Featured Research

from universities, journals, and other organizations

Grazing Animals Help Spread Plant Disease

Date:
January 6, 2009
Source:
Oregon State University
Summary:
Researchers have discovered that grazing animals such as deer and rabbits are actually helping to spread plant disease -- quadrupling its prevalence in some cases -- and encouraging an invasion of annual grasses that threaten more than 20 million acres of native grasslands in California.

Researchers have discovered that grazing animals such as deer and rabbits are actually helping to spread plant disease – quadrupling its prevalence in some cases – and encouraging an invasion of annual grasses that threaten more than 20 million acres of native grasslands in California.

Related Articles


The findings run contrary to what had been predicted by other theories, which had suggested that "consumers" such as deer would help to contain or reduce disease. They point once again to the complexity of natural ecosystems and the many ways in which plants, animals and even viruses interact with each other.

The work will be published the week of December 29 in Proceedings of the National Academy of Sciences, by researchers from Oregon State University, Cornell University and the University of North Carolina.

"We usually think of a disease and its host as very tightly coupled, like a flu virus that infects humans," said Elizabeth Borer, an assistant professor of zoology at OSU. "But in natural ecosystems we're finding it's not nearly that simple, and to understand how plant pathogens work we have to consider the entire food web and many plant/animal interactions of which we are barely aware."

The work is of particular importance, researchers said, because so many elements of ecosystems are undergoing rapid change, from human manipulation, climate change, increase or decrease in various species, new invasive species, and other factors. Any one of those changes could have ripple effects with seemingly unrelated diseases or other issues that are poorly understood – an increase in the abundance of white-footed mice, for instance, has been shown to increase Lyme disease risk in humans.

In this study, scientists examined the effect of herbivores and omnivores such as mule deer, rabbits and feral pigs on the prevalence of barley and cereal yellow dwarf viruses, which can infect more than 100 crop and non-crop plant species, reducing their growth and seed yield. This virus is a major concern for cereal crop production around the world.

In places where most plant eaters were kept out of test plots, the prevalence of this virus was only about 5 percent. It rose to 18 percent, a 3.6-fold increase, in areas that the animals grazed.

The grazers did not directly spread the plant virus, researchers said. Rather, they increased the amounts of annual grasses that are preferred by the aphids which play a role in transmission of this viral plant disease. That allowed for a much greater prevalence of the virus in areas where grazing took place.

"Even in complex natural communities, alternations to food web composition such as consumer invasion or extinction can lead to significant impacts that cascade through entire communities, including changes in infection risk," the researchers wrote in their report.


Story Source:

The above story is based on materials provided by Oregon State University. Note: Materials may be edited for content and length.


Cite This Page:

Oregon State University. "Grazing Animals Help Spread Plant Disease." ScienceDaily. ScienceDaily, 6 January 2009. <www.sciencedaily.com/releases/2008/12/081229200736.htm>.
Oregon State University. (2009, January 6). Grazing Animals Help Spread Plant Disease. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2008/12/081229200736.htm
Oregon State University. "Grazing Animals Help Spread Plant Disease." ScienceDaily. www.sciencedaily.com/releases/2008/12/081229200736.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Tryptophan Isn't Making You Sleepy On Thanksgiving

Tryptophan Isn't Making You Sleepy On Thanksgiving

Newsy (Nov. 27, 2014) Tryptophan, a chemical found naturally in turkey meat, gets blamed for sleepiness after Thanksgiving meals. But science points to other culprits. Video provided by Newsy
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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