Soil Organic δ13C Change Along a Vertical Gradient in the Northern Slop of Tianshan Mountains

Autor: XU Wen-qiang, LUO Ge-ping, CHEN Xi, FENG Yi-xing, LI Chao-fan
Jazyk: čínština
Rok vydání: 2016
Předmět:
the Sangong river watershed was taken as a case. We had estimated the change of vegetation and soil organic along a vertical gradient using the carbon isotopic method
and analyzed the variations of mean SOC δ13C values with the annual precipitation
and researched the variations in SOC and δ13C values with profile depth in the study area. The results showed that the SOC δ13C decreased significantly with the increasing annual precipitation (R2=0.97) where the annual precipitation was less than 300 mm. When the annual precipitation was 300 mm~500 mm
the SOC δ13C was not significant changed with the increasing annual precipitation (R2=0.04). The enrichment effect of SOC δ13C with depth was significant in the sample site of pure C3 vegetation
that means lower layer SOC δ13C of profile was greater than the upper layer. The average difference of SOC δ13C between lower layer and upper layer was 1.01‰. The opposite trend of SOC δ13C was presented in the Desert and Shrubland sites. And that
the SOC δ13C value of upper layer closed to C4 vegetation source
and the lower layer closed to C3 vegetation source. Therefore
we can infer that the vegetation may have experienced from C3 to C4 in the sandy desert and terrene desert sites.
carbon isotope
δ13C value
C3 and C4 vegetation
enrichment effect of δ13C
Sangong river
watershed
Nuclear and particle physics. Atomic energy. Radioactivity
QC770-798
Zdroj: Journal of Isotopes, Vol 29, Iss 3, Pp 140-145 (2016)
Druh dokumentu: article
ISSN: 1000-7512
DOI: 10.7538/tws.2016.29.03.0140
Popis: Soil organic carbon (SOC) pool integrated the vegetation succession information from several years to thousands of years scales. It is an ideal tool to understand carbon isotope composition change and terrestrial ecosystem pathways. In this study, the Sangong river watershed was taken as a case. We had estimated the change of vegetation and soil organic along a vertical gradient using the carbon isotopic method, and analyzed the variations of mean SOC δ13C values with the annual precipitation, and researched the variations in SOC and δ13C values with profile depth in the study area. The results showed that the SOC δ13C decreased significantly with the increasing annual precipitation (R2=0.97) where the annual precipitation was less than 300 mm. When the annual precipitation was 300 mm~500 mm, the SOC δ13C was not significant changed with the increasing annual precipitation (R2=0.04). The enrichment effect of SOC δ13C with depth was significant in the sample site of pure C3 vegetation, that means lower layer SOC δ13C of profile was greater than the upper layer. The average difference of SOC δ13C between lower layer and upper layer was 1.01‰. The opposite trend of SOC δ13C was presented in the Desert and Shrubland sites. And that, the SOC δ13C value of upper layer closed to C4 vegetation source, and the lower layer closed to C3 vegetation source. Therefore, we can infer that the vegetation may have experienced from C3 to C4 in the sandy desert and terrene desert sites.
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