Prairie Pothole
Description:
Prairie potholes are depressional wetlands (primarily freshwater marshes) found in the Northeastern Section of Montana. This formerly glaciated landscape is pockmarked with an immense number of potholes, which fill with snowmelt and rain in the spring. Some prairie pothole marshes are temporary, while others may be essentially permanent. Here a pattern of rough concentric circles develops. Submerged and floating aquatic plants take over the deeper water in the middle of the pothole while less flood tolerant wetland plants grow closer to shore. 1
Function and Value:
The prairie pothole region, because of its numerous shallow lakes and marshes, rich soils, and warm summers is described as being one of the most important wetland regions in the world. The area is home to more than 50 percent of North American migratory waterfowl, with many species dependent on the potholes for breeding and feeding. In addition prairie potholes also absorb surges of rain, snow melt, and flood waters thereby reducing the risk and severity of down stream flooding.
Photos of Prairie Potholes:
Photo by: Jim Ringelman
Prairie potholes dotting an agricultural
landscape in Alan Hills, North-Central
Saskatchewan."
Photo by Mike Rabenburg
"Prairie potholes near Comertown in the
Northeastern corner of Montana, April 1999."
Photo By: Karen Newlon
"Prairie pothole in Northern Blaine County, MT
showing the characteristic vegetative ring zones."
Distribution Map of Prairie Potholes:
Potential Stressors:
Agricultural:
Photo by: Unknown
"The contrast between native pothole regions and
the agricultural landscape that has replaced the
majority of it."
Photo by: Ducks Unlimited, Inc.
"Pothole wetland surrounded by agricultural fields"
Grazing:
Photo by : Bryce Maxell
"The effects of cattle grazing on pothole wetlands."
Photo by: Bryce Maxell
"Cattle hummocking in a wetland where livestock
were allowed to graze and water."
Nutrient Enrichment:
Photo by: Unknown
"Algal growth as a result of nutrient enrichment
from agricultural runoff in a pothole wetland."
Invasive Species:
Photo By: Natalie Byars
"Smooth Brome invasion of a prairie pothole in
Comertown Prairie, Sheridan County, MT."
Ditching and Draining:
Photo by: Larry Urban
"An example of an wetland that has been drained
via piping."
Converting Wetlands to Open Water:
Photo By: Natalie Byars
"Prairie pothole excavated for use as a stock pond."
Reference:
