Short-term effects of logging and bridge construction on habitat of two Kansas intermittent streams

Anthropogenic disturbances to streams have been shown to cause channel instability resulting in increased sedimentation and altered substrate composition. I studied effects of two such disturbances (logging and bridge construction) on habitat among three phases (pre-, during-, and post-disturbance) for two southern Jefferson County (Kansas) intermittent streams. From autumn 2001 to spring 2004, I seasonally sampled six habitat variables (thalweg depth, bank full width, percent bank exposed, riparian thickness, geometic mean, and substrate compaction) along 100 m benchmarks upstream from, at the site of, and downstream from disturbance locations. Using repeated-measure analysis of variance with a sequential Bonferroni correction of a = 0.05 and Tukey's studentized range test for pairwise comparisons, all six variables differed significantly at both the logging location and the bridge construction location among phases, whereas no variables differed significantly upstream from or downstream from either disturbance among the three phases. Results show that both logging and bridge construction can have adverse effects on stream habitat characteristics, and for intermittent streams, the disturbances might be localized due to lack of flow.