Biologists from the Carnegie Museum of Natural History are presently conducting a biotic assessment of two key indicator groups, the vascular plants and insects, found in the Nine Mile Run Conservation Area as part of the baseline data on natural ecosystems for a Rivers Conservation Plan. Plants and insects typically comprise over 90 percent of the biotic diversity in most ecosystems, and as such are valuable tools for assessment of water quality and the general "health" of ecosystems. Plants are often used as biotic indicators due to the fact that they are immobile and thus impacted by even subtle changes in abiotic factors. Insects, because of sheer diversity and habitat-specific life ways, are one of the best groups of animals for use as biological indicators in both terrestrial and aquatic systems.

Within each of four subsites selected to represent different microhabitats within the Nine Mile Run area, selected lineages of insects and vascular plants, are being intensively surveyed. Later this summer, a transect to sample vegetation will be strategically positioned at an angle to the drainage bed, crossing from slag flow to slag flow, and will permit quantitative assessment of the plants across the full gradient of abiotic factors associated with this system.

The overall objective of this assessment is to provide specimen- based biological information that will be critical to informed conservation and land management decisions affecting Nine Mile Run. Specific objectives include:

An annotated list of taxa found in the study area. Assessment of the overall biotic condition of Nine Mile Run. Provide contextual information for data, including historical perspective from CMNH specimens and comparative data from similar less-disturbed sites. Provide quantified data on ecological associations between insects and the vegetation of Nine Mile Run. Identify and provide assessment of species of special conservation concern (e.g., rare, endangered, and threatened taxa). Document the occurrence of pest and introduced taxa as well as comment on both present and potential pest problems. Provide resource data on the natural systems of Nine Mile Run and offer recommendations, linking the results of this survey to land use practices.