Environmental Futures Research Institute, School of Environment and Science, Griffith University, Brisbane, Queensland 4111, Australia.
Environmental Futures Research Institute, School of Environment and Science, Griffith University, Brisbane, Queensland 4111, Australia; Department of Environment and Science, Dutton Park, Queensland 4102, Australia.
Sci Total Environ. 2018 Nov 15;642:879-886. doi: 10.1016/j.scitotenv.2018.06.144. Epub 2018 Jun 17.
As an anthropogenic disturbance, prescribed burning may alter the biogeochemistries of nutrients, including nitrogen (N) cycling, in forest ecosystems. This study aimed to examine the changes in N mineralization, nitrification and denitrification rates following prescribed burning in a suburban forest located in subtropical Australia and assess the interactive relationships among soil properties, functional gene abundances and N transformation rates. After a prescribed burning event, soil pH value increased, but soil labile carbon and mineral N contents decreased. Net N mineralization rates, potential nitrification rates and ammonium-oxidizing archaea and bacteria (AOA and AOB) amoA gene abundances in the soils all increased after 3 months of the prescribed burning. However, the abundances of different functional genes related to denitrification changed differently after the prescribed burning. The net N mineralization rates could be best described by soil abiotic properties, rather than functional gene abundances. In contrast, potential denitrification rates were positively related to soil nirK gene abundances. Potential nitrification rates could be influenced by both soil chemical and microbial properties. The results revealed that the prescribed burning might increase N mineralization and nitrification rates in the forest soil.
作为一种人为干扰，计划火烧可能会改变森林生态系统中养分的生物地球化学特性，包括氮（N）循环。本研究旨在考察亚热带澳大利亚城郊森林计划火烧后氮矿化、硝化和反硝化速率的变化，并评估土壤性质、功能基因丰度和氮转化速率之间的相互关系。计划火烧后，土壤 pH 值升高，但土壤易降解碳和矿质氮含量降低。计划火烧后 3 个月，土壤中净氮矿化速率、潜在硝化速率以及氨氧化古菌和细菌（AOA 和 AOB）amoA 基因丰度均增加。然而，与反硝化作用相关的不同功能基因的丰度在计划火烧后变化不同。净氮矿化速率可以最好地用土壤非生物特性来描述，而不是功能基因丰度。相比之下，潜在反硝化速率与土壤 nirK 基因丰度呈正相关。潜在硝化速率可能受到土壤化学和微生物特性的共同影响。研究结果表明，计划火烧可能会增加森林土壤的氮矿化和硝化速率。
