ALLOCATION OF PRAIRIE WETLANDS
The study reported in this chapter is different from those of earlier chapters in several respects. In the first place, although an effort is made to blend it in with earlier theoretical and empirical materials, with some differences of emphasis from the original, it represents work done primarily under a grant by the Natural Environments program at RFF to Gardner Brown and Judd Hammack. References are made throughout to the published work of Brown and Hammack; the reader interested in a great variety of detail and qualification beyond that presented here might refer to Waterfowl and Wetlands. This chapter is essentially a summary version of their work, modified in a way appropriate to this volume.
Secondly, the resource at issue is not, like the Hells Canyon, the White Cloud Peaks, or Mineral King, a single publicly held (unique) environment; rather it is composed of many private holdings scattered over a relatively large area. The issue is the allocation of the prairie wetlands of the north central United States ( Minnesota and the Dakotas) and neighboring provinces in Canada. The disadvantages of having marshes and ponds on his land encourage the individual farmer to drain and convert them to cropland. Drainage increases the supply of arable land and eliminates the costs of tilling around potholes ( Brown and Hammack, 1972). If left in their natural state, on the other hand, these wetlands play a vital part in the life cycle of migratory waterfowl, which are valued objects of hunting, viewing, and so on. Brown and Hammack, citing Crissey ( 1969), observe that the quantity and quality of the birds' wintering grounds are believed to be adequate, with their summer nesting and breeding grounds the critical factor in determining population. More than 55 percent of all ducks produced in North America in an average year are produced in the prairie wetlands, on just 10 percent of the continental breeding area. Compounding the conflict in resource use is the fact that, although resting and feeding areas along the migration routes are in large part on public