Assessment of Aquatic Macroinvertebrates in a High-Elevation Stream, Great Smoky Mountains National Park.

摘要

A small-watershed study was initiated in Great Smoky Mountains National Park within the Noland Divide Watershed (NDW) in the early 1990s to measure trends in atmospheric deposition and to examine the long-term effects on stream chemistry and on stream biota. Monitoring of macroinvertebrates was initiated in 1991 and continued through 2001. The main objectives of this monitoring were firstly, to compile long-term benthic macroinvertebrate data for Noland Creek; secondly, to determine if benthic macroinvertebrate populations in this area have been adversely influenced by acidic deposition; and thirdly, to examine the relationships among the biotic responses and ecosystem parameters measured simultaneously at the same site. Assessment of the aquatic macroinvertebrate community in the NDW over time has shown a downward trend in diversity measures, particularly in the summer and fall. This decline corresponds with both a pH decline and an ANC decline over the same time period. As regional emissions are reduced, and air quality conditions improve with stricter standards for power plants, water quality in the NDW should also improve, but at a much slower rate due to the low buffering capacity of the system. Monitoring of the aquatic macroinvertebrate community in the future will be a useful tool to assess conditions within this watershed.