Tuesday, September 6, 2011

Alien worm invasion 'threat to forests'

Invasive earthworms can alter the carbon and nitrogen cycles in woodland, as well as undermining native plant species, a study has said.

US researchers found that the presence of non-native worms also accelerated the breakdown of forest litter, increasing the risk of soil erosion.

The worms are spread to new areas by horticulture and land disturbance, they add, as well as on vehicles' tyres.

The findings have been published in the journal Human Ecology.

"The presence of earthworms in temperate hardwood forests may accelerate decomposition of forest litter, which potentially reduces habitat for forest-floor animals, (increases) soil erosion... and affects carbon and nitrogen cycles," the researchers from Colgate University, New York, wrote.

Quoting a previous study, the scientists said that invasive earthworms could reduce the amount of carbon stored in soil by up to 28% as a result of the animals eating fallen leaves, which had a knock-on effect on the temperature of the forest floor. more