Featured Research

from universities, journals, and other organizations

Alien Earthworms Changing Ecology Of Northeast Forests

Date:
June 25, 2003
Source:
University Of Rhode Island
Summary:
Some forests throughout the Northeast are rapidly changing, but most observers won't notice it unless they take a close look at the soil beneath their feet. That's because the driving force behind the changing forests are earthworms, which play a key role in recycling nutrients in the soil but which may also be altering habitat for plants, salamanders, birds and other wildlife.

KINGSTON, R.I. – June 24, 2003 – Some forests throughout the Northeast are rapidly changing, but most observers won't notice it unless they take a close look at the soil beneath their feet. That's because the driving force behind the changing forests are earthworms, which play a key role in recycling nutrients in the soil but which may also be altering habitat for plants, salamanders, birds and other wildlife.

Only a few forest stands are known to be affected to date, according to University of Rhode Island soil scientists Josef Görres and José Amador, but they say the threat to forests is real. Most of the earthworm species found in the Northeast are not native to the area.

Görres and Amador are evaluating the environmental impact of the common nightcrawler, one of the region's 16 to 20 species of earthworms. While the spread of the worms in Rhode Island has not yet been evaluated, the researchers note that bait cups littering popular fishing spots suggest that local forests may be affected soon.

"These exotic earthworms arrived here either in plant materials imported by European settlers, from fishing bait that escaped, and some that were imported here for use in composting," Görres said. "Any native earthworms that may have been in New England thousands of years ago were crushed by the glaciers."

When earthworms move into a new area, they feed on the organic material on the forest floor and bring it down into their burrows. They feed primarily on the top layer of leaf litter, as well as on the duff – the spongy layer of decomposing vegetation beneath the leaf litter.

Görres said that while earthworms do an excellent job of recycling nutrients, "when they eat away the duff layer, all the plant seeds that germinate there, like trillium and mayflowers and wood anemone, may disappear or may not have any place to germinate. Other creatures that live in the duff and forest litter like salamanders and ground-nesting birds may be affected as well. Within a decade or two, the worms can essentially change the soil profile into something like the black mineral-rich soils that are found in many European forests."

Funded by the U.S. Department of Agriculture and the Rhode Island Agricultural Experiment Station, Görres and Amador have set up study plots in local forests to evaluate the impact of the worms. They expect that over time the leaf litter and the duff layer in the protected plots will disappear because of the voracious worms. "At some point, the number of worms that can survive in a given area will be regulated by the amount of new leaf litter that falls," said Amador. "We'll also see a change in the plant and animal communities that live there."

The researchers are also trying to determine whether the worms are increasing the amount of carbon dioxide and methane going into the atmosphere. "The leaf litter and duff layers consist almost entirely of stored carbon, so when the worms eat and process the litter and duff, they release carbon dioxide and possibly methane in their burrows," Amador said. "We're not predicting catastrophe, of course, since the total amount of the gases they release is small. But it's a previously unaccounted potential source of greenhouse gases entering the atmosphere."

All this is not to say that earthworms aren't beneficial. In fact, Amador believes that worms could be used in place of some of the fertilizers used in commercial agriculture.

"One of the tenets of organic agriculture is the reduction of inputs of synthetic fertilizers, and worms can help do this," he said. "We want to demonstrate to farmers that worms can provide a real benefit to crop production. Sustainable agriculture is all about soil quality. We want to come up with hard data about the contribution soil animals make to the quality of soil."

When worms eat the crop litter left from last year's harvest, they release nitrogen – a major component of fertilizer -- from the dead plants, which can then be used by this year's crops to help them grow.

"To make it work, we have to convince farmers not to remove the crop litter from the previous year, and discourage them from tilling the soil, because that has a detrimental effect on the worms," Amador said. "Farmers know they can till and add fertilizer and get a good crop, but how long can they do that before the soil gives out? We want to encourage a less invasive system of crop production, one in which the farmers work with what they've already got in the soil."


Story Source:

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


Cite This Page:

University Of Rhode Island. "Alien Earthworms Changing Ecology Of Northeast Forests." ScienceDaily. ScienceDaily, 25 June 2003. <www.sciencedaily.com/releases/2003/06/030625090207.htm>.
University Of Rhode Island. (2003, June 25). Alien Earthworms Changing Ecology Of Northeast Forests. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2003/06/030625090207.htm
University Of Rhode Island. "Alien Earthworms Changing Ecology Of Northeast Forests." ScienceDaily. www.sciencedaily.com/releases/2003/06/030625090207.htm (accessed April 18, 2014).

Share This



More Plants & Animals News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) — Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) — Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) — A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) — Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. 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:
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