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| Titel |
Soil carbon sequestration in Swedish grasslands |
| VerfasserIn |
Erik Karltun, Anders Jacobson, Tommy Lennartsson |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250053228
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| Zusammenfassung |
| Soil carbon (SOC) sequestration estimations for Swedish grasslands under grazing are
considerably lower than figures reported in the recent international literature (Soussana et al.
2007). In this study we analyzed variation in SOC stocks in grassland with respect to
region, previous land-use, site moisture class, tree biomass and biodiversity. We also
determined soil carbon sequestration rate in grasslands by using two independent
methods.
The primary source of data for this study is the Swedish National Forest Soil Inventory
which also includes grasslands. The inventory is based on an objective sample grid of the
total Swedish land area. Soil carbon stocks are determined by measurement of C
concentration and bulk density measurements in the upper part of the soil profile and
extrapolation to deeper soil layers based on soil type characteristics and soil depth. The
inventory was made 1993 to 2002 and 2003 a re-inventory started which allows
studies of change over a 10-year period. As an independent comparison we used
a mass balance approach that estimates carbon sequestration indirectly through
an input-output budget for N (de Vries et al. 2006). Assuming that C/N ratio is
constant any surplus N is converted to C by multiplying with the C/N ratio. The
N budget accounted for N deposition, N leaching and N uptake in biomass. Data
for the calculations were taken from several Swedish environmental monitoring
databases.
Previous cultivation and wetter soil conditions were the two factors that contributed to
significantly higher C stocks while region, tree biomass and biodiversity had no effect
on the C stock. The average SOC sequestration rate based on the inventory was
61 kg C ha-1 yr-1 while the N balance method estimated the SOC sequestration
rate to 30 kg C ha-1 yr-1. The low SOC sequestration rate can be explained by
the low-intensity management of the permanent grazing land with practically no
fertilization.
References
de Vries, W., Reinds, G.J., Gundersen, P., & Sterba, H. 2006. The impact of nitrogen
deposition on carbon sequestration in European forests and forest soils. Global Change
Biology, 12, (7) 1151-1173.
Soussana, J.F., Allard, V., Pilegaard, K., Ambus, P., Amman, C., Campbell, C., Ceschia,
E., Clifton-Brown, J., Czobel, S., Domingues, R., Flechard, C., Fuhrer, J., Hensen, A.,
Horvath, L., Jones, M., Kasper, G., Martin, C., Nagy, Z., Neftel, A., Raschi, A., Baronti, S.,
Rees, R.M., Skiba, U., Stefani, P., Manca, G., Sutton, M., Tubaf, Z., & Valentini, R.
2007. Full accounting of the greenhouse gas (CO2, N2O, CH4) budget of nine
European grassland sites. Agriculture Ecosystems & Environment, 121, (1-2) 121-134. |
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