Looking Dry in the Western Dakotas

Written by Rob Spangler
Sunday, May 08, 2016

Rob SpanglerWe have finished flying western North and South Dakota and conditions look pretty dry overall with the exception of areas around Pierre, South Dakota. Even though conditions are pretty dry we are seeing a few more birds than last year. Generally wetlands were dryer in the west than in the east. Although this dry spell can mean lower numbers of waterfowl in the short term, there are long term benefits from the dry and wet cycles that occur over time. Yes, drought can be important to breeding ducks! This is particularly true in the depression-type wetlands found in the Dakotas – the Prairie Pothole Region. When these wetlands stay filled over long periods of time, their productivity stagnates. When aquatic plants grow they absorb available nutrients and as they die, they “lock” them up in a layer of detritus (dead material) at the bottom of the pond. Here, available oxygen is used up quickly in the process of decomposition. When the oxygen levels get low, decomposition slows and nutrients are not released but instead, are held in this organic sludge at the bottom. If a wetland is allowed to dry occasionally, this sludge comes in contact with oxygen, microbes, etc., and the decomposition process can continue making the nutrients available again to plants. When the dry wetland fills again, the nutrients are readily available for use by plants and productivity increases dramatically – improving growth of forage and cover for ducks.

Dry wetlands in North Dakota. Photo Credit: Rob Spangler, USFWS

Dry wetlands in North Dakota. Photo Credit: Rob Spangler, USFWS