The maryland state highway administration constructed a 0.8-Hectare freshwater tidal marsh on marley creek, anne arundel county, as mitigation for wetlands filled during the route 10 extension. Research was initiated in june 1987 at the completion of site constructionto investigate aspects of the initial stages of marsh development. Vegetation was sampled in the constructed marsh and in a neighboringnatural marsh by using a random sampling design to determine planted species survival, species occurrence, and vertical distribution. June and october 1987 data indicate that the survival rate of the planted species (scirpus americanus, pelandra virginica, and leersia oryzoides) is not solely dependent on placement within the tidal range. Although peltandra virginica and leersia oryzoides were planted within the elevation ranges determined for these species in the natural marsh, they suffered over 50% and 90% mortality, respectively. Thedata suggest that other factors such as life history, ph, and soil properties are important in determining survival of planted materials. By october 1987, the site was rapidly colonized with 28 additional plant species, most of which were found within the observed naturally occurring tidal range. This paper appears in transportation research record no. 1224, Rest areas, wetlands, and hydrology.
Abstract