Calcareous Fen Inventory

  • Chester calcareous fen with low growing herbaceous plants in foreground and trees the background
  • Calcareous fen surrounded by tamarack with orange needles and standing water in the foreground.

Calcareous fens are among the most imperiled communities in the Upper Midwest. MNR has documented more previously unknown calcareous fens across the state of Minnesota than any other private entity. Our experience is unmatched, and our expertise is often sought by regulatory agencies and private clients on projects involving calcareous fens.

Client: Oil and Gas Infrastructure

Location:  Polk and Norman Counties, MN

Services Provided:   

  • Rare Plant Surveys

  • NPC Classification and Mapping

MNR conducted several calcareous fen inventories in northwestern Minnesota as part of two separate compensatory mitigation efforts proposed by the Minnesota Department of Natural Resources. Compensatory mitigation efforts were associated with impacts resulting from the construction of crude oil pipelines. Fen inventories occurred in Norman and Polk counties associated with the beach ridges of Glacial Lake Agassiz, and were executed over the course of three years.

Inventory efforts included strategically targeting potential calcareous fen features, classifying and mapping native plant communities, and documenting state-listed plant species. Survey efforts resulted in the documentation of 16 previously unknown calcareous fens and 90 separate populations of state-listed plant species.