Does the natural 'microcosm' created by Tuber aestivum affect soil microarthropods? A new hypothesis based on Collembola in truffle culture

摘要

The interactions between fungi and soil fauna are not well known. Some studies suggest that soil microarthropods play an important role in fungi dispersion, but little is still known about the interaction between truffle and soil microarthropods. The aim of this study was to investigate the ability of the truffle Tuber aestivum to modify soil biogeochemistry (i.e. create a zone of scarce vegetation around the host plant, called a burn or brule) and to highlight the effects of the brule on the soil fauna community. We compared soil microarthropod communities found in the soil inside versus outside the T. aestivum brule with the chemistry of soil collected inside versus outside the brule. The study was carried out in three Mediterranean areas, two in Italy and one in Spain. The results confirmed the ability of T. aestivum to modify soil biogeochemistry in the brule: pH was higher and total organic carbon tended to be lower inside the brule compared to outside. Soil fauna communities showed some interesting differences. Some groups, such as Symphyla and Pauropoda, adapted well to the soil; some Collembolan families, and biodiversity and soil quality indices were generally higher outside the brule. Folsomia sp. showed higher abundance in the soil of the brule compared to outside. The results suggest that some Collembola groups may be attracted by the fungal metabolites produced by T. aestivum, while other Collembola and other microarthropods may find an unfavourable environment in the soil of the brule. The next steps will be to confirm this hypothesis and to extend the study to other keys groups such as nematodes and earthworms and to link fluctuations of soil communities with the biological phases of truffle growth. (C) 2014 Elsevier B.V. All rights reserved.