| 摘要: |
| 挺水植物在生长期不仅可以作为“汇”从水体及底泥中吸收养分，在衰亡期还可以作为“源”不断向水环境中释放氮、磷等营养物质，如果生物量庞大则可能引起水体“二次污染”。为探究衡水湖典型挺水植物养分释放规律及影响植物分解的微生物学机制，以优势种芦苇（Phragmites australis）与水烛（Typha angustifolia）为研究对象，于2023年2月底在衡水湖采用分解袋法开展原位分解试验，以水面上未接触水体的试验组模拟植物的“立枯分解”，水面下淹水试验组模拟挺水植物在水体中的腐烂分解。结果表明：①芦苇与水烛在淹水与非淹水条件下分解速率具有极显著差异（p< 0.01），淹水分解更有助于芦苇与水烛腐烂分解的进行，但长时间的淹水可能会导致元素积累。②水烛比芦苇分解快，是由于分解速率与初始N、P含量及氮、磷循环总基因相对丰度呈正相关，与初始纤维素、木质素、可溶性糖含量呈负相关。③固氮基因丰度随分解程度的增加而逐渐增加，芦苇（分解中后期）与水烛凋落物N含量的增加与固氮微生物的固氮基因呈正相关关系。 |
| 关键词: 芦苇 水烛 腐解 挺水植物 影响因素 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
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| Study on the release characteristics and influencing factors of nitrogen and phosphorus during the decomposition of Phragmites australis and Typha angustifolia |
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Li Ziwei1, Huang Wei2, Shi Wenqing3, Chen Kaining4, Liu Cheng4
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1.School of Environmental Science and Engineering,Nanjing University of Information Science and Technology;2.Key Laboratory of Lake and Watershed Science for Water Security,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences;3.:School of Environmental Science and Engineering,Nanjing University of Information Science and Technology;4.Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences
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| Abstract: |
| Emergent plants can not only absorb nutrients from water and sediment as a "sink" during the growth period, but also release nutrients such as nitrogen and phosphorus into the water environment as a "source" during the decline period. If the biomass is large, it may cause "secondary pollution" of water. In order to explore the nutrient release rule of typical emergent plants in Hengshui Lake and the microbial mechanism affecting plant decomposition, the dominant species Phragmites australis and Typha angustifolia were selected as the research objects, and the decomposition bag method was used to carry out in-situ decomposition tests in Hengshui Lake at the end of February 2023. The "vertical decomposition" of plants was simulated in the experimental group which was not in contact with water surface, and the decomposition of emergent plants was simulated in the experimental group which was flooded under water surface. The results showed that: (1) The decomposition rates of P. australis and T. angustifolia were significantly different under flooded and non-flooded conditions (p< 0.01). The decomposition of P. australis and T. angustifolia was more conducive to the decomposition of P. australis and T. angustifolia, but the long-term flooding might lead to the accumulation of elements. (2) The decomposition rate of T. angustifolia was faster than that of P. australis, because the decomposition rate was positively correlated with the initial N and P contents and the relative abundance of nitrogen and phosphorus cycling genes., and negatively correlated with the initial cellulose, lignin and soluble sugar contents. (3) The abundance of nitrogen fixing genes increased gradually with the increase of decomposition degree, and the increase of N content in P. australis and T. angustifolia litter was positively correlated with the nitrogen fixing genes of nitrogen fixing microorganisms. |
| Key words: Phragmites australis Typha angustifolia decomposition emergent plants influencing factors |
