Grazing bison contribute to the health of the ecosystem and greater biodiversity. Bison tend to eat in patches and wander on, leaving a patchwork of grazed and un-grazed areas. Their avoidance of woody plants and forbs favors these species and increases the exchange of gasses, biomass, plant density and cover.
Bison help spread certain species of fungi among grasslands separated by coniferous forests by passing the fungi through their gastrointestinal tracts.
Prairie dogs have an easier time foraging in areas grazed by bison. Ferrets, foxes, hawks and eagles, natural predators of prairie dogs, all benefit, as do small mammals and reptiles, which make their homes in prairie dog colonies.