Influence of connectivity & topsoil management practices of a constructed technosol on pedofauna colonization: A field study

Abstract

At the present time, rehabilitation of polluted urban areas and the restoration of their soil are environmental priorities. The creation of constructed soils appears to be a tempting way to restore, lastingly, a contaminated urban soil provided that they can become fertile and host a functional biodiversity delivering essential ecosystem services.To ensure this, the recolonization of newly established technosols composed of a mixture of compost and in situ deep alluvion was monitored using judiciously chosen bioindicators: springtails, mites, earthworms, carabid beetles and woodlice. These technosols were part of an experimental plot located inside the future “Ecoquartier de l’Union” (Roubaix, France).The results show that, if the connection of the technosols with an element of the local landscape (in this case a railway hedgerow) plays a part chiefly in aiding the first stages of recolonization, notably for earthworms and springtails, technosols management has a lasting impact on the colonization dynamics and the implantation of the different taxa.Establishing an herbaceous cover (flowering meadow, lawn) or a hedge was especially profitable to the pedofaunic communities, which were richer and more abundant, as well as to the technosols functioning (better litter degradation, diversified collembolan communities with regards to functional traits). The same is true for the addition of RCW (Ramial Chipped Wood) which benefits earthworm and mesofauna through the organic components released and the associated fungal development.