Tag: forests

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”

Environment: Can prescribed fires make forests more resilient?

New study focuses on drought-stricken California forests

Beetle-killed forests now dominate the landscape in Summit County. Prescribed fires are needed to help regenerate forests and clear dangerous fuels, according to White River NF supervisor Scott Fitzwilliams.
Prescribed fires could help make forests more tolerant to drought and more resilient in a warmer climate. @bberwyn photo.

Staff Report

A rising tide of insect infestations, tree mortality and wildfires — all caused by global warming — has resulted in political pressure for more logging in U.S. Forests, but there’s plenty of research showing that cutting down trees doesn’t do much good and can even increase the fire danger.

Exploring alternative options for strengthening forest resiliency, researchers with the U.S. Geological Survey and the National Park Service recently found that thinning forests with prescribed fires can reduce drought. Continue reading “Environment: Can prescribed fires make forests more resilient?”

Satellite images map forest-fungi relationships

forest fungi
A new study helps map the relationships between forests and fungi on a large scale. @bberwyn photo.

New analysis offers important forest health information

Staff Report

Colorful mushrooms that pop up in forests around the world are much more than decorative baubles. Much more than realized, fungi are key components of forest ecosystems, helping to regulate the carbon cycle and driving the nutrient exchange between soil and trees.

One recent study showed the the recent bark beetle epidemic across the western U.S. may have wiped out crucial fungi that are critical to forest regrowth, and other research shows they helped stabilize global climate during low-C02 eras. Continue reading “Satellite images map forest-fungi relationships”

Global warming to cut water yield from forests and grasslands

Forests will grow faster, suck up more moisture

Forests will produce less water as global temperatures warm.
Forests may grow faster but will produce less water as global temperatures warm. @bberwyn photo.

Staff Report

After taking a big-picture look at the water cycle, U.S. Forest Service researchers say global warming may decrease the amount of water produced by forests and grasslands across the country — even with increases in precipitation.

National forests and grasslands contribute about 14 percent of the national water supply. Global warming may spur growth on those lands, while water yield simultaneously decreases, as forest water use (through evaporation and transpiration) increases dramatically with higher air temperatures, according to a new study. Continue reading “Global warming to cut water yield from forests and grasslands”

So how, exactly, does global warming kill forests?

Global warming has killed half a billion trees across the U.S.

Global warming is killing forests around the world. @bberwyn photo.

Staff Report

Scientists tracking massive forest die-offs say a new study may help forest managers learn how to predict which trees will succumb to global warming — and what the implications are for the global carbon balance.

“There are some common threads that we might be able to use to predict which species are going to be more vulnerable in the future,” said University of Utah biologist William Anderegg, explaining that recent tree-killing droughts in the western U.S. were marked more by elevated temperature than by a lack of rainfall.

“These widespread tree die-offs are a really early and visible sign of climate change already affecting our landscapes,” Anderegg said.

More stories on global warming and forests:

Continue reading “So how, exactly, does global warming kill forests?”

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

State, federal scientists track forest health

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”