Grizzly Bear
By: David Ferris 3 White
Background
Grizzly Bear
Map of Grizzly Bear Range
Grizzly Bear After Feeding
Why is the Grizzly Bear Endangered?
Ecological Importance
Another ecological role bears play is that they stir up soil. When bears forage for food, they dig into the soil and mix the soil up. Studies show that when the bears dig up soil, it actually increases plant diversity in that area. When bears dig up the soil, it also causes nitrogen from the lower soil levels to be brought up, which plays a vital role in the nitrogen cycle, which can help cleanse our air. Bears can also increase nitrogen when they bring salmon carcasses back behind the river bed.
Grizzly bears can be categorized as a keystone species in Yellowstone National Park, that is they directly influence the ecosystem. They keep the prey population under control and help prevent overgrazing. A study done in Yellowstone found that with the removal of wolves and the grizzly bear the herbivorous prey increased, changing the density and structure of the surrounding plants, which decreased the population of migratory birds.
Economical Importance
Grizzlies also are a keystone species in Yellowstone, so if they did not keep the prey population under control, the herbivorous prey would increase, causing the plant population to significantly decrease, which would also drive down tourism at the national parks, which would be bad for the national parks.