Species → American bison
American bison
Bison bison
What if it disappeared?
Impact ModerateWithout bison grazing and their patchy disturbance of the soil, a prairie would lose the mosaic of vegetation at different regrowth stages that currently increases its plant diversity compared with uniform grazing.
DocumentedDetail
Knapp, A.K., Blair, J.M., Briggs, J.M. et al. (1999). The Keystone Role of Bison in North American Tallgrass Prairie. BioScience, 49(1), 39–50.
At Konza Prairie (Kansas), the authors show that bison graze some areas intensively while leaving others untouched, unlike the more uniform grazing pattern of cattle. This heterogeneity increases the diversity of habitats available for plants and the species that depend on them.
Recreating this heterogeneity across large restored prairies could restore some of the lost plant biodiversity — but no currently reconstituted population reaches the size and freedom of movement of the historical herd studied.
ExtrapolatedDetail
Extrapolation à partir de Knapp et al. (1999) : l'effet mesuré à Konza Prairie appliqué à l'échelle d'une restauration de grande prairie, pas un résultat publié pour cette échelle.
Nearly all bison today live in enclosures or managed herds at a much smaller scale than historical migrations. How much of that scale and freedom of movement is needed to reproduce the effect measured at Konza Prairie remains to be established elsewhere.
What's missing to confirm it: No study confirms at what herd size and area the heterogeneity effect measured at Konza Prairie holds up or fades.
Documentation
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IUCN SSC Bison Specialist Group — Bison bison, statut et effectifs
Accessed August 7, 2026
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Knapp et al. (1999) — The Keystone Role of Bison in North American Tallgrass Prairie, BioScience
Accessed August 7, 2026
Last verified: August 7, 2026