But the grasslands can also lose nitrogen through fire. Fires cause loss of nitrogen from the burning of plant material. However, bison grazing counters this effect of fires by decreasing the plant detritus and increasing the patchiness of the fire due to the patchy results of grazing (Hobbs, et. al. 1990). Areas that are lightly grazed by bison will build up aboveground plant detritus, rendering that area more prone to fires. But the fire allows for a new round of growth which tend to attract bison. The grazing then will mitigate the conditions favoring fires in that area. After a period of perhaps two to three years, the bison will move on, and the aboveground plant detritus will then once more build up, creating a new patch prone to fires (Callenbach 1996. 24-25).
Bison affect animal mass as well through grazing, dying and facilitating habitat. Bison grazed areas increase the foraging of prairie dogs which become a food source for ferrets, hawks, eagles, and foxes, sustaining these species. In addition prairie dog colonies become homes to other small mammals and reptiles (Fallon 2009). During the winter, in areas of deep snow, bison expose forage for others such as pronghorn, deer, birds and small mammals. When bison die, their carcasses become a food source for coyotes, bears, eagles, and ravens. Even small non-savaging birds benefit from bison remains, picking maggots and suet from the carcass (Bailey 2013. 98). The bison carcasses harbor insects which provide food for birds and some small mammals (Baily 2013. 45-46). In addition to disease and other natural causes bison deaths result from predation by wolves who do hunt the bison.
Wolves evolved to hunt hooved animals and in packs become the bison’s primary enemy. But often the wolves are simply opportunists preying on the small mammals that are flushed out by the bison hooves (Lott 2002. 100). But bison are not just “what’s for dinner.” They also provide housing materials such as shed hair for nesting birds and small mammals. There is even a suggestion the shed hair in the nests wards off predators by covering the scent of the bird or small mammal with the scent of the bison (Bailey 2013. 46).
An ecosystem such as the Great Plains constitutes an intricate complex of interactions of diverse plant, animal and insect species along with soil, water, light and fire. Uniquely and significantly interwoven in that complex stands the bison. From their hair to their dung; from their grazing to their wallowing; from their stands into fierce storms to their roaming; from life to death, the bison’s contributions cascade throughout and make possible the biological diversity of the Great Plains. Pte Oyate, the buffalo nation, have proven they are a keystone in that ecosystem. The restoration of the Great Plains, then, lies in the restoration of the bison. Efforts to recover the bison began in the late 19th century, but not until the 1970s and ‘80s did recovery efforts recognize the need for an ecological restoration rather than simply a numerical increase of bison. To achieve this end the Pte Oyate are looking to us to join the endeavor of returning them to the Great Plains.
Bailey, James A. 2013. American Plains Bison: Rewilding an Icon. Helena, MT. Sweetgrass Books.
Callanbach, Ernest. 1996. Bring Back the Buffalo: A Sustainable Future for America’s Great Plains. Berkeley. University of California Press.
Fallon, Sylvia. 2009. The Ecological Importance of Bison in Mixed-Grass Prairie Ecosystems. Retrieved from The Buffalo Field Campaign. http://www.buffalofieldcampaign.org/images/get-involved/students-resource-about-bison/bison-conservation-papers/Fallon-The-ecological-importance-of-bison-in-mixed-grass-prairie-ecosystems-2009.pdf
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