Shrubs have become more abundant in the Arctic over the past 30 years as air temperatures have increased, a change that is likely to affect the grazing of caribou and the communities that rely on them for food. According to an article in the January 2005 issue of BioScience, a variety of evidence now suggests that winter biological processes form a positive feedback mechanism that is contributing to the expansion of shrubs in the Arctic. The effect could have important implications for the global carbon budget, as the mechanism may liberate large stores of carbon that are currently frozen and not participating in the carbon cycle.
The article, by Matthew Sturm of the U.S. Army Cold Regions Research and Engineering Laboratory-Alaska and seven coauthors, notes that the evidence for increasing shrub abundance--including historical photographs-- is most comprehensive in northern Alaska. Information from other arctic regions supports the idea, however. Sturms group argues that observations indicate that shrubs encourage deeper snowdrifts, which warm the soil below, preventing some subsurface water from freezing even during winter. This effect alters and boosts the winter activity of subsurface soil bacteria and fungi that provide accessible nutrients for shrubs, notably nitrogen. As a result, shrubs grow more rapidly, and so the spread continues.
Donna Royston | EurekAlert!
Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University
How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
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23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy