Aim The extent to which bacterial communities exhibit biogeographic patterns in their distribution remains unclear. We examined the relative influence of factors including geographic distance, latitude, elevation and catchment land use on the distribution and taxon richness of stream bacterial communities across New Zealand. Location Bacterial communities were collected from biofilm growing on submerged rocks in 244 streams. Sample sites spanned a north–south gradient of over 970 km, an elevational gradient of c. 750 m and were collected from a variety of catchment types across New Zealand. Methods We used automated ribosomal intergenic spacer analysis, a DNA fingerprinting technique, to characterize the structure and taxon richness of each bacterial community. Key attributes relating to sample location, upstream catchment land use and a suite of additional environmental parameters were collected for every site using GIS procedures. Univariate correlations between measures of bacterial community structure and latitude, elevation and distance were examined. Variance partitioning was then used to assess the relative importance of purely spatial factors versus catchment land use and environmental attributes for determining bacterial community structure and taxon richness. Results Bacterial taxon richness was related to the geographic location of the sample site, being significantly greater at latitudes closer to the equator and reduced at higher elevations. We observed distance decay patterns in bacterial community similarity related to geographic distance and latitudinal distance, but not to elevational distance. Overall, however, bacterial community similarity and taxon richness was more closely related to variability in catchment land use than to climatic variability or geographic location. Main conclusion Our data suggest that stream biofilm communities across New Zealand are more influenced by catchment land use attributes than by dispersal limitation.

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Pervasive human impacts on urban streams make restoration to predisturbance conditions unlikely. The effectiveness of ecologically focused restoration approaches typically is limited in urban settings because of the use of a reference-condition approach, mismatches between the temporal and spatial scales of impacts and restoration activities, and lack of an integrative approach that incorporates ecological and societal objectives. Developers of new frameworks are recognizing the opportunities for and benefits from incorporating societal outcomes into urban stream restoration projects. Social, economic, cultural, or other benefits to local communities are often opportunistic or arise indirectly from actions intended to achieve ecological outcomes. We propose urban stream renovation as a flexible stream improvement framework in which short-term ecological and societal outcomes are leveraged to achieve long-term ecological objectives. The framework is designed to provide additional opportunities for beneficial outcomes that are often unattainable from ecologically focused restoration approaches. Urban stream renovation uses an iterative process whereby short-term ecological and societal outcomes generate public support for future actions, which may provide opportunities to address catchment-level causes of impairment that often exist across broad temporal scales. Adaptive management, education, and outreach are needed to maintain long-term public engagement. Thus, future work should focus on understanding how ecological and societal contexts interact, how to assess societal outcomes to maintain stewardship, developing new methods for effective education and outreach, and multidisciplinary collaborations. We discuss potential abuses and the importance of linking societal outcomes to long-term ecological objectives.