Effect of N addition, moisture, and temperature on soil microbial respiration and microbial biomass in forest soil at different stages of litter decomposition
Effect of N addition, moisture, and temperature on soil microbial respiration and microbial biomass in forest soil at different stages of litter decomposition
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DOI：
10.1007/s11368-015-1331-z
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发表时间：
2016-05
影响因子：
3.6
通讯作者：
Xingkai Xu;Lian Yin;C. Duan;Y. Jing
中科院分区：
文献类型：
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作者：
Xingkai Xu;Lian Yin;C. Duan;Y. Jing
研究了不同温度、氮素添加量和水分交互作用对不同凋落物分解阶段土壤微生物呼吸、微生物生物量和代谢商（qCO 2）的影响（15和25 °C），两种润湿强度（35和50%水填充孔隙空间（WFPS））和两种剂量的N添加（0和4.5 g N m-2，以NH 4 NO3计）。乔木凋落物包括阔叶凋落物、针叶凋落物和阔叶-针叶混合凋落物3种类型。土壤微生物呼吸，微生物生物量，和qCO 2以及其他土壤性质测定在两个分解阶段的树叶litters.Results和discussionThe增加土壤累积二氧化碳（CO2）通量和微生物生物量在孵化过程中依赖于类型的树叶凋落物，N添加，和水热条件。土壤微生物生物量碳（C）、氮（N）和qCO 2在所有凋落物改良土壤中均显著高于未改良土壤。但在孵化后期，特别是在25 °C时，qCO 2的差异逐渐减小。温度、土壤水分和施氮量的交互作用对凋落物分解前期和后期的累积CO2-C通量影响显著。此外，土壤水分和N的交互作用是显着的影响，在后期的凋落物分解，但不早在experiment.ConclusionsThis本研究表明，除了N和水热条件对土壤微生物呼吸，qCO 2，和不稳定的C和N的浓度取决于类型的树叶凋落物和凋落物分解的发展的影响。研究结果表明，在森林生态系统凋落物分解过程中，氮素有效性和水热条件对土壤微生物呼吸和微生物碳利用具有重要的调控作用。
PurposeThe objective of the present study was to investigate the interactive effects of nitrogen (N) addition, temperature, and moisture on soil microbial respiration, microbial biomass, and metabolic quotient (qCO2) at different decomposition stages of different tree leaf litters.Materials and methodsA laboratory incubation experiment with and without litter addition was conducted for 80 days at two temperatures (15 and 25 °C), two wetting intensities (35 and 50 % water-filled porosity space (WFPS)) and two doses of N addition (0 and 4.5 g N m−2, as NH4NO3). The tree leaf litters included three types of broadleaf litters, a needle litter, and a mixed litter of them. Soil microbial respiration, microbial biomass, andqCO2along with other soil properties were measured at two decomposition stages of tree leaf litters.Results and discussionThe increase in soil cumulative carbon dioxide (CO2) flux and microbial biomass during the incubation depended on types of tree leaf litters, N addition, and hydrothermal conditions. Soil microbial biomass carbon (C) and N andqCO2were significantly greater in all litter-amended than in non-amended soils. However, the difference in theqCO2became smaller during the late period of incubation, especially at 25 °C. The interactive effect of temperature with soil moisture and N addition was significant for affecting the cumulative litter-derived CO2-C flux at the early and late stages of litter decomposition. Furthermore, the interactive effect of soil moisture and N addition was significant for affecting the cumulative CO2flux at the late stage of litter decomposition but not early in the experiment.ConclusionsThis present study indicated that the effects of addition of N and hydrothermal conditions on soil microbial respiration,qCO2, and concentrations of labile C and N depended on types of tree leaf litters and the development of litter decomposition. The results highlight the importance of N availability and hydrothermal conditions in interactively regulating soil microbial respiration and microbial C utilization during litter decomposition under forest ecosystems.