Figure 2. Hypothetical pathways of organisms’ dispersal among sites along or among streams in high mountains.

(a) Geographical pathway (overland dispersal); (b) topographical pathway (across mountain barriers); (c) network pathway (along flow direction). The locations of communities are shown as green dots, streams are depicted by blue lines and red lines represent dispersal pathways between locations. The schematic diagrams were created with ArcGIS 10.0 (http://www.esri.com/software/arcgis) and modified with Adobe Photoshop CS6.