Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A computer simulation tool that predicts the influence of forest clearings on soil fertility

08.09.2004


The process of clearing consists of cutting down trees in such a way that those remaining have more resources and can grow more. The question was if too many had been cut down, with the concomitant removal of nutrients, and the manner, therefore, in which this process might affect long-term soil fertility.



A PhD thesis presented in the Public University of Navarre specifically analysed the internal cycle of nutrients in two wooded areas in Pinus sylvestris forests, this species, together with the beech, being the most common tree in the Navarre mountains, especially in the Pyrenees. The areas chosen were in Aspurz and Garde, locations situated at different altitudes.

In the first stage, the above-ground biomass of the wood was measured before and after the clearing is carried out, i.e. we analysed the amount of wood, leaves and bark and each one of the nutrients (such as nitrogen and phosphorous) that existed in the wood. Then the biomass of the dry leaves, branches, etc. of the trees in question fallen onto the floor is measured in order to assess what nutrients returned naturally from the trees to the soil and which, therefore, would be natural fertiliser. The results concluded that the clearings reduced both the above-ground biomass as well as the mineral mass, although no differences in this drop were registered between different intensities of clearings.


In the second study, we start calculating the removal of nutrients from green leaves before they dry out, given that trees have a mechanism to reduce this nutrient loss and increase efficiency in their use. These parameters were not observed to have been influenced by the clearings.

The third experiment consisted of analysing the loss of weight and the chemical composition of the dead leaves. We analysed how this layer of fallen leaves deteriorated, how it breaks up and reconstitutes itself on the ground. In this way we could observe that both woods underwent a slowing down of this process after the clearings took place.

The fourth trial studied the respiration of the soil and its chemical composition and, in this way, the cycle is closed in which the tree first gathers the nutrients to be used to generate biomass, part of this biomass falls, degrades and, once more, reconstitutes itself in the soil to be reused by the tree. We found that respiration was greater in the location at higher temperatures and only in this wood was there detected a passing increase in respiration after the clearings had taken place. Neither did the clearings affect the chemical composition of the soil.

Subsequent to these studies, in the last stage of the thesis, we evaluated the changes in the reserves of nutrients. To this end, we created a computer tool that is a simulation model of the circulation of nutrients based on balances of masses. This has enabled us to predict what will happen to these trees in 60 years time.

A prediction that provides a number of possibilities in this process. It not only tells us that we should carry out clearings, but how often they should be carried out, how many trees should be cut down and whether the whole tree should be cut down or just the trunk or whether the branches and leaves should be left.

Acceptable limit

In any case, it can be affirmed that the management of forest clearings currently comes close to the acceptable limit, although we have to have more data to assess if the mountain is losing fertility. But, in order not to reduce the reserves of nutrients of a forest, the same form of clearings should not be applied to different zones without a prior evaluation of the consequences in each particular case, given that the effect of the clearings on internal cycle of nutrients largely depends on the features of each wooded area.

Garazi Andonegi | alfa
Further information:
http://www.basqueresearch.com
http://www.elhuyar.com

More articles from Agricultural and Forestry Science:

nachricht Fighting a destructive crop disease with mathematics
21.06.2017 | University of Cambridge

nachricht Unusual soybean coloration sheds a light on gene silencing
20.06.2017 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>