Research in Antarctica's McMurdo Dry Valleys indicates that microbes are a source of organic material
Microbes in streams flowing on the surface of glaciers in the Arctic and Antarctic may represent a previously underestimated source of organic material and be part of an as yet undiscovered "dynamic local carbon cycle," according to a new paper published by researchers supported by the National Science Foundation (NSF).
Research in Antarctica's McMurdo Dry Valleys indicates that microbes are a source of organic material.
Credit: Christine Foreman, Montanan State University
The cycle, they argue, could become a significant global source of carbon as temperatures rise worldwide and microbial activity increases.
An international team of researchers from the United States, Germany and Sweden published their results in the online journal Nature Geoscience.
Previously, scientists thought carbon released into polar streams by glaciers came from ancient organic material locked in the ice, or from newer sources, such as dust and soot blown in from fires and other sources around the world and deposited on the ice surface. Ice melt then releases that carbon into streams, which flow into the sea.
In the new study, researchers on a glacier in the Antarctic examined the ecosystem of a "supraglacial" stream -- one that flows over its surface. Though these streams are among the largest ecosystems on most of the world's glaciers, models of glacial contribution to the global carbon cycle have not previously considered their potential impact.
The researchers found that most of the carbon in the stream was produced by bacteria photosynthesizing -- producing food from sunlight -- rather than ancient carbon.
Although this is an initial study of the phenomenon, the research could indicate that as global temperatures rise, particularly in polar ecosystems, which are more sensitive to high temperatures, the microbial output of carbon could increase.
Although individual glacial streams overall may harbor relatively small amounts of carbon, they are important on a global scale because of their sheer mass and surface area, the authors write. Approximately 11 percent of the Earth's surface is covered in ice, and the polar glacial streams "represent an important component of the global carbon cycle," the authors write.
Because the carbon is easily broken down by the organisms, "it is believed that the impact of this material on downstream ecosystems will be amplified," said Christine Foreman, a researcher at Montana State University and an author on the paper.
The researchers say that additional studies are needed to refine the picture of whether the balance of carbon produced by glaciers is weighted more to release of ancient carbon or production by microorganisms.
The researchers examined a stream on the Cotton Glacier in Antarctica's McMurdo Dry Valleys, where NSF supports a Long-Term Ecological Research (LTER) site. The Dry Valleys are the largest ice-free region in Antarctica, representing roughly 2 percent of the surface area of a continent the size of the U.S. and Mexico combined. High winds scour snow and ice from the valleys, creating a landscape that resembles the arid U.S. Southwest, but without any vegetation.
Out of a national network of 28 LTER sites, NSF supports two sites in Antarctica: McMurdo Dry Valleys and Palmer Antarctica.
Diane McKnight, a program officer at NSF, and Foreman are both authors on the paper and associated with the McMurdo Dry Valleys LTER science team. McKnight's NSF award concluded prior to her becoming a program officer.
Through its Office of Polar Programs (OPP), NSF also manages the U.S. Antarctic Program, which coordinates all U.S. research on the southernmost continent. OPP supported the McMurdo Dry Valleys research through a grant and collaborative award, while NSF's Division of Graduate Education supported Foreman through an Integrative Graduate Education and Research Traineeship award.
Peter West | EurekAlert!
Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter
16.08.2018 | National Science Foundation
Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide
15.08.2018 | University of Washington
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
20.08.2018 | Information Technology
20.08.2018 | Life Sciences
20.08.2018 | Information Technology