Forest ecosystems may produce large volumes of nitrous oxide (N2O), an important greenhouse gas, which affects the atmosphere's chemical and radiative properties. Yet, our understanding of controls on forest N2O emissions is insufficient. This study investigates the quantitative and qualitative relationships between nitrogen-cycling and N2O production in European forests.
The authors conclude that changes in forest composition in response to land use activities and global change may have serious implications for regional budgets of greenhouse gases. It also became clear that accelerated nitrogen inputs predicted for forest ecosystems in Europe may lead to increased greenhouse gas emissions from forest ecosystems.
Read article: http://www.biogeosciences.net/3/135/2006/bg-3-135-2006.html
Bacterial carbon sources in coastal sediments: a cross-system analysis based on stable isotope data of biomarkers.
Coastal ecosystems are among the most productive regions in the world ocean. Because of the ample nutrient supplies, the coastal zone accounts for about 20% of oceanic primary production — despite its small geographic extent. Local organic producers span from phytoplankton to bottom-dwelling algae to seagrasses and mangroves. Because of the high rates of sediment accumulation, among other factors, a comparatively large percentage of this new organic matter survives early decay and is buried into the geologic record. Coastal regions also receive large inputs of organic material reworked and transported from surrounding regions by strong currents, including contributions from rivers that drain adjacent land areas. Through the combined effects of high production, large inputs of reworked material, and efficient sequestration, a vast majority of the world’s organic carbon burial occurs in these marginal marine settings.
As the dominant site of oceanic organic carbon burial, the coastal zone factors prominently in most models for short- and long-term carbon cycling and, correspondingly, in scientists’ estimates for CO2 variation in the atmosphere on a variety of time scales. In this paper, Bouillon and Boschker explore this complex organic reservoir through carbon isotope analysis of the many constituents, including large plant fragments and lipid biomarkers that are chemically extracted from the sediments and fingerprint bacterial sources.
Using this approach the authors explored which of the organic components bacteria most easily degrade and thus which have the potential for burial and removal from at least the short-term carbon cycle. Importantly, the authors compared the carbon isotope properties of bacterial biomarkers from a wide range of coastal settings and concluded that the microbes are feeding on a diverse assortment of organic constituents. In fact, at most sites where organic matter is readily available, bacteria show little selectivity in the compounds they decompose.
In light of the previous consensus that such materials should show widely varying biodegradability, this result will certainly raise questions, fuel future work, and ultimately refine our understanding of how carbon flows through its global biogeochemical cycle and impacts the composition of the atmosphere.
Read article: http://www.biogeosciences.net/3/175/2006/bg-3-175-2006.html
Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society
Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine