Some green ash trees show some resistance to emerald ash borers

Jeff Mulhollem, Pennsylvania State University
Genes in green ash trees that may confer some resistance to attacks by the emerald ash borer express themselves only once the tree detects the invasive beetle’s feeding, according to Penn State researchers.

Knowing this, geneticists may be able to selectively breed trees to strengthen them and perhaps move the resistance response earlier to ward off the beetles’ onslaught, explained John Carlson, professor of molecular genetics.

Green ash, an ecologically and economically valuable tree species native to eastern and central North America, is under severe threat from the rapid invasion of emerald ash borer, a wood-boring beetle native to Asia. Penn State scientists and others are trying to save the species.

Prior observations in a green ash provenance trial—an experiment to see how plants adapt—planted at Penn State in 1978 by Kim Steiner, professor of forest biology and director of The Arboretum at Penn State, and colleagues in the U.S. Forest Service, show that a very small percentage of ash trees survive emerald ash borer infestations, seemingly because their tissues do not nourish and perhaps even sicken the beetles.

“Emerald ash borer probably entered the provenance trial unnoticed around 2008 and trees started showing symptoms of attack by 2012,” Carlson said. “All but eight or nine of the approximately 1,800 trees that Kim planted have subsequently been killed by the beetles.”

Ash trees succumb after adult beetles lay eggs on their bark. When the eggs hatch, the larvae bore into the bark and feed on the transportation tissues of the tree. This disrupts the movement of nutrients and water within the tree, girdling it and causing death.

“To better understand the response of green ash trees to emerald ash borer, we compared gene expression data for resistant versus susceptible green ash genotypes exposed to attack by the beetles,” said Carlson, director of Penn State’s Schatz Center for Tree Molecular Genetics. “By comparing RNA-sequence data from stems attacked by emerald ash borer to multiple tree tissues under other stresses, we could identify differences in the gene expression profiles specific to emerald ash borer resistance.”

Source: Some green ash trees show some resistance to emerald ash borers – Phys.org, 2019-07-04

Science can guide replanting trees for storm resistance

By Mark Tancig
We can use science to guide the replanting so that we choose wind-resistant species and implement other best practices to prevent future damage.

In the aftermath of Hurricane Michael, with our neighbors to the west still recovering, many folks may be questioning the wisdom of having trees near their house. The value of trees to our own health (oxygen, air purification, quality of life benefits), home values, energy savings, and wildlife habitat is pretty well agreed upon.

However, many of us, or someone we know, recently experienced a tree coming down on their house, car, or other valuables. There’s nothing like a tree falling through the roof to keep you from wanting to plant another one.

Yet, we need trees. With the continued loss of forests to development and the growing body of knowledge regarding current and future environmental issues we face (think climate change and loss of species), we can’t afford to not keep planting trees. In fact, we should be planting more!

So how do we justify planting more trees in a hurricane-prone area when many of us just witnessed a lot of damage caused by the trees? Well, we can use science to guide the replanting so that we choose wind-resistant species and implement other best practices to prevent future damage as much as possible.

Fortunately, the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) has faculty and staff who collect and synthesize data on how trees handle hurricanes so that citizens can use that information to make better, informed decisions. They noticed trends when studying information collected following nine hurricanes, from 1992 to 2005, that ranged from top winds of 85 to 165 miles per hour.

The researchers broke the results into three different areas that affected the resilience of trees and included lessons learned regarding the health of the community’s urban forest, the individual trees themselves, and the root zone conditions surrounding trees.

Some of the results will seem straightforward.

For example, more trees fall in higher intensity storms and older, poorly structured trees with damaged roots don’t perform as well. Other data collected provided insights into which trees and environmental conditions make for a more resilient urban forest, such as the fact that trees planted in groups fare better. Much information was gathered on which tree species performed best in the face of high winds.

Source: Science can guide replanting trees for storm resistance – Tallahassee Democrat, 2019-06-27

How personalities of wild small mammals affect forest structure

by Elyse Catalina, University of Maine
A mouse scampers through the forest, stopping suddenly at the sight of a tree seed on the ground. A potential meal. And a dilemma.

The mouse must decide if it should eat the seed immediately. Or hide it in a safe place for consumption when food is scarce. Or pass it up in hopes of something better.

Many factors determine what the mouse will do next, including how abundant the seeds are and if the rodent is a fan of that variety.

Personality is another element that might play a role in what the mouse decides, according to a University of Maine researcher.

How animals react to an environment that is transforming due to human behavior and climate change is at the core of research being conducted by Alessio Mortelliti, an assistant professor of wildlife habitat ecology at UMaine.

One study Mortelliti and his students are pursuing focuses on how individual personalities of small mammals affect their response to global change.

Like humans, animals have a personality, according to Mortelliti.

“Anyone that has a pet knows they have a personality,” he says. “It’s the same for squirrels, mice and voles.”

Within a species, individuals can be aggressive or shy, more or less social, Mortelliti explains.

“We’re looking at how this individuality—their own way of being—affects the way they respond to changes in their environment made by humans,” he says of wild small mammals.

When a mouse finds a seed, the decision it makes affects more than the mouse. If the seed is eaten immediately, any chance of a plant sprouting from that seed is gone. If the mouse decides to move and store the seed, a plant has a chance to grow.

Mortelliti believes that by modifying the environment, humans may be favoring certain personality types over others and, in turn, altering the course of evolution and the shape of the forest.

Source: How personalities of wild small mammals affect forest structure – Phys.org, 2019-06-19

Engineered wood stays 12 degrees cooler, saves AC costs by up to 60 percent

By Robert Dalheim
COLLEGE PARK, Md. – The research team behind “super wood” is at it again – this time engineering a wood that’s capable of staying 12 degrees cooler than regular wood.

Researchers at the University of Maryland and the University of Colorado hoped to find a passive way for buildings to dump heat sustainably. The solution is wood – it is already used as a building material, and is renewable and sustainable. Using tiny structures found in wood – cellulose nanofibers and the natural chambers that grow to pass water and nutrients up and down inside a living tree – the researchers engineered wood that radiates away heat.

The UMD team soaked basswood in a solution of hydrogen peroxide, which destroys the wood’s lignin. The team then used a hot press to compress the remaining cellulose and hemicellulose components together. To make it water repellent, they added a super hydrophobic compound that helps protect the wood.

Source: Engineered wood stays 12 degrees cooler, saves AC costs by up to 60 percent – Woodworking Network, 2019-06-14

Hidden giants in forest soils

Only a fraction of the microbes residing in, on and around soils have been identified through efforts to understand their contributions to global nutrient cycles. Soils are also home to countless viruses that can infect microbes, impacting their ability to regulate these global cycles. In Nature Communications, giant virus genomes have been discovered for the first time in a forest soil ecosystem by researchers from the DOE Joint Genome Institute and the University of Massachusetts-Amherst.

Characterizing the diversity of microbial cells in a handful of soil is so complex it was considered impossible. To date, only a small fraction of the microbes residing in, on and around soils have been identified as part of efforts to understand their contributions to the global carbon cycle, and to other nutrient cycles. Soils are also home to countless viruses that can infect microbes, impacting their ability to regulate these global cycles.

Reported November 19, 2018, in Nature Communications, giant virus genomes have been discovered for the first time in a forest soil ecosystem by researchers from the U.S. Department of Energy (DOE) Joint Genome Institute (JGI), a DOE Office of Science User Facility, and the University of Massachusetts-Amherst (UMass Amherst). As the name implies, giant viruses are characterized by disproportionately large genomes and virions that house the viruses’ genetic material. They have been frequently found within protists and algae, and thus they are believed to have a significant impact on their hosts’ population dynamics and the planet’s biogeochemical cycles.

Source: Hidden giants in forest soils – EurekAlert, 2018-11-19

Long-lived wood products are significant carbon capturers

By Pranjal Mehar
A key finding of the study is that positive climate change mitigation effects can be gained only if efforts are made to use more wood for long-lived wood products.

A new study by the University of Eastern Finland has suggested that the way we use wood mitigate climate change. It also supports the economy.

Forests assume a vital job in the worldwide carbon cycle and add to climate change mitigation. Forests ingest carbon from the environment through photosynthesis and store the carbon in living biomass, dead wood, litter and soil.

When wood is collected, a lot of carbon is expelled from the Forest and would then be able to be put away for a considerable length of time in enduring wood items, for example, wooden houses and furniture. Up until this point, numerous examinations have concentrated on carbon put away in Forest, yet fewer investigations have concentrated on the job of wood items.

A new study intends to fill this gap in knowledge. The study analyzed and applied various methods and models in order to estimate the effects of wood use effects on climate change mitigation and to reveal the environmental, economic and even social effects of wood use.

The examination followed the streams of wood in Lithuania and the Czech Republic beginning from the forest through the wood handling industry until the point when the end products, with an accentuation on carbon conventional and atmosphere moderation impacts.

The outcomes demonstrate that traditional carbon bookkeeping strategies for reap wood items may prompt a huge underestimation of the carbon put away in wood items. The examination discovered that in a few nations, the yearly carbon spending plan in wood items is 40% higher when ascertained with a more definite technique.

Source: Long-lived wood products are significant carbon capturers – Tech Explorist, 2018-11-08

Hygroscopic aerosols linked to forest decline

Hygroscopic aerosols — particles in the air that attract water — could be causing forest decline around the world, according to experiments performed in Germany. Researchers believe that aerosol accumulation on trees enables thin bridges of liquid to form between the leaf interior and the leaf surface, causing the plants to dry out much more rapidly.

“In the atmosphere, aerosols act as cloud condensation nuclei,” says Juergen Burkhardt of the University of Bonn, Germany. “Deposited aerosols on leaf surfaces act almost the same way but attract water from inside the plant.”

Plants have developed sophisticated mechanisms for taking up carbon dioxide from the air for photosynthesis without losing too much water but, as the scientists note, it’s a delicate balance. And one that appears to be upset by rising levels of airborne particles.

“Global aerosol concentrations have roughly doubled compared with natural conditions, and the concentration increase over the continents is even higher,” says Burkhardt. “Our results show that aerosols deposited on leaves interfere with this delicate balance, pointing to a direct mechanism by which air pollution can reduce the drought tolerance of plants.”

Burkhardt and colleagues grew three species of tree — Scots pine, silver fir and common oak — for two years in two greenhouses, one ventilated with ambient air and the other fed with air filtered to remove 99% of aerosols. Seedlings grown under filtered conditions had superior drought tolerance to those raised in ambient air, the team found.

Source: Hygroscopic aerosols linked to forest decline – Brinkwire, 2018-09-25

Diverse forests are stronger against drought

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.”

Source: Diverse forests are stronger against drought – University of Utah, 2018-09-19

Planting a mix of tree species ‘could double’ forest carbon storage

By Daisy Dunne
Forests containing several tree species could store twice as much carbon as the average monoculture plantation, research finds.

A study looking at the carbon storage of forests in southern China finds that each additional tree species introduced to a plantation could add 6% to its total carbon stocks.

The findings suggest that afforestation programmes – which aim to plant trees to “suck” CO2 out of the atmosphere – should switch from using just one plant species to a more diverse mix, a study author tells Carbon Brief.

Planting a diverse range of trees could also bring many co-benefits, the author adds, including providing habitats for a larger range of animals.

However, the relatively small scale of the experiment may have led researchers to overestimate the relationship between tree species diversity and carbon storage, other scientists tell Carbon Brief.

Source: Planting a mix of tree species ‘could double’ forest carbon storage – Carbon Brief, 2018-08-22