PS 83-230
Using multiple methods to establish baselines to measure success of the Eagle Creek Restoration project
Stream habitat structure, biodiversity, and ecosystem function are dramatically influenced by surrounding land use. Anthropogenic impacts such as logging, agriculture, urbanization, and damming, impair streams and have negative impacts on biotic communities. In an effort to improve stream health, restoration projects have been implemented across the globe. Prior to being obtained by the college, the Hiram College Eagle Creek restoration site was heavily logged. In addition to other upstream and downstream (a large dam) impacts, these land use changes have caused heavily eroded banks, high turbidity, a sandy benthos, and poor canopy cover to occur within this site. The main goal of the restoration project was to reconnect Eagle Creek with its floodplain and decrease flooding to downstream suburban areas. In an effort to monitor long-term changes in stream health, we used multiple methods to establish a baseline to assess restoration success in future years: Qualitative habitat index (QHEI), measuring abiotic variables (velocity, depth, temperature, canopy cover, turbidity, substrate size, dissolved oxygen, pH), surveys of invertebrate (Invertebrate Community Index [ICI]) and fish (Index of Biological Integrity [IBI]) communities, and ecosystem function through measuring rates in leaf retention (using leaf releases) and leaf decomposition (using artificial leaf packs).
Results/Conclusions
In comparison to our reference stream, turbidity, average depth, and temperature were significantly higher at the restoration site while percent canopy cover and average substrate size were significantly lower. Dissolved oxygen, velocity, and pH were within range of our reference stream. Baseline QHEI scores, varied from fair to good across sampling locations suggesting that some portions are not as heavily impaired as our standard abiotic measurements suggest. ICI scores were substantially higher at our reference site (ICI = 32) than the restoration site (ICI = 20) suggesting invertebrate communities are impaired. Similar to QHEI scores, the IBI scores ranged from poor to very good and did not match ICI scores to indicate overall stream health. Leaf releases showed 67-74% of leaves were retained and decomposition studies show mass loss of 16% of leaf material per day. Our data suggest that multiple methods should be used to measure stream health. All metrics will continue to be collected and compared to these baselines as part of a long-term study of restoration success. In the future we hope to establish a similar poor to excellent scoring system with leaf retention, leaf decomposition in addition to rates of primary production using ceramic tile studies.