Northern Prairie Wildlife Research Center
In aquatic ecosystems, the principal damage has been through indiscriminate artificial drainage, mechanical destruction of plant communities in the undrained wetlands, flooding, and excessive water withdrawals. These activities destroy the suitability of the substrate to support perennial hydrophytes. Important secondary effects on wetland ecosystems arise through improper tillage practices, deposition of nutrients and pollutants, and the cessation of grazing by livestock.
The atmospheric ecosystem in North Dakota often is laden with blowing soil and pesticide drift.
Primary environmental impact to terrestrial ecosystems caused by the industrial, commercial, residential, and public works sectors is also through mechanical destruction of natural plant communities. Secondary impacts stem from inadequate control of soil erosion at construction sites, improper waste treatment and disposal, flooding of upland plant communities, stream bank erosion, disturbance, and noise.
In aquatic ecosystems, the principal damage has occurred through artificial drainage, landfill operations, excessive water diversions, and improper disposal of industrial waste.
Problems affecting the atmospheric ecosystem are improper disposal of industrial and municipal waste and improper pesticide application.
For the region surrounding the ANG Coal Gasification Plant, specific concerns of the Fish and Wildlife Service relate to migratory birds and their habitat.
Terrestrial woodland ecosystems are of primary importance. On seven large tracts destined for coal extraction, woodlands made up only 2% of the acreage. Less than 1% of Mercer County is forest. Biologists are particularly concerned about hardwood draws and the Missouri River bottomland forest. Hardwood draws make up only a tiny portion of the general area around Mercer County, but current studies at the Northern Prairie Wildlife Research Center indicate at least 22% of North Dakota's breeding bird species are found in this habitat type. Current threats to hardwood draws include destruction of the natural vegetation by mining activities, degradation from overgrazing, agricultural soil erosion, pesticide drift, and possible injury to the vegetation from energy-related air pollution. It would be important to find out whether hardwood draws can be avoided by coal mining operations and whether hardwood draws surrounded by reclaimed land could still support their original biota.
The Missouri River bottomland forest has been reduced to less than 10% of its original area due to inundation by reservoirs, agricultural clearing, and urbanization. Much of the remaining acreage is overgrazed and on these areas tree reproduction has ceased. Because it lies in a topographic low and is downwind from the area of intensive energy development, this forest also may face an increased chance of damage from energy-related air pollution. Closing of Garrison Dam in 1955 stopped natural spring flooding of the cottonwood forest. These floods were the principal source of nutrients and there is doubt that the forest can long maintain itself in its currently stressed condition. Cottonwood forest is also being lost to bank erosion caused by the release of large volumes of silt-free water from Garrison Reservoir. Stewart (1975) listed 59 breeding bird species for this forest type. These birds make up 26% of North Dakota's breeding species. The Nature Conservancy recently acquired the largest tract of cottonwood forest remaining in North Dakota. This tract is only a few miles east- southeast of the main coal area and would make a good site for a study of the effects of air pollution on forest wildlife.
Shrublands or brushy thickets are another important woody habitat type in the coal area that deserve consideration. With today's powerful farm equipment, shrublands are now vulnerable to cultivation as well as destruction from mining activities and degradation from overgrazing, pesticide drift, and energy-related air pollution. Little information is available on the extent of this habitat type in North Dakota. Stewart (1975) listed 26 breeding bird species for brushy prairie thickets.
The mixedgrass prairie of Mercer and surrounding counties has been reduced to around 30-35% of its original area. Much of the remainder is overgrazed. Biologists are particularly concerned about grassland birds that have suffered great population declines or can no longer be found in much of their original breeding range in the area. These are mostly passerines and large upland-nesting shorebirds that show a negative relationship to grazing intensity, or raptors, such as the ferruginous hawk, that require large foraging areas and adequate prey populations. If suitably large prairie tracts are included in wildlife mitigation plans for the ANG project, fruitful research could be conducted that would be geared to determine the management practices required to restore the breeding avifauna.
Research should also include the development of methods to save and replace native prairie sod on newly prepared sites. It has been stated that acid rain is not expected to be a problem in alkaline environments, but mixedgrass prairie occurs on a wide variety of soils and physiographic landforms. On some of these, the alkaline minerals have leached far below the surface, and the general environment should probably be considered circumneutral, rather than alkaline. Therefore, studies to determine the impacts of plume discharge on the invertebrate foods used by nesting birds on various types of mixedgrass prairie should also be considered.
Tallgrass prairie was never a common grassland type in the coal area as it was restricted to relatively small areas along streams and river valleys and around natural basin wetlands. Nearly all of these areas were long ago converted to cropland, so opportunities to study the impact of coal gasification on the tallgrass ecosystem are probably foregone.
Among the aquatic ecosystems, palustrine and lacustrine wetlands are primary concerns of the Fish and Wildlife Service. These wetlands are the principal habitat used by breeding waterfowl and other marsh birds in the Prairie Pothole Region, and are also heavily used by other migrant waterfowl and shorebirds during both their spring and fall migration. These wetlands have, of course, declined greatly in abundance and quality due to drainage and degradation from cultivation and siltation. Large-scale withdrawals of groundwater for irrigation could eliminate many more of these bodies of water. About 4,000 acres out of 116,000 acres included in seven large coal tracts near the ANG site were wetlands. Perhaps more noteworthy is the fact that the Prairie Pothole Region, which contains what biologists consider to be the best waterfowl breeding habitat remaining in the North America, lies just to the east and downwind from the major coal areas. As I mentioned earlier, prairie wetlands vary greatly in their ability to maintain fresh water. Some spill frequently and lose water rapidly through bottom seepage. The water in these wetlands tends to remain fresh. Others have little ability to lose salts and nutrients. These act as dead-end systems and over the years could accumulate large amounts of toxic substances from surface water runoff, direct precipitation, and the atmosphere. Toxic substances could also enter groundwater systems and reappear in wetlands many miles away. Thus, we feel it important that studies be undertaken that could determine the fate of toxic substances in the various types of prairie wetlands, and their chronic or long-term effects on the biota. Particularly important to waterfowl and other marsh birds would be information on the effects of plume discharge on the incubation and survival of invertebrates and their larvae and on the reproduction of aquatic plants. Studies should also address the impact of pipeline construction on hydrology of prairie wetlands, especially in areas of glacial outwash and stagnation moraine where lateral movement of groundwater is great.
Riverine wetlands form important habitat for such species as the bald eagle, wood duck, least tern, and belted kingfisher. Thus, tributaries of the Missouri River that drain the coal area and portions of the river itself should be classified as to their habitat suitability for certain species and monitored carefully for energy- related pollutants. It will also be important to ascertain the role of minor water sources, such as intermittent streams, seeps, and springs, in maintaining terrestrial ecosystems such as wooded draws.
Although cropfields are generally unattractive to most breeding birds, they often are heavily used as feeding areas by migratory waterfowl, resident upland game birds, and several species of migrant passerine birds and shorebirds. The waterfowl and upland game birds form a regular part of the diet of many people of North Dakota. We feel it would be wise to regularly test the plant and invertebrate animal populations in these fields for any buildup or transfer of toxic substances that may have entered the food chain. The Environmental Impact Statement for the ANG plant states that leachate from buried wastes is not expected to be a problem, but what will happen if the surface of the strip-mined land is used for cropland rather than pasture? The saline seep problem is severe in many areas of western North Dakota and is directly related to the increased water percolation that results from single crop agriculture and the practice of summerfallow.