Microbial Diversity in the Extreme—Abiotically Driven Biocomplexity in the Antarctic Dry Valleys

Project Leader: Dr. Charles Lee

Project Summary:

Recent discoveries have transformed our view of microbial ecology in the soils of Antarctic Dry Valleys, which evidently harbour significant and extremely localised microbial genetic diversities that are heterogeneous across physicochemical gradients. We seek to elucidate how local abiotic factors, which are reflective of historical and ongoing geological processes, influence ecologically relevant Dry Valley microbiota. Over two field seasons, we will carry out a collection of experiments aimed at elucidating the potentially causal relationship between abiotic factors and microbial ecology, and validate our findings through a multi-valley survey. Using a suite of RNA-based molecular genetic techniques, including a metatranscriptomic study, the proposed research will reveal how these microbial communities structurally and functionally respond to abiotic physicochemical variables. Results from the proposed research will elucidate the relationship between soil microbial ecology and the glacial geomorphology of the Dry Valleys; such information will be extremely valuable for predicting how changes in macro-climatic conditions affect the Dry Valley ecosystem and understanding the geological history of the Dry Valleys. Findings from this study can be projected to similar (i.e., oligotrophic, low biomass) habitats worldwide and answer fundamental questions related to the biogeography and dispersal of microorganisms.

Project History:

First Field Season ('11/'12)
The main goal of the '11/'12 field season will be to collect Dry Valley soils for our Dry Valley permafrost simulators, which are currently under construction. We will need several hundred kilograms of soils to be able to simulate soil surfaces in the Dry Valleys, which are composed of very dry surface soils and permafrost that extends downward from 30 cm of depth. The Dry Valley permafrost plays an important role in soil microbial ecology, since moisture is constantly wicked toward the surface from the permafrost ice and becoming available to soil microorganisms in the process. Once we have the Dry Valley simulators in place, we will be able to perform a series of manipulation experiments that should answer the most important questions for the project: Are there causal relationships between abiotic soil parameters and the microbial life?

Drivers of Microbial Diversity Partners