Featured Research

from universities, journals, and other organizations

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

Date:
February 19, 2013
Source:
Penn State
Summary:
Can existing ecological communities persist intact as temperatures rise? A news 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 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. This image of an adult male caribou in Greenland was taken by Eric Post during his research expedition.
Credit: Eric Post, Penn State University

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.


Story Source:

The above story is based on materials provided by Penn State. The original article was written by Katrina Voss. Note: Materials may be edited for content and length.


Journal Reference:

  1. E. Post. Erosion of community diversity and stability by herbivore removal under warming. Proceedings of the Royal Society B: Biological Sciences, 2013; 280 (1757): 20122722 DOI: 10.1098/rspb.2012.2722

Cite This Page:

Penn State. "Climate change effect on plant communities is buffered by large herbivores, new research suggests." ScienceDaily. ScienceDaily, 19 February 2013. <www.sciencedaily.com/releases/2013/02/130219201601.htm>.
Penn State. (2013, February 19). Climate change effect on plant communities is buffered by large herbivores, new research suggests. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2013/02/130219201601.htm
Penn State. "Climate change effect on plant communities is buffered by large herbivores, new research suggests." ScienceDaily. www.sciencedaily.com/releases/2013/02/130219201601.htm (accessed July 24, 2014).

Share This




More Earth & Climate News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Observation Boat to Protect Cetaceans During Ship Transfer

Observation Boat to Protect Cetaceans During Ship Transfer

AFP (July 22, 2014) As part of the 14-ship convoy that will accompany the Costa Concordia from the port of Giglio to the port of Genoa, there will be a boat carrying experts to look out for dolphins and whales from crossing the path of the Concordia. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com
New Orleans Plans to Recycle Cigarette Butts

New Orleans Plans to Recycle Cigarette Butts

AP (July 21, 2014) New Orleans is the first U.S. city to participate in a large-scale recycling effort for cigarette butts. The city is rolling out dozens of containers for smokers to use when they discard their butts. (July 21) Video provided by AP
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
Spectacular Lightning Storm Hits London

Spectacular Lightning Storm Hits London

AFP (July 19, 2014) A spectaCular lightning storm struck the UK overnight Friday. Images of lightning strikes over the Shard and Tower Bridge in central London. Duration: 00:23 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins