Carbon dioxide and water vapour flux densities over a grassland area in the Netherlands

• Published in: International journal of climatology Vol. 23; no. 13; pp. 1663 - 1675
• Main Authors: Jacobs, Adrie F. G., Heusinkveld, Bert G., Holtslag, Albert A. M.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 15.11.2003; Wiley
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Applied sciences; Atmospheric pollution; A–gs model; Biological and medical sciences; budget; carbon dioxide; Climatology. Bioclimatology. Climate change; co2; conductance; Dispersed sources and other; Earth, ocean, space; eddy-correlation; evapotranspiration; Exact sciences and technology; exchange; External geophysics; Fundamental and applied biological sciences. Psychology; grassland; Meteorology; Netherlands; Pollution; Pollution sources. Measurement results; respiration; Synecology; Terrestrial ecosystems; transpiration; Netherlands; Europe; Grassland; A-gs model; Monocotyledones; Vegetation index; Carbon dioxide; Troposphere; Netherlands; Air biosphere interaction; Gramineae; Greenhouse gas; Angiospermae; Evapotranspiration; Lolium perenne; Warming; Poa trivialis; Biogeochemical cycle; Water vapor; Carbon sequestration; Uptake; Carbon cycle; Flux density; Air pollution; Spermatophyta; Models; Gas exchange; Climate modification; Canopy(vegetation)
• ISSN: 0899-8418; 1097-0088
• DOI: 10.1002/joc.959

Measurements of carbon dioxide and water vapour flux densities were carried out for a grassland area in the centre of the Netherlands during a 12 month continuous experiment using the eddy‐covariance technique. Lolium perenne and Poa trivialis mainly dominated the vegetation of the area. The leaf area index (LAI) of the grassland varied between 2.5 and 3.4, depending on the mowing scheme at the site. Fluxes are also calculated by using a canopy model in which the canopy resistance is related to the assimilation rate (A–gs model). The calculated evapotranspiration fluxes agree within 7% of the measured fluxes (R2 = 0.93;SEE = 23 W m−2). The calculated net carbon dioxide fluxes agree within 12% of the measured fluxes (R2 = 0.79;SEE = 0.16 mg m−2s−1). The net carbon dioxide fluxes consist of two opposite components: the uptake via assimilation and release via soil and plant respiration. It appears that nearly the whole year round the assimilation term dominates, which means an accumulation of carbon dioxide if no other exchange processes are present. For 2002 a net carbon uptake was found of 6.8 tonnes ha−1. Copyright © 2003 Royal Meteorological Society