Zhang Yang, Zhang Qing, Yang Wenjun, Zhang Yan, Wang Ning, Fan Peixian, You Chao, Yu Linqian, Gao Qun, Wang Hui, Zheng Peiming, Wang Renqing
Institute of Ecology and Biodiversity, School of Life Sciences, Shandong University, Qingdao, China.
Shandong Provincial Engineering and Technology Research Center for Vegetation Ecology, Shandong University, Qingdao, China.
Front Plant Sci. 2023 Jul 7;14:1140080. doi: 10.3389/fpls.2023.1140080. eCollection 2023.
The increase of nitrogen (N) deposition and the diversity of its components lead to significant changes in the structure and function of temperate meadow steppe, which could affect plant nutrient uptake, nutrient resorption and litter decomposition, thus affecting the biogeochemical cycle process. The distribution and metabolism of nitrogen and phosphorus in plants determine the growth process and productivity of plants. Plant nutrient uptake, nutrient resorption and litter decomposition play an important role in the nutrient cycling process of ecosystem. This study closely combined these three processes to carry out experiments with different nitrogen dosages and types, and systematically explored the response of nitrogen and phosphorus nutrient cycling to nitrogen deposition. The results showed that nitrogen deposition can greatly affect ecosystem nutrient cycle of nitrogen and phosphorus. Firstly, Nitrogen deposition has significant effect on plant nutrient uptake. Nitrogen uptake of stems and leaves increased with the increase of nitrogen addition dosage, while phosphorus uptake of stems and leaves showed a downward trend or no significant effect. Besides, nitrogen addition type had a significant effect on nitrogen and phosphorus content of stems. Secondly, Nitrogen addition dosage had a significant effect on plant nutrient resorption, while nitrogen addition type had no significant effect on it. Thirdly, nitrogen deposition has significant effect on litter decomposition. With the increase of nitrogen addition dosage, the initial nitrogen content of litters increased and the decomposition rate of litters accelerated. Nitrogen application type had significant effect on stem litter decomposition. These results indicated that nitrogen deposition significantly affects plant nutrient cycling, and thus affects the structure and function of grassland ecosystem.
氮（N）沉降的增加及其组分的多样性导致温带草甸草原的结构和功能发生显著变化，这可能影响植物养分吸收、养分再吸收和凋落物分解，进而影响生物地球化学循环过程。植物中氮和磷的分布与代谢决定了植物的生长过程和生产力。植物养分吸收、养分再吸收和凋落物分解在生态系统的养分循环过程中发挥着重要作用。本研究紧密结合这三个过程，进行了不同氮剂量和类型的实验，并系统地探讨了氮沉降对氮磷养分循环的响应。结果表明，氮沉降会极大地影响生态系统的氮磷养分循环。首先，氮沉降对植物养分吸收有显著影响。茎叶的氮吸收量随施氮量的增加而增加，而茎叶的磷吸收量呈下降趋势或无显著影响。此外，施氮类型对茎的氮磷含量有显著影响。其次，施氮量对植物养分再吸收有显著影响，而施氮类型对其无显著影响。第三，氮沉降对凋落物分解有显著影响。随着施氮量的增加，凋落物的初始氮含量增加，凋落物分解速率加快。施氮类型对茎凋落物分解有显著影响。这些结果表明，氮沉降显著影响植物养分循环，进而影响草地生态系统的结构和功能。
