A Mediterranean earthworm species has been found thriving in an urban farm in Ireland.
Scientists from University College Dublin found a flourishing population of Prosellodrius amplisetosus in an urban farm in Dublin, suggesting rising soil temperatures could be affecting the geographical habitat range of the earthworm.
“Soil decomposer species including earthworms are frequently introduced into non-native soils by human activities like the transportation of nursery plants or live fish bait,” says Dr Olaf Schmidt from the School of Agriculture and Food Science.
“There have been a few recordings of the earthworm P. amplisetosus outside of its native range in the Aquitaine region of south-western France, but now we have discovered a successfully thriving population in Ireland, about 1,000 km north of its native habitat.”
Researchers believe the earthworm may have become established at this new location because urban farms have higher temperatures than rural farms, and because there is little difference in the mean yearly air temperature between the worm’s native habitat and their new one.
P. amplisetosus is not an invasive species in Ireland and does not directly compete with other resident species for resources – it is a soil decomposer that eats organic carbon in parts of the soil the resident worms don’t have access to.
“By comparing the chemical composition of the worms, we discovered that the newcomers feed on a portion of the soil that the other resident earthworms do not use,” says Carol Melody, a PhD student.
However, P. amplisetosus could cause problems, says Dr Schmidt: “If other soil decomposers like P. amplisetosus start to expand their habitat ranges we could see increasing amounts of CO2 being released from the soil where previously this carbon had been locked up because it was inaccessible to native earthworm species.”