Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

"Acid rain” and forest mass: another perspective

14.10.2005


A few years ago the study of the effects of atmospheric deposition on forest ecosystems reached beyond the scientific sphere and the term “acid rain” was coined. This problem, which ignores frontiers, happens because, due to the burning of fossil fuels, the amount of sulphur and nitrogen oxides in the atmosphere is greater than that derived from natural processes.



Oxides, in the presence of water vapour and under the oxido-reduction conditions present in the atmosphere, produce acids that are deposited, amongst other places, on the forest biomass. Also, intensification in the cattle sector, together with stabling and grouping together of herds, have given rise to the concentration of ammonia emissions in certain zones. This compound, deposited close to the sources of emission, is able to react with the acidic ions deposited at the same time. Subsequently, certain bacteria are capable of oxidising the compound, thus forming nitrate and liberating protons that acidify the soil.

Amongst the effects of the deposition of these compounds on the forest mass are the well-known nutrition disorders of the same. One classic effect is that of cation deficit (particularly magnesium) due to the washing both of the forest canopy and the soil produced by these together with anions (sulphates and nitrates). This problem is not very common in forest ecosystems close to the sea given that, in these conditions, the uptake of magnesium with precipitation is high. Another consequence is what is known as the eutrofization of terrestrial ecosystems due to the increase in nitrogen availability (saturation) in systems where historically this element has been the limiting factor in productivity.


In this research, the recycling of nutrients was studied in two, five-year period stages and in two young radiata pine forests (the first stage) and in two oak woods (the second). To this end, weekly samples of rain, transcolation (fraction of the precipitation that passes through the forest canopy), and litterfall (vegetable material fallen from trees: leaves, twigs, fruit, and so on), the first 25 cm of mineral soil and green foliage were taken and analysed chemically, according to standard protocols. The location of parcels was carried out as a function of their distance from different foci of emission of contaminants. A flow equilibrium model for the canopy was drawn up together with a generalised micrometeorological model in order to estimate the total deposition of atmospheric constituents. Also, a model for foliar growth and abscision was designed using proportions of the various cohorts of the samples of green branches and litterfall.

The total nitrogen deposition was greater that that deemed to be the admissible critical load in European forest ecosystems so that the nitrogen saturation of the ecosystems studied is, or shortly will be, a fact. The canopy of the forests was able to neutralise the atmospheric deposition in an effective manner although the potential acidity was greater in those areas near emission foci. The uptake of acidifying ions and nitrogen caused an acceleration of the return of nutrients (amount of nutrients that the vegetation gives back to the soil together with the litterfall and foliar excretion) and a drop in their retranslocation (reabsorption of nutritive elements). Thus, the efficiency in the use of cations was affected by the atmospheric deposition of contaminants. Magnesium deficiency was observed in all the adult formations studied. The acceleration of the return of nutrients and the drop in the efficiency of their use is proposed as an explanation of this disorder.

Thanks to this investigation, it was concluded that the atmospheric deposition of contaminants produces damage in the forest masses of Bizkaia and may be aggravated in the future.

Irati Kortabitarte | alfa
Further information:
http://www.basqueresearch.com

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>