Environmental Futures Centre and Griffith School of Environment, Griffith University, Nathan, Brisbane, QLD 4111, Australia; Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Environmental Futures Centre and Griffith School of Environment, Griffith University, Nathan, Brisbane, QLD 4111, Australia.
Sci Total Environ. 2014 Feb 1;470-471:578-86. doi: 10.1016/j.scitotenv.2013.10.011. Epub 2013 Oct 26.
Fire shapes global biome distribution and promotes the terrestrial biogeochemical cycles. Ammonia-oxidizing bacteria (AOB) and archaea (AOA) play a vital role in the biogeochemical cycling of nitrogen (N). However, behaviors of AOB and AOA under long-term prescribed burning remain unclear. This study was to examine how fire affected the abundances and communities of soil AOB and AOA. A long-term repeated forest fire experiment with three burning treatments (never burnt, B0; biennially burnt, B2; and quadrennially burnt, B4) was used in this study. The abundances and community structure of soil AOB and AOA were determined using quantitative PCR, restriction fragment length polymorphism and clone library. More frequent fires (B2) increased the abundance of bacterium amoA gene, but tended to decrease archaeal amoA genes. Fire also modified the composition of AOA and AOB communities. Canonical correspondence analysis showed soil pH and dissolved organic C (DOC) strongly affected AOB genotypes, while nitrate-N and DOC shaped the AOA distribution. The increased abundance of bacterium amoA gene by fires may imply an important role of AOB in nitrification in fire-affected soils. The fire-induced shift in the community composition of AOB and AOA demonstrates that fire can disturb nutrient cycles.
火塑造了全球生物群落分布，并促进了陆地生物地球化学循环。氨氧化细菌（AOB）和古菌（AOA）在氮（N）的生物地球化学循环中起着至关重要的作用。然而，长期规定燃烧下 AOB 和 AOA 的行为仍不清楚。本研究旨在研究火如何影响土壤 AOB 和 AOA 的丰度和群落。本研究采用了一个长期重复的森林火实验，有三种燃烧处理（从未燃烧过，B0；两年燃烧一次，B2；四年燃烧一次，B4）。使用定量 PCR、限制性片段长度多态性和克隆文库来确定土壤 AOB 和 AOA 的丰度和群落结构。更频繁的火灾（B2）增加了细菌 amoA 基因的丰度，但倾向于降低古菌 amoA 基因。火还改变了 AOA 和 AOB 群落的组成。典范对应分析表明，土壤 pH 值和溶解有机碳（DOC）强烈影响 AOB 基因型，而硝酸盐-N 和 DOC 则影响 AOA 的分布。火引起的 AOB 基因丰度增加可能意味着 AOB 在受火影响土壤中的硝化作用中起着重要作用。AOB 和 AOA 群落组成的火诱导变化表明，火可以干扰养分循环。
