Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Without disturbances in nature the world’s forests will be impoverished

21.06.2004


The forests of the world are not the stable and unchanging ecosystems they have been assumed to be. Without the occurrence of wide-spread disturbances in nature, such as forest fires, icing, or volcanic activity, forests will eventually be impoverished, owing to a lack of phosphorous.

This is shown in a study reported in this week’s issue of the journal Science. The scientists who carried out the investigation are David Wardle, Department of Forest Vegetation Ecology, Swedish University of Agricultural Sciences (SLU), Sweden, Richard Bardgett, University of Lancaster, U.K., and Lawrence Walker, University of Nevada, U.S.

The three researchers have examined soil profiles from forested land in six places around the world: in Arjeplog in Swedish Lapland, Alaska, Hawaii, Eastern Australia, and southern New Zealand (two locations). In all places there are soils of extremely varying age, from very young to several thousand years old. The oldest soil, in Hawaii, was 4.1 million years old.



In all six locations forests grew least well in the oldest soils, because the access to absorbable phosphorous was limited in comparison with access to absorbable nitrogen. When soils age, less phosphorous becomes available to trees, since phosphorous is not biologically replenished in the soil or supplied to the ecosystem in any other way. Nitrogen, on the other hand, is renewable; atmospheric nitrogen is continuously supplied to the soil and is tranformed by soil bacteria to forms of nitrogen that the trees can take up. It is not a lack of nitrogen, as has previously been thought, but a lack of phosporous that lies behind poor growth in forests when they become old.

The shortage of phosphorous in the older soils also influenced the soil organisms in a negative manner, reducing their ability to release soils nutrients. The scientists draw several conclusions from their findings. First of all, they show that greater disturbances are necessary if we wish to renew forest ecosystems. What type of disturbances are required varies with soil type, but forest fires, icing, or volcanic activity can be mentioned. If such disturbances do not occur, forests cannot be endlessly renewed. Ultimately the lack of phosphorous will become such a hindrance that the soil will no longer be able to provide sufficient nourishment for densely planted forests with large trees.

A second conclusion is that productive forests are temporary, seen from the perspective of a thousand or ten thousand years: if no disturbances occur in nature, then such forests will slowly be impoverished. The patterns for how this impoverishment takes place, and its underlying mechanisms, are the same, regardless of what type of forest it is and where it is located on earth. The same processes occur in boreal, temperate, and tropical climates, albeit at different rates.

Carin Wrange | alfa
Further information:
http://www.svek.slu.se

More articles from Studies and Analyses:

nachricht Physics of bubbles could explain language patterns
25.07.2017 | University of Portsmouth

nachricht Obstructing the ‘inner eye’
07.07.2017 | Friedrich-Schiller-Universität Jena

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>