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Hunt for a Missing Nutrient: Part III

Wednesday, February 3rd, 2016

by Kristen Minogue

Image: Tom Jordan beside a V-shaped weir that tracks nutrients in a SERC stream. (SERC)

Tom Jordan beside a V-shaped weir that tracks nutrients in a SERC stream. (SERC)

For years, a team of scientists has been trying to solve a mysterious disappearance at a drainage ditch on the Choptank River Basin, on Maryland’s eastern shore. Every year roughly 32,000 pounds of human-generated nitrogen enters the ditch’s watershed, from fertilizers, air pollution and other sources. But less than a third of that nitrogen typically flows out of the stream.

Tom Jordan has seen it before. A nutrient ecologist at the Smithsonian Environmental Research Center (SERC), Jordan has wrestled with the mystery of the missing nitrogen for more than twenty years.

“It feels like a sort of fatal attraction,” Jordan said. Two decades of trial and error and dead ends only fueled his determination find answers. Now, according to a new January study, Jordan and his colleagues finally have some.

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Phragmites vs. Climate Change: Invasive Reed Better at Taking Up Carbon

Tuesday, December 22nd, 2015

by Kristen Minogue

Image: Josh Caplan holds Phragmites. (Credit: Tom Mozdzer)

Ecologist and lead author Josh Caplan holds a Phragmites plant at the Global Change Research Marsh. Invasive Phragmites can grow up to 15 feet tall. (Thomas Mozdzer)

One of the Chesapeake’s least favorite invaders could end up being an unlikely savior. The invasive reed Phragmites australis, a plant that has exploded across Chesapeake wetlands in the last few decades, is also making those wetlands better at soaking up carbon, ecologists from the Smithsonian Environmental Research Center (SERC) and Bryn Mawr College discovered in a new study.

The common reed, better known as Phragmites australis, grows in dense clusters up to 15 feet tall. North America has several native strains that have co-existed peacefully with many other native plants for at least 30,000 years. It is the invasive strain that arrived from Eurasia in the 1800s that has scientists and environmental managers worried. Eurasian Phragmites grows taller and denser than North American Phragmites, crowding out many smaller plants, and blocking access to light and nutrients. These changes in plant community have a ripple effect on animals that rely on wetlands for habitat.

“The fish communities, the insect communities, the soil and invertebrate communities, all these things change when Phragmites comes in,” says lead author Josh Caplan, a Bryn Mawr postdoc and visiting scientist at SERC. Often, those changes aren’t for the better. “Phragmites is doing a number to these ecosystems.” Click to continue »

Remembering Hurricane Katrina by Studying Marshes of the Future

Friday, August 28th, 2015

by Heather Soulen

The Need for Healthy Marshes

Ten years ago, on August 28, 2005, Hurricane Katrina nicked south Florida and entered the heat-charged waters of the Gulf of Mexico, transforming from a Category 1 hurricane into a super-charged Category 5. In the early morning hours of August 29, it ripped through Louisiana and Mississippi. Thousands died, and hundreds of thousands of homes and businesses were destroyed. Today, much of the Louisiana and Mississippi coasts, and its people, are still recovering from the devastation.

When Katrina hit, some coastal marshes east of the Mississippi River lost approximately 25 percent of their area. In the decade that followed, salt marshes and wetlands in Louisiana have continued to disappear in some places, but not others. The scientific community soon zeroed in on keeping marshes healthy, since, as one scientist remarked “A healthy marsh is pretty resilient, A stressed marsh – storms will physically break the marsh down.” Marshes and wetlands are ecologically and economically important ecosystems. During storms they act like buffers, reducing storm surge and flood damage, but only if they’re healthy. The question is, what factors make a marsh strong or weak?
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Why 900 Years of Ancient Oysters Went Missing

Friday, August 29th, 2014

by Kristen Minogue

Piscataway Indians lived on the Rhode River up to colonial times, though anthropologists believe they used the land for temporary campsites, not permanent settlements.

Piscataway Indians lived on the Rhode River up to colonial times, though anthropologists believe they used the land for temporary campsites, not permanent settlements.

For more than 10,000 years, Native Americans hunted and fished in the Chesapeake. Broken pottery, village sites, burial grounds and other artifacts bear witness to their near-continuous presence around the Bay. But one type of artifact—ancient trash piles called shell middens—hasn’t received as much attention. And these tell another important story.

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Marshes: Pollution Sponges of the Future

Thursday, August 21st, 2014

by Melissa Pastore, biology graduate student at Villanova University

Image: Melissa Pastore in a marsh near Delaware Bay. (Credit: Lori Sutter)

Melissa Pastore in a marsh near Delaware Bay.
(Lori Sutter)

What if we could create a giant sponge capable of soaking up nitrogen pollution? It turns out that the Chesapeake Bay, which has experienced a rapid increase in nitrogen pollution from municipal and agricultural sources over the last few decades, already contains a natural version of this sponge: marshes fringing the Bay. But global change—and the nitrogen pollution itself—could change how this natural sponge operates.

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Using Computer Models to Help Rescue Bay’s Underwater Flora

Thursday, July 17th, 2014

By Sarah Hansen

SERC intern Bridget Smith, immersed in a sea of environmental data.

SERC intern Bridget Smith, immersed in a sea of environmental data. (SERC)

Underwater plants like sea grasses provide habitat and feeding areas for a wide range of aquatic life.  They also help filter the water and put the brakes on erosion.   But in Chesapeake Bay, the coverage of underwater plants, or submerged aquatic vegetation (SAV), has been low for decades, and restoration attempts have had mixed results.  That’s why this summer, Smithsonian Environmental Research Center intern Bridget Smith is grappling with 28 years of data to explore which of a host of factors affects SAV in the Bay and how.

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How much could streamside forests reduce nitrogen pollution in the Bay?

Monday, June 23rd, 2014

by Sarah Hansen

Chester_river_queen_annes_co_md

A buffer on the Chester River in Queen Anne’s County, MD protects the river from nitrogen pollution. (USDA)

Nitrogen pollution in the Chesapeake Bay became a serious concern in the mid-20th century after the advent of nitrogen-rich chemical fertilizers. Bay restoration efforts have reduced nitrogen pollution somewhat, but achieving healthy nitrogen levels in the Bay is still a long way off. Croplands remain an important source of the nitrogen that pollutes Chesapeake Bay.

Don Weller, senior scientist at the Smithsonian Environmental Research Center, and his colleague Matthew Baker, associate professor of geography and environmental systems at the University of Maryland, Baltimore County, report in a new study that just over half the nitrogen from croplands might never reach the Bay—if all crop fields were protected by streamside forests and wetlands.

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Intern Logs: A Bloody Welcome

Tuesday, June 17th, 2014

by Dejeanne Doublet, terrestrial ecology intern

Photo: Dejeanne Doublet inspects a red oak in BiodiversiTree. (Credit: SERC)

Dejeanne Doublet inspects a red oak in BiodiversiTree. (SERC)

Ecological research usually doesn’t evoke thoughts of Stephen King horror movie scenes. Working with plants and animals in the open air shouldn’t provoke nightmares of being drenched in blood. Green is a very different color from red.

However, fellow intern Megan Palmer and I learned on our first week that sometimes, just sometimes, Stephen King references are the best way to describe a day’s work in the field. During our first days at the Smithsonian Environmental Research Center, Palmer and I were asked to do something that made my non-red-meat-eating stomach turn.

“Go spray pig’s blood on all our trees,” Dr. John Parker, the lead terrestrial ecology scientist and our boss told us during one of our first meetings with him. He was referring to the 24,000 tree saplings planted last summer as part of a 100-year experiment on biodiversity, fittingly called BiodiversiTree.

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Learning by Digging: Archeology Project Explores Colonial Life

Tuesday, June 10th, 2014

Scientists, students, and volunteers unearth late 17th– and 18th-century objects behind Sellman House

by Sarah Hansen

Volunteers excavate a new pit at the “Shaw’s Folly” site behind Sellman House.

On a sunny June afternoon at the Smithsonian Environmental Research Center, students and volunteers are hard at work in a cornfield behind the Sellman House.  Some shovel soil out of pits.  Others screen it with giant sieves, looking for artifacts.  Still others use trowels to smooth the bottom and sides of the pit, hoping to reveal differences in soil coloration and texture.  This scene will repeat every Monday, Tuesday, and Friday from about 9a.m. to 4 p.m. until June 20.  Guided by Laura Cripps, acting Chair of Social and Cultural Sciences at Howard Community College, and Jim Gibb, head of SERC’s Archaeology Lab, the group is excavating a site that contains objects and building materials that provide a window into 17th– and 18th-century life.

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What’s Hurting the Chesapeake’s Underwater Plants?

Monday, May 5th, 2014

by Kristen Minogue

Photo: A flounder in a bed of eelgrass. (NOAA)

A flounder in a bed of eelgrass. Seagrasses and other underwater plants provide food and shelter to many iconic Bay creatures, including blue crabs. (NOAA)

It’s been a difficult century for the submerged flora of Chesapeake Bay.

In the 1930s, wasting disease nearly wiped out the eelgrasses of the North Atlantic. In the ‘50s and ‘60s, they faced onslaughts from invasive grasses like water chestnut and Eurasian milfoil. Finally, in the summer of 1972, Hurricane Agnes pummeled underwater plants to the lowest levels ever reported in the Bay. This April, they received news that, at first glance, seemed positive: Submerged grasses rose 24 percent between 2012 and 2013, according to aerial surveys of the Chesapeake Bay Program.

But those increases were largely limited to a single species: widgeon grass, a plant known for wild fluctuations. At 60,000 acres total, submerged plants still didn’t come near a recent mini-peak in 2002, they’re a far cry from the ultimate goal of 185,000 acres across the Bay. What is holding them back? And—more importantly—how we can we help ensure the latest expansion isn’t just a blip?

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