Pesticide effects on soil fauna communities—A meta‐analysis

Abstract

Soil invertebrate communities represent a significant fraction of global biodiversity and play crucial roles in ecosystems. A number of human activities threaten soil communities, in particular intensive agricultural practices such as pesticide use. However, there is currently no quantitative synthesis of the impacts of pesticides on soil fauna communities. Here, using a meta‐analysis of 54 studies and 294 observations, we quantify pesticide effects on the abundance, biomass, richness and diversity of natural soil fauna communities across a wide range of environmental contexts. We also identify scenarios with the most detrimental effects on soil fauna communities by analysing the effects of different pesticides (herbicides, fungicides, insecticides, broad‐spectrum substances and multiple substances), different application rates and temporal extents (short‐ or long‐term), as well as the response of different functional groups of soil animals (body size categories, presence of exoskeleton). Pesticides overall decreased the abundance and diversity of soil fauna communities across studies (Grand mean effect size (Hedge's g) = −0.30 +/− 0.16) and had stronger effects on soil fauna diversity than abundance. The most detrimental scenarios involved multiple substances, broad‐spectrum substances and insecticides, which significantly decreased soil fauna diversity even at recommended rates. We found no evidence that pesticide effects dampen over time, as short‐term and long‐term studies exhibited similar mean effect sizes. Policy implications: Our study highlights that pesticide use has significant detrimental non‐target effects on soil biodiversity, eroding a substantial part of global biodiversity and threatening ecosystem health. This provides crucial evidence supporting recent policies, such as the European Green Deal, that aim to reduce pesticide use in agriculture to conserve biodiversity. The detrimental effects of multiple substances revealed here are particularly concerning because realistic pesticide use often combines several substances targeting different pests and diseases over the crop season. We suggest that future guidelines for pesticide registration, restrictions and banning should rely on data able to fully capture the long‐term consequences of multiple substances for multiple non‐target species in realistic conditions.

The neonicotinoid acetamiprid is highly toxic to wild non-target insects

“…However, this has mainly been studied in freshwater communities (Beketov et al 2013, Rumschlag et al 2020), whereas the effects on terrestrial communities are less well understood. A recent meta-analysis showed that pesticide contamination reduces soil invertebrate diversity (Beaumelle et al 2023). Main et al (2020) have also linked neonicotinoid soil contamination to reduced species richness of wild bees in field margins.…”

Meta‐analysis reveals that the effects of precipitation change on soil and litter fauna in forests depend on body size

“…In addition, existing meta‐analyses on the impacts of global change on soil fauna (This study; Beaumelle et al., 2023; Blankinship et al., 2011; Bristol et al., 2023; Goncharov et al., 2023; Peng et al., 2022; Phillips et al., 2023) use biodiversity metrics related to abundance and alpha diversity, meaning we know little about impacts on more complex aspects of biodiversity such as community composition and functional diversity. We advocate for researchers to collate and use raw data from field studies to allow for more nuanced ‘full data’ analyses which can avoid issues associated with the use of effect sizes (Spake et al., 2023) and that are becoming the gold standard in other fields, such as medicine (Culina et al., 2018; Spake et al., 2022).…”

Deciphering key factors in pathogen-suppressive microbiome assembly in the rhizosphere

“…Practices such as intercropping and crop rotation are widely witnessed to promote plant health through modification of rhizosphere microbiome ( Neupane et al., 2021 ; Chadfield et al., 2022 ; Town et al., 2023 ; Zhou et al., 2023 ). On the other hand, monoculture, intensive tillage, and extensive use of chemical fertilizers and pesticides have been reported to deteriorate plant health through modification of microbial diversity in the rhizosphere ( Li et al., 2022 ; Morugán-Coronado et al., 2022 ; Beaumelle et al., 2023 ).…”