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.
Energy crop production on conservation lands may not boost greenhouse gases
13.03.2017 | Penn State
How nature creates forest diversity
07.03.2017 | International Institute for Applied Systems Analysis (IIASA)
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy