About Dr Margaret Barbour

Understanding how terrestrial ecosystems respond to environmental change will underpin progress on some of the big issues currently facing humans. Issues like how will we feed the global population, how different will the climate be for our grandchildren, and how best can we manage natural ecosystems. My interest lies in improving mechanistic understanding of the exchange of carbon, water and energy between the terrestrial biosphere and the atmosphere, in order to reduce uncertainty in higher scale models.

My current research interests include: * Improving crop water use efficiency and productivity by increasing the rate of diffusion of CO2 within leaves * Scaling leaf-level exchange processes to the canopy * Linking carbon and water cycling within ecosystems using stable isotopes of CO2 and water * Development of process-based models to interpret the stable isotope record in tree rings * Development of laser-based measurement systems for real-time measurement of plant, soil and ecosystem isofluxes My research involves developing and applying new theory and measurement techniques to address issues related to biosphere-atmosphere exchange across a range of scales. I work in controlled-environment growth facilities, managed ecosystems (including cereal crops, pasture and plantation forests), and natural ecosystems such as old-growth forests

Margaret Barbour holds a BSc in Biology and Earth Sciences and an MSc in Biology from the University of Waikato, New Zealand, and a PhD in Plant Science from the Australian National University. During her PhD she developed new understanding, and mechanistic models, of variability in the oxygen isotope composition of plant tissue. Her work was the first to theoretically describe and demonstrate the record of leaf evaporative environment present in the oxygen isotope composition of plant material. This work has subsequently been applied to reconstruct past climates from tree ring stable isotopes, as an indicator of plant regulation of water loss, and as a selection tool for yield in grain crops.
Margaret was employed by Landcare Research in New Zealand from 2001 to 2009, where she led a Foundation-funded objective investigating the exchange of carbon dioxide in terrestrial systems at site scales, and the sensitivities and uncertainties of these processes to variation in climate, environmental and land-use variables. As part of this objective, Margaret developed a suite of novel, laser-based techniques to measure the exchange of isotopes of CO2 and water vapour between the atmosphere and plants, soil and the whole ecosystem. Margaret was awarded the Outstanding Physiologist of the Year 2006, by the New Zealand Society of Plant Biologists.
In 2010 Margaret joined FAFNR as an ARC Future Fellow in Biosphere-atmosphere interactions.

Selected publications

  • Barbour MM, Warren CR, Farquhar GD, Forrester G, Brown H. 2010. Variability in mesophyll conductance between barley genotypes, and effects on transpiration efficiency and carbon isotope discrimination. Plant, Cell & Environment (in press).
  • Millard M, Midwood AJ, Hunt JE, Barbour MM, Whitehead D. 2010. Quantifying the contribution of soil organic matter turnover to forest soil respiration, using natural abundance δ13C. Soil Biology and Biochemistry (in press).
  • Wingate L, Ogee J, Cuntz M, Genty B, Reiter I, Seibt U, Yakir D, Maseyk K, Pendall EG, Barbour MM, Mortazavi B, Burlett R, Peylin P, Miller J, Mencuccini M, Shim JH, Hunt JE, Grace J. (2009) The impact of soil microorganisms on the global budget of δ18O in atmospheric CO2. PNAS 106, 22411-22415.
  • Barbour MM, Hanson DT (2009) Commentary: Stable carbon isotopes reveal dynamics of respiratory metabolism. New Phytologist 181: 243-245.
  • Ogee J, Barbour MM, Wingate L, Bert D, Bosc A, Stievenard M, Lambrot C, Pierre M, Bariac T, Loustau D, Dewar RC (2009) A single-substrate model to interpret intra-annual stable isotope signals in tree-ring cellulose. Plant, Cell & Environment 32: 1071-1090.
  • Barbour MM (2007) Stable oxygen isotope composition of plant tissue: a review. Functional Plant Biology 34: 83-94.
  • Barbour MM, Farquhar GD, Hanson DT, Bickford CP, Powers H, McDowell NG (2007) A new measurement technique reveals temporal variation in δ18O of leaf-respired CO2. Plant, Cell and Environment. 30: 456-468.
  • Barbour MM, Buckley TN (2007) The stomatal response to evaporative demand persists at night in Ricinus communis plants with high nocturnal conductance. Plant, Cell and Environment 30: 711-721.
  • Barbour MM, McDowell NG, Tcherkez G, Bickford CP, Hanson DT (2007) A new measurement technique reveals rapid post-illumination changes in the carbon isotope composition of leaf-respired CO2. Plant, Cell and Environment. 30: 469-482.