Location: The Nature Conservancy, Middletown, Connecticut
Topic: Eightmile River Watershed Project, University of Connecticut Cooperative Extension
Minutes:
· The Eightmile River Watershed Project:
The history of the project was described. In the lower Connecticut River valley, the University of Connecticut Cooperative Extension and partners have embarked on a series of watershed-based projects that are founded on natural resource education and a locally-driven, non-regulatory management structure. These watershed projects build upon the work of the Nonpoint Education for Municipal Officials (NEMO) Project model, which uses geographic information system (GIS) mapping to educate local land use officials about correlations between land use and water pollution, and to inform sound land use planning that will protect water quality. This highly intuitive, visual approach is very useful for projecting and demonstrating the potential impacts of several scenarios of land use on the availability of open space and the quality of water resources in a municipality.
GIS maps are used to document the extent of water resources (including open water and wetlands indicated by soil types), terrestrial resources (delineating forest cover type), developed land, committed open space, and other cover types in the watershed. Cultural (archeological) resources can similarly be mapped. Element occurrences (as determined by the Natural Diversity Database) can be overlain on these maps, as long as sensitive localities remain confidential. Critical areas for protection, namely biodiversity hotspots and sites threatened by imminent development can be documented in this way. Forum participants were asked to help the Project coordinators identify important focal habitats and to evaluate the appropriateness of recommended thresholds for habitat size.
The group discussed habitats that are indicative of high species richness and that should receive primary attention from conservation efforts. Vernal pools, which are ephemeral, may be missed in rapid areal surveys. These formations should be accounted for using ground-truthed field inventories, because they can harbor substantial numbers of (specialized) species. The question was raised of whether high primary productivity is an indicator (proxy) of high species richness. However, many of the most productive areas in many watersheds have been exploited intensively for agriculture and hence show low native species diversity. Moreover, some moderately "unproductive" sites support high species richness and some rare specialists, such as the sunfish. Bedrock ledge complexes may also contain specialized species including reptiles and plants; their aspect and connectivity, rather than size per se, is the most accurate indicator of their potential significance. Certain wetland community types, such as cedar swamps, are also highly sensitive to anthropogenic disturbance, including changes in nutrient inputs and water quality; these should constitute a high priority for mapping. Ideally, we should be able to identify which habitat types inside the watershed are important, which are rare in representation, and which can be linked together to create conservation networks.
Likewise, areas experiencing high levels of habitat fragmentation can be identified readily. However, the potential impacts of fragmentation are difficult to predict, because they will vary among different species that utilize different scales of habitat. It is difficult to educate the general public about the hazards of habitat fragmentation. Nevertheless, documenting the intensity of fragmentation is necessary for assessing threats to species and, most importantly from the perspective of the project, modelling impacts on water quality.
Finally, the utility of protecting large tracts of unfragmented land (within the constraints of a densely populated watershed) were discussed. Multiple benefits of large areas and high connectivity have been demonstrated for some wide-ranging species. Some particularly charismatic species (red-shouldered hawk, bear), and others that serve a demonstrable ecological function (barred owls that regulate white-footed mice, carriers of Lyme disease) are useful for justifying the protection of large tracts. It is unknown how often small watersheds can represent the range of habitats encompassed by large watersheds.
It was resolved that the Project will return to the Forum with refined models for further discussion, and that participants will advise on research programs needed to answer some of these fundamental questions.