Degradation and restoration of vegetation cover strongly influence soil properties and ecological processes in temperate ecosystems. In northern Iran, intensive forest exploitation has altered vegetation structure and soil quality, highlighting the importance of monitoring soil biological indicators together with physical properties such as texture. Although many studies have focused on soil physical and chemical characteristics, biological fertility indices remain relatively understudied. This study examined the effects of vegetation degradation and restoration on soil biological fertility and texture across seven land-use types in the Hyrcanian region: natural forest, degraded forest, Alnus subcordata plantation, Acer insigne plantation, mixed Alnus–Acer plantation, Sequoia sempervirens plantation, and grassland. During summer 2025, 36 soil samples were collected from three depths (0–10, 10–20, and 20–30 cm) and analyzed using analysis of variance and Duncan’s test. Results showed that grassland had the highest clay ratio indices, while Acer insigne had the lowest. Sequoia and mixed Alnus–Acer stands exhibited the highest critical organic matter, whereas grassland showed the lowest values at all depths. Soil biological fertility at 0–10 cm was classified as good in natural forest and Alnus subcordata plantations, while all other land uses displayed moderate fertility. Principal component analysis revealed positive relationships among basal respiration, cumulative respiration, microbial biomass carbon, and soil organic matter. Overall, vegetation type significantly affected soil biological quality. These results emphasize including soil biological fertility indices in restoration assessments and identify Alnus subcordata as an effective option for improving soil biological conditions in similar temperate regions.