Gullies and Moraines Are Islands of Biodiversity in an Arid, Mountain Landscape, Asgard Range, Antarctica

Cold, dry, and nutrient-poor, the McMurdo Dry Valleys of Antarctica are among most extreme terrestrial environments on Earth. Numerous studies have described microbial communities low elevation soils streams below glaciers, while less is known about in higher above glaciers. We characterized life four landscape features (habitats) a mountain Taylor Valley. These habitats varied significantly soil moisture include moist (1) lateral glacial moraine, (2) gully that terminates at very dry (3) southeastern slope (4) sites near gully. Using rRNA gene PCR amplicon sequencing Bacteria Archaea (16S SSU) eukaryotes (18S SSU), we found all habitat types harbored different bacterial eukaryotic these differences were apparent when comparing had macroscopically visible crusts (gully moraine) to with no (near slope). driven by relative predominance Actinobacteria Colpodella sp. non-crust habitats, phototrophic bacteria (e.g., moss) predators tardigrades) biological moraine). The moraine also 16S 18S ESV richness than other two types. further many share high sequence identity phototrophs from wet areas elsewhere cold desert ecosystems. Moss ( Bryum sp.), several algae Chlorococcum sp.) cyanobacteria Nostoc Phormidium spp.). Overall, results reported here broaden diversity been studied suggest future avenues research more definitively understand biogeography factors controlling this unique ecosystem.