Soil Arthropod Diversity and Biological Soil Quality: A Web-Based Framework for Standardized EMI Attribution in...

Soil arthropods play a crucial role in soil functioning, contributing to organic matter decomposition, nutrient cycling, soil structure formation, and microbial regulation. The Soil Biological Quality index based on arthropods (QBS-ar) is widely used to assess soil quality through the eco-morphological adaptation of soil microarthropods. However, Eco-Morphological Index (EMI) attribution often relies on qualitative criteria and operator experience, highlighting the need for more standardized and transparent scoring procedures. Similar limitations affect Collembola-based approaches, where trait interpretation and score assignment may vary among users. Here, we present two web-based tools designed to support a more standardized and transparent attribution of EMI scores in QBS-ar and QBS-c. The first is an interactive identification key for major soil arthropod groups linked to explicit EMI scoring rules and automatic QBS-ar calculation. The second is a trait-based framework for Collembola (QBS-c) that translates the original rationale of Parisi's approach into a quantitative procedure based on seven morphological traits. The QBS-c framework can also support EMI assignment for Collembola within QBS-ar when direct attribution is uncertain. The tools transform expert-based qualitative criteria into structured decision pathways, standardized trait classes, and reproducible outputs, with built-in consistency checks to improve traceability. Together, they provide a standardized and openly accessible framework for EMI assignment in soil arthropod bioindication, supporting methodological transparency, training, and future inter-operator validation of QBS-based methods.