Yellowstone’s free moving large bison herds provide a glimpse of their past ecosystem function

While momentum is building to restore bison across North America, most
efforts focus on small, managed herds, leaving it unclear how large,
migrating bison shape landscapes and whether their effects enhance or
degrade ecosystems. We assessed carbon and nitrogen dynamics across the
migratory landscape of bison in Yellowstone, one of the last large
migratory populations. Bison stabilized net aboveground production while
accelerating nitrogen turnover, increasing aboveground nitrogen pools
while carbon pools remained stable, which improved landscape nutritional
quality. Effects were strongest in wet, nutrient-rich habitats that
received higher bison densities and grazing than recommended in rangeland
management, while soil and plant conditions suggested landscape
resilience. Restoration should embrace heterogeneity in densities and
effects across habitats and spatial scales beyond those guiding most
current recovery efforts.