Overgrazing leads to significant degradation of semi-arid grasslands, while enclosure serves as an essential nature-based restoration strategy. Despite its importance, the effects of varying enclosure durations on plant functional traits and ecosystem functions remain poorly understood. In this study, we investigated a 41-year grazing exclusion chronosequence in a temperate steppe ecosystem, quantifying community-weighted means (CWM) of twelve key leaf and root traits, species and functional diversity, aboveground net primary productivity (ANPP), and soil organic carbon (SOC) concentration. This comprehensive approach enabled us to examine how different enclosure durations influence plant resource-use strategies and the coordination of above- and belowground traits, along with their cascading effects on ANPP and SOC. Our findings reveal that prolonged enclosure enhances traits related to light capture and nutrient conservation. In contrast, short-term enclosure and continuous grazing strengthen correlations between leaf and root traits associated with resource acquisition, thereby reinforcing the leaf-root economic spectrum and increasing trait correlation networks. This coordination enhances ANPP but often at the expense of SOC due to accelerated nutrient and carbon cycling. Conversely, longterm enclosure promotes traits for light acquisition and greater mycorrhizal dependence, facilitating SOC sequestration even without further increases in ANPP. Notably, CWM traits emerged as better predictors of changes in ANPP and SOC than species or functional diversity metrics. These results highlight the critical role of plant functional traits in balancing productivity and SOC sequestration in response to varying enclosure durations, emphasizing the significance of trait-based approaches in grassland restoration.