Temperate zone fens of the glaciated Midwestern USA

James P. Amon, Carol A. Thompson, Quentin J. Carpenter, James Miner

Research output: Contribution to journalArticlepeer-review


A study of more than 70 fens in the Midwestern United States and a review of the literature indicates that these temperate zone wetlands may differ from fens of the boreal zone and are not adequately differentiated from them by present classification systems. Fens of the Midwestern temperate zone 1) are wetlands with high botanical diversity, 2) are supported in part by ground water with conductivity > 100mS/ cm and circumneutral pH, 3) contain water in the root zone during most of the growing season yet are not usually inundated, and 4) accumulate organic and/or carbonate substrates. Individually, none of these descriptors is adequate to distinguish fens from other wetland communities of the Midwest such as marshes, sedge meadows, and wet prairies; yet, when they are taken together, such discrimination is possible. While fens of this zone share many species, our study does not support using indicator species because too few are both faithfully represented and geographically widespread. Midwestern temperate fens are sustained by forces of climate, landscape, and geology, which permit ground water to seep continuously into the root zone in a focused location. Since water availability in the temperate Midwest is less than in the boreal zone, continuous discharge is needed to maintain the saturation conducive to peat formation.

Original languageEnglish (US)
Pages (from-to)301-317
Number of pages17
Issue number2
StatePublished - Jun 2002
Externally publishedYes


  • Chemistry
  • Definition
  • Fens
  • Flora
  • Ground water
  • Hydrogeology
  • Hydrology
  • Midwestern USA
  • Mire
  • Peatland
  • Sedge meadow
  • Soils
  • Temperate zone
  • Wet meadow

ASJC Scopus subject areas

  • Environmental Chemistry
  • Ecology
  • General Environmental Science


Dive into the research topics of 'Temperate zone fens of the glaciated Midwestern USA'. Together they form a unique fingerprint.

Cite this