Waterbird use of dynamic sheetwater wetlands in Iowa's Prairie Pothole Region

摘要: Substantial landscape alteration has occurred from the westward expansion of European settlement starting in 18 th Century form conversion large expanses land to agricultural production. This was facilitated by development and installation artificial subsurface drainage convert previously saturated unproductive soil topographic depressions, also known as prairie potholes, into highly productive tillable land. Most are currently drained but persist ephemerally sheetwater wetlands fields valued migratory waterbirds. Our objective document their extent Iowa’s Prairie Pothole Region (PPR) using spatially replicated road-based surveys develop a model wetland size dynamics at this scale. We hypothesized that these were common across PPR they would be largely dependent on local precipitation regimes. Surveys conducted spring 2011 2012 resulted 8415 observations 519 unique ten townships PPR. Wetlands predominantly observed dry or absent state (7399 observations, 87.9%), when wet smaller classes with smallest class 0-0.1 ha (769 observations) comprising 76.2% all where contained water 9.2% total (wet dry) observations. utilized multi-state program MARK predict daily probability transition between recorded