Decomposition of stumps in successive rotation of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantations was studied using a chronosequence approach. The results showed that decomposition rate constant of Chi...Decomposition of stumps in successive rotation of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantations was studied using a chronosequence approach. The results showed that decomposition rate constant of Chi- nese fir stump was 0.02695 as calculated from Olson’s model. The N content of stump increased during the first two-year decomposition. When the dead stump C/N ratio was 463.2 ± 27.3, the stumps started to release N. The pattern of P release was similar to that for N. However, K content of stumps showed a consistent declining trend over time during the whole decomposition. 13C nuclear magnetic resonance spec- troscopy with cross polarization and magic-angle spinning (13C CPMAS-NMR) was used to analyse organic carbon (C) components in decomposing stumps. The 13C CPMAS-NMR spectra of stumps displayed that stump was dominated by cellulose and hemicellulose. The spectra also showed the ac- cumulation of intensity in alkyl C, aromatic C, and carboxyl C spectral regions, which was expected as the labile cellulose and hemicellulose components in O-alkyl C spectral region were selectively decomposed first.展开更多
The microbial flora in bamboo stump at different decomposition degree was studied. The results showed that the logarithmic values of bacterial concentrations ranged from 5.477 to 7.380; the logarithmic values of funga...The microbial flora in bamboo stump at different decomposition degree was studied. The results showed that the logarithmic values of bacterial concentrations ranged from 5.477 to 7.380; the logarithmic values of fungal concentrations ranged from 5.301 to 6.903; the logarithmic values of actinomycetes concentrations ranged from 5.740 to 7.000; the logarithmic values of cellulose-degrading bacterial concentrations ranged from 4.301 to 6.447; the logarithmic values of lignin-degrading bacterial concentrations ranged from 4.415 to 6.799. During the decomposition of bamboo stump, all the microorganisms grew rapidly at the initial stage; the logarithmic values of bacterial, fungal and actinomycetes concentrations changed constantly at the middle stage; and the logarithmic values were all higher at the late stage.There were assistance and competition among microorganism to certain extent. Understanding the decomposition rule of bamboo stump before its cutting down can provide some reference for the future decomposition of bamboo stump, and provide basic data for the isolation of microorganisms from bamboo stump at the species level.展开更多
基金This work was supported by the National Natural Science Foundation of China (Grant No.30300054).
文摘Decomposition of stumps in successive rotation of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) plantations was studied using a chronosequence approach. The results showed that decomposition rate constant of Chi- nese fir stump was 0.02695 as calculated from Olson’s model. The N content of stump increased during the first two-year decomposition. When the dead stump C/N ratio was 463.2 ± 27.3, the stumps started to release N. The pattern of P release was similar to that for N. However, K content of stumps showed a consistent declining trend over time during the whole decomposition. 13C nuclear magnetic resonance spec- troscopy with cross polarization and magic-angle spinning (13C CPMAS-NMR) was used to analyse organic carbon (C) components in decomposing stumps. The 13C CPMAS-NMR spectra of stumps displayed that stump was dominated by cellulose and hemicellulose. The spectra also showed the ac- cumulation of intensity in alkyl C, aromatic C, and carboxyl C spectral regions, which was expected as the labile cellulose and hemicellulose components in O-alkyl C spectral region were selectively decomposed first.
基金Supported by Youth Innovation Fund of Hunan Academy of Forestry(2013LQJ09)~~
文摘The microbial flora in bamboo stump at different decomposition degree was studied. The results showed that the logarithmic values of bacterial concentrations ranged from 5.477 to 7.380; the logarithmic values of fungal concentrations ranged from 5.301 to 6.903; the logarithmic values of actinomycetes concentrations ranged from 5.740 to 7.000; the logarithmic values of cellulose-degrading bacterial concentrations ranged from 4.301 to 6.447; the logarithmic values of lignin-degrading bacterial concentrations ranged from 4.415 to 6.799. During the decomposition of bamboo stump, all the microorganisms grew rapidly at the initial stage; the logarithmic values of bacterial, fungal and actinomycetes concentrations changed constantly at the middle stage; and the logarithmic values were all higher at the late stage.There were assistance and competition among microorganism to certain extent. Understanding the decomposition rule of bamboo stump before its cutting down can provide some reference for the future decomposition of bamboo stump, and provide basic data for the isolation of microorganisms from bamboo stump at the species level.
