Commercially valuable tree stands take hit in Pacific Northwest
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”→
Study says disastrous tipping points could be reached by 2050
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”→
Climate change is wiping out forests on a staggering scale
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.
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.
New study focuses on drought-stricken California forests
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.
New analysis offers important forest health information
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.
Dried grass glows under afternoon sunlight against the backdrop of a dark forest in Thayatal National Park, Lower Austria.
Late afternoon light shimmers on budding trees in Thayatal National Park, Lower Austria.
A fallen beech in Thayatal National Park, Austria.
Green tinged fields in Lower Austria under an evening sky.
A spring rainstorm builds above the agricultural plains north of Vienna, Austria.
The Lower Austrian landscape encompasses everything from wild beech forests and deep river canyons to manicured fields — not to mention acres and acres of vineyard, but that’s another story! Austrians are still getting used to the concept of national parks. Thayatal was founded in 2002, so some local visitors still don’t quite understand why the park managers simply leave downed trees on the ground. It’s considered a waste by some, and the park features signs explaining how it’s a deliberate effort to recreate landscapes where natural processes are left to function without much interference. In this small country, nearly every acre of land is spoken for, most of it outside towns and cities dedicated to agriculture, but slowly, resource managers are making some headway in restoring natural ecosystems in a few areas, to the benefit of native species.
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”→