A Keystone Species is one having a disproportionately large effect on its ecosystem relative to its abundance. Its removal would cause significant changes to the ecosystem, potentially leading to its collapse. Essentially, they play a crucial role in maintaining the balance and diversity of their environment.
Outsized Impact:
Keystone species have a greater impact on their ecosystem than their numbers might suggest.
Ecosystem Engineers:
Some keystone species, like beavers, modify their environment, creating new habitats and increasing Biodiversity!
Apex Predators:
Top predators, like wolves or sharks, can also be keystone species by controlling populations of their prey. This usually limits the destructive effect of conditions like “over-grazing” in one area, or preventing the growth of important vegetation.
Pollinators:
Species like bees and hummingbirds, which are essential for plant reproduction, can be keystone mutualists.
Consequences of Removal:
If a keystone species is removed, the ecosystem can experience dramatic changes, including a decline in biodiversity and even collapse.
Buffalo are considered a Keystone species. When significant numbers of Buffalo were re-introduced to the prairie in South Dakota there was a significant improvement in the health and biodiversity of the land. Before the Buffalo were re-established, there was very little plant or animal, or insect biodiversity. Because of the way they graze and roam on the prairie, restoration happened faster than expected. This restoration is ongoing, with Buffalo grazing on nearly 60,000 acres across two properties.
Buffalo graze the grasses at different heights, providing nesting grounds for birds. They also roll around and pack down the soil in depressions in the ground known as wallows. These wallows fill with rainwater and offer breeding pools for amphibians and sources of drinking water for wildlife across the landscape. The Buffalo’s split hooves also create smaller depressions that can hold water, giving it time to be absorbed into the ground. Over time, this can raise the level of groundwater.
During the late 1880’s, Buffalo were hunted for their hides, and to remove the main food source for nomadic Native Americans. By 1900, it was estimated that there were fewer than 1,000 bison left in North America. In 1800, the Buffalo population in North America was estimated to have been between 30 and 60 million. It is possible that this drastic decline of the Buffalo from the Great American Prairie contributed to the dust storms of the 1930s. This would be an example of what can happen when a Keystone species is removed or eliminated from its environment. It can also demonstrate the amazing result of bringing back the Keystone Species.
