Concurrent adoption of multiple less intensive practices is essential for effectively preserving earthworm diversity in agroecosystems: a global meta-analysis

Abstract

The impact of intensifying land use on biodiversity has been extensively examined through efforts to synthesize available data. Nevertheless, there is still a lack of a thorough synthesis describing the earthworm response to land-use intensification on earthworms. We conducted a global meta-analysis synthesizing 113 publications across 44, yielding 1040 pairwise comparisons of earthworm density and biomass, and 536 pairwise comparisons of earthworm diversity. Arable cropland has significantly lower earthworm density (-18%), biomass (-15%), and species richness (-27%) compared to undisturbed sites. Conversely, higher earthworm density, biomass and species richness were observed in extensive pastures, sites under agroforestry, crop management with fallow periods and crop-livestock integration. In regions with continental climates characterized by cool summers exhibit more favorable earthworm responses to intensification. In compacted sites with low organic matter content the adverse effects of intensification are exacerbated. However, highly heterogeneous earthworm responses cannot be explained by the individual evaluation of climatic, soil-related, or management factors. Our results guide future efforts to address the data limitations that enable us enhance our understanding of the interactive effects of various factors on earthworm responses to land-use intensification, as well as evidence-based and management strategies targeted at promoting sustainable agricultural systems while preserving soil biodiversity.