Cyanobacteria in early soil development of deglaciated forefields: Dominance of non-heterocytous filamentous cyanobacteria and phosphorus limitation of N-fixing Nostocales

Abstract

Cyanobacteria are integral to soil development in the earliest stages of primary succession by fixing carbon (C) and nitrogen (N) essential for organismal growth. In this study, we examined soil cyanobacterial communities at the earliest stage of succession (<5 years) at two disparate glacial forefields to reveal cyanobacterial patterns central to ecosystem development. Despite vast differences in climate and the relative dominance of heterotrophic versus autotrophic bacteria in these forefields, we found common patterns in cyanobacterial community composition in early soils. This work adds to limited research suggesting the importance of non-heterocytous filamentous cyanobacteria in initial soil colonization and development of primary succession of glacier forefields. Further, a phosphorus (P) addition experiment suggests P-limitation as a mechanism underlying the restricted presence of ecologically important, putatively N-fixing, Nostocales in these emerging landscapes.