Biology ETDs

Publication Date

Fall 11-13-2021


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.

Project Sponsors

McMurdo Dry Valleys LTER




Microbial Ecology, Soil Microbiology, McMurdo Dry Valleys, Microbial Biomass

Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Cristina D. Takacs-Vesbach

Second Committee Member

David Van Horn

Third Committee Member

Jennifer Rudgers