Unlike some other North American grasslands, such as the short grass prairies of the Great Plains and tall grass prairies of the Midwest, neither fires nor extensive grazing by large herbivores (like bison) were historically a part of the Palouse grassland ecology. When European settlers moved into the Palouse at the end of the nineteenth century, they brought both fire and grazers. These two influences had a huge impact on the native plants: the perennial bunchgrasses were not resistant to the heavy grazing, and were eventually largely replaced by plants better-adapted to these conditions, typically annual herbs and grasses.