Plant diversity and functional identity alter ant occurrence and activity in experimental grasslands

Abstract Increasing plant species richness has been shown to positively affect the diversity of a range other organisms, both above‐ and belowground. Although ants have multitude interactions with organisms through their role as predators mutualists, are taxon that rarely investigated in studies biodiversity effects. Ants known respond changes microclimatic conditions such temperature humidity, these be affected by vegetation characteristics standing biomass, which turn can diversity. We effects (1–60), number functional groups (FGs; 1–4), presence particular FGs on occurrence activity ants, context grassland experiment. Ant abundance, estimated mean workers pitfall traps, colonies within plots, but not ant richness, were negatively also identity FGs, particularly legumes (negative effects) grasses (positive effects). Statistical approaches showed largely mediated biotic (aboveground biomass: negative effect) abiotic variables (soil temperature: positive effect). Notably, activity, measured foraging baits disproportionate dominance single ( Lasius niger ), more complex pattern, where interacted explain differential attractiveness different resources (represented sugar tuna baits), likely representing current nutritional requirements for ants. Similarly, increasing soil increased level indicating factors might impose thermal constraints ectotherms inhabiting temperate grasslands. Our results indicate higher biomass had effect experimental Understanding responses an ecologically important group will allow us infer loss could animal‐mediated ecosystem processes.