2023-06-282023-06-282018HEINO, Jani et al. Subtropical streams harbour higher genus richness and lower abundance of insects compared to boreal streams, but scale matters. Journal of Biogeography, Hoboken, v. 45, n. 9, p. 1983-1993, 2018. DOI:  10.1111/jbi.13400. Disponível em: https://onlinelibrary.wiley.com/doi/abs/10.1111/jbi.13400. Acesso em: 2 jun. 2023.0305-0270e- 1365-2699https://onlinelibrary.wiley.com/doi/abs/10.1111/jbi.13400Aim:Biological diversity typically varies between climatically different regions, andregions closer to the equator often support higher numbers of taxa than those clo-ser to the poles. However, these trends have been assessed for a few organismgroups, and the existing studies have rarely been based on extensive identical sur-veys in different climatic regions.Location:We conducted standardized surveys of wadeable streams in a boreal(western Finland) and a subtropical (south‐eastern Brazil) region, sampling insectsidentically from 100 streams in each region and measuring the same environmentalvariables in both regions.Taxon:Aquatic insects.Methods:Comparisons were made at the scales of local stream sites, drainagebasins and entire regions. We standardized the spatial extent of the studyareas by resampling regional richness based on subsets of sites with similarextents. We examined differences in genus richness and assemblage abundancepatterns between the regions using graphical and statistical modellingapproaches.Results:We found that while genus accumulation and rank‐abundance curveswere relatively similar at the regional scale between Finland and Brazil, regionalgenus richness was higher in the latter but regional abundance much higher inthe former region. These regional patterns for richness and abundance werereproduced by basin and local genus richness that were higher in Brazil than inFinland, and assemblage abundance that was much higher in Finland than in Bra-zil. The magnitude of the difference in genus richness between Brazil and Finlandtended to increase from local through basin to regional scales.Main conclusions:Our findings suggest that factors related to evolutionarydiversification might explain differences in genus richness between these two climatically different regions, whereas higher nutrient concentrations of streamwaters might explain the higher abundance of insects in Finland than in Brazil.engAcesso RestritoAalpha diversityStream insectsLatitudinal diversity gradientRegional diversityLow–high latitude comparisonRankabundanceNutrientsNutrientsArtigo10.1111/jbi.13400