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通过实验室凋落物培养试验,对南京紫金山地区4种典型植被凋落物的分解差异进行了比较研究.结果表明,含凋落物土壤有机碳矿化包含快速分解和缓慢分解2个过程,前者日均分解量大持续时间短,后者与之相反.4种含凋落物土壤在培养初期矿化速率迅速达到最大,大小依次为狗牙根凋落物土壤(CK+BMD)(23.88±0.62)mg.d-1、马尾松凋落物土壤(CK+PML)(17.93±0.99)mg.d-1、麻栎凋落物土壤(CK+QAC)(15.39±0.16)mg.d-1和青冈栎凋落物土壤(CK+CGO)(7.26±0.34)mg.d-1,相互间差异均达到显著水平(p<0.05),此顺序与凋落物初始化学元素组成关系不明显.培养3个月,含凋落物土壤有机碳累积矿化量分别为:(CK+BMD)(338.21±6.99)mg、(CK+QAC)(323.48±13.68)mg、(CK+PML)(278.34±13.91)mg和(CK+CGO)(245.21±4.58)mg.从凋落物自身分解率分析,4种凋落物在培养期间共释放了198.17~297.18 mg的CO2-C,占到加入凋落物中有机碳总量的20.29%~31.70%.对有机碳矿化速率和累积矿化量变化趋势分析后发现,乘幂曲线模型能很好地描述其变化,且相关性较好.
Through litter culture experiments in laboratory, the differences of litter decomposition of four typical vegetation types in Nanjing Zijin Mountain were compared.The results showed that the organic carbon mineralization of litter contained two processes: rapid decomposition and slow decomposition, The amount of decomposition was short and the duration was short, while the latter was the opposite. The mineralization rates of four litter-containing soils reached the maximum rapidly at the early stage of culture, followed by the soil (CK + BMD) of bermudagrass (23.88 ± 0.62) mg. (CK + PML) (17.93 ± 0.99) mg.d-1, CK + QAC (15.39 ± 0.16) mg.d-1 and litter of Cyclobalanopsis glauca (CK + CGO) (7.26 ± 0.34) mg.d-1, the differences among them reached significant level (p <0.05), and the sequence had no obvious relationship with the initial chemical composition of litter.After cultured for 3 months, The cumulative mineralized amounts of organic carbon in soils were (CK + BMD) 338.21 ± 6.99 mg, CK + QAC 323.88 ± 13.68 mg, CK + PML 278.34 ± 13.91 mg and CK + CGO) was 245.21 ± 4.58 mg. From litter decomposition rate analysis, four litterfalls released 198.17 ~ 297.18 mg of CO2-C during the cultivation period, accounting for 20.29% of the total organic carbon added into the litter. 31.70%. After analyzing the change tendency of mineralization rate and cumulative mineralization, it is found that the power curve model can describe the change well and the correlation is good.