Interactions between Soil Structure and Soil Organic Matter: Contribution of Pedofauna Activity

Soil fauna plays an important role in the interaction between soil structure and soil organic matter. Burrowing and excretionactivities induce new pore formation and stabilization of pre-existing ones modifying soil functioning also in its role of carbon pool.In this study we aimed to identify and quantify the contribution of different soil organisms on soil structure using soil imageanalysis techniques at soil micromorphology scaleUndisturbed soil sampling and soil micro- and macro-fauna identification were performed in sites characterized by different soilmanagement and soil types in Valle Telesina, Benevento, Italy.Different biological features (faecal pellets, organic residues, channels and chambers, etc.) have been identified by means of soilthin sections observation and their contribution to the soil pore and aggregate size distribution was quantified by means of imageanalysis procedures based on mathematical morphology.The results of this preliminary study have allowed to observe that the combination of different biological activities in the same soilproduce a pronounced multimodality in pore size distribution, and then an increase of the complexity and of the quality of soilstructure. Moreover different organisms induce specific signals on soil pore size distribution, providing data useful to simulate thecontribution of different biological activities in fluid and solute transport.