This session aims to explore innovative methodologies for assessing soil fauna and ecosystem functionality, integrating both molecular and classical approaches. Next-Generation sequencing has allowed integration of techniques such as DNA metabarcoding and environmental DNA (eDNA) has revolutionised our understanding of soil ecosystems, allowing for unprecedented insights into microbial and faunal communities. The synergy between Sanger Sequencing, Next Generation Sequencing (NGS) and traditional classification methods can offer a comprehensive and more reliable view of soil biodiversity, enhancing our understanding of soil fauna, their roles and interactions. This session invites researchers to present and discuss novel methodologies, the associated challenges, and the integration of these techniques into broader biogeoscientific research. Through case studies and theoretical frameworks, this session will foster discussions on the pivotal role of molecular methods in advancing our understanding of soil biodiversity while emphasising the continued importance of traditional approaches.