Stream diatom assemblages in an Arctic catchment: diversity and relationship to ecosystem-scale primary production

We quantified benthic diatom diversity in streams the Miellajokka catchment, about 200 km north of Arctic circle Sweden. Beta among sites was related to local-scale environmental heterogeneity (occurring on order 1 or less), and its magnitude equal (Sørensen Index = 0.62) levels previously reported for rivers regional gradients across hundreds kilometres Fennoscandia. Species turnover dominant (77%) component beta catchment. Small, stress-tolerant taxa dominated assemblages, there were no clear patterns functional class sites. Site ordinates from non-metric dimensional scaling most strongly correlated with flood frequency (r 0.83) water temperature 0.89), which higher harsh tundra than below treeline. Additionally, site ecosystem-scale gross primary production — indicative a link between ecosystem function. Our results advance understanding by quantifying variation that is understudied this region, identifying consequences an process.