Simulating stream health sensitivity to landscape changes due to bioenergy crops expansion

In order to study the impacts of bioenergy crop expansions on stream health the adaptive neural-fuzzy inference system (ANFIS) was used to simulate three macroinvertebrate and one fish stream health measure. Macroinvertebrate measures considered were the Hilsenhoff Biotic Index (HBI), Family Index of Biological Integrity (Family IBI), and Number of Ephemeroptera, Plecoptera, and Trichoptera taxa (EPT taxa) and the fish measure used was the Index of Biological Integrity (IBI). Water quality and quantity variables obtained from a high-resolution biophysical model (Soil and Water Assessment Tool) were considered as inputs to the stream health predictive models. In order to examine the potential impacts of bioenergy crop expansions on stream health measures, 20 different rotations were examined in the Saginaw Bay basin. Overall, for the second-generation of biofuel crops, improvement in water quality was associated with less intensive agricultural activities, while traditional intensive row crops generated more pollution than current landuse conditions. Regarding the impacts of landuse changes on stream health measures, all three macroinvertebrate measures were negatively impacted under intensive row crops scenario while these measures were improved under perennial crops. However, for the fish measures, the expansion of native grass, switchgrass, and miscanthus resulted in negative impacts on IBI compared to first-generation row crops.