Background on Prairie Ecology

Prairie, or grassland as it is also called, are one of the earth's major biomes.   They are semiarid, which means that the climate is dry but not as dry as a desert.   Grasslands get 10 to 20 inches of precipitation per year.   Badlands National Park averages 16 inches of precipitation, meeting this criteria for a grassland environment.   This climate makes it too dry for most trees but grasses and grasslike plants called forbs thrive here.   The few trees and shrubs that do live on the prairie are usually found along streams or in low areas where there is more moisture.

Grasslands are mostly flat with some rolling areas. Those that occur in temperate zones, like the prairies of Badlands, have distinct hot and cold season.   The winters can be very cold with high winds while the summers are typically hot and dry.   Because of the dryness of all grasslands, periodic fires commonly spread across them and temporarily clear the area of the few shrubs and trees that have eked out a life.   Grasses survive the heat and regrow because most of the growing parts of grasses are below ground.

Grasslands across the earth support a large variety of wildlife, including many grazing hoofed animals.   Specifically, in Badlands National Park visitors find pronghorn antelope and bison.   These animals trample grass seeds into the ground and fertilize the soil with their droppings, which helps the grass grow.   Burrowing animals, like prairie dogs, live underground where they are relatively safe from predators and fires.   Their burrowing also helps break and mix up the soil, which helps the soil absorb water and thus helps the grasses and other plants grow.   Besides these herbivores, a variety of prairie carnivores can be found, namely the coyote, hawks, owls, and the elusive black-footed ferret.

All grassland organisms are adapted to distinct wet and dry seasons, including droughts, or extended periods of unusually low rainfall.   Some of the plants become dormant in the dry season and resume their growth when it rains.   Some develop long roots that can find water at greater depths.   Most animals migrate to find food and water during dry periods, returning with the rains that restore the land with life.