Evidence of a European seed dispersal crisis

Editor’s summary

Plants rely on seed dispersal, often by animals, for individual movement and population spread. Habitat loss and environmental change are known to threaten many plant and animal species, but the effects of population declines on the potential for seed dispersal are largely unknown. To address this knowledge gap, Mendes et al. synthesized data on plant-animal seed dispersal interactions for the whole of Europe and characterized each species interaction as being of low, high, or very high concern based on the species’ conservation statuses and population trajectories. Almost one-third of all species interactions were found to be of high or very high concern, potentially further threatening plant species’ persistence. However, data gaps are substantial, and this finding requires further study and evaluation. —Bianca Lopez

Abstract

Seed dispersal is crucial for ecosystem persistence, especially in fragmented landscapes, such as those common in Europe. Ongoing defaunation might compromise effective seed dispersal, but the conservation status of pairwise interactions remains unknown. With a literature review, we reconstructed the first European-wide seed dispersal network and evaluated the conservation status of interactions by assessing each interacting partner’s IUCN (International Union for Conservation of Nature) conservation status and population trends. We found that a third of the disperser species and interactions face potential extinction and that 30% of the plant species have most of their dispersers threatened or declining. Our study reveals a developing seed dispersal crisis in Europe and highlights large knowledge gaps regarding the dispersers and conservation status of zoochorous plants, urging further scrutiny and action to conserve the seed dispersal service.