Quantifying nighttime ecosystem respiration of a meadow using eddy covariance, chambers and modelling

Aim of the present paper is to quantify the ecosystem respiration of a mountain meadow in the Austrian Alps during the vegetation period 2002 by constraining nighttime eddy covariance measurements with ecosystem respiration derived from (i) daytime eddy covariance, (ii) ecosystem chamber and (iii) scaled up leaf and soil chamber measurements. The study showed that the discrimination of valid nighttime eddy covariance measurements based on friction velocity (u * ), the so-called u * -correction, is very sensitive to the imposed quality control criteria. Excluding half-hourly nighttime data, which deviate more than 30% from the stationarity and integral turbulence tests caused the magnitude of the u * -correction to be significantly reduced. Based solely on nighttime eddy covariance data, we are currently unable to decide whether the observed high CO2 fluxes during intermittent turbulence represent artefacts and should be screened out, or whether these reflect a genuine transport of CO2 not accounted for by the storage term and must be retained. Evidence against the inclusion of these data is derived from soil respiration rates measured in situ and calculated inversely from the other approaches, which were significantly lower as compared to soil respiration calculated from inversion of the half-hourly nighttime data inclusive of the observations which failed to meet the specified quality control criteria. Seasonal (8 March–8 November 2002) nighttime carbon balances simulated based on the parameters derived from the remaining approaches agreed with each other to within 35%, which is of the order of the uncertainty of each individual approach. # 2004 Elsevier B.V. All rights reserved.

[1]  P. Niklaus,et al.  Respiratory carbon loss of calcareous grasslands in winter shows no effects of 4 years’ CO2 enrichment , 2002 .

[2]  Österreichische Akademie der Wissenschaften,et al.  Struktur und Funktion von Graslandökosystemen im Nationalpark Hohe Tauern , 1989 .

[3]  Michael G. Ryan,et al.  Seasonal and annual respiration of a ponderosa pine ecosystem , 1999 .

[4]  G. Katul,et al.  Organised Motion and Radiative Perturbations in the Nocturnal Canopy Sublayer above an Even-Aged Pine Forest , 2004 .

[5]  Anderson,et al.  Annual carbon cost of autotrophic respiration in boreal forest ecosystems in relation to species and climate , 2007 .

[6]  J. Lloyd,et al.  Current perspectives on the terrestrial carbon cycle , 1999 .

[7]  M. Aubinet,et al.  Horizontal and Vertical Co2 Advection In A Sloping Forest , 2003 .

[8]  A. Knapp,et al.  Responses of Soil Respiration to Clipping and Grazing in a Tallgrass Prairie , 1998 .

[9]  Denis Loustau,et al.  The annual carbon budget of a French pine forest (Pinus pinaster) following harvest , 2003 .

[10]  Andrew E. Suyker,et al.  Year‐round observations of the net ecosystem exchange of carbon dioxide in a native tallgrass prairie , 2001 .

[11]  K. Davis,et al.  Component and whole-system respiration fluxes in northern deciduous forests. , 2004, Tree physiology.

[12]  M. G. Ryan,et al.  Comparing nocturnal eddy covariance measurements to estimates of ecosystem respiration made by scaling chamber measurements at six coniferous boreal sites , 1997 .

[13]  Y. Goto,et al.  Characteristics of CO2 flux over a forest on complex topography , 2003 .

[14]  Annette Freibauer,et al.  Winter wheat carbon exchange in Thuringia, Germany , 2004 .

[15]  Yanhong Tang,et al.  Grazing intensity alters soil respiration in an alpine meadow on the Tibetan plateau , 2004 .

[16]  S. Wofsy,et al.  Factors Controlling Long- and Short-Term Sequestration of Atmospheric CO2 in a Mid-latitude Forest , 2001, Science.

[17]  Peter A. Coppin,et al.  Parameter estimation in surface exchange models using nonlinear inversion: how many parameters can we estimate and which measurements are most useful? , 2001 .

[18]  John Moncrieff,et al.  The propagation of errors in long‐term measurements of land‐atmosphere fluxes of carbon and water , 1996 .

[19]  William J. Massman,et al.  Influence of high-frequency ambient pressure pumping on carbon dioxide efflux from soil , 2004 .

[20]  Eric Ceschia,et al.  The carbon balance of a young Beech forest , 2000 .

[21]  W. Oechel,et al.  CO2 flux measurements in Russian Far East tundra using eddy covariance and closed chamber techniques , 2003 .

[22]  M. Bahn,et al.  A nitrogen sensitive model of leaf carbon dioxide and water vapour gas exchange: application to 13 key species from differently managed mountain grassland ecosystems , 1998 .

[23]  J. M. Norman,et al.  Soil surface CO2 fluxes and the carbon budget of a grassland , 1992 .

[24]  Ü. Rannik,et al.  Gap filling strategies for defensible annual sums of net ecosystem exchange , 2001 .

[25]  J. Monteith,et al.  Boundary Layer Climates. , 1979 .

[26]  M. Monsi.  Uber den Lichtfaktor in den Pflanzengesellschaften und seine Bedeutung fur die Stoffproduktion , 1953 .

[27]  J. C. Kaimal,et al.  Atmospheric boundary layer flows , 1994 .

[28]  W. Oechel,et al.  Seasonality of ecosystem respiration and gross primary production as derived from FLUXNET measurements , 2001 .

[29]  Yiqi Luo,et al.  Substrate regulation of soil respiration in a tallgrass prairie: Results of a clipping and shading experiment , 2003 .

[30]  D. Reicosky,et al.  Chamber and micrometeorological measurements of CO2 and H2O fluxes for three C4 grasses , 1997 .

[31]  Christopher B. Field,et al.  The effects of chamber pressurization on soil‐surface CO2 flux and the implications for NEE measurements under elevated CO2 , 1999 .

[32]  M. Aubinet,et al.  Long term carbon dioxide exchange above a mixed forest in the Belgian Ardennes , 2001 .

[33]  T. Griffisa,et al.  Ecophysiological controls on the carbon balances of three southern boreal forests , 2003 .

[34]  Michael Bahn,et al.  Inter‐specific variation of the biochemical limitation to photosynthesis and related leaf traits of 30 species from mountain grassland ecosystems under different land use , 1999 .

[35]  William J. Massman,et al.  High-frequency pressure variations in the vicinity of a surface CO2 flux chamber , 2003 .

[36]  G. Farquhar,et al.  Effect of temperature on the CO2/O2 specificity of ribulose-1,5-bisphosphate carboxylase/oxygenase and the rate of respiration in the light , 1985, Planta.

[37]  Dennis D. Baldocchi,et al.  Assessing ecosystem carbon balance : Problems and prospects of the eddy covariance tech-nique． , 2001 .

[38]  F. M. Kelliherb,et al.  Spatial and temporal variation in respiration in a young ponderosa pine forest during a summer drought , 2001 .

[39]  Andrew E. Suyker,et al.  Gross primary production and light response parameters of four Southern Plains ecosystems estimated using long‐term CO2‐flux tower measurements , 2003 .

[40]  Dennis Baldocchi,et al.  On Measuring Net Ecosystem Carbon Exchange Over Tall Vegetation on Complex Terrain , 2000, Boundary-Layer Meteorology.

[41]  R. Valentini,et al.  Cross validation of open-top chamber and eddy covariance measurements of ecosystem CO2 exchange in a Florida scrub-oak ecosystem , 2003 .

[42]  Christopher B. Field,et al.  The Terrestrial Carbon Cycle: Implications for the Kyoto Protocol , 1998, Science.

[43]  R. McMillen,et al.  An eddy correlation technique with extended applicability to non-simple terrain , 1988 .

[44]  T. Foken,et al.  Tools for quality assessment of surface-based flux measurements , 1996 .

[45]  Ulrike Tappeiner,et al.  Land-use changes in European mountain ecosystems : ECOMONT-concept and results , 1999 .

[46]  W. Oechel,et al.  FLUXNET: A New Tool to Study the Temporal and Spatial Variability of Ecosystem-Scale Carbon Dioxide, Water Vapor, and Energy Flux Densities , 2001 .

[47]  D. Baldocchi.  Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems: past, present and future , 2003 .

[48]  W. Massman,et al.  Eddy covariance flux corrections and uncertainties in long-term studies of carbon and energy exchanges , 2002 .

[49]  C. J. Moore.  Frequency response corrections for eddy correlation systems , 1986 .

[50]  V. Dantec,et al.  Soil CO2 efflux in a beech forest: comparison of two closed dynamic systems , 1999, Plant and Soil.

[51]  C. Osmond,et al.  Relationship between Photosynthesis and Respiration: The Effect of Carbohydrate Status on the Rate of CO(2) Production by Respiration in Darkened and Illuminated Wheat Leaves. , 1983, Plant physiology.

[52]  Dennis D. Baldocchi,et al.  Seasonal variation in carbon dioxide exchange over a Mediterranean annual grassland in California , 2004 .

[53]  J. Lloyd,et al.  On the temperature dependence of soil respiration , 1994 .

[54]  K. Pilegaard,et al.  Large seasonal changes in Q10 of soil respiration in a beech forest , 2003 .

[55]  Nicanor Z. Saliendra,et al.  Bowen ratio and closed chamber carbon dioxide flux measurements over sagebrush steppe vegetation , 2001 .

[56]  J. William Munger,et al.  Measurements of carbon sequestration by long‐term eddy covariance: methods and a critical evaluation of accuracy , 1996 .

[57]  R. Albrizio,et al.  Automated closed-system canopy-chamber for continuous field-crop monitoring of CO2 and H2O fluxes , 2002 .

[58]  T. A. Black,et al.  Ecophysiological controls on the carbon balances of three southern boreal forests , 2003 .

[59]  D. Fitzjarrald,et al.  Observing subcanopy CO2 advection , 2004 .

[60]  Yadvinder Malhi,et al.  A Re-Evaluation of Long-Term Flux Measurement Techniques Part I: Averaging and Coordinate Rotation , 2003 .

[61]  T. Meyers,et al.  Measuring Biosphere‐Atmosphere Exchanges of Biologically Related Gases with Micrometeorological Methods , 1988 .

[62]  A. Held,et al.  Dark Leaf Respiration in Light and Darkness of an Evergreen and a Deciduous Plant Species , 1995, Plant physiology.

[63]  M. Keller,et al.  Carbon in Amazon Forests: Unexpected Seasonal Fluxes and Disturbance-Induced Losses , 2003, Science.

[64]  Ü. Rannik,et al.  Estimates of the annual net carbon and water exchange of forests: the EUROFLUX methodology , 2000 .

[65]  C. Bernhofer,et al.  The Influence of Advection on the Short Term CO2-Budget in and Above a Forest Canopy , 2003 .

[66]  Georg Wohlfahrt,et al.  Estimation of plant area index of grasslands from measurements of canopy radiation profiles , 2001 .