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| Titel |
Soil CO2 efflux in a sand grassland: contribution by root, mycorrhizal and basal respiration components |
| VerfasserIn |
Marianna Papp, János Balogh, Krisztina Pintér, Dóra Cserhalmi, Zoltán Nagy |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250098862
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| Publikation (Nr.) |
 EGU/EGU2014-14580.pdf |
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| Zusammenfassung |
| Grasslands play an important role in global carbon cycle because of their remarkable
extension and carbon storage capacity. Soil respiration takes a major part in the carbon cycle
of the ecosystems; ratio of its autotrophic and heterotrophic components is important also
when considering their sensitivity to environmental drivers. The aim of the study was to
estimate the contribution by root, mycorrhizal and basal components to total soil CO2
efflux.
The study was carried out in the semi-arid sandy grassland dominated by Festuca
pseudovina at the Kiskunság National Park in Hungary (Bugac site) where C-flux
measurements have been going on since 2002. The soil CO2 effluxes were measured in the
following treatments: a./ control, b./ root-exclusion, c./ root and mycorrhiza exclusion by
using 80 cm long 15 cm inner diameter PVC tubes and micro-pore inox meshes.
Inox mesh was used to exclude roots, but let the mycorrhiza filaments to grow
into the tubes. 10 soil cores were excavated, sieved, then root-free soil was packed
back layer by layer into the cores giving 6 and 4 repetitions in b and c treatments
respectively. Basal respiration is referred to as the heterotrophic respiration without
influence of roots or mycorrhiza. Difference between root-exclusion and root and
mycorrhiza exclusion treatment gave the value of mycorrhizal respiration and control
(non-disturbed) plots the total soil CO2 efflux. The contribution by the above components
was evaluated.
Soil CO2 efflux was measured continuously by using an automated open system of 10 soil
respiration chambers. Data was collected in every two hours from each treatment (one of the
chambers recorded basal respiration, 3 chambers were settled on root-excluded treatments
and 6 chambers measured control plots). Chambers were moved in every 2 weeks between
the repetitions of the treatments. Soil CO2 efflux (mycorrhiza-free, root free, control) data
were fitted using a soil respiration model, where soil temperature, soil water content and
vegetation index (NDVI) act as independent variables (mycorrhiza-free R2 = 0.7348, root
free R2=0.5850, control R2=0.8094, p |
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