Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Savannahs help to slow climate change


Tropical rainforests have long been considered the Earth’s key ecosystem as they sequester a substantial amount of carbon dioxide from the atmosphere, thereby slowing down the increasing greenhouse effect and climate change.

Researchers from the Max Planck Institute for Biogeo-chemistry in Jena, Germany, participated in a global research project that now shows that semi-arid ecosystems occupying the transition zone between rainforest and desert are as important as rainforests, dominating the ongoing increase in carbon dioxide sequestration by ecosystems globally as well as large fluctuations between wet and dry years.

Savannah landscape in Tansania

Picture: Fritz/Heinrich

Carbon dioxide (CO2) exists naturally in the atmosphere, but it is also the greenhouse gas that is most altered by human activities, most notably fossil fuel combustion and tropical deforestation. The Earth’s vegetation reduces the increase in atmospheric CO2 concentrations by sequestering over a quarter of anthropogenic emissions.

This so-called carbon sink results from the balance between plant photosynthesis, which annually takes up a significant fraction of the CO2 in the atmosphere, and a slightly smaller quantity of CO2 that is released back to the atmosphere through life processes (respiration) and wild fires.

The vegetation’s resultant carbon sink slows down the rate of increase of greenhouse gases in the atmosphere and helps mitigate global climate change, thus providing a vital ecosystem service.

In an international study released in Science this week, researchers from the Max Planck Institute for Biogeochemistry in Jena, Germany, coauthored an international study led by researchers from Lund University in Sweden. They show that semi-arid ecosystems—savannahs and shrublands—play an extremely important role in controlling carbon sinks and the climate-mitigating ecosystem service they represent.

„Forest ecosystems including tropical and other major forest biomes take up most of the CO2 “, says Sönke Zaehle, group leader at the Max Planck Institute for Biogeochemistry. Tropical rainforests are highly productive, taking up a lot of carbon dioxide, but rainforests are crowded places with little room to fit in more plants to do more photosynthesis and to store carbon. In addition, the typical moist, hot weather conditions are ideal for growth and do not change much from year to year.

In savannahs it is different. As productivity increases there is room to fit in more plants whose growing biomass provides a sink, or store, for carbon sequestered from the atmosphere. In addition, savannahs spring to life in wetter years, thus causing large interannual fluctuations in carbon dioxide uptake between wet and dry years. Large enough, the scientists show, to dominate the variability of the carbon dioxide increase in the atmosphere.

“Despite contributing only 20% to the vegetation’s carbon sink, savannahs are the largest controlling factor for year-to-year variations of the terrestrial carbon budget” says Markus Reichstein.

We have long known that we need to protect the rainforests but, with this study, the researchers show that a heightened effort is needed to manage and protect the semi-arid regions of the world as well. They will become even more important in the future as climate variability and extremes increase in a warmer world.

“This study brings out clearly the importance of directing attention towards savannahs and other dry-climate ecosystems that have been largely neglected so far in climate policy discussions, and that moreover characterize the landscapes of some of the poorer countries of the Earth", says Benjamin Smith, Professor of Ecosystem Science at Lund University, Sweden. (aa/ef/sz/mr)

Original publication:
The dominant role of semi-arid ecosystems in the trend and variability of the land CO2 sink
Anders Ahlström, Michael R. Raupach, Guy Schurgers, Benjamin Smith, Almut Arneth, Martin Jung, Markus Reichstein, Josep G. Canadell, Pierre Friedlingstein, Atul K. Jain, Etsushi Kato, Benjamin Poulter, Stephen Sitch, Benjamin D. Stocker, Nicolas Viovy, Ying Ping Wang, Andy Wiltshire, Sönke Zaehle, Ning Zeng.
Science. DOI: 10.1126/science.aaa1668

Weitere Informationen: Department webpage

Dr. Eberhard Fritz | Max-Planck-Institut für Biogeochemie

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

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: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>