Discussing variance of forest soil organic carbon by analysis of δ13C
Four typical samples of forest soil profiles were collected in the middle of Guizhou Province. The processes of source, transport and transformation of soil organic carbon ( SOC) and dissolved organic carbon (DOC) were discussed through analyzing the ratios of δ13CSOC, δ13CDOC and δ13C SOC of litter. The results indicate that the 13C was enriched and the δ13CSOC increased by 0.1 %-0.3% during litter degrading to SOC in surface soil. The litter-rich surface soil had high content of DOC and the δ13CDOC was similar to δ13C of litter. The litter-lack surface soil had low content of DOC,and the δ13CSOC was different from δ13CSOC. It suggests that DOC derives from litter in the litter-rich surface soil. In some mature soil profiles,δ13CSOC and δ13CDOC have a positive trend with the increase of soil depth. The degradation degree of SOC was more thoroughly with the increase of soil depth. The variation trend of δ13CSOC and δ13CDOC in soil profiles and the absolute values of Δ(δ13CDOC-δ13CSOC) decreased with the increase of soil depth. The ratio of DOC from degradation of humus to the amount of DOC was on the increase with soil depth. In the premature soil profiles, the variation of δ13CSOC reflects the mixture of young and old SOC.
国家科技期刊平台
NSTL
万方数据
维普
