Central Poor Fen

Definition

Detailed Community Description from Ecological Landscapes of Wisconsin

General natural community overview

These open, acidic, low nutrient peatlands occur within the Central Sand Plains of Wisconsin. Central poor fens are floristically depauperate and generally sedge dominated (Carex oligosperma, C. lasiocarpa, and C. utriculata). Bluejoint grass (Calamagrostis canadensis) is a frequent associate and may co-dominate some stands. Sphagnum moss carpets are common but typically lack pronounced hummocks and hollows. Shrubs are present but not dominant, hard-hack (Spiraea tomentosa) is the most consistent in presence, and cover of ericads is generally low. Other characteristic associates include wool grass (Scirpus cyperinus), cotton-grasses (Eriophorum spp.), swamp-candles (Lysimachia terrestris), and Kalm's St. John's-wort (Hypericum kalmianum). A zone of northern tall shrubs is sometimes present, composed of black chokeberry (Aronia melanocarpa, hollys (Ilexspp.), and bog birch (Betula pumila). This community often intergrades with northern tamarack swamp or black spruce swamp. Disturbance of this community through mossing may significantly alter community composition, as recolonization by at least some of the vascular plants is very slow. Many plants characteristic of poor fen communities farther north are rare or absent in these central sands peatlands.

Defining Characteristics and Similar Communities

Central poor fens can be distinguished from poor fens by their location in the Central Sand Plains ecological landscape and their relative lack of calciphiles, carnivorous plants, and pink-flowered orchids. Central poor fens are similar to northern and southern sedge meadows in that sedges are dominant, but are much more acidic, usually with a nearly continuous carpet of Sphagnum moss. In contrast, Sphagnum is usually sparser in northern sedge meadows, which range from acidic to neutral, and is usually absent in southern sedge meadows, which tend to have neutral to calcareous soils. Central poor fens may resemble open bogs but lack the pronounced hummock-hollow topography and dominance of leatherleaf and other ericads typical of open bogs. Central poor fens are often bordered by northern tamarack swamp or black spruce swamp but are distinguished by having <25% tree cover. They are also commonly bordered by alder thicket but have <50% cover of tall shrubs.

Rare animals

Species of Greatest Conservation Need

The following Species of Greatest Conservation Need are listed according to their level of association with the Central Poor Fen natural community type, based on the findings in Wisconsin's 2015 Wildlife Action Plan.

Scores: 3 = high association, 2 = moderate association, and 1 = low association. See the key to association scores for complete definitions.

Please see Section 2. Approach and Methods of the Wildlife Action Plan to learn how this information was developed.

Rare plants

The Natural Heritage Inventory has developed scores indicating the degree to which each of Wisconsin's rare plant species is associated with a particular natural community or ecological landscape. This information is similar to that found in the Wildlife Action Plan for animals. As this is a work in progress, we welcome your suggestions and feedback.

Landscapes

The following Ecological Landscapes have the best opportunities to manage for Central Poor Fen, based on the Ecological Landscapes of Wisconsin Handbook.

Major (3 on map)
A major opportunity for sustaining the natural community in the Ecological Landscape exists, either because many significant occurrences of the natural community have been recorded in the landscape or major restoration activities are likely to be successful maintaining the community's composition, structure, and ecological function over a longer period of time.

Important (2 on map)
Although the natural community does not occur extensively or commonly in the Ecological Landscape, one to several occurrences do occur and are important in sustaining the community in the state. In some cases, important opportunities may exist because the natural community may be restricted to just one or a few Ecological Landscapes within the state and there may be a lack of opportunities elsewhere.

Present (1 on map)
The natural community occurs in the Ecological Landscape, but better management opportunities appear to exist in other parts of the state.

Threats/Actions

What are conservation actions?

Conservation actions respond to issues or threats, which adversely affect species of greatest conservation need (SGCN) or their habitats. Besides actions such as restoring wetlands or planting resilient tree species in northern communities, research, surveys and monitoring are also among conservation actions described in the WWAP because lack of information can threaten our ability to successfully preserve and care for natural resources.

Threats/issues and conservations actions for natural communities

Photos

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Central Poor Fen Photos

Note: photos are provided to illustrate various examples of natural community types. A single photograph cannot represent the range of variability inherent in a given community type. Some of these photos explicitly illustrate unusual and distinctive community variants. The community photo galleries are a work in progress that we will expand and improve in the future.