Australian Journal of Botany Australian Journal of Botany Society
Southern hemisphere botanical ecosystems

The utility of the eddy covariance techniques as a tool in carbon accounting: tropical savanna as a case study

Lindsay B. Hutley A D , Ray Leuning B , Jason Beringer C and Helen A. Cleugh B

A Tropical Savanna CRC and School of Science and Primary Industries, Charles Darwin University, Darwin, NT 0909, Australia.

B CSIRO Marine and Atmospheric Research, PO Box 1666, Canberra, ACT 2601, Australia.

C School of Geography and Environmental Science, Monash University, PO Box 11A, Clayton, Vic. 3800, Australia.

D Corresponding author. Email:

Australian Journal of Botany 53(7) 663-675
Submitted: 22 September 2004  Accepted: 24 February 2005   Published: 29 November 2005


Global concern over rising atmospheric CO2 concentrations has led to a proliferation of studies of carbon cycling in terrestrial ecosystems. Associated with this has been widespread adoption of the eddy covariance method to provide direct estimates of mass and energy exchange between vegetation surfaces and the atmosphere. With the eddy covariance method, fast-response instruments (10–20 Hz) are typically mounted above plant canopies and the fluxes are calculated by correlating turbulent fluctuations in vertical velocity with fluctuations in various scalars such as CO2, water vapour and temperature. These techniques allow the direct and non-destructive measurement of the net exchange of CO2 owing to uptake via photosynthesis and loss owing to respiration, evapotranspiration and sensible heat. Eddy covariance measurements have a high temporal resolution, with fluxes typically calculated at 30-min intervals and can provide daily, monthly or annual estimates of carbon uptake or loss from ecosystems. Such measurements provide a bridge between ‘bottom-up’ (e.g. leaf, soil and whole plant measures of carbon fluxes) and ‘top-down’ approaches (e.g. satellite remote sensing, air sampling networks, inverse numerical methods) to understanding carbon cycling. Eddy covariance data also provide key measurements to calibrate and validate canopy- and regional-scale carbon balance models. Limitations of the method include high establishment costs, site requirements of flat and relatively uniform vegetation and problems estimating fluxes accurately at low wind speeds. Advantages include spatial averaging over 10–100 ha and near-continuous measurements. The utility of the method is illustrated in current flux studies at ideal sites in northern Australia. Flux measurements spanning 3 years have been made at a mesic savanna site (Howard Springs, Northern Territory) and semi-arid savanna (Virginia Park, northern Queensland). Patterns of CO2 and water vapour exchange at diurnal, seasonal and annual scales are detailed. Carbon dynamics at these sites are significantly different and reflect differences in climate and land management (impacts of frequent fire and grazing). Such studies illustrate the utility of the eddy covariance method and its potential to provide accurate data for carbon accounting purposes. If full carbon accounting is implemented, for ideal sites, the eddy covariance method provides annual estimates of carbon sink strength accurate to within 10%. The impact of land-use change on carbon sink strength could be monitored on a long-term basis and provide a valuable validation tool if carbon trading schemes were implemented.


Anderson MC Norman JM Mecikalski JR Torn RD Kustas WP Basara JB 2004 A multiscale remote sensing model for disaggregating regional fluxes to micrometeorological scales. Journal of Hydrometeorology 5 343 363 DOI

Arya P 2001 ‘Introduction to micrometeorology.’ Academic Press San Diego, CA

Aubinet M Heinesch B Longdoz B 2002 Estimation of the carbon sequestration by a heterogeneous forest: night flux corrections, heterogeneity of the site and inter-annual variability. Global Change Biology 8 1053 1071 DOI

Baldocchi DD Hicks BB Meyers TP 1988 Measuring biosphere–atmosphere exchanges of biologically related gases with micrometeorological methods. Ecology 69 1331 1340

Baldocchi D Valentini R Running S Oechel W Dahlman R 1996 Strategies for measuring and modelling carbon dioxide and water vapour fluxes over terrestrial ecosystems. Global Change Biology 2 159 168

Baldocchi DD Finnigan JJ Wilson KW Paw UKT Falge E 2000 On measuring net ecosystem carbon exchange in complex terrain over tall vegetation. Boundary-Layer Meteorology 96 257 291

Baldocchi D Falge E Gu LH Olson R Hollinger D Running S Anthoni P Bernhofer C Davis K Evans R Fuentes J Goldstein A Katul G Law B Lee XH Malhi Y Meyers T Munger W Oechel W U KTP Pilegaard K Schmid HP Valentini R Verma S Vesala T Wilson K Wofsy S 2001 FLUXNET: a new tool to study the temporal and spatial variability of ecosystem-scale carbon dioxide, water vapor, and energy flux densities. Bulletin of the American Meteorological Society 82 2415 2434

Baldocchi DD 2003 Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems, past, present and future. Global Change Biology 9 479 492

Barrett D Hill M Hutley LB Beringer J Xu J Cook GD Carter J Williams RJ 2005 Prospects for improving savanna biophysical models using multiple-constraints model-data assimilation methods. Australian Journal of Botany 53 689 714

Beringer J Hutley LB Tapper NJ Coutts A Kerley A O’Grady AP 2003 Fire impacts on surface heat, moisture and carbon fluxes from a tropical savanna in north Australia. International Journal of Wildland Fire 12 333 340

Beringer J , Hutley LB , Tapper NJ (2004) Savanna fires and their impact on net ecosystem productivity, 26th conference on agricultural and forest meteorology, 23–27 August, Vancouver, BC, Canada. Paper 4.6 (

Blackmon M Boville B Bryan F Dickinson R Gent P Kiehl J Moritz R Randall D Shukla J Solomon S Bonan G Doney S Fung I Hack J Hunke E Hurrell J Kutzbach J Meehl J Otto-Bliesner B Saravanan R Schneider EK Sloan L Spall M Taylor K Tribbia J Washington W 2001 The Community Climate System Model. Bulletin of the American Meteorological Society 82 2357 2376 DOI

Bonan GB Oleson KW Vertenstein M Levis S Zeng XB Dai YJ Dickinson RE Yang ZL 2002 The land surface climatology of the community land model coupled to the NCAR community climate model. Journal of Climate 15 3123 3149 DOI

Chen X Hutley LB Eamus D 2003 Carbon balance of a tropical savanna of northern Australia. Oecologia 137 405 416 DOI

Cook GD Heerdegen RG 2001 Spatial variation in the duration of the rainy season in monsoonal Australia. International Journal of Climatology 21 1723 1732 DOI

Cook PG Hatton TH Pidsley D Herczeg AL Held A O’Grady A 1998 Water balance of a tropical woodland ecosystem, northern Australia: a combination of micro-meteorological, soil physical and groundwater chemical approaches. Journal of Hydrology 210 161 177 DOI

Davidson EA Savage K Verchot LV Navarro R 2002 Minimizing artefacts and biases in chamber-based measurements of soil respiration. Agricultural and Forest Meteorology 113 21 37 DOI

Denmead OT Dunin FX Wong SC Greenwood EAN 1993 Measuring water use efficiency of eucalypt trees with chambers and micrometeorological techniques. Journal of Hydrology 150 649 664 DOI

DePury DGG Farquhar GD 1997 A commentary on the use of a sun/shade model to scale from the leaf to a canopy. Agricultural and Forest Meteorology 95 257 260 DOI

Eamus D Hutley LB O’Grady AP 2001 Daily and seasonal patterns of carbon and water fluxes above a north Australian savanna. Tree Physiology 21 977 988

Falge E Baldocchi D Tenhunen J Aubinet M Bakwin P Berbigier P Bernhofer C Burba G Clement R Davis KJ Elbers JA Goldstein AH Grelle A Granier A Guomundsson J Hollinger D Kowalski AS Katul G Law BE Malhi Y Meyers T Monson RK Munger JW Oechel W Paw KT Pilegaard K Rannik U Rebmann C Suyker A Valentini R Wilson K Wofsy S 2002 Seasonality of ecosystem respiration and gross primary production as derived from FLUXNET measurements. Agricultural and Forest Meteorology 113 53 74

Finnigan J 2002 Momentum transfer to complex terrain. Geophysical Monograph Series 129 285 300

Finnigan JJ Clement R Malhi Y Leuning R Cleugh HA 2003 A re-evaluation of long-term flux measurements techniques part I, averaging and coordinate rotation. Boundary-Layer Meteorology 107 1 48

Goulden ML Munger WJ Fan SM Daube BC Wofsy SC 1996 Measurements of carbon sequestration by long-term eddy covariance: methods and a critical evaluation of accuracy. Global Change Biology 2 69 182

Hanan NP Kabat P Dolman JA Elbers JA 1998 Photosynthesis and carbon balance of a Sahelian fallow savanna. Global Change Biology 4 523 538

House JI Prentice IC Ramankutty N Houghton RA Heimann M 2003 Reconciling apparent inconsistencies in estimates of terrestrial CO2 sources and sinks. Tellus. Series B, Chemical and Physical Meteorology 55 345 363

Hooper DU Cardon ZG Chapin FS Durant M 2002 Corrected calculations for soil and ecosystem measurements of CO2 flux using the LI-COR 6200 portable photosynthesis system. Oecologia 132 1 11

Hutley LB O’Grady AP Eamus D 2000 Evapotranspiration from eucalypt open-forest savanna of Northern Australia. Functional Ecology 14 183 194 DOI

Isaac PR Leuning R Hacker JM Cleugh HA Coppin PA Denmead OT Raupach MR 2004 Estimation of regional evapotranspiration by combining aircraft and ground-based measurements. Boundary-Layer Meteorology 110 69 98 DOI

IPCC 2001 IPCC Third Assessment Report. Climatic Change. Intergovernmental Panel on Climate Change Geneva, Switzerland

Kaminski T Heimann M 2001 Inverse modeling of atmospheric carbon dioxide fluxes. Science 294 259 DOI

Kruijt B Elbers JA von Randow C Araújo AC Oliveira PJ Culf A Manzi AO Nobre AD Kabat P Moors EJ 2004 The robustness of eddy correlation fluxes for Amazon rain forest conditions. Ecological Applications 14 S101 S113

Law BE Falge E Gu L Baldocchi DD Bakwin P Berbigier P Davis K Dolman AJ Falk M Fuentes JD Goldstein A Granier A Grelle A Hollinger D Janssens IA Jarvis P Jensen NO Katul G Mahli Y Matteucci G Meyers T Monson R Munger W Oechel W Olson R Pilegaard K Paw KT Thorgeirsson H Valentini R Verma S Vesala T Wilson K Wofsy S 2002 Environmental controls over carbon dioxide and water vapor exchange of terrestrial vegetation. Agricultural and Forest Meteorology 113 97 120

Leuning R 2004 Measurements of trace gas fluxes in the atmosphere using eddy covariance, WPL corrections revisited. In ‘Handbook of micrometeorology, a guide for surface flux measurements and analysis’. Lee X Massman W Law B 119 132 Kluwer Academic Publishers Dordrecht, The Netherlands

Leuning R Judd MJ 1996 The relative merits of open- and closed-path analysers for measurements of eddy fluxes. Global Change Biology 2 241 253

Leuning R Kelliher FM DePury DGG Schulze E-D 1995 Leaf nitrogen photosynthesis conductance and transpiration scaling from leaves to canopies. Plant, Cell & Environment 18 1183 1200

Leuning R Cleugh HA Zegelin S Hughes D 2005 Carbon and water fluxes over a temperate Eucalyptus forest and a tropical wet/dry savanna in Australia: measurements and comparison with MODIS remote sensing estimates. Agricultural and Forest Meteorology 129 151 173

Massman WJ Lee X 2002 Eddy covariance flux corrections and uncertainties in long-term studies of carbon and energy exchanges. Agricultural and Forest Meteorology 113 121 144

McGuire AD Sitch S Clein JS Dargaville R Esser G Foley J Heimann M Joos F Kaplan J Kicklighter DW Meier RA Melillo JM Moore B Prentice I Ramankutty N Reichenau T Schloss A Tian H Williams LJ Wittenberg U 2001 Carbon balance of the terrestrial biosphere in the twentieth century: analyses of CO2, climate and land use effects with four process-based ecosystem models. Global Biogeochemical Cycles 15 183 206 DOI

Miranda AC Miranda HS Lloyd J Grace J Francey RJ McIntyre JA Meir P Riggan P Lockwood R Brass J 1997 Fluxes of carbon, water and energy over Brazilian cerrado: an analysis using eddy covariance and stable isotopes. Plant, Cell & Environment 20 315 328 DOI

Moncrieff JB Malhi Y Leuning R 1996 The propagation of errors in long-term measurements of land-atmosphere fluxes of carbon and water. Global Change Biology 2 231 240

Monteny BA Lhomme JP Cehbouni A Troufleau D Amado M Sicot M Verhoef A Galle S Said F Lloyd CR 1997 The role of the Sahelian biosphere on the water and the C cycle during the HAPEX–Sahel experiment. Journal of Hydrology 188–189 516 535

Mott JJ Williams J Andrew MH Gillison AN 1985 Australian savanna ecosystems. In ‘Ecology and management of the world’s savannas’. Tothill JC Mott JJ Australian Academy of Science Canberra

Papale D Valentini A 2003 A new assessment of European forests carbon exchanges by eddy fluxes and artificial neural network spatialization. Global Change Biology 9 525 535 DOI

Paul KI Polglase PJ 2004 Prediction of decomposition of litter under eucalypts and pines using the FullCAM model. Forest Ecology and Management 191 73 92 DOI

Paul KI Polglase PJ Richards GP 2003 Sensitivity analysis of predicted change in soil carbon following afforestation. Ecological Modelling 164 137 152 DOI

Richards GP 2001 The FullCAM carbon accounting model: development, calibration and implementation for the National Carbon Accounting System, National Carbon Accounting System Technical Report No. 28 Australian Greenhouse Office, Canberra

Roderick ML Farquhar GD Berry SL Noble IR 2001 On the direct effect of clouds and atmospheric particles on the productivity and structure of vegetation. Oecologia 129 21 30 DOI

Schulze E-D Wirth C Heimann M 2000 Managing forests after Kyoto. Science 289 2058 2059 DOI

Steffen W Noble I Candell J Apps M Schulze E-D Jarvis PG Baldocchi DD Ciais P Cramer W Ehleringer J Farquhar G Field CB Ghazi A Gifford R Heimann M Houghton R Kabat P Körner C Lambin E Linder S Mooney HA Murdiyarso D Post WM Prentice IC Raupach M Schimel DS Shivdenko A Valentini R 1998 The terrestrial carbon cycle implications for the Kyoto Protocol. Science 280 1393 1394 DOI

Swinbank WC 1951 The measurement of vertical transfer of heat and water vapor by eddies in the lower atmosphere. Journal of Meteorology 8 135 145

Valentini R 2003 EUROFLUX: an integrated network for studying the long-term responses of biospheric exchanges. In ‘Fluxes of carbon, water and energy of European forests’. Valentini R 1 8 Springer Berlin

Valentini R Matteucci G Dolman AJ Schulze E-D Rebmann C Granier A Gross P Jensen NO Pilegaard K Grelle A Bernhofer C Grunwald T Kowalski AS Vesala T Rannik U Berbigier P Loustau D Guomundsson J Thorgeirsson H Ibrom A Morgenstern K Clement R Moncrieff J Montagnani L Minerbi S Jarvis PG 2000 Respiration as the main determinant of carbon balance in European forest. Nature 404 861 865

Verhoef A Allen SJ De Bruin HAR Jacobs CMJ Heusinkveld BG 1996 Fluxes of carbon dioxide and water vapour from a Sahelian savanna. Agricultural and Forest Meteorology 80 231 248 DOI

Wang Y-P Barrett DJ 2003 Estimating regional terrestrial carbon fluxes for the Australian continent using a multiple constraint approach. I. Using remotely sensed data and ecological observations of net primary production. Tellus 55B 270 289

Wang Y-P Leuning R 1998 A two-leaf model for canopy conductance photosynthesis and portioning of available energy. I. Model description and comparison with a multi-layered model. Agricultural and Forest Meteorology 91 89 111

Wang YP Leuning R Cleugh HA Coppin PA 2001 Parameter estimation in surface exchange models using non-linear inversion: how many parameters can we estimate and which measurements are most useful? Global Change Biology 7 495 510 DOI

Webb EK Pearman GI Leuning R 1980 Correction of flux measurements for density effects due to heat and water vapour transfer. Quarterly Journal of the Royal Meteorological Society 106 85 100 DOI

Williams RJ Griffiths AD Allan G 2002 Fire regimes and biodiversity in the wet–dry tropical savanna landscapes of northern Australia. In ‘Flammable Australia: the fire regimes and biodiversity of a continent’. Bradstock RA Williams JA Gill AM 281 304 Cambridge University Press Cambridge

Williams RJ Hutley LB Cook GD Russell-Smith J Edwards A Chen X 2004 Assessing the carbon sequestration potential of mesic savannas in the Northern Territory, Australia: approaches, uncertainties and potential impacts of fire. Functional Plant Biology 31 415 422 DOI

Williams RJ Zerihun A Montagu K Hoffman M Hutley LB Chen X 2005 Allometry for estimating aboveground tree biomass in tropical and subtropical eucalypt woodlands: towards general predictive equations. Australian Journal of Botany 53 607 619

Wilson KB Baldocchi DD Aubinet M Berbigier P Bernhofer C Dolman H Falge E Field C Goldstein A Granier A Grelle A Halldor T Hollinger D Katul G Law BE Lindroth A Meyers T Moncrieff J Monson R Oechel W Tenhunen J Valentini R Verma S Vesala T Wofsy S 2002 Energy partitioning between latent and sensible heat flux during the warm season at FLUXNET sites. Water Resources Research 38 1294

Woinarski JCZ Milne DJ Wanganeen G 2001 Changes in mammal population in relatively intact landscapes of Kakadu National Park, Northern Territory, Australia. Austral Ecology 26 360 370

Xiao XM Hollinger D Aber J Goltz M Davidson EA Zhang QY Moore B 2004 Satellite-based modeling of gross primary production in an evergreen needleleaf forest. Remote Sensing of Environment 89 519 534 DOI

Export Citation