Impact of the Conservation Reserve Program on Duck
Recruitment in the U.S. Prairie Pothole Region
Study Area and Selection of Study Sites
Our study area was the portion of North Dakota and South Dakota east and north of the Missouri River, and Daniels, Roosevelt and Sheridan Counties in northeast Montana (Fig. 1). This area approximates the Prairie Pothole Region of these states (Stewart and Kantrud 1973) which is the primary breeding area for many duck species (Batt et al. 1989). The area is a glacially influenced landscape (Bluemle 1991) characterized by numerous wetland basins that attract many breeding pairs when wetland conditions are favorable (Cowardin et al. 1995). Cowardin et al. (1995) identified a stratified random sample of 335 10.4-km² plots in our study area (Fig. 1). Those 335 plots (hereafter sample plots) constituted the pool from which we selected study plots for data collection (selection described in Methods) and were the basis for production modeling.
| Fig. 1. Study area for assessing the impact of the Conservation Reserve Program (CRP) on duck recruitment in the Prairie Pothole Region of North Dakota, South Dakota, and northeast Montana, USA. Circles represent 335 randomly selected 10.4-km² sample plots from Cowardin et al. (1995) where duck breeding population and habitat data were collected during 1992-1997 for input into productivity models. Dark shaded circles show the subsample of 98 study plots from which data were collected to estimate nest daily survival rates for 5 species of ducks nesting in CRP cover and planted cover on Waterfowl Production Areas, 1992-1995. |
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