Earthworms Gaia’s best friends
It is said that earthworms ventured out from the sea 500M years ago and colonized terrestrial environments.
Since then, they have developed a large diversity of life forms distributed among several thousand species able to exploit any ecological niche in the soil and litter environment. They have developed strong interactions with all soil organisms through their remarkable activity as soil ecosystem engineers. Their widely acknowledged participation in the provision of soil ecosystem services has been described in many scientific outlets. Earthworms are also described as efficient protectors of plants through still little understood molecular (and other) mechanisms. So far we only know that very intimate interactions involving plant gene expression are at hand.
Earthworms must have gone through a number of major disturbances and changes. The shift from Gymnosperm to Angiosperm dominant vegetation likely affected the quality of organic inputs to litter and soils greatly. More recently, they lived through the great Quaternary glaciations and recolonized the newly formed soils after glacial retreat in Northern Europe and America. The Anthropocene is now at hand. Many earthworm species will likely disappear as a result of conversion or modification of their natural habitat, many of them without ever having been given a scientific name. Conservation implies creation of a very dense network of relatively small reserve areas.
However, a small number of peregrine species, specially adapted to great disturbances, are already mitigating damages to soils and plant communities. The remarkable ability of this group to create new species will likely help them to replace the extinct groups of poorly adapted species, at a fast, although still geological, pace. Earthworms will remain Gaia’s best friends and help through yet another great disturbance.
International Symposium of Earthworm Ecology (ISEE 9), Xalapa, Mexico, 5-9 september 2010. Introductory Conference