A Landscape-Based Ecological Classification System for River Valley Segments in Michigan's Upper Peninsula

–I developed a classification system for streams in Michigan’s Upper Peninsula (UP) using a landscape-based approach that was originally developed for Lower Peninsula (LP) Michigan streams. Multiple linear regression, cluster analysis, and graphical techniques were used to examine stream attribute data (stream size, temperature, hydrology, gradient, water chemistry, valley type, fish community, and connectivity to one of the Great Lakes) and watershed attributes (surficial geology, land use, elevation, expected groundwater flow) to develop classification categories. Stream segments were classified based on examination of watershed characteristics and known relationships between these characteristics and stream attributes. I classified a total of 81 UP river systems into 596 discrete segments. Classified stream segments ranged from 0.4 to 187 km long and represented a broad range of stream types. Classifications used for UP rivers were modified from those developed for LP streams for water temperature, stream hydrology, stream gradient, and fish community because of substantial differences between UP and LP rivers. The UP VSEC system should be helpful to resource managers as a communication and learning tool as they manage UP stream resources. Efforts should now be directed to combining the UP and LP classifications into a single statewide stream classification system. This would provide resource managers statewide with a valuable tool for understanding and managing Michigan’s stream resources. Research directed at gaining a better understanding of the factors influencing Michigan’s stream habitats and fish communities in the Lower Peninsula (LP) resulted in the development of a river classification framework termed Valley Segment Ecological Classification (VSEC) (Seelbach et al. 2006; Wehrly et al. 2006; Zorn et al. 2002). The VSEC system classifies river valley segments according to expected streamflow regime, temperature regime, fish community composition, etc. The classification process places breakpoints between adjacent river valley segments where significant change occurs in the river network (e.g., a major tributary junction, change in channel gradient and sinuosity, change in surficial geology). The VSEC system of classification is based on relationships between watershed characteristics and stream attributes. The VSEC process relies on catchment-scale attributes (e.g., surficial geology, land use, gradient) and mathematical models to assign attributes to stream segments. For example, multiple linear regression models were developed for LP rivers and these models were used to predict stream temperature from surficial geology, maximum daily air temperature, riparian shading, etc. (Wehrly et al. 2006). Classifying streams according to discrete attributes helps our understanding of rivers as systems and can be used to enhance communication about stream resources. The original development of the VSEC system did not include Upper Peninsula (UP) rivers in part because the physical, climatic, and