Overview

Project Highlight:

  • Work at the interface of ecosystem science and climate change.
  • Determine the controls on arctic methane flux from an area of significant current production now, and potentially unprecedented emissions in the future.
  • Training in cutting edge and interdisciplinary techniques in, biogeochemistry and microbiology

Methane (CH4) is an important greenhouse gas that is ~25 times more powerful than CO2 at trapping the Sun's energy. Methane cycling is intrinsically linked to microbial processes.
Arctic ecosystems such as tundra are a substantial source of this gas and the region is subject to rapid environmental change. There is therefore considerable interest in the processes involved in CH4 production in waterlogged soils in the arctic, and in the processes that lead to its emission to the atmosphere. It is generally thought that CH4 produced in waterlogged soils is emitted by a combination of three processes: 1) by diffusion through water-filled pores, 2) by abrupt release of bubbles, and 3) through internal spaces in the stems of grass-like plants which are adapted to live in waterlogged soils. Further, until recent research by members of our team, it was thought that most methane was emitted during the summer. This has been challenged by findings suggesting that substantial quantities of methane can be produced during the autumn as soil profiles hover around the 0 0C mark during freeze in: the so called ‘zero curtain’ (Zona et al PNAS 2016). It is hypothesised that methane oxidation is suppressed by the surface freeze in which permits more methane to escape that would otherwise be expected. This leaves us with questions as to how the methane is emitted through plants and how microbes function with respect to rhizosphere methane production and oxidation under such conditions. In this project the student will collect Arctic soil cores from Alaska and, under controlled laboratory conditions, simulate the ‘zero curtain’ period to examine the role of plants and microbes in determining emissions under such conditions.

Diagram of the hypothesized soil physical structure influencing CH4 production and oxidation depending on the time of the season. We expect that during autumn the frozen near surface soil layer decreases CH4 oxidation, resulting in substantial CH4 emissions even with lower CH4 production (Zona et al. 2016).

Methodology

The student will:

  1. Collect frozen intact soil cores complete with surface vegetation for shipping to the Open University controlled environment facility.
  2. Develop modified freezers so that the zero curtain can be simulated for individual cores
  3. make methane flux measurements from these mesocosms during the simulated zero curtain;
  4. study microbial methane production and uptake within soils subject to freeze, which will include  molecular identification and culturing.

Training and Skills

Students will be given training in biogeochemical techniques (e.g. quantum cascade laser spectroscopy) for the analysis of methane in air and also for the analysis of methane produced or consumed within soils. In addition, the student will gain training in in process level microbiology and microbial ecology. The Ecosystems and Geobiology Laboratory has comprehensive laboratory facilities for such analyses. The student will also gain training in field research and in the design of field campaigns and manipulation experiments. Use of the OU’s controlled environment facility allows training in closely controlled manipulation experiments so as to minimise confounding factors that may be encountered in field studies.

CENTA students will be provided with 45 days training from CENTA through their PhD which includes a 5-day residential and a 10-day work placement. In the first year, students will undertake training in general environmental science, research methods and core skills as a single cohort. Training in years 2 and 3 will progress from core skills to masterclasses specific to the project and overall scientific theme.

Timeline

Year 1: Perform a literature review, collect cores and initiate controlled environment mesocosm experiments

Year 2: Perform the bulk of the measurements of methane exchange while investigating the microbiology of the soils. Submit manuscript 1 on mesocosm findings. Present at BES.

Year 3: Finalise data collection and analysis, submit manuscripts 2 and 3 on mesocosm emissions and on microbial processes respectively and complete thesis, present at EGU in Vienna.

Partners and collaboration (including CASE)

CEH offer expertise in plant-soil interactions.

Further Details

Students should have a strong background in, and enthusiasm for environmental science, geography or environmental biology. The student will join a well-established team researching biogeochemistry, microbial ecology and ecosystem science at the Open University. A valid driving license is essential.

Please contact Vincent Gauci (vincent.gauci@open.ac.uk)  for further information.

http://www.open.ac.uk/people/vg8

Applications should include:

Apologies that some bits of information are requested multiple times on different forms. Please fill in everything requested.

Applications should be sent to

STEM-EEES-PhD-Student-Recruitment@open.ac.uk  

by 5 pm on 25th January 2017