Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Climate change effect on plant communities is buffered by large herbivores, new research suggests

20.02.2013
Can existing ecological communities persist intact as temperatures rise?

This is a question of increasing relevance in the field of climate change and is the focus of a new study to be published in the journal Proceedings of the Royal Society of London on 20 February. The study suggests that the answer to this question may have as much to do with the biological interactions that shape communities as with the effects of climate change itself.

The study's insights are based on a novel approach by Eric Post, a Penn State University professor of biology, who simulated climate change and integrated the effects of large, plant-eating mammals in a 10-year arctic field experiment. The results of the research suggest that plant communities in the Arctic are more likely to resist destabilization by climate change if populations of caribou, musk ox, and other large herbivores remain intact. "The study demonstrates that grazing by these large herbivores maintains plant species diversity, while warming reduces it," Post said. "Plant communities with lower diversity display a greater tendency toward instability under warming, a pre-cursor to the loss of such communities."

Post explained that climate-change research in the 1980s and 1990s was focused primarily on how fluctuations in such factors as temperature, precipitation, and nutrient availability directly affected plant communities. "That research was important and enlightening, but what it did not emphasize were the indirect effects of climate change -- how interactions among species may shape the responses of those species to warmer temperatures," Post said. "If the planet continues to warm by 1.5-to-3.0 degrees Celsius over the next century, as the models predict, we need to know not only what the warming will do to plants and animals directly, but also how species' interactions may influence those effects of warming."

Post began the study in a remote, low-Arctic plant community near Kangerlussuaq, Greenland in 2002. To simulate the effects of the 1.5-to-3.0-degrees-Celsius warming that is predicted to occur over the next century, he erected special warming chambers -- cone-shaped hollow structures that create a greenhouse effect. Some areas on which these warming chambers were placed were left open to grazing by caribou and musk ox -- two ecologically important large herbivores in the Arctic -- while separate 800-square-meter areas that also received warming chambers were fenced off to exclude the animals. In this way, Post created two very different environments: one in which plants and herbivores continued to live together as the temperatures climbed within the warming chambers; the other in which the animals were not present and the plants were left ungrazed.

"The study tested a classic ecological hypothesis, but with a new angle," Post said. "Ecologists have argued for decades over whether species-rich plant communities are more stable, and, hence, persistent in the face of environmental disturbance, than species-poor communities. This study added a layer of complexity by asking whether large herbivores contribute to the diversity-stability relationship in a climate-change context."

After 10 years of careful observation of the Kangerlussuaq, Greenland plant communities, Post found that the grazed and ungrazed sections of land did indeed fare quite differently in their responses to warmer temperatures. "This study confirmed that caribou and musk ox act as a buffer against the degradative effects of warming on plant species diversity," Post said. He found that shrubs such as willow and birch became the dominant plants in response to warming where the herbivorous animals were excluded from the ecosystem. "When these shrubs expand in the plant community, they tend to shade their neighbors, and the build-up of leaf litter around the shrubs tends to cool the soil surface, reducing the availability of soil nutrients for other plants," Post said. "As a result, shrubs can quickly out-compete other plants and reduce species diversity in the process. On the other hand, in those areas where caribou and musk ox were able to graze freely, shrub responses to warming were muted, and species diversity within the plant community was maintained."

Post said the take-home message from his study is that, in a warming climate, intact populations of large herbivores may be crucial to the maintenance of plant-community diversity and to the persistence of existing plant communities. "What this experiment suggests is that factors that threaten the persistence of large herbivores may threaten the plant communities they exist in, as well. Conservation of these herbivores in the rapidly changing Arctic will require careful mediation of interacting stressors such as human exploitation, mineral extraction, and the direct effects of climate change," Post said.

Post said that the next step in his research will be to study the contribution of plant diversity to long-term stability of carbon dynamics in the atmosphere and in the soil.

The research was funded by the National Geographic Society's Committee for Research and Exploration, with additional funding from the Office of Polar Programs at the U.S. National Science Foundation.

[ Katrina Voss ]

CONTACTS

Barbara Kennedy (PIO) science@psu.edu, 814-863-4682

Eric Post esp10@psu.edu
IMAGES
High-resolution images associated with this research are online at http://www.science.psu.edu/news-and-events/2013-news/Post2-2013.

CAPTIONS

(for all images): Eric Post, Penn State University

IMAGE CAPTIONS (top to bottom on the webpage listed above)

Image 1: An adult male caribou in Greenland.
Image 2: Two adult male muskoxen in Greenland.
Image 3: Inland ice shelves in Greenland.
Image 4: To study how ecological communities react to rising temperatures, Eric Post erected special warming chambers to simulate a greenhouse effect in a remote, low-Arctic plant community near Kangerlussuaq, Greenland.
Image 5: An adult male muskox in Greenland.
Image 6: Adult male caribou in Greenland.
Image 7: Two adult male muskoxen in Greenland.
Image 8: A cotton-grass plant grows in Greenland.
Image 9: Inland ice shelves in Greenland.
GRANT NUMBERS
National Geographic Society (7442-03)
National Science Founcation (DEB-0124031)

Barbara Kennedy | EurekAlert!
Further information:
http://www.psu.edu

More articles from Ecology, The Environment and Conservation:

nachricht Coorong Fish Hedge Their Bets for Survival
27.03.2015 | University of Adelaide

nachricht Greener Industry If Environmental Authorities Change Strategy
27.03.2015 | University of Gothenburg

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: Gemeinsam auf der Suche nach Wirkstoff gegen MRSA

Neues Projekt bündelt Kompetenzen des HZI und des Lead Discovery Center in Dortmund

Krankenhauskeime stellen in Deutschland ein immer größeres Problem dar. Der Grund: viele von ihnen sind resistent gegen die meisten herkömmlichen Antibiotika....

Im Focus: Rostocker Forscher entwickeln Mess-System für Schiffbau-Versuchsanstalten

Durch wissenschaftlich fundierte Daten der Forscher um Professor Nils Damaschke vom Institut für Allgemeine Elektrotechnik der Universität Rostock wird es künftig möglich, die Propellerform für Schiffe so zu optimieren, dass weniger Kraftstoff verbraucht und der Propellerverschleiß auf Grund von Kavitation reduziert werden kann. Die Wissenschaftler arbeiten inzwischen an der weiteren Verfeinerung eines kommerziellen Mess-Systems für die weltweit agierenden Schiffbau-Versuchsanstalten.

Kleinste Partikel spielen im täglichen Leben eine immer größere Rolle. Ob es sich um Schadstoffe in der Luft (Feinstaubbelastung) oder Zerstäubungsprozesse...

Im Focus: Den Synapsen bei der Arbeit zusehen

Göttinger Forscher beobachten Synapsenaktivität im Gehirn lebender Fruchtfliegen

Wissenschaftler der Universität Göttingen haben mit einer neuen Methode die Aktivität von Nervenzellen im Gehirn lebender Fruchtfliegen beobachtet. Bislang...

Im Focus: FiberLab-Roboter begeistert auf Photonics West in San Francisco

Mit ihrem „humanisierten“ Roboter zeigten Anna Lena Baumann und Wolfgang Schade erstmalig die erfolgreiche Umsetzung der 3D-Navigation über eine neuartige Lasermethode, der Standard Single-Mode-Glasfaser. Mehr als 17.000 Teilnehmer konnten den Roboter und FiberLab, das erste Projekt des Photonik Inkubators in Göttingen, auf der Photonics West in San Francisco kennen lernen.

Mit Hilfe eines in die Kleidung eingenähten Fasersensors wurden Armbewegungen eines Probanden dokumentiert und nach entsprechender Auswertung an den Roboter...

Im Focus: Femto Photonic Production: Neue Verfahren mit Ultrakurzpulslasern für die Fertigung von morgen

Für die deutsche Wirtschaft spielt die Lasertechnik eine herausragende Rolle: Etwa 40 Prozent der weltweit verkauften Strahlquellen und 20 Prozent der Lasersysteme für die Materialbearbeitung stammen aus Deutschland.

Beim Einsatz von Lasern in der Produktion sind deutsche Unternehmen führend. Diese Stärken gilt es zu erhalten und auszubauen. Deswegen hat das...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Premiere für die "innteract conference"

30.03.2015 | Veranstaltungen

Startup Weekend: In 54 Stunden von der Gründungsidee zur Firmengründung

30.03.2015 | Veranstaltungen

Große Bühne für Wissenschaft in drei Minuten

30.03.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Einfluss von Materialporen beim Crash-Verhalten von Automobilbauteilen

31.03.2015 | HANNOVER MESSE

Ausschreibung Deutscher Journalistenpreis Neurologie 2015: Mensch im Blick – Gehirn im Fokus

31.03.2015 | Förderungen Preise

Staubige Strukturen in einer weit entfernten Galaxie

31.03.2015 | Physik Astronomie