Lin Litao, Yu Huiyi, Sun Xuekai, Ai Guiyan, Bai Jie
Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
CAS Key Laboratory of Forest Ecology and Silviculture, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Plants (Basel). 2025 Jun 22;14(13):1915. doi: 10.3390/plants14131915.
The capacity to develop resilience to global change, such as nitrogen deposition, is an important topic for the management of key ecological functional zones. In this study, nitrogen enrichment (10 g N m yr, NE) and control plots (0 g N m yr, CL), each with eight replications, were randomly established in the Horqin Sandy Land to investigate how grassland carbon sequestration functions and herdsmen's livelihoods respond to nitrogen deposition. In addition, three grazing scenarios (non-grazing, light grazing, and moderate grazing) were simulated to determine whether human activities affect the relationships (trade-off vs. synergistic) among forage supply, carbon sequestration, and windbreak and sand-fixing services under nitrogen deposition. The results showed that NE exhibited a significant increase in aboveground carbon storage (99.40 g C m, 117.34%) and the shoot carbon/root carbon ratio (1.90) when compared to the CL (0.95) ( < 0.05). NE significantly decreased soil carbon storage ability, particularly in the 10-30 cm soil layer ( < 0.05). The reduction in soil carbon storage was offset by increases in plant carbon storage, resulting in a neutral effect of the NE treatment on the total grassland carbon storage ( > 0.05). The synergistic effects of NE on grassland forage supply and windbreak and sand-fixing functions were observed under a light grazing scenario, which balanced ecological safety and livelihood more effectively than the non-grazing and moderate grazing scenarios. These findings indicate that the structure of grassland carbon storage is influenced by nitrogen deposition and that light grazing would enhance ecosystem services and promote sustainable grassland development.
发展对全球变化（如氮沉降）的适应能力，是关键生态功能区管理的一个重要课题。本研究在科尔沁沙地随机设置了氮添加（10 g N m² yr⁻¹，NE）和对照样地（0 g N m² yr⁻¹，CL），各8个重复，以研究草地碳固存功能和牧民生计如何响应氮沉降。此外，模拟了三种放牧情景（不放牧、轻度放牧和中度放牧），以确定人类活动是否会影响氮沉降下牧草供应、碳固存以及防风固沙服务之间的关系（权衡与协同）。结果表明，与CL（0.95）相比，NE显著增加了地上碳储量（99.40 g C m⁻²，增加了117.34%）和地上碳/地下碳比（1.90）（P < 0.05）。NE显著降低了土壤碳储存能力，尤其是在10 - 30 cm土层（P < 0.05）。土壤碳储量的减少被植物碳储量的增加所抵消，导致NE处理对草地总碳储量产生中性影响（P > 0.05）。在轻度放牧情景下观察到NE对草地牧草供应和防风固沙功能的协同作用，这比不放牧和中度放牧情景更有效地平衡了生态安全和生计。这些发现表明，草地碳储存结构受氮沉降影响，轻度放牧将增强生态系统服务并促进草地可持续发展。
