Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education, Fujian Normal University, Fuzhou, 350007, China.
School of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China.
Environ Sci Pollut Res Int. 2022 Jan;29(5):6678-6687. doi: 10.1007/s11356-021-16152-y. Epub 2021 Aug 28.
Spatial and temporal variations in soil denitrification and anaerobic ammonium oxidation (anammox) across the freshwater-oligohaline wetlands in subtropical estuary have not been well understood. In this study, continuous-flow soil core incubation combined with nitrogen isotope tracer was used to determine denitrification and anammox rates across freshwater-oligohaline tidal wetlands in Min River Estuary, Southeast China. Areal rates of denitrification and anammox varied from 3.89 to 19.0 μmol m h and from 0.15 to 1.11 μmol m h, respectively, across these wetlands and throughout sampling months. Denitrification rates were higher in warm months (July, September) than in cool months (November, January), whereas anammox did not vary significantly across the sampling months. Average denitrification rates throughout the sampling months were higher in freshwater than in oligohaline wetlands, while anammox rates did not vary among the wetlands. Relative contribution of anammox (R) to N production (including denitrification and anammox) varied from 1.03 to 18.3% across the sampling months and wetlands. Denitrification rates differed significantly across the wetlands and sampling months. Anammox rates and R did not vary significantly among the sampling months. Denitrification rates were positively correlated with water content, total organic carbon (TOC), total nitrogen, dissolved organic nitrogen, NH, NO, Fe, and Fe/Fe, but negatively related to pH. Anammox rates showed negative relationships with water content and TOC. Water content, temperature, and pH were crucial for organic carbon and Fe availability with important implications on denitrification and anammox. Therefore, denitrification rates vary significantly, whereas anammox rates do not vary significantly across freshwater-oligohaline wetlands in the Min River Estuary.
在亚热带河口地区的淡水寡盐水湿地中，土壤反硝化和厌氧氨氧化（anammox）的时空变化尚未得到很好的理解。本研究采用连续流动土壤芯培养结合氮同位素示踪技术，测定了中国东南闽江河口淡水寡盐水潮汐湿地的反硝化和 anammox 速率。这些湿地和整个采样月份的反硝化和 anammox 的面积速率分别为 3.89 至 19.0 μmol m h 和 0.15 至 1.11 μmol m h。反硝化速率在温暖的月份（7 月、9 月）高于凉爽的月份（11 月、1 月），而 anammox 速率在整个采样月份没有明显变化。整个采样月份的平均反硝化速率在淡水中高于寡盐湿地，而 anammox 速率在湿地之间没有差异。anammox（R）对氮生产（包括反硝化和 anammox）的相对贡献在整个采样月份和湿地中从 1.03 到 18.3%不等。反硝化速率在湿地和采样月份之间有显著差异。anammox 速率和 R 在采样月份之间没有显著差异。反硝化速率与水含量、总有机碳（TOC）、总氮、溶解有机氮、NH、NO、Fe 和 Fe/Fe 呈正相关，与 pH 值呈负相关。anammox 速率与水含量和 TOC 呈负相关。水含量、温度和 pH 值对有机碳和 Fe 的可用性至关重要，对反硝化和 anammox 有重要影响。因此，反硝化速率在闽江河口淡水寡盐水湿地之间有显著差异，而 anammox 速率没有显著差异。
