<p>Nitrogen (N) and phosphorus (P) are vital nutrients in terrestrial ecosystems, essential for vegetation growth, plant survival, development, and the maintenance of plant diversity. While the effects of N and P additions on plant nutrient concentrations and diversity have been extensively studied, the impact of various stages of natural forest ecosystem restoration after disturbance, particularly on plant N, P nutrients, and diversity, is less understood. This study investigates the influence of anthropogenic disturbance on soil N: P ratios, plant community-level N: P, and species diversity in Liaodong oak forests in northern China during early (about 10 years), mid-to-late (about 30 years), and late (about 40 years) restoration stages (it is a space for time substitution method). We observed that soil total nitrogen to total phosphorus ratio (TN: TP) and soil available nitrogen to phosphorus ratio (AN: AP) were significantly lower in the mid-to-late and late stages of restoration compared to the early restoration stages. Concurrently, plant community level leaf nitrogen-phosphorus ratio (CWM_{N: P}) were notably lower in these later stages. Additionally, species richness showed a decline as restoration time increased. These findings highlight that decreasing soil N: P ratio over time exacerbates plant N limitation and reduces plant richness, emphasizing the critical role of soil nutrient dynamics in forest restoration post-disturbance. Our results provide important insights for forest management and restoration practices, contributing to a better understanding of ecosystem restoration processes.</p>