Song Xiu-Lin, Wang Zi-Jie, Yin Xian-Wei, Sun Yan-Lin, Jang Dong-Jin, Hong Soon-Kwan
School of Life Sciences, Ludong University, Yantai, 264025, China.
Zibo Eco-Environment Monitoring Center of Shandong Province, Zibo, China.
Sci Rep. 2025 May 14;15(1):16755. doi: 10.1038/s41598-025-00578-2.
Nitrogen deposition is a crucial factor in global change, which is widespread across various regions globally. It has drawn extensive attention due to its direct modification of soil nitrogen retention and nitrogen species distribution, thereby influencing nitrogen metabolism across entire ecosystems. Previous studies on its influence on nitrogen metabolism have not reached a consensus. In an urban ryegrass lawn mesocosm experiment, we set two levels of nitrogen deposition and soil nutrients respectively, aiming to study the impacts of these factors on the N-cycling process through metagenomic analysis. The results demonstrated nitrogen deposition increased nitrification, nitrogen fixation, denitrification, and dissimilatory nitrate reduction, but decreased assimilatory nitrate reduction in the nitrogen metabolism process by changing soil nitrogen availability and the abundance of N-cycling functional genes in the soil microbial community. The soil nutrient levels exhibited effects opposite to those of nitrogen deposition, negatively impacting nitrification, denitrification, and nitrogen fixation in the nitrogen metabolism process. This work further elucidates the impacts of nitrogen deposition on the ecological functions of the ryegrass lawn with different soil nutrient levels, and predicts the potential impacts of intensified nitrogen deposition on these ecological functions. It provides valuable theoretical support for understanding and evaluating complex ecological interactions.
氮沉降是全球变化的一个关键因素，在全球各个地区广泛存在。由于它直接改变土壤氮素保持和氮素形态分布，进而影响整个生态系统的氮代谢，因此受到了广泛关注。先前关于其对氮代谢影响的研究尚未达成共识。在一项城市黑麦草草坪中型实验中，我们分别设置了两个水平的氮沉降和土壤养分，旨在通过宏基因组分析研究这些因素对氮循环过程的影响。结果表明，氮沉降通过改变土壤氮素有效性和土壤微生物群落中氮循环功能基因的丰度，在氮代谢过程中增加了硝化作用、固氮作用、反硝化作用和异化硝酸盐还原作用，但降低了同化硝酸盐还原作用。土壤养分水平表现出与氮沉降相反的效应，在氮代谢过程中对硝化作用、反硝化作用和固氮作用产生负面影响。这项工作进一步阐明了不同土壤养分水平下氮沉降对黑麦草草坪生态功能的影响，并预测了强化氮沉降对这些生态功能的潜在影响。它为理解和评估复杂的生态相互作用提供了有价值的理论支持。
