Betula utilis is a native tree and important tree line species in the Indian Himalayan Region (IHR). Due to various natural and anthropogenic factors, the population of the species has become dwindling. Therefore, study was conducted to; assess population, regeneration, habitat suitability model, size class distribution and physico-chemical properties of the soil in sub-alpine ecosystem of Great Himalayan National Park. Total 64 populations assessed to determine the density, Total Basal Area, Species diversity index, Concentration of dominance and regeneration pattern of seedlings and saplings. Amongst the identified populations, total trees density ranged from 10–730 Ind ha−1; total basal area 0.00–43.32 m2 ha−1; total shrubs density 340–3490 Ind ha−1; total herbs density 8.54–152.77 Ind m−2; total saplings density 9–3050 Ind ha−1 and total seedlings density 10–1840 Ind ha−1. Species diversity of trees was ranged from 0.00 to 0.37; Concentration of dominance ranged from 0.00 to 1.00. Size class distribution revealed that maximum number of individuals was fallen in the range of 52.6–73.5 cm whereas lowest numbers of individuals were fallen in the range of 136.6–157.5 cm and ≥ 220.6 cm. The model calibration test for B.utilis yielded satisfactory results (AUC Mean = 0.91 ± 0.02) indicated that MaxEnt could be used to predict the potentially suitable habitats for in-situ or ex-situ conservation. The model predicted 268 km2 area suitable for reintroduction. Frequent monitoring of populations for understanding the dynamics and identifying natural habitats for the in-situ conservation of the species are suggested.
