Northern Prairie Wildlife Research Center
About 4% of North Dakota is used to raise perennial forage crops such as alfalfa, clover, and bromegrass. Forage crops are usually mowed twice during the growing season. Several species of birds nest in these habitats, but production is usually low due to high rates of mechanical nest destruction. Pocket gophers, ground squirrels, and badgers are considered nuisance animals in these fields.
About 6 million acres of North Dakota remain in native grassland. This is about 15% of the original acreage. Nearly all of this land is grazed by cattle and by lesser numbers of sheep and horses. The normal grazing season is summer and early fall, but some pastures are grazed year-round. Most of the native grasslands are now found in the western half of the state on land too rocky, hilly, or droughty to plow. Plants and animals naturally adapted to heavily grazed conditions still can be found in large numbers on larger native pastures, but other species have undergone significant reductions in population and distribution within the state.
Tame grass plantings total about 3.5 million acres or 8% of the state area. Most of this land is pastured. An unknown proportion of this land is former cropland that was seeded back to grass or grass- legume mixtures following the drought of the 1930's and in later years under various federal cropland retirement programs. Tame grass plantings also include some federal and state land that is devoted to wildlife production. When idle, these plantings may attract large numbers of nesting birds. However, these lands may be grazed or mowed for emergency hay supplies during dry years. Because of low plant species diversity, grazing periods on tame pastures are generally shorter than on native grassland. The relatively simple plant associations found on tame pastures also greatly lessen their use by wildlife.
It is estimated that about 500,000 acres or 74% of North Dakota's original woodlands remain. Most losses of woodlands are due to agricultural clearing and inundation by reservoirs. Well over half of the woodlands are grazed, much of them to the point where tree reproduction has ceased. Of the 500,000 acres of woodlands, about 300,000 acres are considered commercial timber. As the forests have been cleared or flooded, there has, of course, been a proportional loss of the woodland fauna. Most plant and animal species whose breeding distribution within the state is severely limited by a lack of suitable habitat or by climate are found in woodlands.
The total area of brushlands likely has decreased considerably, but in some areas brushy species have increased greatly due to fire suppression.
Wetland ecosystems have suffered greatly due to agricultural development. Natural palustrine, lacustrine, and riverine wetlands now total an estimated 2.2 million acres or 56% of their original area. Palustrine wetlands have been extensively drained for crop production, especially in the glaciated plains and Agassiz lake plain. Drainage usually creates the need for more drainage and larger ditches, the result being that all the wetlands are lost over many square miles. Well over half of the undrained palustrine wetlands are cultivated for crop production whenever they are dry. Others are grazed by livestock, mowed for hay, or left idle. Populations of most marsh and aquatic birds and mammals have suffered drastic declines due to wetland drainage and changes in land use in North Dakota. During the early 1960's, great international concern for the well-being of the economically important waterfowl group prompted the United States Government to launch a program to protect palustrine wetland habitat in the Prairie Pothole Region. In North Dakota, about a quarter million wetland acres have been purchased, and three-quarters of a million wetland acres have been protected by easements.
About 1.6 million acres or 4% of North Dakota has undergone development into the transportation network, urban areas, reservoirs, and mines. The greatest impact to the biotic community occurred along the Missouri River where nearly 500,000 acres of riverine wetlands and cottonwood floodplain forest were inundated by reservoirs during the 1950's and 60's. Development has accelerated greatly in western North Dakota during recent years with the advent of large-scale lignite mining, drilling of oil and gas wells, construction of coal-fired electrical generation plants and transmission lines, and the associated increase in urbanization.
The overall impact of development on the natural plant communities that once existed in North Dakota has been severe. Only about 15% of the native grasslands remain unplowed and much of this acreage is overgrazed and infested with noxious introduced plants such as leafy spurge. Of the tallgrass type, perhaps only 1 or 2% of the original acreage remains. About 44% of the original statewide wetland acreage has not been drained, but plant communities in most of these remaining wetlands have been degraded by cultivation, siltation, and other factors. Native woodlands have been reduced to about 74% of their original acreage and tree reproduction on much of the remaining acreage has ceased due to overgrazing. Only two plants, both of which are species of the tallgrass prairie, are now considered threatened in North Dakota, but an additional 120 uncommon or rare plant species could easily be lost from our flora if habitat destruction continues. Concurrently, about 150 species of plants, many of which are noxious weeds, have been added to our flora.
Impact of development on the fauna has been no less severe. The great plains wolf, Audubon's sheep, and passenger pigeon are extinct. Wild breeding populations of the trumpeter swan, as well as the bison, plains grizzly bear, marten, wolverine, whooping crane, mountain plover, whip-poor-will, gray jay, and common raven have been extirpated from the state. The sandhill crane typifies species now classified as endangered as a breeding species in North Dakota. This list also includes the black bear, northern swift fox, fisher, black-footed ferret, river otter, bald eagle, white-winged scoter, common merganser, peregrine falcon, and merlin. Ten additional birds, mammals, and fish are considered threatened. Concurrently, about eight introduced species of birds, mammals, and fish have established breeding populations in the state.