Featured Research

from universities, journals, and other organizations

Earthworms Threaten Minnesota Forests

Date:
September 7, 2000
Source:
University Of Minnesota
Summary:
Earthworms may be our friends in the vegetable garden and a useful addition to the bait bucket, but according to University of Minnesota scientists Cynthia Hale, Lee Frelich and Peter Reich, they appear to be an unwelcome intruder in Minnesota's hardwood forests

MINNEAPOLIS / ST. PAUL -- Earthworms may be our friends in the vegetable garden and a useful addition to the bait bucket, but according to University of Minnesota scientists Cynthia Hale, Lee Frelich and Peter Reich, they appear to be an unwelcome intruder in Minnesota's hardwood forests. Hale presented a talk, "Impacts of Invading European Earthworms on Understory Plant Communities in Previously Worm-free Hardwood Forests of Minnesota," Monday, Aug. 7, in Snowbird, Utah, during the annual meeting of the Ecological Society of America. Her presentation was part of a session on Invertebrate Herbivore-Plant Interactions.

Invading earthworms appear to be causing widespread loss of native forest plant species and affecting the stability of hardwood-forest ecosystems, said Hale, a graduate student in the university's department of forest resources. During the last few decades, European earthworm species have moved into hardwood forests in the northern tier of the United States.

"We have documented significant damage in the Chippewa National Forest and in isolated forest preserves in and near the Twin Cities area in southern parts of Minnesota," Hale noted.

Minnesota's hardwood forests, which developed in the absence of native earthworms after the last glaciers retreated, contain a thick forest floor that serves as a perfect rooting medium for many species of forest herbs and tree seedlings. In the 1800s European settlers arrived, bringing with them European earthworm species in potted plants. European earthworms have been part of the habitats surrounding human habitation ever since.

When earthworms invade a forested area, they consume the forest floor, and herbaceous plant diversity and tree seedling density decrease dramatically. Heavily impacted stands have been observed with only one species of native herb and virtually no tree seedlings remaining.

"Ninety-nine percent of the populations of native plant species normally found in hardwood forests, including large-flowered trilliums, yellow violets, and Solomon's seal, are destroyed in affected areas," said Frelich, a research associate in forest resources. "In many areas, the remaining bare soil is simply eroding away."

Although it is not possible to reverse the continued migration of the earthworms, there are things people can do to help the forests recover.

"It is likely earthworms will eventually spread to all the hardwood forests except those whose soils are sandy or extremely shallow,00" said Frelich, "but we certainly don't want to speed up the process. People have always been told worms are good for the environment, so at the end of fishing vacations they dump the leftover worms near the lake. They don't understand how harmful earthworms can be to a forest."

Replanting native plant species is another way to help forests recover from earthworm damage. Native plants, grown from locally harvested seeds, are now available. A small industry is developing to provide native woodland plant species, a restoration effort similar to what has been happening with prairie plants.

"We're sharing the study results now," said Hale, "so ecologists become aware of the issue, realize that the presence of earthworms is an important criterion when evaluating an area, and begin to understand what their presence means." Hale and Frelich are continuing their research by conducting a formal survey of several Minnesota hardwood forests over the next two years. The third author, Peter Reich, is a professor of forest resources.

For more information on the meeting, visit the Ecological Society of America's Web site at http://esa.sdsc.edu/snowbird2000.htm.


Story Source:

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


Cite This Page:

University Of Minnesota. "Earthworms Threaten Minnesota Forests." ScienceDaily. ScienceDaily, 7 September 2000. <www.sciencedaily.com/releases/2000/09/000904130558.htm>.
University Of Minnesota. (2000, September 7). Earthworms Threaten Minnesota Forests. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2000/09/000904130558.htm
University Of Minnesota. "Earthworms Threaten Minnesota Forests." ScienceDaily. www.sciencedaily.com/releases/2000/09/000904130558.htm (accessed September 17, 2014).

Share This



More Plants & Animals News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
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