Climate Change

...now browsing by category

 

Surprising Tree Emissions Show Forests Consume Less Methane Than Thought

Tuesday, May 9th, 2017

by Ryan Greene

White chambers attached to tree trunks. Multi-colored tubes run from the chambers to a black box in the undergrowth.

Methane flux chambers keep track of how much methane a tree trunk releases or consumes. Credit: Pat Megonigal/SERC

Rainbow-colored tubes snake through the undergrowth. White acrylic chambers sit mounted to tree trunks like giant bleached snails. At first glance, it’s not quite clear what the heck is going on. Cryptic as it may seem, these tubes and chambers are the key to a recent study showing that trees in upland forests are capable of emitting the planet-warming greenhouse gas, methane.

Scientists have long considered upland forests to be methane sinks due to the presence of methane-hungry microbes called methanotrophs in their soils. But new research by Pat Megonigal, an ecosystem ecologist who heads up the Biogeochemistry Lab at the Smithsonian Environmental Research Center (SERC), and Scott Pitz, a graduate student from Johns Hopkins, has shown that when it comes to upland forest methane cycling, soil isn’t the only game in town. Trees and their emissions are part of the equation too.

In a recently published study in New Phytologist, Megonigal and Pitz found that trees in upland forests are actually capable of emitting methane through their trunks. This means that some of the methane absorbed by methanotrophs in the forest soils may be offset by tree emissions.

Why, though, does any of this even matter?

When researchers think about global climate change, they need to think about heat-trapping greenhouse gases like carbon dioxide (CO2) and methane (CH4). Specifically, they’ve got to track these gases to see where they’re coming from (their sources) and where they’re getting stored (their sinks). Carbon dioxide receives much of the spotlight (and rightfully so, given its enormous impact on the global climate), but it’s also critical to keep an eye on methane. Although methane stays in the atmosphere for far less time than carbon dioxide, it’s capable of trapping up to 45 times more heat. In other words, methane is a big deal. If temperate forests are consuming less of it than we thought, as Megonigal and Pitz’s research suggests, that could be a big deal too. Click to continue »

Ten Reasons We’re Earth Optimists After 2016

Friday, January 13th, 2017
Dawn Miller in forest

Ecologist Dawn Miller surveys trees in a SERC forest. (SERC)

by Kristen Minogue

The Smithsonian has a new resolution for 2017: Earth Optimism. This is the year the Smithsonian is celebrating environmental success stories, and shifting the focus to how we can fight battles to save species and preserve our planet—and win. Despite breaking a wide swath of climate records, 2016 gave us reasons for optimism as well. In our 2016 Year in Review, we’ve pulled out the most encouraging stories and discoveries at the Smithsonian Environmental Research Center from the previous year. Here are the top 10 that make us hopeful about the planet’s future:

Click to continue »

Jekyll or Hyde? The Many Faces of Phragmites

Friday, December 16th, 2016

by Kristen Minogue

Scientist beside a Phragmites experiment on the water.

Pat Megonigal studies the invasive reed Phragmites australis on the Smithsonian’s Global Change Research Wetland.
(Tom Mozdzer)

It’s easy to dislike Phragmites. The invasive brown reed can grow over 15 feet tall and tends to crowd out anything in its shadow. But in the story of global change, Phragmites is a gray character, like Mad Men’s Don Draper, or the enigmatic Professor Snape. Beneath the surface, Phragmites australis—a European reed sweeping over East Coast wetlands—can empower wetlands to grow higher soils and possibly survive rising seas. Biogeochemist Pat Megonigal of the Smithsonian Environmental Research Center (SERC) prefers an analogy from classic literature: Jekyll and Hyde.

“The Jekyll part is that Phragmites helps marshes maintain elevation and keep pace with sea level rise,” he said. “The Hyde part is that they are poor habitat for native plants and animals.”

The latest discovery in Megonigal’s lab could tip things in favor of Mr. Hyde. Phragmites’ deep-growing roots were once thought an advantage that helps wetlands build soil. But those same roots could be disturbing ancient soils deep underground—triggering them to release planet-warming carbon dioxide (CO2).

Click to continue »

When the Going Gets Tough, Baby Oysters Get Growing

Friday, September 23rd, 2016

by Kristen Minogue

Andrew Keppel

Andrew Keppel (Credit: Rebecca Burrell/SERC)

Baby oysters are a lot stronger than they look. Living mainly in shallow coastal waters, where oxygen plummets and acidity spikes on a nightly basis, building a decent shell should be a challenge. But after a couple of weeks, young oysters are often able to adjust to the harsh conditions—and, sometimes, even grow more quickly to make up for lost time.

The discovery came from a team of marine ecologists at the Smithsonian Environmental Research Center (SERC), who published the new study in the journal PLOS ONE.

“It’s really impressive what these oysters are able to do in terms of acclimating to potentially harmful conditions,” said lead author Andrew Keppel, who worked on the project as a graduate student and later technician in SERC’s Marine Ecology Lab, before becoming an oceanography lab manager at the U.S. Naval Academy. Click to continue »

Students ASSEMBLE! How comics can help with science learning

Wednesday, September 14th, 2016
Student learning science from science comic

Student learning science with Balliett’s comic

by Heather Soulen

Middle school can be a tough and unforgiving rite of passage, filled with raging hormones, ill-fitting highwater pants, voices akin to trumpet-wielding geese, and a multitude of distractions. Trying to learn while being swept up in puberty’s turbulence can be challenging. Equally challenging is trying to teach science to often-distracted tweens and teens. Right now, as most U.S. schools begin a new school year, some science educators might be looking for ways to engage their middle-school students with science. One science educator suggests meeting them where their interests lie – comics.

Click to continue »

Unsolved Mysteries: Rising Temps, Falling Marshes?

Thursday, September 8th, 2016
Scientist holds fistful of soil

SERC biogeochemist Pat Megonigal holds up soil from a marsh in Costa Rica. Marsh soils store vast amounts of carbon, but as temperatures warm, microbes in the soil could release into the atmosphere. (SERC)

by Kristen Minogue

All over the world, marshes are hanging in a precarious balance. Rising temperatures from climate change could help them grow stronger and store more carbon—or cause them to flood and disappear, says a new article from the Smithsonian Environmental Research Center (SERC). To find answers, scientists need to look underground.

The article is part of a much larger report on the future of warming oceans, released Monday at the International Union for Conservation of Nature’s annual conference. Tidal marshes sit right on the boundary of the land and the ocean. For humanity, marshes act as Mother Nature’s guardians. They provide habitat for fish and shellfish, filter out pollution in estuarine water, and help shield homes along the coast from flooding. They’re also hot spots of carbon storage, burying carbon 10 times faster than an equal area of forest. Yet much of their fate remains a mystery.  Click to continue »

Sink or Swim? Divining the Fate of Life-Giving Wetlands

Friday, August 12th, 2016

By Emily Li

You might have heard of The Giving Tree, a children’s picture book by Shel Silverstein about a boy and a tree. As the boy grew, he began to want more from the tree, and the tree happily gave and gave and gave: her apples, her branches, and even her trunk. While Silverstein’s heartbreaking story was a fiction, the plot is happening in wetlands around the world—and this time, it’s for real. Marshes improve water quality, mitigate hurricane damage, sequester atmospheric carbon, and serve as ideal habitats and nurseries for wildlife. In return, as sea levels rise, they’re in line to be the first casualties.

SERC intern Jefferson Riera shows off his sunburn.

SERC intern Jefferson Riera shows off his sunburn after a day in the field. (Photo: Emily Li/SERC)

That said, marshes are hardly a serene paradise. To Smithsonian Environmental Research Center intern Jefferson Riera, wetlands are ruined shoes caked in mud. Wetlands are wasp stings on his lips. Wetlands are spider webs of scratches from marsh vegetation. Wetlands are sunburns so severe his skin doesn’t match itself anymore.

And yet, he knows that they’re worth protecting. That’s why he, and the rest of SERC’s Ecological Modeling Lab, are working to develop a baseline understanding of local marsh elevation to educate policymakers on the state of wetlands—before their fates are sealed by the sea.

Click to continue »

An Acid Test for the Coasts

Monday, August 1st, 2016
Graham cleans her equipment of marine organisms

SERC intern Jasmin Graham cleans her equipment of marine organisms (Photo: Emily Li/SERC)

by Emily Li

Watching educational programs like Animal Planet or That’s My Baby—a series that documents pregnant animals—might evoke memories of flickering classroom projectors for most. But for Jasmin Graham, an intern with the Smithsonian Environmental Research Center (SERC), these shows were her childhood. Her love for marine science and wildlife followed her through high school science fairs and university research on shark genetics at the College of Charleston. Now, at an internship with SERC’s Ocean Acidification Lab, she studies acidification not in the open ocean, but in a far more dramatic arena, where the marine celebrities she grew up with may be at risk.

Click to continue »

How Clay Caterpillars Help Unlock Biodiversity’s Secrets

Friday, July 22nd, 2016
Anna Nordseth surveys clay caterpillars for damage in BiodiversiTREE plot

Anna Nordseth surveys clay caterpillars for predation damage in BiodiversiTREE plot (Credit: Emily Li/SERC)

by Emily Li

Anna Nordseth, a summer intern for the Smithsonian Environmental Research Center’s Terrestrial Ecology Lab, wasn’t surprised to be taking work home the first week and a half of her internship. What she wasn’t expecting was to be making nearly a thousand clay caterpillars.

Each caterpillar began life as a half gram of green clay, with a wire spine and ends rolled into a worm-like silhouette. By the time Nordseth had finished—several podcasts and three seasons of House of Cards later—she had 900 caterpillars and the hand cramps to prove it. But she was ready to begin her research.

Click to continue »

Climate Change Could Release Ancient Soil Carbon

Friday, July 1st, 2016

by Kristen Minogue

Blanca with soil core

Blanca Bernal extracts a soil core from a SERC marsh. (Credit: SERC)

Just beneath our feet, there’s a slumbering pool of carbon that has largely been ignored.

Earth’s deep soils store vast reservoirs of carbon centuries to millennia old. Left undisturbed, they can store that carbon for thousands of years longer. But if triggered, those reservoirs could release carbon dioxide (CO2) into the atmosphere, a team of scientists discovered in a new study from the Smithsonian Environmental Research Center.

Click to continue »