Biocrusts are associations of various prokaryotic and eukaryotic microorganisms in the top millimeters of soil, which can be found in every climate zone on Earth. They stabilize soils and introduce carbon and nitrogen into this compartment. The worldwide occurrence of biocrusts was proven by numerous studies in Europe, Africa, Asia and North America, leaving South America understudied. Using an integrative approach, which combines morphological and molecular characters (small subunit rRNA and ITS region), we examined the diversity of key biocrust photosynthetic organisms at four sites along the latitudinal climate gradient in Chile. The most northern study site was located in the Atacama Desert (arid climate), followed by open shrubland (semiarid climate), a dry forest region (Mediterranean climate) and a mixed broad leaved-coniferous forest (temperate climate) in the south. The lowest species richness was recorded in the desert (18 species), whereas the highest species richness was observed in the Mediterranean zone (40 species). Desert biocrusts were composed exclusively of single-celled Chlorophyta algae, followed by cyanobacteria. Chlorophyta, Streptophyta and cyanobacteria dominated semiarid biocrusts, whereas Mediterranean and temperate Chilean biocrusts were composed mostly of Chlorophyta, Streptophyta and Ochrophyta. Our investigation of Chilean biocrust suggests high biodiversity of South American biocrust phototrophs.

The international journal of Aerosol and Air Quality Research (AAQR) covers all aspects of aerosol science and technology, atmospheric science and air quality related issues.

The polyphasic approach has been widely applied in cyanobacterial taxonomy, which frequently led to additions to the species inventory. Increasing our knowledge about species and the habitats they were isolated from enables new insights into the ecology of newly established genera and species allowing speculations about the ecological niche of taxa. Here, we are describing three new species belonging to three genera that broadens the ecological amplitude and the geographical range of each of the three genera. Cyanocohniella crotaloides sp. nov. is described from sandy beach mats of the temperate island Schiermonnikoog, Netherlands, Oculatella crustae‐formantes sp. nov. was isolated from biological soil crusts of the Arctic Spitsbergen, Norway, and Aliterella chasmolithica originated from granitic stones of the arid Atacama Desert, Chile. All three species could be separated from related species using molecular sequencing of the 16S rRNA gene and 16S–23S ITS gene region, the resulting secondary structures as well as p‐distance analyses of the 16S–23S ITS and various microscopic techniques. The novel taxa described in this study contribute to a better understanding of the diversity of the genera Cyanocohniella, Oculatella, and Aliterella in different habitats.