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| Titel |
Organic and inorganic carbon in the topsoil of the Mongolian and Tibetan grasslands: pattern, control and implications |
| VerfasserIn |
Y. Shi, F. Baumann, Y. Ma, C. Song, P. Kühn, T. Scholten, J.-S. He |
| 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 ; 9, no. 6 ; Nr. 9, no. 6 (2012-06-27), S.2287-2299 |
| Datensatznummer |
250007131
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| Publikation (Nr.) |
 copernicus.org/bg-9-2287-2012.pdf |
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| Zusammenfassung |
| Soil carbon (C) is the largest C pool in the terrestrial biosphere and includes
both inorganic and organic components. Studying patterns and controls of
soil C help us to understand and estimate potential responses of soil C to
global change in the future. Here we analyzed topsoil data of 81 sites
obtained from a regional survey across grasslands in the Inner Mongolia and
on the Tibetan Plateau during 2006–2007, attempting to find the patterns and
controls of soil inorganic carbon (SIC) and soil organic carbon (SOC). The
averages of inorganic and organic carbon in the topsoil (0–20 cm) across the
study region were 0.38% and 3.63%, ranging between 0.00–2.92% and
0.32–26.17% respectively. Both SIC and SOC in the Tibetan grasslands
(0.51% and 5.24% respectively) were higher than those in the Inner
Mongolian grasslands (0.21% and 1.61%). Regression tree analyses
showed that the spatial pattern of SIC and SOC were controlled by different
factors. Chemical and physical processes of soil formation drive the spatial
pattern of SIC, while biotic processes drive the spatial pattern of SOC. SIC
was controlled by soil acidification and other processes depending on soil
pH. Vegetation type is the most important variable driving the spatial
pattern of SOC. According to our models, given the acidification rate in
Chinese grassland soils in the future is the same as that in Chinese
cropland soils during the past two decades: 0.27 and 0.48 units per 20 yr
in the Inner Mongolian grasslands and the Tibetan grasslands respectively,
it will lead to a 30% and 53% decrease in SIC in the Inner Mongolian
grasslands and the Tibetan grasslands respectively. However, negative
relationship between soil pH and SOC suggests that acidification will
inhibit decomposition of SOC, thus will not lead to a significant general
loss of carbon from soils in these regions. |
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