For their experiment at the Ecological-Botanical Garden of the University of Bayreuth the researchers installed underground heating on their plots, thereby enabling five additional thawing periods to take place in the winter of 2005/2006.
They found that on the manipulated plots ten percent more biomass grew compared to on the control plots. Such increased plant productivity can be explained by several factors, like for example an increase in nitrogen supply in the spring, according to the researchers account in the scientific journal New Phytologist.
Soils that experience seasonal freeze-thaw cycles currently cover c. 55 million km2. This equates to more than half of the total land area of the northern hemisphere. Forecasts such as the IPCC-Report 2007 anticipate that due to global warming the soil temperature there in the future will fluctuate more frequently around the freezing point. The change between freeze-thaw cycles is considered to be one of the major factors for the release of nitrogen into the soil and consequently for an increase in microbial activity.
Due to global warming and a greater absence of an insulating snow cover, these cyclic processes are likely to increase. In spite of this and apart from a study from the North of Sweden there are hitherto practically no investigations that have conducted research on the significance of these cyclic processes for plants. Scientists working together with Jürgen Kreyling therefore set up an experimental site on the outskirts of Bayreuth to investigate the effects of extreme weather events such as droughts, torrential rain and freeze-thaw processes. The site is located at the transition between oceanic and continental climates, where the average air temperature in January is -1° C. On 30 of the 4m2 plots one hundred common plants (grasses and herbs) were planted. As soon as the temperature had remained continuously below 0° C for 48 hours the soil was heated until the temperature remained above 0° C for 48 hours. In the cold winter of 2005/06, which was 2° C colder than the long-term average, there were a total of 62 days with ground frost.
The researchers added 5 artificial freeze-thaw cycles to the three natural ones and compared the results from the different plots. In the following summer the plants were harvested twice, dried and then weighed. Here it was found that the manipulated plots produced 10 percent more above-ground biomass than the control plots on which in the previous winter less freeze-thaw cycles had occurred. In comparison it was also found that root length up to five centimetres soil depth was reduced.
Tilo Arnhold | alfa
Further reports about: > Biomass production > Climate > Climate change > Ecological-Botanical Garden > Helmholtz > control plots > cyclic processes for plants > frequent freeze-thaw cycles > global warming > grassland productivity > manipulated plots > nitrogen into > oceanic and continental climates > snow cover > soil processes
International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
World Water Day 2017: It doesn’t Always Have to Be Drinking Water – Using Wastewater as a Resource
17.03.2017 | ISOE - Institut für sozial-ökologische Forschung
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...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy