Stream-lake interaction: Understanding a coupled hydro-ecological system

Despite the obvious hydrologic connection between streams and lakes in many regions of the world, rarely has this linkage been recognized conceptually. Most watersheds contain lakes or artificial reservoirs, so the linkages between these systems are widespread. Drawing on recent research in temperate and arctic regions, we describe a conceptual model of stream-lake interactions to examine how hydrologic connections between streams and lakes can influence material transport and retention in watersheds. Stream-lake interactions affect temperature, flow regime, and sediment transport, resulting in distinctive habitats for periphyton, benthic invertebrates, and fishes. As coupled ecosystems, stream-lake interfaces generate important feedbacks that affect hydrological and ecological functioning, yet the responses of these to different elements of environmental change (land-use, land-cover change, atmospheric deposition, water development, and climate change) are uncertain