Influence of global change drivers on fine scale determinants of soil fauna

Comunicación oral (TS.14-O-12) presentada en the 1st Meeting of the Iberian Ecological Society (SIBECOL) & XIV AEET meeting. Barcelona, Spain, 4th – 7th February 2019
Soil fauna plays an essential role for nutrient cycling processes, but the drivers promoting changes in its abundance and diversity, particularly within a global change context are largely unknown. In spring 2016, we built a rainfall exclusion experiment (30% rainfall reduction) to explore soil fauna responses to simulated climate change in a mixed oak forest of southern Spain invaded by the exotic soil-borne pathogen Phytophthora cinnamomi. We identified soil fauna groups at the suborder taxonomic level and its trophic position at the beginning of the experiment and after one year in both experimental and control plots. We then analysed the effect of the rainfall reduction treatment on temporal changes in the abundance and diversity of soil measofauna. We also explored statistical correlations with fine-scale biotic and abiotic parameters by means of structural equation models. Primarily, we observed that one year of experimental rainfall reduction strongly decreased predator abundance but not detritivore abundance. Moreover, light availability, tree defoliation and the abundance of P. cinnamomi were identified as the main drivers of the changes in the abundance of particular detritivore groups. Our results demonstrate rapid responses of the abundance and composition of the litter mesofauna to climate change-related drought, with the organisms in the higher trophic levels being the more susceptible to increasing dryness. Multiple tree and litter characteristics influenced litter fauna abundance at local scale, suggesting that global change drivers as climate change and invasive exotic species are modifying these complex relationships.