Screening methods to evaluate plant community structure and phytotoxicity in wetlands

While the regulatory requirements of Superfund frequently influence the selection of the biological and ecological tools used in conducting an ecological risk assessment, the application of these ``standard methods`` can be critical to the evaluation of habitats at risk. For example, in evaluating a wetland impacted by heavy metals, a relatively straightforward ecological effects assessment was developed. Plant community structure was evaluated using a Level 2 wetlands delineation protocol, and phytotoxicity was evaluated using standard plant tests. While the wetland delineation was required from a regulatory perspective for a determination of a jurisdictional wetlands the Level 2 protocols that were used in conducting the evaluation gathered data related to plant community structure and composition, as well as soils and hydrology. This ecological information was subsequently used in the risk assessment process in order to interpret the biological effects measured in the phytotoxicity assessments that were completed as part of the soil and sediment toxicity assessment. When these data were integrated into a relatively complete picture of the landscape rather than interpreted as a set of data strings that were poorly understood within an ecological context, the assessment of ecological effects suggested that no acute effects were currently being expressed withinmore » the plant communities in the wetlands but monitoring programs should be developed to evaluate long-term chronic effects potentially expressed by plants exposed to metals in wetland soils and sediments.« less