Humanity’s redistribution of global biomass flows

The biosphere is connected by flows of organic material (biomass), through biogenic (e.g., animal migration) or anthropogenic pathways (e.g., trade). We argue that humans have drastically altered Earth’s biomass flows by disrupting animal movement, directly transporting biomass and creating novel biotic pathways. In 2023, transnational anthropogenic transport of biomass through trade far exceeded estimates of all long-distance biogenic biomass flows combined. Human population growth and consumption typically drive anthropogenic flows across longitudes, whereas biogenic flows follow seasonal (typically latitudinal) or local gradients in resources, as individuals spill over from areas of higher to lower resource availability or actively move towards high resource availability. Shifting flows affect organic waste and nutrients, change resource availability to local hunting and fisheries, and disrupt fundamental ecological and evolutionary processes.