Soil microbial community and bacterial functional diversity at Machu Picchu, King George Island, Antarctica

Abstract.

The objective of this study was to evaluate the potential contribution of the soil microbial community in the vicinity of two plant covers, Sanionia uncinata and Deschampsia antarctica, at Machu Picchu Station, King George Island, Antarctica. Soil samples were collected at the study site during the southern (pole) summer period from 0–5 cm and 5–10 cm depths, for chemical and biological analyses. Soil microbial biomass reached a maximal value of 144 µg g^–1 in soil samples taken from under the S. uncinata upper layer plant. qCO₂ ranged from 167 to 239 µg CO₂ ^.mgC_mic ^.h^–1 at the 0–5 and 5–10 cm depths, respectively. CO₂ evolution showed values of 54.3 mg^.m^–2 h^–1 beneath plant cover and 55.9 mg^.m^–2 h^–1 in the open space. CO₂ evolved by substrate induced respiration in the soil samples taken under the plant cover in the summer period, oscillated between 0.25 and 4.78 µg CO₂ g^–1 h^–1. The data obtained from this short study may provide evidence that both activity and the composition and substrate utilization of the microbial community appear to change substantially across the moisture level and sample location.