Emergent functions in the chemodiversity landscape

Nature produces countless metabolites that regulate organismal performance and the functioning of ecosystems. Specialised metabolites are particularly diverse and mediate ecological interactions across all geographic scales and levels of biological organisation. While chemodiversity, i.e., the richness, relative abundance and disparity of specialised metabolites within a blend of metabolites, has received substantial interest at the level of pairwise interactions (e.g. between plants and interaction partners), much less is known about how metabolites produced by multiple individuals across the tree of life merge into higher-level blends at population, community and ecosystem scales. We synthesise evidence for emergent functions that arise from such higher-level chemodiversity. We examine how blends change in composition as they move through air, water, and soil, and vary in time and space, thereby creating a dynamic ‘chemodiversity landscape’. We further discuss the applied potential of these chemodiversity landscapes and the threats that could compromise them. We outline key questions that will help guide research on how higher-level chemodiversity contributes to ecological processes and functioning across scales.