Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Through Microbes, Nitrogen Alters Soil Carbon Cycle

19.07.2010
Soil scientists studying bacterial communities in hardwood forests have found evidence that extra human-derived nitrogen deposited from the atmosphere can change the composition of the soil microbial community, with implications for carbon cycling and sequestration.

Don Zak and Sarah Eisenlord from the University of Michigan conducted a study on the response the soil bacterial community to levels of nitrogen accumulation expected by mid-century. They used molecular techniques to quantify the abundance of actinobacteria, a microbe involved in plant litter decomposition, and compared the differences in bacteria species found in experimental versus normal conditions. The results are reported in the July-August 2010 edition of the Soil Science Society of America Journal, published by the Soil Science Society of America.

Contrary to the author’s expectations, simulated atmospheric nitrogen deposition did not affect the abundance of actinobacteria in the forest floor, but did decrease total extractable DNA and gene abundance in the surface soil. This indicates that nitrogen deposition from human activities has a negative effect on soil microbial communities.

Moreover, this study identified significant and consistent changes in the type and abundance of microbes across the study’s four sites. Experimental sites contained unique groups of bacteria compared to communities under a normal nitrogen environment.

Specifically, there were decreases in a family whose members are known to degrade lignin, a plant component, and increases in a poorly understood sub-order. Another unexpected result was that a species commonly thought to be a dominant soil bacteria made up less than 4% of the experimental communities.

These changes in community compositions coincided with the slowing of litter decay and the enhanced production of dissolved organic carbon, a by-product of plant matter decomposition.

“Our observations are consistent with the idea that compositional shifts in soil microbial communities can elicit functional responses that influence the rates of soil carbon cycling,” says Sarah Eisenlord, regardless of the current limited understanding of actinobacterial ecology and physiology.

Understanding the mechanisms which alter the decay of leaf litter debris is crucial in understanding the dynamics of soil carbon storage in a changing climate. Fungi and Actinobacteria are the primary mediators in plant litter decay in the forest floor.

According to Eisenlord, the analysis of these communities has given rise to more questions about the diversity, identity, and function of microbes in forest soil ecosystems. This study uncovered a surprising diversity and distribution of un-cultured and un-characterized species, and is a call to further understand how these organisms interact with their environment to complement the advances in molecular techniques in the field.

The study sites have continuously received experimental nitrogen deposition beginning in 1994. With support from the National Science Foundation, Don Zak from the University of Michigan, Kurt Pregitzer from the University of Idaho and Andy Burton from Michigan Technological University have examined the effects of simulated atmospheric nitrogen deposition on forest carbon dynamics in northern hardwood forests dominated by sugar maple, a dominant forest type in eastern North America.

The full article is available for no charge for 30 days following the date of this summary. View the abstract at https://www.soils.org/publications/sssaj/abstracts/74/4/1157.

Soil Science Society of America Journal, http://soil.scijournals.org, is a peer-reviewed international journal published six times a year by the Soil Science Society of America. Its contents focus on research relating to physics; chemistry; biology and biochemistry; fertility and plant nutrition; genesis, morphology, and classification; water management and conservation; forest, range, and wildland soils; nutrient management and soil and plant analysis; mineralogy; and wetland soils.

The Soil Science Society of America (SSSA) is a progressive, international scientific society that fosters the transfer of knowledge and practices to sustain global soils. Based in Madison, WI, and founded in 1936, SSSA is the professional home for 6,000+ members dedicated to advancing the field of soil science. It provides information about soils in relation to crop production, environmental quality, ecosystem sustainability, bioremediation, waste management, recycling, and wise land use.

SSSA supports its members by providing quality research-based publications, educational programs, certifications, and science policy initiatives via a Washington, DC, office.

Sara Uttech | Newswise Science News
Further information:
http://www.sciencesocieties.org
http://www.soils.org

More articles from Agricultural and Forestry Science:

nachricht New 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

nachricht Fighting a destructive crop disease with mathematics
21.06.2017 | University of Cambridge

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Abrupt motion sharpens x-ray pulses

Spectrally narrow x-ray pulses may be “sharpened” by purely mechanical means. This sounds surprisingly, but a team of theoretical and experimental physicists developed and realized such a method. It is based on fast motions, precisely synchronized with the pulses, of a target interacting with the x-ray light. Thereby, photons are redistributed within the x-ray pulse to the desired spectral region.

A team of theoretical physicists from the MPI for Nuclear Physics (MPIK) in Heidelberg has developed a novel method to intensify the spectrally broad x-ray...

Im Focus: Physicists Design Ultrafocused Pulses

Physicists working with researcher Oriol Romero-Isart devised a new simple scheme to theoretically generate arbitrarily short and focused electromagnetic fields. This new tool could be used for precise sensing and in microscopy.

Microwaves, heat radiation, light and X-radiation are examples for electromagnetic waves. Many applications require to focus the electromagnetic fields to...

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

 
Latest News

New 3-D imaging reveals how human cell nucleus organizes DNA and chromatin of its genome

28.07.2017 | Health and Medicine

Heavy metals in water meet their match

28.07.2017 | Power and Electrical Engineering

Oestrogen regulates pathological changes of bones via bone lining cells

28.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>