Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Climate change enhances grassland productivity - more frequent freeze-thaw cycles intensify soil processes

27.01.2009
More frequent freeze-thaw cycles in winter can increase biomass production according to the results of a recent study conducted by the Helmholtz Center for Environmental Research (UFZ), the University of Bayreuth and the Helmholtz Center in Munich.

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 information:
http://www.ufz.de/index.php?en=17550

More articles from Ecology, The Environment and Conservation:

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Explaining how 2-D materials break at the atomic level

18.01.2017 | Materials Sciences

Data analysis optimizes cyber-physical systems in telecommunications and building automation

18.01.2017 | Information Technology

Reducing household waste with less energy

18.01.2017 | Ecology, The Environment and Conservation

VideoLinks
B2B-VideoLinks
More VideoLinks >>>