Vegetation degradation and declining soil quality are among the most significant consequences of overgrazing, recurrent droughts, and unsustainable land-use practices in rangeland ecosystems. Seeding is widely recognized as an effective biological restoration technique aimed at enhancing vegetation establishment and improving soil quality. This study was conducted to compare ecological characteristics between a seeded rangeland with the rangeland species Agropyron elongatum (Host.) Beauv. and Prangos ferulacea (L.) Lindl. and an adjacent untreated (control) rangeland in the Sepidar rangelands of Boyer-Ahmad County in 2025.Vegetation attributes, soil surface characteristics, soil chemical, and biological properties were evaluated. Soil samples were collected from two depths (0–15 and 15–30 cm), and the data were analyzed using an independent samples t-test. The results indicated that seeding significantly increased vegetation cover and litter cover while significantly reducing bare soil compared with the control site (p<0.01). Soil chemical analyses revealed significantly higher levels of organic matter, cation exchange capacity (CEC), phosphorus, and potassium in the seeded rangeland than in the control area (p<0.01). In contrast, electrical conductivity (EC), soil pH, and sodium adsorption ratio (SAR) did not differ significantly between treatments. Furthermore, biological indicators, including basal respiration, substrate-induced respiration, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and the microbial biomass C:N ratio, were significantly greater in the seeded rangeland (p<0.01). Soil depth primarily influenced several chemical properties, whereas most biological indicators showed no significant response to depth. Overall, the seeded rangeland demonstrated markedly improved chemical and biological soil conditions relative to the adjacent control, a difference that can be linked to enhanced vegetation cover and greater organic matter inputs. The observed improvements in soil properties and ecological processes were positively correlated with vegetation establishment. Consequently, seeding represents a viable and practicable option for the restoration of degraded rangelands across the cold-climate zones of the Zagros region.