Estimating the microarthropod diversity in cropping systems by comparing ecological indices across Europe

Microarthropods are pivotal components of the soil mesofauna, significantly contributing to the enhancement of soil quality and structural properties. The evaluation of microarthropod diversity provides valuable information on soil health, owing to their contribution to specific ecosystem services of soil. To monitor mesofauna diversity, the definition and validation of structural ecological indices capable of comprehensively assessing microarthropod community diversity and functionality is needed. In this work, several ecological indices (Hill's number, Acari:Collembola, QBS-ar, FEMI, QBS-ab) based on microarthropod biological forms (BFs) were applied to evaluate soil mesofauna biodiversity in 17 agroecosystem sites under either organic or integrated management. In addition, a novel calculation of the QBS-ar, which consider all observed BFs, called QBS-ar_BF, was proposed and compared to the other indices. The frequency and abundance of BFs highly adapted to soil life differ between management systems (integrated < organic) and crop duration (pluriannual > annual). Overall, the indices that best discriminated the different management in cropping systems were those based on the QBS approach (QBS-ar and QBS-ar_BF) . Moreover, the newly developed QBS-ar_BF index highlighted a higher discrimination capacity due to its inclusion of all observed BFs, i.e. all microarthropod community spectrum information. This study confirmed the pivotal role of edaphic mesofauna in highlighting the differences between soil management and crops across Europe, opening perspectives to new monitoring frameworks to detect shifts in community structure and functional traits.