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| Titel |
Carbon balance of a grazed grassland in Belgium |
| VerfasserIn |
E. Jérôme, Y. Beckers, B. Bodson, C. Moureaux, M. Aubinet |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250067392
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| Zusammenfassung |
| This work seeks to analyze the C balance of a Belgian grassland grazed by the “Blanc Bleu
Belge” breed of cattle.
The site is located at Dorinne in the Belgian Condroz (50Ë 18’ 44” N; 4Ë 58’ 07” E; 248
m asl.). It is permanent grassland of ca. 4.2 ha with a moderate slope of 1 to 2 %.
Homogeneity and topography criteria are met to ensure high quality turbulent flux
measurements.
The experimental field was equipped with an eddy covariance system. Flux correction,
quality control and data gap filling were performed following standardised procedures. This
device was completed by a micrometeorological station that measured temperature and
humidity respectively in the air and within the soil, radiation, atmospheric pressure and
precipitations. Carbon exported through mowing (CNBP,export), imported through compost
application (CNBP,import) or through complementary feeds for cattle (CNBP,complement)
was also measured. In addition, the vegetation development was followed in order to estimate
herbage production and dry matter intake by grazing animals. Carbon lost through CH4
emissions (CNBP,CH4) was finally estimated, allowing the establishment of a full C
budget.
After one year of measurements (May 2010 - May 2011), the grassland was a net CO2
source (Net Ecosystem Exchange (NEE) = 172 ± 94 g C m-2 year-1). Net Biome
Productivity (NBP) was calculated from NEE by taking into account imports and export of
organic C and losses of carbon as CH4. Contribution of CNBP,CH4to NBP was small as it
was 12 ± 1 g C m-2 year-1. The balance between CNBP,import and CNBP,export created
not such a large departure of NBP from NEE, which is not the case of CNBP,complement.
The NBP was finally estimated at 102 ± 95 g C m-2 year-1. At this stage, it is
premature to conclude about the sink or source behaviour of the plot because the
NBP value is very close to its uncertainty. Moreover, this result was obtained under
particular climate conditions, characterised by drought during summer 2010 and
spring 2011. First year full carbon budget will be discussed in relation with climate
conditions and management practices. A second year of measurements will be also
presented.
Key words: grassland, carbon budget, carbon dioxide exchange, eddy covariance |
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