Conservation value of artificial subterranean systems: a case study in an abandoned mine in Italy

Subterranean ecosystems often harbour unique and specialised biocoenoses of considerable scientific interest and high potential conservation value. In view of the peculiar species assemblage in the abandoned tunnels of a talc mine complex in the north-western Italian Alps (Germanasca Valley, Province of Turin, NW Italy), the aims of the present work were (i) to investigate the subterranean invertebrate fauna, (ii) to assess the impact of tourism activities on the invertebrate fauna, and (iii) to assess the conservation value of the terrestrial invertebrate community and associated habitats. The study was carried out at four sites: one tunnel restored for tourism purposes; two abandoned tunnels; and a wild cave. The results of several statistical analyses, including ANOVA, PCA and CCA, showed that the eutrophic conditions induced by past human activity could improve the quality of the subterranean habitat. On the other hand, a massive intervention for tourism purposes could seriously jeopardise the survival of the most sensitive species. The increased thermic instability and mean temperature had a significant negative effect on the local populations of cave-dwelling arthropods, whose ecological optimum is determined primarily by low thermic instability, cold temperatures and intermediate conditions of eutrophy. On the basis of our results we strongly recommend to avoid thermic isolation of any part of tunnels, as it is the primary factor affecting the most sensitive species.