State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China; School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China.
College of Environment and Resources, Fuzhou University, Fuzhou 350116, China.
Sci Total Environ. 2021 Mar 25;762:143996. doi: 10.1016/j.scitotenv.2020.143996. Epub 2020 Dec 8.
The dynamic changes of soil microorganisms after Phragmites australis straw addition in the incubation tubes were analyzed by phospholipid fatty acid stable isotope probing (PLFA-SIP). After comparing soils from different freshwater pumping areas in the Yellow River Estuary (10-year pumping area, 15-year pumping area and natural salt marsh without pumping), the results showed that the total PLFA contents significantly increased by 59.99%-146.93% after the addition of straw to surface soils (0-10 cm) in the pumping areas, whereas the changes in deeper soils (10-20 cm) were not significant. In particular, the PLFA results showed that bacteria and fungi were significantly increased after 10 days with straw addition. Straw treatment also improved the ratio of fungi to bacteria (F:B) in the surface soils of all sampling sites. The soil microorganisms directly absorbed straw-derived C, where Gram-negative bacteria (GN) were found to have the highest PLFA-C values during the 40-day decomposition process. Soil characteristics can significantly affect microbial community composition. Accordingly, soil organic carbon (SOC) was found to be significantly positively related to bacterial, fungal and other microbial biomasses, while moisture, electric conductivity (EC) and soil aggregate composition were important factors of influence on the microbial community. The findings indicated that both fungi and bacteria were essential microbial communities in straw decomposition, the significant increase of fungi biomass and the absorption of straw-derived C by bacteria were the main changes of microbial community. Long-term freshwater pumping can promote straw decomposition by increasing microbial biomass and changing microbial community composition.
采用磷脂脂肪酸稳定同位素探针（PLFA-SIP）技术分析了芦苇秸秆添加到培养管后土壤微生物的动态变化。通过比较黄河口不同淡水抽水区（10 年抽水区、15 年抽水区和自然盐沼无抽水区）的土壤，结果表明，秸秆添加到抽水区表层土壤（0-10 cm）后，总 PLFA 含量显著增加了 59.99%-146.93%，而深层土壤（10-20 cm）的变化不明显。特别是，PLFA 结果表明，秸秆添加 10 天后细菌和真菌明显增加。秸秆处理还提高了所有采样点表层土壤中真菌与细菌的比例（F:B）。土壤微生物直接吸收秸秆衍生的 C，在 40 天的分解过程中发现革兰氏阴性菌（GN）具有最高的 PLFA-C 值。土壤特性可以显著影响微生物群落组成。因此，土壤有机碳（SOC）与细菌、真菌和其他微生物生物量呈显著正相关，而水分、电导率（EC）和土壤团聚体组成是影响微生物群落的重要因素。研究结果表明，真菌和细菌都是秸秆分解过程中必不可少的微生物群落，真菌生物量的显著增加和细菌对秸秆衍生 C 的吸收是微生物群落的主要变化。长期淡水抽取可以通过增加微生物生物量和改变微生物群落组成来促进秸秆分解。
