杉木根系和凋落物对土壤微生物学性质的影响

通过模拟试验，研究了杉木根系和凋落物及其交互作用对土壤微生物学性质的影响.结果表明：杉木根系和凋落物在土壤生态过程中发挥的作用有所不同.与对照相比，杉木根系处理的土壤微生物生物量碳（MBC）、土壤基础呼吸、土壤有机碳（TOC）和微生物熵显著增加，土壤呼吸熵（qCO₂）显著降低（P<0.05）；凋落物处理中，仅土壤基础呼吸和qCO₂显著降低（P<0.05），而MBC、TOC和微生物熵没有显著变化（P>0.05）.杉木根系和凋落物对土壤基础呼吸和qCO₂的影响具有显著的交互作用.qCO₂与土壤可溶性碳（R²=0.325）及TOC（R²=0.209）含量呈显著正相关，说明微生物对碳的利用效率随土壤有机碳数量的增加而降低.与凋落物相比，杉木根系在土壤生态过程中发挥着更重要的作用.

Effects of root system and litter of Chinese fir on soil microbial properties

A simulation test was conducted to study the effects of the root system and litter of Chinese fir (Cunninghamia lancceolata) on soil microbial pro
perties. After the amendment with C. lancceolata root system, the soil microbial biomass C, basal respiration, total organic C, and microbial quotient increased significantly (P<0.05), while soil metabolic quotient (qCO₂) presented an opposite trend. In the treatment amended with C. lancceolata litter, the soil basal respiration and qCO₂ decreased significantly (P<0.05), whereas soil microbial biomass C, total organic C, and microbial quotient had less change. A significant interaction between C. lancceolata root system and litter was observed on soil basal respiration and qCO₂. The qCO₂ had significant positive correlations with soil total organic C (R²=0.209) and dissolved organic C (R²=0.325), suggesting that the C use efficiency of soil microbes decreased with increasing soil organic C content. Comparing with litter, the root system of C. lancceolata played more important roles in soil ecological processes.