retreat of forests to higher elevations’

A June, 2011 wildfire in Keystone Gulch burned within a few hundred feet of vacation homes and full-time residences at the Colorado resort.
A June, 2011 wildfire in Keystone Gulch burned within a few hundred feet of vacation homes and full-time residences at the Colorado resort. @bberwyn photo.

Staff Report

Global warming is likely one of the main factors that’s preventing some Colorado forests from regenerating after wildfires.

When they started studying eight wildfire sites that burned across 162,000 acres of low-elevation forests along the Front Range, University of Colorado Boulder researchers said they expected to see young trees popping up all over the place, but that’s not what they found.

There were no seedlings at all in 59 percent of the study plots and 83 percent showed a very low density of seedlings. Future warming and associated drought may hinder significant further recovery, the researchers concluded. Only 2 to 38 percent of plots surveyed, depending on the fire site, were considered stocked, or on their way to recovery. Continue reading “Global warming hampers post-fire forest regrowth in Colorado”

Spruce beetles still on the march in Colorado

Global warming taking a toll on forests worldwide

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Aerial surveys help track the health of Colorado forests. @bberwyn photo.

By Bob Berwyn

Spruce beetles continued to expand in Colorado in 2016, at least in part due to global warming and drought, as well as the density of old-growth spruce forests.

In all, spruce beetles were active across 350,000 acres of higher-elevation stands of Engelmann spruce statewide, including about 136,000 acres of new activity, causing widespread tree mortality, according to the results of the latest aerial surveys conducted by the U.S. Forest Service and the Colorado State Forest Service. Since 1996, spruce beetle outbreaks have caused tree mortality on more than 1.7 million acres in Colorado. Continue reading “Spruce beetles still on the march in Colorado”

How will boreal forests respond to global warming?

New satellite data helps track photosynthesis in evergreens

How will forests respond to global warming? @bberwyn photo.
An aerial photo of forests in western Colorado. New satellite data will help show how evergreen forests are responding to climate change. @bberwyn photo.

Staff Report

Despite the huge importance of forests in the global carbon cycle, researchers still aren’t exactly certain how they will respond to climate change. But that could soon change thanks to satellite sensors that can track photosynthesis in evergreen forests by monitoring slight color shifts.

The new information could help assess the health of northern forests over time, showing how they are responding to global warming. Photosynthesis is easy to track in deciduous trees — when leaves bud or turn yellow and fall off. But until recently, it had been impossible to detect in evergreen conifers on a large scale. Continue reading “How will boreal forests respond to global warming?”

Climate change may be factor in spread of tree fungus

Signs of hope? A single Douglas-fir grows at the base of the clearcut area along Swan Mountain Road. It'll be interesting to watch the area during the next few years to see how it regenerates.
Global warming may be promoting growth of a tree-damaging fungus in the Pacific Northwest. @bberwyn photo.

Commercially valuable tree stands take hit in Pacific Northwest

Staff Report

Global warming may be a factor in the spread of a fungus affecting valuable Douglas fir forests in the Pacific Northwest. Needle cast disease has recently spread across 590,000 acres in Oregon,  quadrupling since the start of surveys in 1996. The annual economic loss has been estimated at $128 million.

“The correlation between disease severity and climate factors, such as spring moisture and warm winter temperatures, raises the question of a link between disease expansion and climate change,” said  researcher Gabriela Ritokova. “Those factors, in combination with lots of Douglas fir and with large springtime fungal spore production, have us where we are now.” Continue reading “Climate change may be factor in spread of tree fungus”

Forests may not benefit from rising CO2 levels

Intense aspen and scrub oak color in this aerial view of Eagle County, Colorado.
Aspen and scrub oak forests in western Colorado. @bberwyn photo.

Study says disastrous tipping points could be reached by 2050

Staff Report

Forests of the future may not be able to remove heat-trapping CO2 from the atmosphere as effectively as previously thought, scientists said in a new study that’s based on an extensive analysis of tree ring data from the past.

“We utilized a network of more than two million tree-ring observations spanning North America. Tree-rings provide a record into how trees that grow in different climates respond to changes in temperature and rainfall,” said Brian Enquist, a professor in the UA’s Department of Ecology and Evolutionary Biology and a fellow of the Aspen Center for Environmental Studies in Aspen, Colorado.

The research challenges assumptions about how forests will respond to warmer average temperatures, increased greenhouse gas emissions, and shifting rainfall patterns. It also suggests that the warming climate already is rapidly pushing many forests towards an ecological tipping point, which may be reached as early as 2050, Exposure to unprecedented temperatures hampers tree growth and makes them susceptible to other stress factors. Continue reading “Forests may not benefit from rising CO2 levels”

California tree deaths part of global wave of forest mortality

Climate change is wiping out forests on a staggering scale

forests dying because of global warming
Red and dead lodgepole pines in Colorado. @bberwyn photo.
A beetle-killed lodgepole pine branch in Summit County, Colorado.
A beetle-killed lodgepole pine branch in Summit County, Colorado. @bberwyn photo.

Staff Report

California’s multiyear drought killed even more trees than previously thought, the U.S. Forest Service announced this week. Aerial and ground surveys show that 26 million trees across six counties in Southern California died, in addition to the 40 million trees that died statewide from 2010 to October 2015. Four years of drought, high temperatures and an outbreak of tree-killing bark beetles all contributed the historic levels of tree die-off, the agency said.

The tree mortality in California is the latest crest in a wave of forest die-offs in the past few decades linked with global warming. In the Southwest, an outbreak of ips beetles after the 2002 drought killed 80 percent of the piñon pine forests in the Four Corners region.

Around the same time, pine beetles started spreading across northern Colorado, parts of Wyoming and North Dakota, ultimately killing millions of acres of forest. And just as the pine beetle infestation waned, a spruce beetle outbreak in southern Colorado started to spread. Since 1996, spruce beetles have killed trees across about 1.5 million acres of forest.

Huge swaths of Colorado aspen forests also died in the early 2000s in a mortality event linked with extreme heat, and forest researchers say hardwood forests in the northern U.S. are also at risk from global warming. Continue reading “California tree deaths part of global wave of forest mortality”