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| Titel |
Soil fertility controls soil–atmosphere carbon dioxide and methane fluxes in a tropical landscape converted from lowland forest to rubber and oil palm plantations |
| VerfasserIn |
E. Hassler, M. D. Corre, A. Tjoa, M. Damris, S. R. Utami, E. Veldkamp |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 19 ; Nr. 12, no. 19 (2015-10-13), S.5831-5852 |
| Datensatznummer |
250118123
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| Publikation (Nr.) |
 copernicus.org/bg-12-5831-2015.pdf |
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| Zusammenfassung |
| Expansion of palm oil and rubber production, for which global demand is
increasing, causes rapid deforestation in Sumatra, Indonesia, and is expected
to continue in the next decades. Our study aimed to (1) quantify changes in
soil CO2 and CH4 fluxes with land-use change and (2) determine
their controlling factors. In Jambi Province, Sumatra, we selected two
landscapes on heavily weathered soils that differ mainly in texture: loam and
clay Acrisol soils. In each landscape, we investigated the reference land-use
types (forest and secondary forest with regenerating rubber) and the
converted land-use types (rubber, 7–17 years old, and oil palm plantations,
9–16 years old). We measured soil CO2 and CH4 fluxes monthly from
December 2012 to December 2013. Annual soil CO2 fluxes from the
reference land-use types were correlated with soil fertility: low extractable
phosphorus (P) coincided with high annual CO2 fluxes from the loam
Acrisol soil that had lower fertility than the clay Acrisol soil (P < 0.05).
Soil CO2 fluxes from the oil palm (107.2 to 115.7 mg
C m−2 h−1) decreased compared to the other land-use types
(between 178.7 and 195.9 mg C m−2 h−1; P < 0.01). Across
land-use types, annual CO2 fluxes were positively correlated with soil
organic carbon (C) and negatively correlated with 15N signatures,
extractable P and base saturation. This suggests that the reduced soil
CO2 fluxes from oil palm were the result of strongly decomposed soil
organic matter and reduced soil C stocks due to reduced litter input as well
as being due to a possible reduction in C allocation to roots due to improved
soil fertility from liming and P fertilization in these plantations. Soil
CH4 uptake in the reference land-use types was negatively correlated
with net nitrogen (N) mineralization and soil mineral N, suggesting N
limitation of CH4 uptake, and positively correlated with exchangeable
aluminum (Al), indicating a decrease in methanotrophic activity at high Al
saturation. Reduction in soil CH4 uptake in the converted land-use types
(ranging from −3.0 to −14.9 μg C m−2 h−1) compared
to the reference land-use types (ranging from −20.8 to −40.3 μg
C m−2 h−1; P < 0.01) was due to a decrease in soil N
availability in the converted land-use types. Our study shows for the first
time that differences in soil fertility control the soil–atmosphere exchange
of CO2 and CH4 in a tropical landscape, a mechanism that we were
able to detect by conducting this study on the landscape scale. |
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