Overview

Project Highlights:

  • Exciting field based project on carbon cycle processes in Arctic tundra
  • Novel remote sensing technique of plant activity based on solar induced fluorescence
  • Strong team with international links


The Arctic region is undergoing rapid change in response to the warming climate and other global change processes. The impact of these changes on ecosystem function, carbon balance and associated climate feedbacks remain uncertain. Warming has been stimulating productivity in many Arctic ecosystems over recent decades, resulting in sequestration of atmospheric CO2 in plant biomass. However, recently there have been incidences of vegetation die-back associated with warmer and drier conditions, which reduce productivity and the increase the potential for net CO2 loss from the ecosystem. In addition to CO2, the Arctic region is central player in the global budget of methane, the second most important greenhouse gas after CO2. There is potential for large amounts of methane to be released from the Arctic in the future due to the large soil organic carbon stocks and melting permafrost associated with the ongoing warming of the region. Understanding controls and drivers of methane production and the sensitivity of ecosystem productivity to climate drivers of Arctic ecosystems is therefore critical for understanding carbon-climate feedbacks of the region.

Central to ecosystem carbon balance is photosynthesis; the carbon flux into the system. While much of the carbon assimilated by photosynthesis is incorporated into plant growth, a proportion finds its way into soil either as plant litter or through root exudates. This fresh soil carbon can stimulate soil microbial activity, including methanogens, leading to proposed links between recent photosynthesis and methane production. However, a key challenge in carbon cycle studies is quantifying photosynthesis at the ecosystem level. Measurements at scales above the leaf or branch (e.g. by eddy covariance or with surface chambers) inevitably involve a respiration component, limiting our information on photosynthesis on spatial and temporal scales. An emerging approach to probe photosynthesis at canopy and larger scales is through the use of solar induced fluorescence (SIF). SIF is emitted from active photosystems and is directly linked to the photochemical component of photosynthesis. Emission peaks occur at wavelengths that coincide with atmospheric spectral windows of high absorption, leading to the ability to detect SIF from mast, airborne and satellite platforms. This project will conduct pioneering SIF measurement in Arctic tundra ecosystems to investigate ecosystem productivity and carbon cycle processes.

Wet and dry Arctic tundra, areas of potential carbon release and sequestration through CO2 and methane exchange with the atmosphere. Credit: K. Newsham, BAS.

Methodology

The field sites for this project are three established research sites in Arctic Alaska: Barrow, Atqasuk and Ivotuk. These locations cover a 300 km latitudinal gradient on the North Slope and represent a range of tundra types. Measurements of SIF from surface vegetation will be made using a lightweight, dual-field-of-view spectrometer system designed for field-based SIF measurements. This system, called the Piccolo Doppio, makes simultaneous down-welling solar irradiance and up-welling surface radiance measurements. Autonomous operation and data logging is controlled by a Raspberry Pi based control board. In addition to surface SIF, measurements of leaf-level chlorophyll fluorescence parameters (PAM technique) will be made using a portable fluorimeter. Surface exchange of CO2 and methane will be made using surface chambers interfaced with gas analysers, and samples will be collected for various chemical analyses. Measurements will be made within the footprint of eddy covariance towers, providing the opportunity to link across scales.

Training and Skills

The student will receive full training in all necessary instrument use. The student will acquire specific skills in conducting field-based research for work in the Arctic; handling and processing of large data sets; plant ecophysiology; and scientific communication and networking with local and international partners. They will also be encouraged to undertake training in ecological statistics or modelling relevant to the data analysis that will be required.

CENTA students are required to complete 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to CENTA research themes. 

Timeline

Year 1: Instrument training, data processing and analysis routines. Prepare literature review. First field campaign. Lab analyses on collected samples.

Year 2: Data analysis, manuscript from first season. Second field campaign and analyses. Local conference presentation.

Year 3: Complete data analysis. Prepare second manuscript and present results at international conference. Write up thesis.

Partners and collaboration (including CASE)

This project is linked to a larger NERC-funded project on Under-recognized Arctic Methane Sources, and through this there will be opportunities to develop collaborations with researchers from The Uni. of Sheffield, Royal Holloway Uni. of London and the UK Center for Ecology and Hydrology, as well as European and American polar research programmes.  The British Antarctic Survey (BAS) will be project partners, and the project will involve collaboration with the NERC Field Spectroscopy Facility, based at the University of Edinburgh, for the development and use of the Piccolo system.

Further Details

We invite applications from students with a strong background in plant, soil or ecosystem ecology or physiology, an interest in global change processes, and an enthusiasm for field work and independent work. Familiarity with micro-processor systems control and/or instrument set-up an advantage. The student will join a well-established team researching ecosystem processes at the Open University.

Please contact Kadmiel Maseyk for further information kadmiel.maseyk@open.ac.uk

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