Wang Nan, Wang Chuan Kuan, DI Xue Ying, Quan Xian Kui
Center for Ecological Research, Northeast Forestry University, Harbin 150040, China.
Key Laboratory of Sustainable Forest Ecosystem Management, Ministry of Education, Northeast Forestry University, Harbin 150040, China.
Ying Yong Sheng Tai Xue Bao. 2019 Aug;30(8):2757-2766. doi: 10.13287/j.1001-9332.201908.040.
Soil microbial community dynamics during the spring freezing-thawing period could affect carbon and nutrient cycling in the subsequent growing season. During spring soil freezing-thawing period, we monitored temporal dynamics of soil microbial community in different soil substrates for Larix gmelinii forest using phospholipid fatty acids (PLFAs) as biomarkers every 3-7 days. The results were as followed: 1) the total PLFAs content, the PLFAs content and relative abundance of each soil microbial group, the ratio of Gram-positive bacteria to Gram-negative bacteria (G/G), the ratio of saturated PLFAs to unsaturated PLFAs (S/NS) and the ratio of bacteria to total fungi (fungi + arbuscular mycorrhizal fungi) (B/F) all varied among sampling times; 2) soil total organic carbon (TOC) and nitrogen (TN) were the main factors affecting soil microbial community in the early stage of soil freezing-thawing period; soil moisture, TOC and TN were the main driving factors in the middle stage of soil freezing-thawing period; soil microbes were affected by soil tempera-ture, moisture, TOC, TN and C/N in the late stage of soil freezing-thawing period; 3) the total PLFAs content, the PLFAs content and relative abundance of each soil microbial group (except the relative abundance of bacteria), B/F, G/G and S/NS all showed significant difference between soil substrates, and soil TOC, TN and C/N were the key determination factors. Soil temperature, moisture, and nutrient availability were the main factors affecting soil microbial community during the spring soil freezing-thawing period, but the degree of influence varied with the freezing-thawing stages and microbial groups.
春季冻融期土壤微生物群落动态可能会影响随后生长季节的碳和养分循环。在春季土壤冻融期，我们以磷脂脂肪酸（PLFAs）作为生物标志物，每隔3 - 7天监测不同土壤基质中落叶松林土壤微生物群落的时间动态。结果如下：1）总PLFAs含量、各土壤微生物类群的PLFAs含量和相对丰度、革兰氏阳性菌与革兰氏阴性菌的比率（G/G）、饱和PLFAs与不饱和PLFAs的比率（S/NS）以及细菌与总真菌（真菌 + 丛枝菌根真菌）的比率（B/F）在采样时间之间均有变化；2）土壤总有机碳（TOC）和氮（TN）是土壤冻融期早期影响土壤微生物群落的主要因素；土壤水分、TOC和TN是土壤冻融期中期的主要驱动因素；土壤微生物在土壤冻融期后期受土壤温度、水分、TOC、TN和碳氮比（C/N）的影响；3）总PLFAs含量、各土壤微生物类群的PLFAs含量和相对丰度（细菌相对丰度除外）、B/F、G/G和S/NS在土壤基质之间均存在显著差异，且土壤TOC、TN和C/N是关键决定因素。土壤温度、水分和养分有效性是春季土壤冻融期影响土壤微生物群落的主要因素，但影响程度随冻融阶段和微生物类群而变化。
