The increasing levels of carbon dioxide in the air are leading us to expect climate change with higher temperatures in the future. The principal cause is the combustion of fossil fuels, but there are other processes that can lead to increases in carbon dioxide as well. For thousands of years, plants in peat bogs and other fens have absorbed carbon dioxide from the air for their photosynthesis, binding it in the form of layers of peat that can reach depths of 10 meters. Such binding of carbon dioxide serves as a carbon trap and can counteract the release of carbon dioxide to some extent.
“Now there are signs that indicate that nitrogenous compounds in the air make peat bogs start to give off more carbon dioxide than they bind, and that they may tip over from being a carbon trap to being a carbon source, thereby aggravating the greenhouse effect instead,” says Håkan Rydin, professor of plant ecology, who directed the study.
The amount of carbon contained in peat layers is equivalent to 40-50 percent of the total amount of carbon dioxide in the atmosphere. The most important peat-forming plants are bog mosses (NOT the same as the reindeer lichens used in advent candle settings). Bog mosses have several unique properties. They soak up water like sponges, making the environment waterlogged and low on oxygen, which counteracts their being degraded by microorganisms and leads to the accumulation of plant remains in the form of peat. Another reason peat is formed is that bog mosses produce organic substances, such as polyphenols, that make them difficult to break down. They are therefore highly deficient in nutrition and are directly impacted by the amounts of nitrogen found in precipitation as a result of air pollution.
In the present study, a network of scientists show, from samples taken from bogs in Europe with varying levels of nitrogen in the precipitation, that bog mosses growing in areas with higher levels of nitrogen form smaller amounts of polyphenols and are therefore more susceptible to degradation by microorganisms than those growing in areas with low levels of nitrogen, such as the Nordic countries. This increased degradation entails that bogs give off more carbon dioxide to the atmosphere.
They have also found that precipitation with high levels of nitrogen promotes the growth of grass and sedge, which also occur on bogs. These plants do not add to peat build-up in the same way as bog mosses. All in all, this means that bogs can aggravate the greenhouse effect in areas with high levels of nitrogen in precipitation, by both giving off more and binding less carbon dioxide.
Anneli Waara | alfa
Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen
A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
22.09.2017 | Life Sciences
22.09.2017 | Medical Engineering
22.09.2017 | Physics and Astronomy