Predictor variables
For each case, data for model moderators, such as the taxonomic group,
body size, and habitat type were collected. Taxonomic names were
harmonised to those used by the Global Soil Biodiversity Atlas (GSBA;
(Table S2). From the GSBA harmonisation, each taxonomic group was
assigned to a body-size category (micro-, meso-, macro-fauna) if that
had not already been done by the original author. Body-size categories
were also based on . Microarthropods were assigned to meso-fauna,
macro-arthropods and macro-invertebrates were assigned to macro-fauna.
Any cases where authors did not classify the data to a taxonomic or size
unit (e.g., described as ‘All soil fauna’), were classed into one
category, “All Sizes”. The type of habitat the samples were from was
also classified into one of six predefined classifications; agriculture,
grassland, woody, cold/dry, wetlands, or artificial.
To help ensure consistency in data extraction, all project members
followed a data extraction protocol created at the start of the project.
In addition, data extracted from nearly all articles were checked by a
second individual.