Trees talk to each other and scientists have mapped the network

By Robert Dalheim
Scientists discovered that trees talk to each other through the Wood Wide Web. And now, they’ve mapped it.

Do trees actually talk to each other? And if so, how do they do it?

Just over 20 years ago, ecologist Suzanne Simard discovered that trees do communicate with each other, and it’s through a fungal network scientists have nicknamed the Wood Wide Web.

And now, an international team of scientists has created the first global map of the vast underground network. They did this by creating a computer algorithm to analyze a database from the Global Forest Inititiave, which includes 1.2 million trees in more than 70 countries.

The algorithm takes into account the different fungal species that associate with each tree species. It also takes into account local climate factors – which the scientists say has the biggest role to play.

“It’s the first time that we’ve been able to understand the world beneath our feet, but at a global scale,” Thomas Crowther, an author of the study from ETH Zurich, told the BBC. “Just like an MRI scan of the brain helps us to understand how the brain works, this global map of the fungi beneath the soil helps us to understand how global ecosystems work.

“What we find is that certain types of microorganisms live in certain parts of the world, and by understanding that we can figure out how to restore different types of ecosystems and also how the climate is changing,” he said.

Source: Trees talk to each other and scientists have mapped the network – Woodworking News, 2019-05-16

Eastern forests shaped more by Native Americans’ burning than climate change

By Jeff Mulhollem
Native Americans’ use of fire to manage vegetation in what is now the Eastern United States was more profound than previously believed, according to a Penn State researcher who determined that forest composition change in the region was caused more by land use than climate change.

“I believe Native Americans were excellent vegetation managers and we can learn a lot from them about how to best manage forests of the U.S.,” said Marc Abrams, professor of forest ecology and physiology in the College of Agricultural Sciences. “Native Americans knew that to regenerate plant species that they wanted for food, and to feed game animals they relied on, they needed to burn the forest understory regularly.”

Over the last 2,000 years at least, according to Abrams — who for three decades has been studying past and present qualities of eastern U.S. forests — frequent and widespread human-caused fire resulted in the predominance of fire-adapted tree species. And in the time since burning has been curtailed, forests are changing, with species such as oak, hickory and pine losing ground.

“The debate about whether forest composition has been largely determined by land use or climate continues, but a new study strongly suggests anthropogenic fire has been the major driver of forest change in the East,” said Abrams. “That is important to know because climate change is taking on an ever larger proportion of scientific endeavor.”

Source: Eastern forests shaped more by Native Americans’ burning than climate change – Penn State University, 2019-05-21

Resilience of Yellowstone’s forests tested by unprecedented fire

By Kelly April Tyrrell, University of Wisconsin
In August 2016, areas of Yellowstone National Park that burned in 1988 burned again. Shortly after, in October 2016, ecologist Monica Turner and her team of graduate students visited the park to begin to assess the landscape.

“We saw these areas where everything was combusted and we hadn’t seen that previously,” says Turner, a professor of integrative biology at the University of Wisconsin–Madison who has closely studied Yellowstone’s response to fire since 1988. “That was surprising.”

In a study published this week [May 20, 2019] in the Proceedings of the National Academy of Sciences, Turner and her team describe what happens when Yellowstone — adapted to recurring fires every 100 to 300 years — instead burns twice in fewer than 30 years. Yellowstone as we know it faces an uncertain future, the researchers say, and one of the big questions they hope to answer is whether the forests can recover.

“We were essentially able to reconstruct what the forest looked like before the fire happened, how many trees there were and how big they would have been,” Braziunas says. “Because we also measured nearby stands (of trees) that didn’t burn, we could compare what happens after the reburns and game out the scenarios in the model.”

The estimate, she and Turner say, represents a best-case, conservative scenario. With a warming climate and increased frequency of drought, the forests are likely to burn again in short intervals.

However, the forest has long shown itself to be resilient.

“The landscapes are going to look different than they have in the past,” says Turner, “but that doesn’t mean they won’t be beautiful. There will be species that benefit and species that see their ranges contract.”

“Change is going to happen and change is going to happen more quickly than we thought it would,” she adds. “We are learning how the system responds, but we don’t know to what degree it will be resilient or adapt in the future. But I am not ready to write it off. We have been surprised in the past.”

Source: Resilience of Yellowstone’s forests tested by unprecedented fire – Wildfire Today, 2019-05-21

Researchers map symbiotic relationships between trees and microbes worldwide

by Taylor Kubota, Stanford University
In and around the tangled roots of the forest floor, fungi and bacteria grow with trees, exchanging nutrients for carbon in a vast, global marketplace. A new effort to map the most abundant of these symbiotic relationships—involving more than 1.1 million forest sites and 28,000 tree species—has revealed factors that determine where different types of symbionts will flourish. The work could help scientists understand how symbiotic partnerships structure the world’s forests and how they could be affected by a warming climate.

In and around the tangled roots of the forest floor, fungi and bacteria grow with trees, exchanging nutrients for carbon in a vast, global marketplace. A new effort to map the most abundant of these symbiotic relationships—involving more than 1.1 million forest sites and 28,000 tree species—has revealed factors that determine where different types of symbionts will flourish. The work could help scientists understand how symbiotic partnerships structure the world’s forests and how they could be affected by a warming climate.

Source: Researchers map symbiotic relationships between trees and microbes worldwide – Phys.org, 2019-05-15

Can Humans Help Trees Outrun Climate Change?

By Moises Velasquez-Manoff
A dark synergy of extreme weather and emboldened pests could imperil vast stretches of woodland. Foresters are only starting to wrestle with solutions.

Foresters began noticing the patches of dying pines and denuded oaks, and grew concerned. Warmer winters and drier summers had sent invasive insects and diseases marching northward, killing the trees.

If the dieback continued, some woodlands could become shrub land.

Most trees can migrate only as fast as their seeds disperse — and if current warming trends hold, the climate this century will change 10 times faster than many tree species can move, according to one estimate. Rhode Island is already seeing more heat and drought, shifting precipitation and the intensification of plagues such as the red pine scale, a nearly invisible insect carried by wind that can kill a tree in just a few years.

The dark synergy of extreme weather and emboldened pests could imperil vast stretches of woodland.

So foresters in Rhode Island and elsewhere have launched ambitious experiments to test how people can help forests adapt, something that might take decades to occur naturally. One controversial idea, known as assisted migration, involves deliberately moving trees northward. But trees can live centuries, and environments are changing so fast in some places that species planted today may be ill-suited to conditions in 50 years, let alone 100. No one knows the best way to make forests more resilient to climatic upheaval.

These great uncertainties can prompt “analysis paralysis,” said Maria Janowiak, deputy director of the Forest Service’s Northern Institute of Applied Climate Science, or N.I.A.C.S. But, she added, “We can’t keep waiting until we know everything.”

Source: Can Humans Help Trees Outrun Climate Change? – New York Times, 2019-04-25

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

Take a Look at How Quickly a Forest Can Recover From Fire

By Andy Newman
Though it appears destructive, fire in the New Jersey Pinelands is a force of renewal.
On April 22, a spring wildfire roared through Penn State Forest in the New Jersey Pine Barrens, sending 100-foot flames shooting from the crowns of the pitch pines. The fire consumed half a square mile in 40 minutes and could be seen from space. By the time the New Jersey Forest Fire Service got it under control, it had burned 843 acres, an area the size of Central Park.

A week later, even as ash still swirled through air heavy with the creosote scent of burned resin and a cedar log smoldered at the edge of a swamp, the forest was being reborn. Pine cones that open only under extreme heat had released their seeds. Though the trees themselves were charred, almost all survived the fire. Where chest-high blueberry and huckleberry had burned down to pointy stubs, tufts of grass were sprouting.

Destructive fires in the West dominated the news this summer, but for eons fire has been not just an inevitable feature of the landscape, but essential to the forest’s health and continuity. In the vast wilderness of the Pine Barrens, the forest regenerates so fast that scientists studying the physics of fire use it as a laboratory.

Eleven weeks after the fire in Penn State Forest, at the height of summer’s greening, new blueberry bushes were already shin high. A grass that flowers only after fire had put forth purple-brown seeds. And scattered all through the fire site, bursts of bright-green pitch-pine needles grew straight out of scorched trunks.

Source: Take a Look at How Quickly a Forest Can Recover From Fire – New York Times, 2018-09-25

Scientists thought they had created the perfect tree. But it became a nightmare.

By Adrian Higgins
A pear seedling selection named Bradford was cloned by the gazillion to become the ubiquitous street tree of America’s postwar suburban expansion. Then it turned invasive.

Carole Bergmann pulls her small parks department SUV into an aging 1980s subdivision in Germantown, Md., and takes me to the edge of an expansive meadow. A dense screen of charcoal-gray trees stands between the open ground and the backyards of several houses. The trees are callery pears, the escaped offspring of landscape specimens and street trees from the neighborhood. With no gardener to guide them, the spindly wildlings form an impenetrable thicket of dark twigs with three-inch thorns.

Bergmann, a field botanist for the Montgomery County Parks Department, extricates herself from the thicket and in the meadow shows me that what I take to be blades of grass are actually shoots of trees, mowed to a few inches high. There are countless thousands, hiding in plain sight in Great Seneca Stream Valley Park. If it were not cut back once a year, the meadow would become like the adjacent screen, wall upon wall, acre upon acre of black-limbed, armored trees worthy of Sleeping Beauty’s castle.

“You can’t mow this once and walk away,” said Bergmann, who began her 25-year career in the department as a forest ecologist but has been consumed by an ever-pressing need to address the escape of the Bradford pear and other variants of callery pear, a species that originated in China, along with other invasive exotics.

Source: Scientists thought they had created the perfect tree. But it became a nightmare. – The Washington Post, 2018-09-17

Loosing the forest for the trees – the tragedy of modern forestry

By Dr. Ranil Senanayake
What is known by science reveals the forest as an ecosystem of tremendous complexity. The trees, while providing the essential framework of a forest constitutes only a fraction of the total biodiversity. It contains a huge array of organisms, that continually change in form and function. Thus biodiversity is what gives a forest its identity. It should also be borne in mind that, from the small bushes of an area after a fire to the tall growth fifty years later, the species and architecture goes through many changes, and all these ecosystems are expressions of the growing, maturing forest.

The international response to the loss of natural forest ecosystems can be seen in the massive global investment in forestry. However, a great majority of these revegetation programs around the world do not seem to provide an environment that is hospitable for sustaining local forest biodiversity. A situation brought about by neglect of the ecological and biodiverse reality of a forest in project planning. There is no excuse to be found in the argument that there was no information. Forest Ecology has a long and distinguished history in the scientific literature. The result of this neglect was that institutional forestry activity was centered around the growing of even aged monocultures of fast growing trees with no requirement to attend to the rehabilitation of forests.

The discussions on the sustainable management of forests still lack clear definitions creating a sense of confusion in the identification of goals. For instance, the inability to distinguish between plantations and forests have allowed processes that have led to a massive reduction of forest biodiversity. A clear definition of ‘a Forest’ needs to be clarified and harmonized in statements transmitted from the CBD to the IPF or the CSD. As forests are biological entities, any criteria or indicator chosen to represent biodiversity status must be rooted in biological variables. The current practices of assessing physical cover alone will not adequately indicate forest quality and trends. In this context, socio-cultural values should also be incorporated into the setting of criteria and indicators. Further, for every acre of forest that stands today, hundreds of acres of forest have been lost in the surrounding countryside. Yet there has been no mention of the need for rehabilitation and recovery of the biodiversity status of such degraded lands. If these fundamental issues are not addressed, the loss of forests and biodiversity in these critical ecosystems cannot be contained.

Source: Loosing the forest for the trees – the tragedy of modern forestry. Forests-Beyond The Wood IV. – The Island, 2018-09-07