Monitoring the soil microbial communities following forest management practices is vital since soil microorganism play a critical role in sustaining forest productivity, nutrient cycling and soil CO₂ emission. Here, biomass and the structures of soil microbial communities in aerially seeded Pinus massoniana plantations across three growing and three non-growing seasons following canopy tree thinning and understory removal were investigated using PLFA method, and soil environmental factors were analyzed. Both overall microbial community structures and mean microbial biomass did not significantly differ among control (CK), heavily thinning (HT), light thinning (LT) and understory removal (UR), but were significantly affected by time following treatment. In spite of non-significant effects of treatment, thinning and UR tended to decrease soil microbial biomass in non-growing seasons, and to increase the microbial biomass in the 2nd and 3rd growing seasons following treatment. Soil moisture, carbon to nitrogen ratio and nitrogen (i.e. total N and mineral N) were the main drivers of soil microbial community changes. Lower soil moisture and higher soil nitrogen led to significant differences in soil microbial biomass in the 2nd year after treatment. Thinning significantly increased fungi to bacteria ratio (FB ratio), which was significantly positively correlated with soil heterotrophic respiration. Our study confirms that forest management practices such as thinning and understory removal exert strong effects on environmental conditions (i.e. microclimate and soil nutrient availability), which further influences FB ratio, and consequently might impact soil C cycling and forest productivity.

遵循森林管理实践来监测土壤微生物群落至关重要，因为土壤微生物在维持森林生产力，养分循环和土壤CO ₂排放中起着至关重要的作用。在此，飞播马尾松生物量和土壤微生物群落结构利用PLFA方法研究了树冠间伐和林下去除后三个生长季和三个非生长季的人工林，并分析了土壤环境因素。总体微生物群落结构和平均微生物生物量在对照（CK），重度稀释（HT），轻度稀释（LT）和林下去除（UR）之间没有显着差异，但治疗后的时间显着影响。尽管处理效果不显着，但间伐和UR往往会在非生长季节减少土壤微生物量，并在处理后的第二个和第三个生长季节增加微生物量。土壤水分，碳氮比和氮（即总氮和矿质氮）是土壤微生物群落变化的主要驱动力。在处理后的第二年，较低的土壤湿度和较高的土壤氮素导致土壤微生物量的显着差异。间伐显着增加了真菌与细菌的比率（FB比），这与土壤异养呼吸显着正相关。我们的研究证实，森林管理实践（例如间伐和林下除草）对环境条件（即小气候和土壤养分的可利用性）产生了强烈影响，进一步影响了FB比率，因此可能影响土壤碳循环和森林生产力。