1. Prairie: This is the most dominant ecosystem in North Dakota, covering a vast majority of the state. It's characterized by tall grasses, wildflowers, and a variety of wildlife like bison, prairie dogs, and pronghorn antelope. There are several types of prairies, including tallgrass, mixed-grass, and shortgrass prairies.

2. Mixed Grass Prairie: Found mainly in the western part of the state, this ecosystem features a mix of tall and short grasses, along with wildflowers, shrubs, and trees. It is home to diverse wildlife, including burrowing owls, black-tailed jackrabbits, and coyotes.

3. Oak Savanna: This ecosystem is found in the eastern part of the state and features scattered oak trees with a mix of grasses and wildflowers. It provides habitat for animals like deer, squirrels, and woodpeckers.

4. Riparian Forest: These are narrow bands of trees and shrubs that grow along rivers, streams, and lakes. They provide important habitat for a variety of wildlife, including birds, fish, and mammals. Common trees found in riparian forests include cottonwood, willow, and elm.

5. Wetlands: North Dakota is home to a variety of wetlands, including marshes, swamps, and bogs. These areas are vital for water quality and provide habitat for numerous birds, amphibians, and mammals. They are also important breeding grounds for migratory waterfowl.