Does soil fauna like truffles just as humans do? One-year study of biodiversity in natural brûlés of Tuber aestivum Vittad

Identification of Dipteran species inhabiting Tuber aestivum (the summer truffle) ascomata

Tuber spp. (Ascomycota) forms hypogeous fruiting bodies (truffles) that host many microbial species as well as invertebrates which feed on them. Despite the larvae and adults of Diptera and Coleoptera are commonly found to inhabit truffles, molecular investigations assessing their occurrence are still few and the number of species is probably underestimated. In this study, 52 larvae and adults of Diptera from 23 T. aestivum ascomata collected in two provinces of northern and central Italy were molecularly characterized. The sequences fell into four Diptera families, and four taxa were identified as Cheilosia soror, Phaonia cf. trimaculata, Drosophila subobscura, and Suillia gigantea. Morphology of adults belonging to these species confirmed their identity. Additional three taxa belonging to the Helomyzidae remained unclassified. The study highlighted the coexistence of different Diptera species in the same ascoma, suggesting potential lack of competitive exclusion. Geographical distribution analysis reveals non-site specificity for most species. This research contributes insights into the diversity of Dipteran species and their interactions with truffles and lays the groundwork for their monitoring, at a time where truffle resources are threatened by anthropic and environmental factors.

Soil functional biodiversity and biological quality under threat: intensive land use outweighs climate change

Climate change and land use intensification are the two most common global change drivers of biodiversity loss. Like other organisms, the soil meso-fauna are expected to modify their functional diversity and composition in response to climate and land use changes. Here, we investigated the functional responses of Collembola, one of the most abundant and ecologically important groups of soil invertebrates. This study was conducted at the Global Change Experimental Facility (GCEF) in central Germany, where we tested the effects of climate (ambient vs. 'future' as projected for this region for the years between 2070 and 2100), land use (conventional farming, organic farming, intensively-used meadow, extensively-used meadow, and extensively-used pasture), and their interactions on the functional diversity (FD), community-weighted mean (CWM) traits (life-history, morphology), and functional composition of Collembola, as well as the Soil Biological Quality-Collembola (QBS-c) index. We found that land use was overwhelmingly the dominant driver of shifts in functional diversity, functional traits, and functional composition of Collembola, and of shifts in soil biological quality. These significant land use effects were mainly due to the differences between the two main land use types, i.e. cropland vs. grasslands. Specifically, Collembola functional biodiversity and soil biological quality were significantly lower in croplands than grasslands. However, no interactive effect of climate × land use was found in this study, suggesting that land use effects on Collembola were independent of the climate change scenario. Overall, our study shows that functional responses of Collembola are highly vulnerable to land use intensification under both climate scenarios. We conclude that land use changes reduce functional biodiversity and biological quality of soil.