Organic Sedge Meadow

Description

The reference plant community is categorized as a groundwater-fed slope wetland community, dominated by hydrophytic herbaceous vegetation. The one community phase within the reference state is dependent on consistent groundwater seepage to maintain the plant community. Drought and occasional fires have more localized impacts in the reference state, but do contribute to overall species composition, diversity, cover, and productivity.

Submodel

Description

The expansion of ruderal woody and herbaceous species into Organic Sedge Meadows can arise due to a complex interaction of fire suppression, hydrological alterations, and edge effects. Subsurface water reduction from agricultural tiling, ditching, or off-site development in conjunction with the removal of periodic fires allows woody species to encroach, casting shade on the native plant community and altering the natural light regime. In addition, edge effects can arise from indirect land management practices (e.g., cropping, herbicide drift) on directly adjacent sites that lead to a transition in the herbaceous species composition to taller, ruderal species (Pearson and Leoschke 1992; NatureServe 2015).

Submodel

Description

The forage state arises when the site is converted to a farming operation that emphasizes domestic livestock production, known as grassland agriculture. Fire suppression, periodic cultural treatments (e.g., clipping, drainage, soil amendment applications, planting new species and/or cultivars, mechanical harvesting) and grazing by domesticated livestock transition and maintain this state (USDA-NRCS 2003). Early settlers seeded non-native species, such as smooth brome (Bromus inermis Leyss.) and Kentucky bluegrass (Poa pratensis L.), to help extend the grazing season (Smith 1998). Over time, as lands were continuously harvested or grazed by herds of cattle, these species were able to spread and expand across the landscape, reducing the native species diversity and ecological function.

Submodel

Description

The cropland state is the dominant land condition throughout the MLRA today. Agricultural tile drains used to lower the water table and the continuous use of tillage, row-crop planting, and chemicals (i.e., herbicides, fertilizers, etc.) have effectively eliminated the reference community and many of its natural ecological functions in favor of crop production. Corn and soybeans are the dominant crops for the site, and oats (Avena L.) and alfalfa (Medicago sativa L.) may be rotated periodically. These areas are likely to remain in crop production for the foreseeable future.

Submodel

Description

A small percentage of historic Organic Sedge Meadows in the MLRA have been impounded or excavated for ponds in order to support watering livestock, creating waterfowl habitat, and establishing fisheries (Pearson and Leoschke 1992). Through excavation, the native vegetation is removed, and groundwater seepage can rapidly fill the exposed area and transition the diverse organic sedge meadow into an open water habitat. Over time, sediments may accumulate along the edges of the pond where emergent vegetation, introduced by wind or wildlife, can germinate and establish.

Submodel