Conservation and Management
Marl fens are threatened by development and its associated run-off (e.g., agriculture, residential, roads), recreational overuse (e.g., ATVs, hiking trails), and habitat alteration in the adjacent landscape (e.g., mining, excessive logging, pollution). Alteration to the natural hydrology (e.g., ditching, blocked culverts, beaver) is a threat to this community type. Marl fens are threatened by invasive species, such as reed grass (Phragmites australis ssp. australis) and purple loosestrife (Lythrum salicaria).
Conservation Strategies and Management Practices
Consider how water flows around and into this wetland. As most of the water inputs are from underground, management for the prevention of altered water quality and quantity is particularly difficult for this natural community, but also of utmost priority. Projects that occur near this community must consider the proximity of the development to this wetland and the potential for changing how water flows, both above ground and below ground, into this wetland. Concerning the proximity to the wetland, terrestrial buffers provide nesting habitat for resident salamanders, frogs, and turtles and additional food sources for locally nesting birds. Consultation with a hydrologist is important to determine patterns of runoff and underground water sources for the wetland; however, impervious surfaces that rapidly divert water to the wetland should be avoided. Rapid influxes of surface water dilute the limey, mineral rich waters, decrease the robustness of the native fen species, and increase the likelihood of invasion by non-native species.
Development and Mitigation Considerations
When considering road construction and other development activities, minimize actions that will change what water carries and how water travels to this community, both on the surface and underground. Water traveling over-the-ground as run-off usually carries an abundance of silt, clay, and other particulates during (and often after) a construction project. While still suspended in the water, these particulates make it difficult for aquatic animals to find food; after settling to the bottom of the wetland, these particulates bury small plants and animals and alter the natural functions of the community in many other ways. Thus, road construction and development activities near this community type should strive to minimize particulate-laden run-off into this community. Water traveling on the ground or seeping through the ground also carries dissolved minerals and chemicals. Road salt, for example, is becoming an increasing problem both to natural communities and as a contaminant in household wells. Fertilizers, detergents, and other chemicals that increase the nutrient levels in wetlands cause algae blooms and eventually an oxygen-depleted environment where few animals can live. Herbicides and pesticides often travel far from where they are applied and have lasting effects on the quality of the natural community. So, road construction and other development activities should strive to consider: 1. how water moves through the ground, 2. the types of dissolved substances these development activities may release, and 3. how to minimize the potential for these dissolved substances to reach this natural community.
Inventory known examples of marl fen and survey undocumented fens adjacent to known occurrencs of marl pond and marl pond shore. Additional inventory efforts in regions with calcareous bedrock and promising wetlands will likely turn up a few additional sites. Resurveys of known sites will provide important information to help assess short and long term changes. Survey fens that provide habitat for rare species.
Research better ways to accurately and efficiently measure and understand the groundwater hydrology and what conditions are conducive for marl production in these fens. Further research into determining the proportion of fen water inputs is needed (e.g., groundwater vs. surface). If a fen is strongly groundwater influenced, traditional wetland buffers aimed at reducing surface water run-off may not sufficiently protect fen groundwater hydrology.
- Anticlea elegans var. glauca (White Death Camas)
- Carex buxbaumii (Brown Bog Sedge)
- Carex crawei (Crawe's Sedge)
- Carex meadii (Mead's Sedge)
- Carex sartwellii (Sartwell's Sedge)
- Cypripedium candidum (Small White Lady's Slipper)
- Eleocharis quinqueflora (Few-flowered Spike Rush)
- Glyptemys muhlenbergii (Bog Turtle)
- Juniperus horizontalis (Creeping Juniper)
- Panicum flexile (Wiry Witch Grass)
- Pedicularis lanceolata (Marsh Lousewort)
- Pycnanthemum verticillatum var. verticillatum (Whorled Mountain Mint)
- Regina septemvittata (Queen Snake)
- Scleria verticillata (Low Nut Sedge)
- Sistrurus catenatus (Eastern Massasauga)
- Solidago ohioensis (Ohio Goldenrod)
- Triantha glutinosa (Sticky False Asphodel)
- Trichophorum cespitosum ssp. cespitosum (Deer's Hair Club Sedge)
- Triglochin palustris (Marsh Arrow Grass)
- Valeriana uliginosa (Marsh Valerian)
- Viola nephrophylla (Northern Bog Violet)