Variability of annual CO 2 exchange from Dutch grasslands
International audience ; An intercomparison is made of the Net Ecosystem Exchange of CO 2 , NEE , for eight Dutch grassland sites: four natural grasslands, two production grasslands and two meteorological stations within a rotational grassland region. At all sites the NEE was determined during at least 10 months per site, using the eddy-covariance (EC) technique, but in different years. The NEE does not include any import or export other than CO 2 . The photosynthesis-light response analysis technique is used along with the respiration-temperature response technique to partition NEE into Gross... Mehr ...
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Dokumenttyp: | Artikel |
Erscheinungsdatum: | 2007 |
Verlag/Hrsg.: |
HAL CCSD
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Schlagwörter: | [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO] / [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] / [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces / environment / [SDU.OCEAN]Sciences of the Universe [physics]/Ocean / Atmosphere / [SDU.STU]Sciences of the Universe [physics]/Earth Sciences |
Sprache: | Englisch |
Permalink: | https://search.fid-benelux.de/Record/base-28585167 |
Datenquelle: | BASE; Originalkatalog |
Powered By: | BASE |
Link(s) : | https://hal.science/hal-00297645 |
International audience ; An intercomparison is made of the Net Ecosystem Exchange of CO 2 , NEE , for eight Dutch grassland sites: four natural grasslands, two production grasslands and two meteorological stations within a rotational grassland region. At all sites the NEE was determined during at least 10 months per site, using the eddy-covariance (EC) technique, but in different years. The NEE does not include any import or export other than CO 2 . The photosynthesis-light response analysis technique is used along with the respiration-temperature response technique to partition NEE into Gross Primary Production ( GPP ) and Ecosystem Respiration ( R e ) and to obtain the eco-physiological characteristics of the sites at the field scale. Annual sums of NEE , GPP and R e are then estimated using the fitted response curves with observed radiation and air temperature from a meteorological site in the centre of The Netherlands as drivers. These calculations are carried out for four years (2002?2005). Land use and management histories are not considered. The estimated annual R e for all individual sites is more or less constant per site and the average for all sites amounts to 1390±30 gC m ?2 a ?1 . The narrow uncertainty band (±2%) reflects the small differences in the mean annual air temperature. The mean annual GPP was estimated to be 1325 g C m ?2 a ?1 , and displays a much higher standard deviation, of ±110 gC m ?2 a ?1 (8%), which reflects the relatively large variation in annual solar radiation. The mean annual NEE amounts to ?65±85 gC m ?2 a ?1 . From two sites, four-year records of CO 2 flux were available and analyzed (2002?2005). Using the weather record of 2005 with optimizations from the other years, the standard deviation of annual GPP was estimated to be 171?206 gC m ?2 a ?1 (8?14%), of annual R e 227?247 gC m ?2 a ?1 (14?16%) and of annual NEE 176?276 gC m ?2 a ?1 . The inter-site standard deviation was higher for GPP and R e , 534 gC m ?2 a ?1 (37.3%) and 486 gC m ?2 a ?1 (34.8%), respectively. ...