Joel White

Doctoral Student

Research areas and keywords

Keywords

  • Methane, Metagenomics, Wetlands, LPJ-GUESS, Flux Measurements, Plant-atmosphere exchange processes

Research

Natural controllers of the biogeochemical carbon cycle and greenhouse gas balance in ecosystems are the rate of CO2 uptake through primary production and the type and rate of metabolism of soil microorganisms. Northern wetland ecosystems comprise one of the largest sinks for atmospheric CO2 globally due to oxygen depleted soil conditions, which reduce heterotrophic respiration, resulting in storage of carbon as peat. The O2-depleted soil conditions in wetlands however simultaneously lead to microbial production of the important greenhouse gas CH4.

This project aims to address knowledge gaps on how functional potential of microbial
metabolism controls the biogeochemical carbon cycle in wetlands, with special emphasis on the CH4 cycle.

Increased understanding of these microbial community’s functional potential will provide insight into CH4 production pathways and help to understand how these ecosystems may respond to future climate change.

To address specific key issues predicted to influence the biogeochemical C-cycle in earth’s ecosystems over the 21st century, the project will include studies at a number of wetland sites ranging from temperate to the high Arctic.

The project will use captured metagenomics (CM) with custom designed, hybridization-based oligonucleotide probes that target functional genes related to CH4 metabolism in complex metagenomes. Therefore, the specific aims of the project are to:

1) Determine the taxonomic diversity of soil microorganism and identify the functional genes that regulate CH4 production and heterotrophic respiration.

2,3) Combine the CM sequence data with in-situ measurements of other likely controllers of the biogeochemical cycle to address current knowledge gaps.

4) Use these findings to improve the parameterization of processes in a wetland-enabled version of the dynamic global vegetation model LPJ-GUESS.