By Guy Kovner
Sudden oak death has killed up to 50 million trees and 100 million more may be infeceted, according to new research.
A dry winter curtailed the presence of a deadly forest pathogen this year in Sonoma County and 13 other Northern and Central California counties, but experts still expect the oak-killing disease to spread and warned landowners to be vigilant.
Since the mid-1990s, sudden oak death has killed up to 50 million trees from Big Sur to southwest Oregon and is entrenched in the woodlands, spreading rapidly after wet winters and slower during dry years.
“It’s constant, it’s emerging,” said Richard Cobb, an assistant professor of forest health at Cal Poly San Luis Obispo. “It’s probably going to get a lot worse.”
Cobb said Monday he’s about to publish his estimate of tree mortality, 90 percent of which are tanoaks and most of the rest coast live oaks. Another 100 million trees may be infected by the insidious pathogen that typically takes one or two years to produce symptoms in the infected trees, he said.
The pathogen can be spread by human footprints and nursery plants, but in nature it rides on water droplets blown from the leaves of bay laurel trees, a host species that abounds among the oak and tanoak trees susceptible to the disease.
“We know there’s a lot of disease out there,” said Matteo Garbelotto, director of the forest pathology and mycology laboratory at UC Berkeley, which has organized annual sudden oak death surveys, known as the SOD Blitz, since 2008.
This year’s survey found the estimated rate of infection — based on lab analysis of leaves collected from bay laurels and tanoaks — at 3.5 percent throughout the 14-county region, a marked decline from 12.8 percent last year.
Sonoma County, divided into three areas, also showed sharp declines, which Garbelotto said were anticipated because the 2017 survey, conducted in the wake of two straight wet winters, found the highest infection rate ever recorded in 11 years.
But the survey conducted in May found another consequence — the presence of oaks showing symptoms of infection had increased to 12.2 percent throughout the region, up from 9.4 percent last year.
Next year’s rate should be higher, Garbelotto said, coming two years after the 2017 rains and matching the time it takes for symptoms, such as bleeding cankers in oak tree bark, to appear.
By JoAnna Klein
The grove of 47,000 quivering aspen trees in Utah is being diminished by mule deer, foraging cattle and human mismanagement.
On 106 acres in Fishlake National Forest in Richfield, Utah, a 13-million-pound giant has been looming for thousands of years. But few people have ever heard of him.
This is “the Trembling Giant,” or Pando, from the Latin word for “I spread.” A single clone, and genetically male, he is the most massive organism on Earth. He is a forest of one: a grove of some 47,000 quivering aspen trees — Populus tremuloides — connected by a single root system, and all with the same DNA.
But this majestic behemoth may be more of a Goliath, suggests a study published Wednesday in PLOS ONE. Threatened by herds of hungry animals and human encroachment, Pando is fighting a losing battle.
The study, consisting of recent ground surveys and an analysis of 72 years of aerial photographs, revealed that this unrealized natural treasure and keystone species — with hundreds of dependents — is shrinking. And without more careful management of the forest, and the mule deer and cattle that forage within him, the Trembling Giant will continue to dwindle.
By Carl Zimmer
Islands of greenery, called refugia, survive even the worst fires, sheltering species and renewing charred landscapes.
Forests have burned in spectacular fashion this year. From California to Colorado, Portugal to Greece, photographers have captured terrifying images of infernos soaring into the sky and spreading to the horizon.
The fires left scenes of ashen destruction, but they did not wipe out everything. Scattered about the ravaged landscapes were islands of trees, shrubs and grass that survived unharmed.
It’s easy to overlook these remnants, which ecologists call fire refugia. But they can be vital to the long-term well-being of forests. These havens shelter species that are vulnerable to fires. Afterward, they can be starting points for the ecosystem’s regeneration.
“Those trees are lifeboats,” said Meg Krawchuk, a fire ecologist at Oregon State University.
Writing recently in the journal BioScience, Dr. Krawchuk and her colleagues argued that it’s urgent to better understand fire refugia, because they may be seriously threatened in future decades by climate change. Without them, many species may become threatened and the surrounding ecosystems may take longer to recover from wildfires.
The shift from fossil-based industries to a bioeconomy is creating a growing demand for biobased chemicals, materials and fuels as sustainable and renewable alternatives. One possible source is fructose from wood for use in the production of bioplastics.
Lignocellulosic biomass is typically nonedible plant material, including dedicated crops of wood and grass, as well as waste material from agroforestry. It is also the single most abundant renewable resource on earth and available all year round. Furthermore, lignocellulosic biomass does not need valuable space in fields as it has no agricultural or nutritional use. It’s noteworthy, that wood can be harvested sustainably from certified forests. In the Nordic countries, more forest is grown than gets harvested each year.
Compared to other lignocellulosic feedstocks like straw, wood-based feedstocks for biorefinery have the greatest potential to replace fossil derived compounds in the chemical industry. Establishing competitive value chains based on lignocellulosic feedstock will not only secure an abundant alternative industrial feedstock but also strengthen the competitive position of biobased chemicals and materials compared to their fossil-based counterparts.
The EU-funded Horizon 2020 ReTAPP project investigated the production of fructose sugar using lignocellulosic biomass from hardwood and softwood feedstocks. “Researchers employed enzyme solutions to replace food/starch-based-fructose with wood derived fructose and prepared the entire value chain for launching the product onto the market,” says project coordinator Matti Heikkilä.
By Jerry Painter for AP
U.S. officials recommended approval on Friday of a plan to block new mining claims for 20 years on the forested public lands that make up Yellowstone National Park’s mountainous northern boundary.
Regional Forester Leanne Marten submitted a letter to the Bureau of Land Management endorsing the plan to withdraw 30,000 acres (12,140 hectares) in Montana’s Paradise Valley and the Gardiner Basin from new claims for gold, silver, platinum and other minerals, U.S. Forest Service spokeswoman Marna Daley said.
A final decision is up to the office of U.S. Interior Sec. Ryan Zinke, who favors the withdrawal. Zinke said in a statement that it could be finalized in coming weeks.
The Trump administration’s support is notable given the president’s outspoken advocacy for the mining industry and his criticism of government regulations said to stifle economic development. The proposal has received bipartisan backing in Montana, with Democrats and Republicans alike eager to cast themselves as protectors of the natural beauty of the Yellowstone region.
By Josephine Marcotty
As Minnesota’s ash trees fall to the invasion of emerald ash borer in the next decade, the forest that borders the 72-mile stretch of the Mississippi River in the Twin Cities metro area is expected to lose one-fifth of its canopy.
Turns out that’s not all bad.
Conservation groups that work in the 54,000-acre Mississippi National River and Recreation Area are using that environmental disaster to thwart a much larger one on the way — climate change.
By replacing ash with other kinds of trees, as well as bushes and other plants, they hope to establish a forest that is more likely to thrive in a future of higher average temperatures and much more erratic precipitation.
Diversity is strength, even among forests. In a paper published in Nature, researchers led by University of Utah biologist William Anderegg report that forests with trees that employ a high diversity of traits related to water use suffer less of an impact from drought. The results, which expand on previous work that looked at individual tree species’ resilience based on hydraulic traits, lead to new research directions on forest resilience and inform forest managers working to rebuild forests after logging or wildfire.
Surprisingly, says Anderegg, a forest’s hydraulic diversity is the predominant predictor of how well it can handle a drought.
“We expected that hydraulic traits should matter,” he says, “but we were surprised that other traits that a lot of the scientific community have focused on weren’t very explanatory or predictive at all.”
By George Plaven
Timm Locke relishes a chance to drive around Portland and showcase the latest commercial buildings made with mass timber, a construction material that uses wood beams and panels instead of concrete and steel.
First stop: Albina Yard, a four-story office building that opened in 2016 featuring cross-laminated timber panels from D.R. Johnson, a lumber company south of Roseburg.
Every piece of cross-laminated timber — or CLT for short — is prefabricated, designed for a specific part of the building, said Locke, director of forest products at the Oregon Forest Resources Institute. That means buildings go up faster, with fewer workers.
Wood is also environmentally superior to steel and concrete, Locke said, because it sequesters carbon and takes less energy to produce.
“There are so many benefits, it doesn’t matter which one you choose to start with,” Locke said.
First developed in Europe, mass timber is now catching on in the U.S., and Oregon is working to position itself as the industry hub, kick-starting rural economies that have traditionally relied on forest products. On Aug. 1, Oregon became the first state to approve language in its building codes allowing for wood-framed buildings up to 18 stories tall.
By Dylan Love
Called Forester, this robot uses a technique called “sounding” to help arborists identify sick trees and diagnose them.
After hearing a radio program describe the labor-intensive work of forest pathologists — basically, tree doctors — Maksim Mikhailov had an idea: what if a robot helped collect their data?
Mikhailov is a 16-year-old student at ITMO University, the renowned science and technology institution in St. Petersburg, Russia. As a member of the school’s Youth Robotics Lab, he was perfectly positioned to bring his idea to life. With a full team working on the the project, the robot won the gold medal at last year’s World Robot Olympiad; it can record tree locations within a forest, identify their species, measure the widths of their trunks, and even identify if a tree is healthy or not.
Its name is Forester, and most of its job is to explore forests and hit trees with its mallet. It’s a robotic adaptation of a technique that human tree experts often use, called “sounding,” to help their appraisal of a tree’s health.
“The robot hits a tree and its microphone records the sound,” Mikhailov explained. “Since sick trees have cavities or low wood density in their trunk, they make a sound with a lower overall frequency than that of a healthy tree.” The robot makes use of an algorithm that analyzes the recorded sound to determine if it came from a healthy tree.
Forester also takes a photograph of the tree and feeds the image to a neural network, identifying 12 different species of trees with accuracy better than 90 percent.
Peter Krzystek, Professor for Photogrammetry and Remote Sensing at Munich University of Applied Sciences tells about new investigations into the 3D mapping of forests.
Modern remote sensing sensors offer completely new possibilities for an extensive and detailed 3D capture of tree populations, making it possible to map at very large-scale. In particular, LiDAR is today an established technique for fast and highly accurate 3D scanning from the aircraft, helicopter or drone where pulses of visible or near-infrared laser light at a particular wavelength are used to create 3D images. These 3D images are typically made up of a high density of data points, known as ‘point clouds’. The new full waveform technology, which reconstructs the complete path of the laser beam through the vegetation, makes it possible to map the forest structures in 3D more precisely. Moreover, digital aerial cameras enable a detailed reconstruction of the forest surface and provide – if fused with LiDAR data – extra spectral information in the infrared range for a characterisation of the tree species. All in all, these new technologies are ideally suited for the automatic and cost-effective collection and characterisation of forest stands.