QUANTIFICATION OF SOIL MICROBIAL BIOMASS IN THE MCMURDO DRY VALLEYS, ANTARCTICA

• Main Author: Reynebeau, Emily Ruth
• Format: Text
• Language: English
• Published: UNM Digital Repository 2021
• Subjects: Microbial Ecology; Soil Microbiology; McMurdo Dry Valleys; Microbial Biomass; Biology; Environmental Microbiology and Microbial Ecology; Antarc*; Antarctica
• Online Access: https://digitalrepository.unm.edu/biol_etds/343; https://digitalrepository.unm.edu/cgi/viewcontent.cgi?article=1372&context=biol_etds

Quantifying microbial biomass is important for understanding microbial contribution to nutrient cycling and population flux. Widely accepted biomass estimation methods are sufficient for well-studied and high biomass systems, though are often not sensitive enough for systems with extremely low biomass. The McMurdo Dry Valleys of Antarctica are characterized as an extremely harsh environment with severe restrictions on life, with perhaps some of the lowest biomass in the world. We measured prokaryote biomass across Taylor and Wright Valleys using four estimation metrics to determine the most appropriate method for this ecosystem. The chloroform fumigation method was not sensitive enough for the extreme low biomass, with roughly half of the results negative values. Total DNA quantification was highly correlated with the most edaphic variables, including pH and conductivity. Soil moisture did not show a relationship with any of the metrics. Nucleic acid methods of quantifying prokaryote biomass are sensitive enough for low biomass systems, and produce biologically meaningful results.