Great bison belt
The great bison belt is a tract of rich grassland that ran from Alaska to the Gulf of Mexico from around 9000 BC.
The great bison belt was supported by spring and early summer rainfall that allowed short grasses to grow.
These grasses retain their moisture at the roots which allowed for grazing ungulates such as bison to find high-quality nutritious food in autumn.
About 50–75 million years ago, surging molten rock formed the mountain ranges of the west, including the Black Hills.
About 10 million years ago, geological forces shaped the rest of the great bison belt, the largest terrestrial biome in North America.
[1] When the Pleistocene epoch ended about 10,000 years ago, warmer and drier weather came to dominate the region, making the biome ideal for grasslands and vegetation.
[2] Before human intervention, the great bison belt included most of the present-day United States as well as parts of Canada and Mexico.
These grasses have deep and dense root structure and retain large amounts of water, making them well suited to survive dramatic environmental fluctuations.
[10] The protein to carbohydrate ratio in the short grass provided an ideal diet for large numbers of bison.
The most consequential way by which the Indigenous peoples of North America affected the ecology of the great bison belt was by expanding it through fire.
By initiating controlled burns at regular intervals, Native Americans were able to expand shortgrass plains into formerly forested areas, and maintain them by preventing the regrowth of brush.
Woodland is not commonly changed to prairie by one burning, but by several successive conflagrations; the first will kill the undergrowth, which causing a greater opening, and admitting the sun and air more freely, increases the quantity of grass the ensuing season: the conflagration consequently increases, and is not sufficiently powerful to destroy the smaller timber; and on the third year, you behold an open prairie.
By initiating burns to cause regrowth which is rich in nutrients, they could artificially create ideal conditions for bison to graze in.
By setting fires in a path, they were able to drive ruminants (such as bison and deer) towards hunters, allowing for easier kills.
At the same time, deforestation to the north and east combined with the growth of the cattle market to the south, placing even greater pressure on the bison.
[citation needed] Additionally, some groups continue to initiate controlled burns, so as to maintain healthy grassland.
[22] The area that makes up the great bison belt continues to be a breadbasket for North America, with farmland to the east and cattle to the west.
