Shaping the Physical Template: Biological, Hydrological, and Geomorphic Connections in Stream Channels

Abstract Stream channels are scaled to the amount of water and sediment they convey. The amount and size of bed sediment, composition of bank material, type of channel vegetation (both riparian and in-stream), and valley morphology (slope and width) influence channel size and shape. Interactions and feedbacks among these six bio-hydro-geomorphic controls dictate channel stability and how channels respond to changes in the environment. In this chapter, we use these six interdependent variables as context in which to demonstrate how connections among hydrology, geomorphology, and vegetation; (1) set the range of variability in channel morphology; (2) understand disturbance-recovery regimes in streams; (3) illustrate how bio-hydro-geomorphic templates influence important abiotic components of stream ecosystems; and (4) present management strategies that incorporate bio-hydro-geomorphic connections. Finally, we discuss some of the important challenges that lay ahead in connecting fluvial geomorphology and stream ecology.