Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 


Due to landscape fragmentation, Brazil's rainforests are releasing more CO2 than previous


Because of the deforestation of tropical rainforests in Brazil, significantly more carbon has been lost than was previously assumed.

As scientists of the Hemholtz Centre for Environmental Research (UFZ) write in the scientific journal Nature Communications, the effect of the degradation has been underestimated in fragmented forest areas, since it was hitherto not possible to calculate the loss of the biomass at the forest edges and the higher emission of carbon dioxide. The UFZ scientists have now closed this knowledge gap. According to their calculations, the forest fragmentation results in up to a fifth more carbon dioxide being emitted by the vegetation.

Shown are Forest fragments of the Brazilian Atlantic Forest in the North-East of Brazil, surround by sugar cane plantations. Credit: Mateus de Dantas de Paula

To estimate the additional carbon emissions at the forest edges, the UFZ scientists developed a new approach that integrates the results from remote sensing, ecology and forest modelling. For their study, they initially modelled the percentage loss of carbon in forest border after the deforestation of the surrounding area.

These losses of the differently fragmented and differently sized forest areas were determined in comparison to large, unchanged forests in the tropical rainforests in the Amazon and in the Brazilian coastal tropical forest Mata Atlântica (Brazilian Atlantic Forest). The scientists defined a strip of 100 meters that runs from the edge of the forest into the inner forest as the peripheral area.

The consequences for the trees at the newly created edges of the forest are known. The climate conditions change significantly: The sun's rays are stronger, the temperatures rise and there are areas where the wind is provided with a more effective target. This means that stress increases for trees in peripheral areas. Especially the larger specimens die off. "Tree mortality increases, so that they can't store as much carbon as healthy trees in the centre of the forest, the core area" says Dr. Sandro Pütz, the main author of the study.

In order to calculate these degradation effects, the UFZ scientists used the forest simulation model FORMIND. This makes it possible to determine the percentage loss of carbon of forest fragments of different sizes. According to this, the percentage loss of stored biomass rises in inverse proportion to the size of the remaining rest of the forest. It is only when a forest area of 10,000 hectares is reached that the percentage loss recedes to almost zero depending on the shape of the forest fragment.

The UFZ scientists also used satellite images to analyse how the tropical rainforest is spatially distributed in the Amazon region and the coastal tropical forest. To take as many small forest areas as possible into account, they worked with a very high resolution of up to approx. 30 meters: "In science, this is the processing limit, since the data volumes for the Amazon are very large," says UFZ scientist Prof. Dr. Andreas Huth.

According to the records, the coastal tropical forest with a total of eleven percent of its original surface area only takes up 157,000 square kilometres and is split into 245,173 fragments. 90 percent of the forest remains are smaller than 100 hectares, which means that they have very many edges. A total of 46 percent of the forests in the Mata Atlântica lie in these peripheral areas.

This has certain consequences: Due to the changed microclimate at the forest edges, more than 68 million tonnes of carbon are lost in ten years. "This is an enormous loss in relation to the small total area of the Brazilian Atlantic Forest," Pütz concludes. The 3.1 million sqkm of the Brazilian part of the rainforest in the Amazon consists of over 300,000 forest fragments. However, the peripheral areas only amount to about seven percent of the entire area. This means that the additional loss of carbon in the entire rainforest of the Amazon due to the peripheral effects amounts to approx. 600 million tonnes in ten years.

For the first time, the UFZ researchers also calculated how much this border effect would affect the storage of carbon in tropical forests worldwide. Currently, there are 830 billion tonnes of carbon in the atmosphere. Every year, the carbon increases by four billion tonnes.

A quarter of this is caused by deforestation around the globe. Because the calculations of the UFZ model indicate that ten percent of the forest areas in the tropics worldwide lie at the edges of forests, these degradation effects result in an increase of up to 0.2 billion tonnes of carbon getting into the atmosphere per year.

This share has so far not been included in the carbon balance calculations. "It is a forgotten process in the global carbon circulation of the vegetation," Huth states. This aspect has been not directly included in the calculations of the IPCC (Intergovernmental Panel on Climate Change). “However, this effect should urgently be taken into account," the ecologist demands.

The UFZ scientists' results are also interesting for practical aspects in climate protection policy. On the one hand it makes sense to require a minimum size of at least around 10,000 hectares for forest island areas because the relative loss of carbon is only minimal at the edges at that size.

On the other hand, the peripheral areas and not the interior parts of forests should be used for forestry or agriculture in future, since the loss of biomass in these areas does not have as much of an effect. For the first time, this examination shows a methodical way in which ecological effects in small areas can be used for large-scale environmental assessments. Additional studies are planned. Benjamin Haerdle

Sandro Pütz, Jürgen Groeneveld, Klaus Henle, Christoph Knogge, Alexandre Camargo Martensen, Markus Metz, Jean Paul Metzger, Milton Cezar Ribeiro, Dantas de Paula, M. & Andreas Huth. Long-term carbon loss in fragmented Neotropical forests. Nature Communications 5:5037 doi: 10.1038/ncomms6037 (2014).

For further information please contact:
Helmholtz-Centre für Environmental Research (UFZ)
Dr Sandro Pütz / Prof Dr Andreas Huth / Dr Jürgen Groeneveld
Telefon: +49-(0)341-2434-482; +49-(0)341-235-1719, -1711
or via
Tilo Arnhold, Susanne Hufe (UFZ-PR)
phone: +49-(0)341-235-1635, -1635

Additional Links:
T. Wiegand, S. Gunatilleke, N. Gunatilleke, and A. Huth (2007): How individual species structure diversity in tropical forests. Proc.Nat.Acad.Sci.USA 104:19029-19033

Research project Mata Atlântica:

FORMIND: an individual based forest model:

Helmholtz-Allianz Remote Sensing and Earth System Dynamics:

Overview in „Nature“ about long-term fragmentation experiments in forests.

Pretzsch, H., Biber, P., Schütze, G., Uhl, E., Rötzer, Th., (2014):
Forest stand growth dynamics in Central Europe have accelerated since 1870,
Nat. Commun. 5:4967

In the Helmholtz Centre for Environmental Research (UFZ), scientists conduct research into the causes and consequences of far-reaching environmental changes. Their areas of study cover water resources, biodiversity, the consequences of climate change and possible adaptation strategies, environmental technologies and biotechnologies, bio-energy, the effects of chemicals in the environment and the way they influence health, modelling and social-scientific issues. Its guiding principle: Our research contributes to the sustainable use of natural resources and helps to provide long-term protection for these vital assets in the face of global change. The UFZ employs more than 1,100 staff at its sites in Leipzig, Halle and Magdeburg. It is funded by the federal government, Saxony and Saxony-Anhalt.

The Helmholtz Association contributes to solving major and urgent issues in society, science and industry through scientific excellence in six research areas: Energy, earth and environment, health, key technologies, structure of matter as well as aviation, aerospace and transportation. The Helmholtz Association is the largest scientific organisation in Germany, with 35,000 employees in 18 research centres and an annual budget of around €3.8 billion. Its work is carried out in the tradition of the great natural scientist Hermann von Helmholtz (1821-1894).

Tilo Arnhold | UFZ News

Weitere Nachrichten aus der Kategorie Ökologie Umwelt- Naturschutz:

nachricht Von der Weser bis zur Nordsee: PLAWES erforscht Mikroplastik-Kontaminationen in Ökosystemen
20.09.2017 | Universität Bayreuth

nachricht Der Monsun und die Treibhausgase
18.09.2017 | Forschungszentrum Jülich

Alle Nachrichten aus der Kategorie: Ökologie Umwelt- Naturschutz >>>

Die aktuellsten Pressemeldungen zum Suchbegriff Innovation >>>

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

Im Focus: Hochpräzise Verschaltung in der Hirnrinde

Es ist noch immer weitgehend unbekannt, wie die komplexen neuronalen Netzwerke im Gehirn aufgebaut sind. Insbesondere in der Hirnrinde der Säugetiere, wo Sehen, Denken und Orientierung berechnet werden, sind die Regeln, nach denen die Nervenzellen miteinander verschaltet sind, nur unzureichend erforscht. Wissenschaftler um Moritz Helmstaedter vom Max-Planck-Institut für Hirnforschung in Frankfurt am Main und Helene Schmidt vom Bernstein-Zentrum der Humboldt-Universität in Berlin haben nun in dem Teil der Großhirnrinde, der für die räumliche Orientierung zuständig ist, ein überraschend präzises Verschaltungsmuster der Nervenzellen entdeckt.

Wie die Forscher in Nature berichten (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005), haben die...

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Wundermaterial Graphen: Gewölbt wie das Polster eines Chesterfield-Sofas

Graphen besitzt extreme Eigenschaften und ist vielseitig verwendbar. Mit einem Trick lassen sich sogar die Spins im Graphen kontrollieren. Dies gelang einem HZB-Team schon vor einiger Zeit: Die Physiker haben dafür eine Lage Graphen auf einem Nickelsubstrat aufgebracht und Goldatome dazwischen eingeschleust. Im Fachblatt 2D Materials zeigen sie nun, warum dies sich derartig stark auf die Spins auswirkt. Graphen kommt so auch als Material für künftige Informationstechnologien infrage, die auf der Verarbeitung von Spins als Informationseinheiten basieren.

Graphen ist wohl die exotischste Form von Kohlenstoff: Alle Atome sind untereinander nur in der Ebene verbunden und bilden ein Netz mit sechseckigen Maschen,...

Im Focus: Hochautomatisiertes Fahren bei Schnee und Regen: Robuste Warnehmung dank intelligentem Sensormix

Schlechte Sichtverhältnisse bei Regen oder Schnellfall sind für Menschen und hochautomatisierte Fahrzeuge eine große Herausforderung. Im europäischen Projekt RobustSENSE haben die Forscher von Fraunhofer FOKUS mit 14 Partnern, darunter die Daimler AG und die Robert Bosch GmbH, in den vergangenen zwei Jahren eine Softwareplattform entwickelt, auf der verschiedene Sensordaten von Kamera, Laser, Radar und weitere Informationen wie Wetterdaten kombiniert werden. Ziel ist, eine robuste und zuverlässige Wahrnehmung der Straßensituation unabhängig von der Komplexität und der Sichtverhältnisse zu gewährleisten. Nach der virtuellen Erprobung des Systems erfolgt nun der Praxistest, unter anderem auf dem Berliner Testfeld für hochautomatisiertes Fahren.

Starker Schneefall, ein Ball rollt auf die Fahrbahn: Selbst ein Mensch kann mitunter nicht schnell genug erkennen, ob dies ein gefährlicher Gegenstand oder...

Alle Focus-News des Innovations-reports >>>



im innovations-report
in Kooperation mit academics

Die Erde und ihre Bestandteile im Fokus

21.09.2017 | Veranstaltungen

23. Baltic Sea Forum am 11. und 12. Oktober nimmt Wirtschaftspartner Finnland in den Fokus

21.09.2017 | Veranstaltungen

6. Stralsunder IT-Sicherheitskonferenz im Zeichen von Smart Home

21.09.2017 | Veranstaltungen

Weitere VideoLinks >>>
Aktuelle Beiträge

OLED auf hauchdünnem Edelstahl

21.09.2017 | Messenachrichten

Weniger (Flug-)Lärm dank Mathematik

21.09.2017 | Physik Astronomie

In Zeiten des Klimawandels: Was die Farbe eines Sees über seinen Zustand verrät

21.09.2017 | Geowissenschaften