Institute of Coastal Environmental Pollution Control, Key Laboratory of Marine Environment and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
Institute of Coastal Environmental Pollution Control, Key Laboratory of Marine Environment and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China.
Sci Total Environ. 2018 Jan 1;610-611:951-960. doi: 10.1016/j.scitotenv.2017.08.166. Epub 2017 Aug 19.
Biochar can sequestrate carbon (C) in soils and affect native soil organic carbon (SOC) mineralization via priming effects. However, the roles of soil aggregation and microbial regulation in priming effects of biochars on SOC in coastal wetland soils are poorly understood. Thus, a coastal wetland soil (δC -22‰) was separated into macro-micro aggregates (53-2000μm, MA) and silt-clay fractions (<53μm, SF) to investigate the priming effect using two C enriched biochars produced from corn straw (δC -11.58‰) at 350 and 550°C. The two biochars induced negative priming effect on the native SOC mineralization in the both soil aggregate size fractions, attributed to the enhanced stability of the soil aggregates resulting from the intimate physico-chemical associations between the soil minerals and biochar particles. Additionally, biochar amendments increased soil microbial biomass C and resulted in a lower metabolic quotient, suggesting that microbes in biochar amended aggregates could likely incorporate biomass C rather than mineralize it. Moreover, the biochar amendments induced obvious shifts of the bacterial community towards low C turnover bacteria taxa (e.g., Actinobacteria and Deltaproteobacteria) and the bacteria taxa responsible for stabilizing soil aggregates (e.g., Actinobacteria and Acidobacteria), which also accounted for the negative priming effect. Overall, these results suggested that biochar had considerable merit for stabilizing SOC in the coastal soil and thus has potential to restore and/or enhance "blue C" sink in the degraded coastal wetland ecosystem.
生物炭可以在土壤中固定碳（C），并通过激发效应影响本地土壤有机碳（SOC）矿化。然而，土壤团聚体和微生物调节在生物炭对沿海湿地土壤 SOC 激发效应中的作用还知之甚少。因此，将一种沿海湿地土壤（δC -22‰）分离成大-微团聚体（53-2000μm，MA）和粉粘粒级（<53μm，SF），以使用两种由玉米秸秆在 350 和 550°C 下产生的富含 C 的生物炭（δC -11.58‰）来研究激发效应。这两种生物炭对两种土壤团聚体大小级分中的本地 SOC 矿化均产生负激发效应，这归因于土壤矿物质和生物炭颗粒之间的物理化学结合导致土壤团聚体的稳定性增强。此外，生物炭的添加增加了土壤微生物生物量 C，并导致代谢商降低，这表明生物炭添加的团聚体中的微生物可能会将生物量 C 纳入而不是矿化。此外，生物炭的添加导致细菌群落明显向低 C 周转率细菌类群（例如，放线菌和δ变形菌）和负责稳定土壤团聚体的细菌类群（例如，放线菌和酸杆菌）发生转变，这也解释了负激发效应。总的来说，这些结果表明，生物炭在稳定沿海土壤中的 SOC 方面具有相当大的优势，因此有潜力恢复和/或增强退化沿海湿地生态系统中的“蓝碳”汇。
