<b>Decade-long zinc addition modulates species-specific physiological responses to nitrogen enrichment and mowing in a meadow steppe</b>

Global change factors such as nitrogen deposition and land management practices like mowing can alter plant resource availability and demand. While the effects on major nutrients like nitrogen are well-studied, the role of essential micronutrients, particularly zinc, in mediating plant physiological responses under these conditions remains a critical gap in our understanding. To address this, we conducted a decade-long field experiment in a meadow steppe in Inner Mongolia to investigate how zinc addition interacts with nitrogen addition and mowing to influence the growth, photosynthesis, and antioxidant physiology of four dominant plant species representing different functional groups. Our study yielded several novel findings. We found that plant growth and physiological responses to these treatments were highly species-specific. Notably, zinc addition alleviated the negative effects of nitrogen on legume growth by increasing superoxide dismutase activity. Furthermore, we found that antioxidant parameters generally explained more variation in plant biomass than photosynthetic parameters, underscoring the critical, yet often overlooked, role of micronutrient-driven stress mitigation in determining plant performance. This work was financially supported by the National Natural Science Foundation of China (32471647, 32271677), the Natural Science Foundation of Hebei Province (C2024201064), and the Excellent Youth Research Innovation Team of Hebei University (QNTD202409).