Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2021

Erindi/veggspjald / Talk/poster V43

Microbial Diversity in Young Volcanic Soils

Höfundar / Authors: Tanner Tobiasson Thelmudóttir1, Ragnhildur Guðmundsdóttir2, Utra Mankasingh1, Snædís Huld Björnsdóttir1, and Guðrún Gísladóttir1

Starfsvettvangur / Affiliations: 1 Faculty of Life and Environmental Sciences, University of Iceland; 2 Natural History Museum of Iceland

Kynnir / Presenter: Tanner Tobiasson Thelmudóttir

Microbial communities are almost considered a "black box" in soil systems and nutrient cycling. Furthermore, studies of microbes below the surface of Icelandic soils have been few. Frequent disturbances to the soil formation process, such as volcanic activity and aeolian deposition, make Iceland an ideal place to study soil system progression from the early stages. Analysis of bacterial SSU rRNA genes can give insight into the composition of microbial communities and the processes they may influence. Soil samples were collected from the fringe of the South Iceland Highlands at depths ranging from 0-30 cm. An incubation experiment was done over 50 days, with replicates at three temperatures (5, 15, 25°C). Genetic material was extracted at 5, 12, and 50-day intervals, and genes encoding SSU rRNA genes were amplified and sequenced. Microbial richness was found to be higher in the youngest, sparsely vegetated soils (vitrisols), compared to the relatively older, more developed, vegetated andisols. Higher richness was also found closer to the soil surface (0-5 cm), than at lower depths (> 5 cm). Taxonomic assignment of bacteria showed high proportions of the phyla Proteobacteria and Actinobacteriota in both soil types, with variation by depth, incubation temperature, and time. This study has the potential to connect soil microbial diversity to carbon cycling in Iceland by comparison to a parallel study on carbon respiration.