Connectedness of habitat fragments boosts conservation benefits for butterflies, but only in landscapes with little cropland

Context Global change pressures (GCPs) imperilspecies and associated ecosystem functions, but studies investigating interactions of landscape-scale pressures remain scarce. Loss of species-rich habitat and agricultural expansion are major threats for biodiversity, but if or how these factors interactively determine community-level shifts and conservation outcomes remains unclear. Objectives We tested whether matrix simplification (dominance of cropland) and reduced connectivity (i.e. landscape-scale habitat loss) either additively, synergistically or antagonistically cause community shifts in butterflies, a group of high conservation relevance. Methods We surveyed butterflies on 30 small calcareous grassland fragments (