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| Titel |
How does a land use change from annual food crop to perennial energy crop affect the CO2 balance? A study on net ecosystem exchange of carbon dioxide from Danish fen peatland grown with spring barley and reed canary grass |
| VerfasserIn |
T. P. Kandel, L. Elsgaard, P. E. Lærke |
| 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 |
250064178
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| Zusammenfassung |
| It is important to evaluate how land use change from annual arable food crop to
perennial energy crop cultivation changes the carbon balance in cultivated peatland. We
measured CO2 balance in a riparian fen peatland used for growing reed canary
grass (RCG) and spring barley (SB) on adjacent field plots for a complete year
with a dynamic closed chamber. Carbon dioxide fluxes measured with chamber
were divided into a light dependent part as gross photosynthesis (GP) and a light
independent part as ecosystem respiration (RE). GP and RE in both cropping system
showed a strong seasonal pattern with weather condition and vegetation. A high
ecosystem respiration in RCG (1532 ± 32 g CO2-C m-2) and SB (1080 ± 32 g
CO2-C m-2) during growing season was offset by higher gross photosynthesis in
RCG (-1782 ± 53 g CO2-C m-2) and SB (-1225 ± 59 g CO2-C m-2)making both
cropping system net sink of CO2 during the growing season. The estimated gross
photosynthesis in cold-season from October to March was 17% and 6% of annual GP in SB
and RCG plots, respectively. This higher uptake of CO2 during cold-season in SB
plots was caused by growth of volunteer grass during winter which was completely
suppressed in RCG plots due to its invasive nature. Both GP and REwere significantly
higher in RCG plots than SB plots in an annual scale but net ecosystem exchange
was not significantly different. Total estimated annual ecosystem respirations were
1887 ± 10 g CO2-C m-2 in RCG plots and 1288 ± 12 g CO2-C m-2 in SB plots.
Similarly, total estimated annual GP were 1885 ± 100 g CO2-C m-2in RCG plots
and 1408 ± 24 g CO2-C m-2 in SB plots making a net ecosystem exchange of
2 ± 88 g CO2-C m-2 in RCG plots and -120 ± 25 g CO2-C m-2 in SB plots. |
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