CapeCod.com - MBL Scientists Study Impact on Nitrate in Salt Marshes

Posted 6 days, 17 hours ago @

Great Sippewissett Marsh in Falmouth. Salt marshes store carbon at higher rates than in ecosystems on land. Photo: Daniel Buckley

WOODS HOLE – Scientists at the Marine Biological Laboratory have studied salt marshes and concluded that nitrate, a common coastal water pollutant, stimulates the decomposition of organic matter in these marshes.

The matter would normally have remained stable over a long period of time.

The increase of decomposition might alter the salt marshes’ carbon capacity due to the release of carbon dioxide. Normally, salt marshes storing carbon could offset effects of climate change due to carbon dioxide building up in the atmosphere.

The study was led by scientists from the MBL in Woods Hole and Northeastern University. It was published in Global Change Biology.

The research team is now looking to analyze the microbial that has decreased the carbon build up in salt marshes.

Author: Brendan Patrick

Originally published in CapeCod.com

Salt Marshes' Capacity to Store Carbon may be Threatened by Nitrogen Pollution

Posted 3 weeks, 2 days ago @
Salt marshes sequester carbon at rates more than an order of magnitude greater than their terrestrial counterparts. Core samples for this study where taken from this marsh in Rowley, Mass., part of the Plum Island Ecosystems NSF-LTER site. Credit: Aber, Aber, and Valentine 2009.

Salt marshes sequester carbon at rates more than an order of magnitude greater than their terrestrial counterparts. Core samples for this study where taken from this marsh in Rowley, Mass., part of the Plum Island Ecosystems NSF-LTER site. Credit: Aber, Aber, and Valentine 2009.

Deep in the waterlogged peat of salt marshes, carbon is stored at much greater rates than in land ecosystems, serving as an offset to climate change due to carbon dioxide (CO2) build-up in the atmosphere.

However, a new study indicates that a common pollutant of coastal waters, nitrate, stimulates the decomposition of organic matter in salt marsh sediments that normally would have remained stable over long periods of time. This increase in decomposition, which releases CO2, could alter the capacity of salt marshes to sequester carbon over the long term. The study, led by scientists at the Marine Biological Laboratory (MBL), Woods Hole, and Northeastern University, is published in Global Change Biology.

“Traditionally, we have viewed salt marshes as resilient to nitrogen pollution, because the microbes there remove much of the nitrogen as gas through a process called denitrification,” writes first author Ashley Bulseco, a postdoctoral scientist at the MBL.

“But this research suggests that when nitrate is abundant, a change occurs in the microbial community in salt marsh sediments that increases the microbes’ capacity to degrade organic matter. This potentially reduces the ability of the marsh to store carbon,” Bulseco writes.

Ashley Bulseco, pictured, and team used a controlled flow-through reactor experiment to determine how nitrate affected organic matter decomposition and microbial community structure in salt marsh sediments. Credit: MBL Ecosystems Center

Ashley Bulseco, pictured, and co-authors used a controlled flow-through reactor experiment to determine how nitrate affected organic matter decomposition and microbial community structure in salt marsh sediments. Credit: MBL Ecosystems Center

As global temperatures continue to rise, a number of carbon capture strategies have been proposed, including sequestering CO2 in “blue carbon” habitats such as salt marshes, mangroves and seagrass meadows. However, coastal nitrogen pollution is also still rising in many areas due to agricultural and urban runoff, and sewage.

“Given the extent of nitrogen loading along our coastlines, it is imperative that we better understand the resilience of salt marsh systems to nitrate, especially if we hope to rely on salt marshes and other blue carbon systems for long-term carbon storage,” the authors write.

The next phase of this research, already in progress, is to analyze the microbial community responsible for degrading carbon in a salt marsh ecosystems, especially when exposed to high concentrations of nitrate.

Among Bulseco’s co-authors are Jennifer Bowen, professor of marine and environmental sciences at Northeastern University, and Anne Giblin, director of the Ecosystems Center at the MBL, who were her PhD advisors.

Citation:

Ashley N. Bulseco et al (2019) Nitrate addition stimulates microbial decomposition of organic matter in salt marsh sediments. Global Change Biology, DOI: 10.1111/gcb.14726

Originally published in The Well.

Team Explores the Recovery, Resilience of a Stressed Salt Marsh

July 29th, 2019 @

Day in and day out for 13 years, scientists slowly dripped fertilizers into a pristine section of salt marsh north of Boston. They were simulating, in a controlled experiment, the pollution that marshes in densely Team Explores the Recovery, Resilience of a Stressed Salt Marshpopulated areas receive from sewage, lawn fertilizer, and other human sources.

By the time they stopped dripping the nutrients — nitrogen and phosphorus — in 2016, they had observed changes in the marsh’s plant and animal community and even in its physical structure.

The creek banks had begun to crack and slump down, indicating that the over the long term, nutrient pollution could be a factor in converting “a vegetated marsh into a mudflat, which is a much less productive ecosystem,” said MBL Fellow Linda Deegan, lead investigator of the project at the Plum Island Ecosystems Long-Term Ecological Research Site (PIE-LTER).

Losses of healthy salt marsh have accelerated in recent decades, with some losses caused by sea-level rise and development. “Salt marshes are a critical interface between the land and sea,” Deegan said. “They provide habitat for fish, birds, and shellfish; protect coastal cities from storms; and take nutrients out of water coming from upland areas, which protects coastal bays from pollution.”

Now, the team wants to know, “Will this marsh be able to recover?” Buoyed by a new, three-year grant from the National Science Foundation, they are watching how the marsh is responding now that the nutrient addition has stopped.

Nutrient addition over 13 years led to cracking and slumping of creek banks in the experimental site. Now, the TIDE team is studying how the salt marsh responds to a reduced nutrient load. Credit: Shanna Baker, MBL Logan Science Journalism Program

“We want to see how microbes, plants and animals respond to a decrease in nutrients,” said Anne Giblin, who directs the MBL Ecosystems Center as well as the PIE-LTER. “We will also see if the changes in the marsh’s physical structure that we observed after fertilization began will continue in the same direction, or reverse course.”

This marks the latest phase in the ecosystem-scale TIDE Project, which began in 2002. The scientists now hope to illuminate “the legacy effects of stress-induced changes (genotypic to landscape) on ecosystem recovery, and the limits of landscape resilience.”

Giblin received this collaborative NSF grant with Deegan, a senior scientist at Woods Hole Research Center, and James A. Nelson, assistant professor at University of Louisiana.

Top photo: Lush cordgrass (Spartina patens) at a salt marsh in Ipswich, Mass., part of the Plum Island Ecosystems study site. Credit: David S. Johnson, TIDE Project

Originally published in: The Well: MBL News from the Source

Scientists Urge Formation of National Network to Accelerate Climate Change Action

April 4th, 2019 @

A non-federal network that will leverage science to manage climate change risks in the United States is urgently needed, recommends a report released today by a group of 36 climate researchers, state/local/tribal officials, and other experts including Jerry Melillo, Distinguished Scientist at the Marine Biological Laboratory (MBL) and former chairman of the U.S. National Climate Assessments.

An early online version of the report, “Evaluating Knowledge to Support Climate Action,” is published today by the Bulletin of the American Meteorological Society. The report summary and a full press release are available here.

The report’s key recommendations are to establish a non-federal network to assess how to apply science in making and implementing decisions; focus these assessments on the common problems and challenges that climate risk managers face; and use new methods such as artificial intelligence to support climate risk management.

“This network will build off the U.S. National Climate Assessments to help communities establish pragmatic, science-based actions and pathways to manage the climate risks that are specific to their region,” said Melillo.

To provide interim leadership for this national network, the group also announced today the establishment of the Science for Climate Action Network (SCAN), which will coordinate preparation of a next-generation of climate assessments and serve as a backbone organization for groups that already are beginning to incorporate climate science in their work.

In 2016, a Federal Advisory Committee was convened to recommend how to increase the application of the National Climate Assessments to inform action. This committee was disbanded by the Trump Administration in 2017, but members and additional experts reconvened as the Independent Advisory Committee to complete the present report.

by Diana Kenney

Originally posted on The Well

 

Rooted in research: A study looks at effects of climate change on a less visible matter

January 15th, 2019 @

Global warming brings to mind scenes of devastating natural disasters and polar bears on shrinking ice caps. But new research is studying the effects of climate change on a less visible matter — interactions between plant roots and the surrounding soil, particularly relative to carbon.

The results of the study could shed light on global warming’s influence on food production and carbon storage.

“This is the frontier of what we don’t understand,” said Marco Keiluweit, a biogeochemist and assistant professor at the University of Massachusetts Amherst. “It will give us the opportunity to explore these broader problems of climate change.”

Full article by Ysabelle Kempe, Globe Correspondent, available on BostonGlobe.com

Team Studies how Viral Infections in Plants may Affect Carbon Storage in Soil

January 9th, 2019 @

Photo illustration by Zoe Cardon

MBL Senior Scientist Zoe Cardon has received a collaborative grant from the Department of Energy to study how viral infections in plants can affect the fate of the largest pool of organic carbon stored in soils: organic carbon bound to minerals.

As carbon dioxide (CO2) concentrations in the atmosphere continue to rise, driving further climate change, it becomes more and more urgent to understand how plant roots, soil microbes, and soil minerals interact to control whether soils store carbon or release CO2.

One way that plant roots strongly contribute to soil carbon storage is by producing sugars, organic acids, and even whole cells that are lost to soil. But there is a twist in the story. Certain types of compounds derived from roots may also destabilize the bonds between soil  minerals and existing soil organic matter (SOM), making that SOM more vulnerable to microbial attack and decomposition. Soil carbon loss, instead of storage, may result.

The question then becomes what types of compounds, and how much of them, are lost from plant roots to soils. Cardon and colleagues have found that, upon infection with particular plant viruses, plant roots can lose so many compounds to their surroundings that they become literally “sticky” to the touch. Understanding whether and how these “sticky roots” drive increased decomposition of existing mineral-stabilized soil carbon promises to transform our understanding of the importance of common virus infection for soil carbon dynamics and global change.

Co-principal investigators with Cardon, the lead principal investigator on this project, include Marco Keiluweit, University of Massachusetts, Amherst; Carolyn Malmstrom, Michigan State University; and William J Riley, Lawrence Berkeley National Laboratory.

 

Originally published in The Well

Improving Predictions of Soil Microbe Responses to Global Change

November 27th, 2018 @

In most soil microbial communities, the controls on growth and metabolism are poorly understood and are simply too complex to be included in computer models of climate, soil fertility for agriculture, or waste Improving Predictions of Soil Microbe Responses to Global Changemanagement.

To determine the principles by which soil microbial communities function under varying environmental constraints, development of a scalable biogeochemical modeling approach is critical.

In a new collaborative project funded by the National Science Foundation (NSF), MBL Senior Scientists Joe Vallino and Zoe Cardon will develop a flexible framework for analyzing microbial biogeochemistry from the perspective of maximum entropy production (MEP) (a concept that proposes complex systems will likely organize to maximize dissipation of useful energy).

The work takes advantage of the high diversity of microbial communities to enable thermodynamically based predictions about system-level biogeochemical responses to global change.

Ultimately, the goal is to integrate sensor-derived information of soil properties with the MEP model to predict shifting activities of microbial communities in soils using far fewer model parameters than would be required with conventional modeling. The project will also support undergraduate research activities as part of the MBL’s Semester in Environmental Science program.

This grant is through the NSF’s “Signals in the Soil” program.

Caption: Example of a simplified soil metabolic network model representing the conversion of soil organic matter (SOM) to methane (CH4) or carbon dioxide (CO2) overlaying an image of methanogens stained with SYBR green. Credit: Joe Vallino and Zoe Cardon

Originally Posted in The Well.

Five Reasons the Earth’s Climate Depends on Forests | Climate and Land Use Alliance

October 10th, 2018 @
MBL Distinguished Scientist Jerry Melillo and MBL Fellow Robert Howarth of Cornell University are among the 40 signatories to this statement issued by the Climate and Land Use Alliance.

Statement from Scientist SignatoriesFive Reasons the Earth’s Climate Depends on Forests | Climate and Land Use Alliance

“The Intergovernmental Panel on Climate Change (IPCC) will issue a new report soon on the impacts of 1.5°C of global warming. Limiting average temperature rise to 1.5°C requires both drastic reduction of carbon dioxide (CO2) emissions and removing excess carbon dioxide from the atmosphere. While high-tech carbon dioxide removal solutions are under development, the “natural technology” of forests is currently the only proven means of removing and storing atmospheric CO2 at a scale that can meaningfully contribute to achieving carbon balance.

In advance of the IPCC report, we highlight five often overlooked reasons why limiting global warming requires protecting and sustainably managing the forests we have, and restoring the forests we’ve lost. Read more …

Source: Five Reasons the Earth’s Climate Depends on Forests – Climate and Land Use Alliance

Long-Term Study of Oil Spill Impacts in Gulf of Mexico is Renewed

October 10th, 2018 @

Anne Giblin, Interim Director of the MBL Ecosystems Center, has received funding for a study on “Oil Spills as Stressors in Coastal Marshes: The Legacy and the Future.”

Long-Term Study of Oil Spill Impacts in Gulf of Mexico is Renewed

The grant is a sub-award from the Louisiana Universities Marine Consortium (LUMCON), which has been tracking the effects of the Deepwater Horizon oil rig explosion in the Gulf of Mexico in 2010. This accident caused the largest offshore oil spill in U.S. history and caused extensive damage to the habitats along the Gulf Coast.

Giblin’s research will focus on understanding the impact of oil on plant production and biogeochemical cycles in Gulf of Mexico marshes, including in controlled experiment areas being subjected to several levels of oiling.

LUMCON, which partners with numerous ecosystems scientists from across the country, has been studying the impacts of Deepwater Horizon for seven years. This continuing award from the Gulf of Mexico Research Initiative will allow the team to complete aspects of experiments and synthesize the impacts of the Deepwater Horizon spill on coastal Louisiana communities, including topics such as:

  • possible linkages between oil contaminants and shoreline erosion
  • changes to coastal vegetation
  • differences in greenhouse gas emissions from coastal ecosystems
  • changes in carbon flows through wetland food webs
  • constructing computer models of how post-spill oil moved through localized sections of the Gulf Coast, and
  • testing the impacts of oil on Gulf Coast marshes using controlled experiments.

Photo: Sediment in the Gulf of Mexico. Credit: MODIS Satellite Image – NASA

Originally published in The Well: MBL News from the Source

MBL Team to Assess How Managing Forests May Reduce Nitrogen Load to Cape Cod Waters

August 21st, 2018 @

MBL Ecosystems Center scientists Ivan Valiela and Javier Lloret have received a grant to quantify the potential of forested land cover management to reduce nitrogen loads in several Cape Cod watersheds. This subaward is from the U.S. Geological Survey via the University of Massachusetts Water Resources Research Center.

MBL Team to Assess How Managing Forests May Reduce Nitrogen Load to Cape Cod Waters

To protect the quality of fresh and estuarine waters, the Commonwealth of Massachusetts has issued regulations requiring reductions of nitrogen loads in every coastal municipality. The cost of updating conventional sewage treatment plants is currently prohibitive, so there is growing interest in assessing alternative options for controlling nitrogen loads. The Cape Cod Commission has assumed a leading role in compiling information on assessing and applying alternative options, and in transferring that information to a variety of stakeholders by creating a Technologies Matrix database.

With this award, Valiela and Lloret will develop a section of the Cape Cod Commission Technologies Matrix on land cover management as an option for controlling nitrogen loads. To carry this out, they will model nitrogen inputs to several Cape Cod watersheds with different degrees of forest cover. They will quantify decadal trajectories of forest cover and associated nitrogen retention; partition retention of nitrogen in forests and other land covers; and test whether degree of urban development, decreases in atmospheric nitrogen deposition, lag effects during transit through the watersheds, and land cover configuration alter nitrogen retention within forests.

This grant is a collaboration with Heather McElroy and Anne Reynolds of the Cape Cod Commission.

Photo: Waquoit Bay, Falmouth, Mass., one of the Cape Cod watersheds under study. Credit: Javier Lloret

Story originally published on The Well


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