A meta-analysis of ant-mediated effects on soil carbon cycling and organic matter stability

Ants are key engineers in biogeochemical cycling, yet their effects on soil organic carbon (SOC) turnover and greenhouse gases emissions remain debated. Based on a meta-analysis of 2232 observations from 136 studies worldwide, we show that ant activities increased SOC storage by 22% compared to the adjacent ant-free locations and also raised CO2 emissions by 84%, with ant respiration as the key contributor. Ant species and nesting strategies are key functional traits mediating these effects on carbon storage and fluxes. Climate indirectly influences organic matter processing by regulating ant functional traits. The relative effects of ants on SOC storage are especially pronounced in mid-latitude ecosystems with low initial SOC content. These findings highlight the pivotal role of ants as ecosystem engineers that regulate organic matter processing and reshape soil carbon pathways across terrestrial ecosystems. Ants are common soil engineers that influence carbon cycling. This meta-analysis shows that ants increase soil organic carbon storage by 22% and CO2 emissions by 84%, with effects shaped by species, nesting strategy, and climate.