Invasive earthworm article

Discussions and news related to invasive and exotic species affecting our trees and forests.

Moderators: edfrank, dbhguru

User avatar
Lee Frelich
Posts: 155
Joined: Mon Mar 15, 2010 3:24 pm

Invasive earthworm article

Post by Lee Frelich » Wed May 06, 2015 9:35 am

ENTS:

Interesting article on invasive earthworms in today's Minneapolis Star Tribune:
http://www.startribune.com/sports/outdo ... y#continue

Lee

User avatar
dbhguru
Posts: 4501
Joined: Mon Mar 08, 2010 9:34 pm

Re: Invasive earthworm article

Post by dbhguru » Wed May 06, 2015 3:41 pm

Lee,

Congratulations on getting attention devoted to this huge problem. If the newspaper article and other educational outreaches can penetrate the thick skulls in the fishing community and gardening communities, you will have pulled off a minor miracle.

Tomorrow, your colleague Dr. Tim Whitfeld is picking me up in the morning and we're heading to Ice Glen to start the earthworm study you have been advising him on.

Bob
Robert T. Leverett
Co-founder, Native Native Tree Society
Co-founder and President
Friends of Mohawk Trail State Forest
Co-founder, National Cadre

User avatar
Lucas
Posts: 837
Joined: Tue Jul 29, 2014 11:55 am

Re: Invasive earthworm article

Post by Lucas » Wed May 06, 2015 5:07 pm

We travel the Milky way together, trees and men. - John Muir

User avatar
Rand
Posts: 1217
Joined: Tue Mar 16, 2010 9:25 pm

Re: Invasive earthworm article

Post by Rand » Wed May 06, 2015 8:01 pm

Lee,

Any thoughts on spreading these suckers around? i.e. What could possibly go wrong?
Bipalium adventitium (Fig.2) is an exotic land planarian that feeds on earthworms. Thought to be a native of Southeast Asia, B. adventitium was first described in 1943 from specimens collected in California. It was probably introduced to North America accidentally during the 1900s in soil on the roots of horticultural plants. Since its original description from California, new reports of its discovery have been published in Connecticut, Massachusetts, Maryland, New York, Pennsylvania, Tennessee, and Washington. Recently, dozens of specimens of B. adventitium were collected from a residential area in Urbana, Illinois, further expanding its known distribution in North America. Because the planarians appear most commonly in urban and suburban settings, their dispersal appears to be passive, most likely in soil on horticultural plants and turf in the horticultural trade. Subsequent dispersal is active, with planarians eventually being found in some wooded and agricultural habitats.

Despite early suggestions that it may also prey on slugs, laboratory studies to date indicate that B. adventitium is primarily an earthworm predator. In all published studies, B. adventitium attacked all species of earthworms presented to it (eight species in all). In laboratory trials with B. adventitiumfrom Illinois, all species of earthworms presented were attacked, including three species of earthworms not previously reported as prey. Earthworms many times the size of the planarians were attacked, and earthworms up to 10 times greater in size rarely survive attacks.

The pattern of colonization of B. adventitium in North America is very similar to that of an ecologically similar New Zealand land planarian,Artioposthia triangulata, that was accidentally introduced into Ireland in the early 1960s. Where this planarian has become established, it has been shown to reduce earthworm populations to below detectable levels, possibly to extinction. Few ecological studies of B. adventitium populations in North America have been conducted thus far, and it is not known what impact its establishment may have on earthworm populations or on the important soil processes that earthworms mediate, such as soil formation, organic matter transformations, and nutrient cycling.
http://wwx.inhs.illinois.edu/resources/ ... un00/worm/

Joe

Re: Invasive earthworm article

Post by Joe » Thu May 07, 2015 10:46 am

Regarding invasive species- my view, which is rare indeed, is that it's really a problem for humans because we don't like change- despite having changed everything on this planet. It seems inevitable, that, over geologic time, every life form that could thrive somewhere else- will get there- it will be a different world, in no way inferior, just different- maybe better. The only really dangerous, disruptive, invasive species in the human race.
Joe

User avatar
Lee Frelich
Posts: 155
Joined: Mon Mar 15, 2010 3:24 pm

Re: Invasive earthworm article

Post by Lee Frelich » Mon May 11, 2015 11:41 am

Yes, we have thought about introducing Asian flatworms, but can't be sure they won't kill other native things in the soil. Maybe we don't have to decide whether to introduce them, they seem to be getting around on their own. They have been found in Wisconsin as well other states listed.

The flatworms will probably be just one of many mechanisms that will come into play to limit European and Asian earthworm species abundance in North America over the next few thousand years as our forest ecosystems come into balance with these major exotic ecosystem engineers.

Lee

User avatar
Lucas
Posts: 837
Joined: Tue Jul 29, 2014 11:55 am

Re: Invasive earthworm article

Post by Lucas » Thu May 21, 2015 10:02 am

http://www.sciencedaily.com/releases/20 ... 122838.htm

Metal pollutants in earthworms may threaten forest predators, study finds

Invasive earthworms in New England's forests are absorbing toxic metal pollutants in potentially hazardous levels that may be contributing to a decline in birds, amphibians and mammals that feed on them, a study finds.
We travel the Milky way together, trees and men. - John Muir

Joe

Re: Invasive earthworm article

Post by Joe » Thu May 21, 2015 1:42 pm

Lucas wrote:http://www.sciencedaily.com/releases/20 ... 122838.htm

Metal pollutants in earthworms may threaten forest predators, study finds

Invasive earthworms in New England's forests are absorbing toxic metal pollutants in potentially hazardous levels that may be contributing to a decline in birds, amphibians and mammals that feed on them, a study finds.

the article says, " the last ice age 11,000 years ago forced the region's original earthworms to move southward"

So, why not make an effort to return the native earthworms?
Joe

User avatar
Lucas
Posts: 837
Joined: Tue Jul 29, 2014 11:55 am

Re: Invasive earthworm article

Post by Lucas » Tue Jul 28, 2015 12:48 pm

https://www.youtube.com/watch?v=seQ_5cmi49k&feature=youtu.be

The unkillable myth of worms.
We travel the Milky way together, trees and men. - John Muir

User avatar
Lucas
Posts: 837
Joined: Tue Jul 29, 2014 11:55 am

Re: Invasive earthworm article

Post by Lucas » Tue Sep 06, 2016 12:58 pm

https://www.sciencedaily.com/releases/2 ... 103358.htm

European earthworms decrease species diversity in North America
Burrowing invaders conquest North American forests
Date:
September 6, 2016

In Europe, they are classified as beneficial organisms, but many North American ecosystems are not adapted to these subterranean burrowers. This is because almost all earthworms became extinct there during the last ice age, which ended about 12,000 years ago. When the ice retreated, new ecosystems that are adapted to soils without earthworms emerged. But by now, several earthworm species live again in North America. They were introduced by European settlers and spread by anglers. An earthworm invasion is making its way through the forests at approximately five metres per year and is altering the physical and chemical properties of soils.

Earthworms mix soils and build extensive burrows, which interrupts the symbiotic relationship between plants and fungi (mycorrhiza). The mixing also affects soil pH: the best-known earthworm in central Europe, the Lumbricus terrestris, carries alkaline soil upwards from deeper layers. On the forest floor, the leaf litter vanishes as it is eaten up by the worms and turned into humus. As a result, the nutrients stored in the leaves become quickly available to the plants. Furthermore, the soils dry out easily as water drains away readily.

Many native plants cannot thrive under these unusual circumstances, which is why the species diversity of the forest understory is decreasing. Wherever the worm creeps, the goblin fern (Botrychium mormo), for example, has become rare. Other plants are also threatened by the earthworm invasion, such as the largeflower bellwort (Uvularia grandiflora), the Japanese angelica tree (Aralia elata), the forest lily (Trillium spp.), the Solomon's seal (Polygonatum spp.) or the tormentil (Potentilla erecta).

Conversely, the worms literally prepare the soil for non-native (exotic) plants, which are used to living with earthworms. Grasses also grow well in invaded forests because their fine roots can quickly absorb soil nutrients, particularly nitrogen, and can tolerate summer droughts. Moreover, earthworms eat small seeds of certain plant species and thus directly influence the composition of the forest understory. Because earthworms live in different soil layers and their effects are cumulative, the more types of earthworms that live together in one location, the more plant species vanish.

The researchers have brought together and evaluated data from 14 studies and published their findings in the journal Global Change Biology. Their results demonstrate, for the first time, a general pattern between the decline in species diversity in North American forests and the spread of European earthworms. 'The earthworm invasion has altered the biodiversity and possibly functioning of the forest ecosystems, because it affects the entire food web as well as water and nutrient cycles', says Dylan Craven, lead author of the study.

'The long-term impact could be massive and be exacerbated further still by climate change', adds director of studies, Professor Nico Eisenhauer. Both are scientists at the German Centre for Integrative Biodiversity Research (iDiv) and at the Leipzig University and have conducted their study together with colleagues from the United States and Canada. Eisenhauer had recently raised 1.5 million euros in funding from the EU to investigate the consequences of the earthworm invasion.
We travel the Milky way together, trees and men. - John Muir

Post Reply

Return to “Invasive Species and Tree Diseases”