Patch characteristics include: size, size distribution within the landscape, juxtaposition, diversity, duration, and mechanisms affecting patch formation. Several topics of current interest in lotic ecology are examined from a patch-dynamics perspective: (1) response of periphyton communities to nutrient patches; (2) effects of patch dynamics on nutrient spiralling; (3) riparian patch dynamics and effects of leaf litter characteristics on lotic food webs; (4) beaver-induced patch dynamics; and (5) patch dynamics of river floodplains. We conclude that a patch-dynamics perspective coupled with a strong experimental approach can enhance the utility and predictive power of unifying concepts in lotic ecology, such as the river continuum hypothesis and nutrient spiralling, through its focus on organismal and process-specific building blocks of lotic systems. The effectiveness of a patch-dynamics approach lies in the strength of the linkage between reductionist and whole-stream perspectives. (DBO)