By Morgan Erickson-Davis
Nations are hurrying to reduce greenhouse gas emissions and slow global warming, and one way they’re going about this is by encouraging the protection of forests. Trees trap carbon in their biomass and in the soil, and it’s hoped that keeping them in the ground will keep their carbon out of the atmosphere.
Climate-focused forest conservation policies and programs tend to be focused on rainforests. Covering vast areas, rainforests have earned the moniker “lungs of the planet” for their ability to sequester carbon dioxide while producing oxygen.
But pound for pound, other types of forest give rainforests a run for their money. A hectare of mangrove, for instance, can store four times more carbon than can a hectare of rainforest. And now, new research shows that even temperate forests in cities may be able to sequester nearly as much carbon as a similarly sized area of rainforest.
The study was conducted by a team of scientists from University College London, who mapped the carbon stores of areas of tree cover in the London Borough of Camden. Their results were published recently in the journal Carbon Balance and Management.
The team used remotely sensed LiDAR (which stands for “Light Detection and Ranging”) data that provided high-resolution information about tree structure. Armed with specific numbers on the dimensions and extent of Camden’s aboveground biomass (i.e., the parts of trees that aren’t underground), the researchers were able to estimate how much carbon is contained in each pocket of urban forest.
“Urban trees are a vital resource for our cities that people walk past every day,” said lead author Phil Wilkes. “We were able to map the size and shape of every tree in Camden, from forests in large parks to individual trees in back gardens. This not only allows us to measure how much carbon is stored in these trees but also assess other important services they provide such as habitat for birds and insects.”
Their results indicate Camden’s trees contain more carbon than estimated by previous studies. And while, as a whole, the borough’s median carbon density is on the low side when compared to many natural ecosystems – roughly equivalent to subtropical steppe – its urban forests are carbon storage powerhouses. The maximum value they uncovered was in a large, 320-hectare park called Hampstead Heath. There, carbon density approaches that of tropical rainforest.
By Kathleen Masterson
A new University of Vermont study finds that harvesting trees in a way that mimics old growth forests not only restores critical habitat for animals and plants, but also stores a surprising amount of carbon…
The “old growth” engineering technique succeeded in creating diverse habitats. But the kicker, Keeton says, is that it has also allowed the forest to store a significant amount of carbon, much more than several other conventional tree selection harvesting techniques. That’s key to fighting climate change.
Now, forests that are left alone — with no trees harvested — store the most carbon. But Keeton’s study is finding that it is possible to manage the forest to maximize carbon capture, and still keep it a working forest.
“This greater amount of carbon storage as compared to the conventional treatments was actually a combination of having left more trees behind in the first place, and growth rates that were actually 10 percent higher in this treatment as compared to the conventional harvest,” Keeton says. “And that was really surprising.”
Keeton says after 10 years, the old growth forest management plot stored nearly as much carbon as the unlogged control forest. It came within 16 percent of carbon storage in the unharvested plots.
In the Microbial Sciences Building at the University of Wisconsin-Madison, the incredibly efficient eating habits of a fungus-cultivating termite are surprising even to those well acquainted with the insect’s natural gift for turning wood to dust.
According to a study published today (April 17, 2017) in the journal Proceedings of the National Academy of Sciences, when poplar wood undergoes a short, 3.5-hour transit through the gut of the termite, the emerging feces is almost devoid of lignin, the hard and abundant polymer that gives plant cells walls their sturdiness. As lignin is notorious for being difficult to degrade, and remains a costly obstacle for wood processing industries such as biofuels and paper, the termite is the keeper of a highly sought after secret: a natural system for fully breaking down biomass.
“The speed and efficiency with which the termite is breaking down the lignin polymer is totally unexpected,” says John Ralph, a UW-Madison professor of biochemistry, researcher at the Great Lakes Bioenergy Research Center (GLBRC) and lignin expert. “The tantalizing implication is that this gut system holds keys to breaking down lignin using processes that are completely unknown.”
By Scott Miller
New insights into the impact forests have on surface temperature will provide a valuable tool in efforts to mitigate climate change, according to a new research paper co-authored by Clemson University scientist Thomas O’Halloran.
For the first time, scientists have created a global map measuring the cooling effect forests have by regulating the exchange of water and energy between the Earth’s surface and the atmosphere. In many locations, this cooling effect works in concert with forests’ absorption of carbon dioxide. By coupling information from satellites with local data from sensors mounted to research towers extending high above tree canopies, O’Halloran and his collaborators throughout the world have given a much more complete, diagnostic view of the roles forests play in regulating climate.
Their findings have important implications for how and where different types of land cover can be used to mitigate climate change with forest protection programs and data-driven land-use policies. Results of their study were recently published in the journal Nature Climate Change.
By Jennifer Mcnulty
Tropical reforestation is an important part of the global effort to mitigate climate change, but ecologist Karen Holl says current international goals may be overly ambitious.
“The science and practice of restoration are often quite separate, says Holl, an expert in tropical forest restoration. “Scientific research takes place at a small scale, and we’ve rarely tried to integrate results on the broad scale people are talking about. There’s a mismatch between these really big goals and what’s being done on the ground.”
For decades, tropical forests around the world have been cleared to make way for agricultural and wood products, leaving a wake of environmental devastation behind. Tropical deforestation is a significant contributor to climate change, generating 12-15 percent of global carbon emissions.
To turn that around, the international environmental community has embraced ambitious forest restoration goals: Thirty countries have signed on to restore areas equivalent to the size of Venezuela by 2020; participants at the 2014 United Nations Climate Summit set a global target of nearly four times that by 2030.
Given the current scale of scientific research, those goals may be unattainable, warns Holl, who advises nongovernmental organizations (NGOs) and policy makers around the world and recently authored a “Perspectives” column in Science magazine on this topic.
Most scientific studies are done on relatively small plots—typically a few acres—and results are literally rooted in local conditions, making them difficult to scale up to anywhere near the scope of international agreements.
Restoring vast amounts of forest will require major shifts in planning and science, says Holl.
By Rachel Sargent
For many of us, winter in the Northeast means cold temperatures and piles of snow, drifting through forests and across fields. It’s hard to imagine that winter here could be different, but the prospect of climate change has scientists asking just what our winters might look like in the future – and how those changes might influence forest ecology.
At the U.S. Forest Service’s Hubbard Brook Experimental Forest, scientists are thinking about the year 2100. How much warming will occur isn’t certain, but some projections suggest that average air temperatures in our region may increase 5.5 to 9 degrees over the course of this century. The effects are likely to be complex and are difficult to predict, with benefits and costs for different organisms. Some tree species, for example, may benefit from longer and warmer growing seasons, but they may also sustain root damage from more frequent soil freezing.
It may seem counterintuitive that soils would freeze more often during warm winters. The reason is a projected lack of snow. The blanket of snow that usually accumulates during winter insulates the soil below, preventing it from experiencing the full, sub-freezing temperatures of the air. When warmer temperatures leave a thinner blanket of snow, or none at all, the soil is more likely to freeze when cold snaps strike.
Researchers from across Europe, led by University of Limerick (UL), Ireland, have begun a project to produce carbon fiber from forestry by-products.
Carbon fiber is a reinforcement which when added to plastic improves its mechanical properties thereby forming a composite material. Composites are used in many products including automotive parts and wind-turbine blades. However, carbon fiber is currently produced from petroleum which is expensive and detrimental to the environment.
The LIBRE project, led by Dr Maurice Collins of the Stokes Labs, Bernal Institute at UL, aims to create carbon fiber materials in a cost-effective and more environmentally friendly way, by producing them from a naturally derived wood product called ‘lignin’.
“The production of carbon fiber from lignin will allow us to move away from the reliance on fossil fuel,” Dr Collins explained.
A steady increase in sea levels is pushing saltwater into U.S. wetlands, killing trees from Florida as far north as New Jersey. But with sea level projected to rise by as much as six feet this century, the destruction of coastal forests is expected to become a worsening problem worldwide.
RIVERSIDE, Calif. (www.ucr.edu) — Lignocellulosic biomass—plant matter such as corn residues, grasses, straws, and wood chips—is an abundant and sustainable waste product ideal for the production of renewable fuels and chemicals. But breaking down biomass, through a process known as pretreatment, is one of the most expensive and energy-intensive steps in its conversion to renewable products.
In research published recently in the Journal of the American Chemical Society, a team from the U.S. Department of Energy’s (DOE’s) Oak Ridge National Laboratory (ORNL) and the University of California, Riverside (UCR) has now discovered new mechanisms that assist in biomass breakdown during aqueous pretreatment.
The University of Tennessee Institute of Agriculture is participating in a three-year, $3-million grant by the National Science Foundation to develop a user-friendly interface that will help forest scientists everywhere record and share their genomic data for various tree species.