Associations among Selection Logging History, Brook Trout, Macroinvertebrates, and Habitat in Northern Michigan Headwater Streams

Abstract

Selection logging is a dominant forest management technique in mixed-hardwood forests of the Laurentian Great Lakes region, yet little is known about its potential effects on neighboring streams and their communities. We surveyed nine headwater streams of the Otter River watershed in Michigan's Upper Peninsula for which the adjacent forest had undergone selection logging in the previous 2 to 30 years to examine whether the abundance of brook trout Salvelinus fontinalis was related to the logging history, stream habitat conditions, or aquatic macroinvertebrate composition. Mean abundances of age-1 and older brook trout were estimated by electrofishing replicate 100-m sections of each stream in 1999 and 2000. Aquatic macroinvertebrates were surveyed in 1999, and stream habitat was surveyed in 2000. Correlation models showed that brook trout density and biomass were substantially lower in streams bordering more recently logged forests. Brook trout abundance was also positively correlated with the relative combined abundance of the disturbance-sensitive taxa Ephemeroptera, Plecoptera, and Trichoptera (EPT), which is an indicator of coldwater stream habitat quality. Streams in recently logged stands had substrates with higher fine sediment content and lower overall habitat quality as estimated by a multimetric habitat index. Neither brook trout density nor EPT was correlated with the abundance of fine sediments in the streams. Fine sediment abundance was negatively related to stream canopy cover. Volume of instream woody debris and other specific elements of instream habitat were not significantly correlated with years since logging, nor did they explain significant variation in biotic variables. Results from this chronological-sequence comparison study suggest that selection logging alters stream habitat and influences associated stream communities, although the specific mechanistic linkages remain to be determined.