Fens
JB: This is Earth and Sky, on a special type of wetland – found at northerly latitudes and at high elevations – called a fen.
DB: A fen is a plant-rich environment that has a constant inflow of ground water – so the ground is always squishy. Fens provide critical habitat for many rare plants. Some birds prefer fens to other habitats for feeding and breeding. Some moose, beaver, fish and small mammals depend on fens, too. So the future of many plants and animals is tied up with the future of fens.
JB: Because of the regular saturation, the soil in a fen doesn’t have enough oxygen to break down plant litter completely. What accumulates from the dead plants is known as peat, which builds up extremely slowly. It can take hundreds or even thousands of years for a few centimeters of peat to accumulate. So once its peat is removed, a fen disappears for a very long time or maybe forever – what happens isn’t fully understood.
DB: That’s why the mining of peat for gardening and agriculture – and minor changes in water flow in and around a fen – are of concern to environmentalists. And it’s why forest managers are developing conservation strategies for fens – in an effort to protect these wetland environments.
JB: That our show – special thanks today to our friends at the U.S. Forest Service. We’re Block and Byrd for Earth and Sky.
Thanks to the following individuals who aided in preparation of this script:
Dr. David Cooper
Research Scientist
Colorado State University
Fort Collins, CO
Dr. Brad Johnson
Research Scientist
Biology Department
Colorado State University
Fort Collins, CO
Dr. Dennis Buechler
Senior Staff Specialist for Federal Activities
U.S. Fish and Wildlife Service
Mountain Prarie Region
Web links to related information:
Groundwater Dominated Wetlands: Fens (North Carolina State University)
Fens (Canada’s Aquatic Environments)
If you found this program interesting, try these books for more information: Tiner, R.W. Wetland Indicators (Lewis Publishers, 1999). Tiner, Ralph W. In Search of Swampland (Rutgers University Press).
Author’s Notes:
Other interesting points about fens: A big problem that I didn’t mention in the piece is that when the water table is lowered as a result of pumping, etc., the soil begins to decompose and releases lots of nutrients and environmental contaminants that it has absorbed over thousands of years. This is not good for water downstream. Heavy metals such as uranium are released in large amounts – sometimes uranium levels go up four levels of magnitude in the area where the fen was. And there are no drinking water standards for uranium!
Additional Teacher Resources
U.S. Fish & Wildlife Service, Mountain-Prairie Region: Fen Restoration in Cherry County
An example of efforts of fen conservation in Cherry County, Nebraska. Besides aspects of fen restoration this document also covers the hydrology, vegetation, and biological makeup of a fen.
Michigan Department of Natural Resources, Wildlife and Habitat: Wetland Types
A brief description accompanied by images of a variety of wetland types found in the United States, including the fen.
