Ecological assessment and germination patterns of Rhododendron arboreum in the Himalaya for conservation strategies

Rhododendron arboretum Sm., valued for its ecological, economic, and aesthetic significance, faces various anthropogenic and natural pressures in Himachal Pradesh. This study assessed the regeneration and germination status of the species across 233 sites in seven forest divisions of Shimla district. Seeds were collected from each division to examine phenological and morphological traits, and tested for germination percentage (GP), germination energy (GE), and germination value (GV). Results revealed that total seed output correlates directly with the size and number of capsules per inflorescence, with considerable variation across divisions. Seeds from Theog division exhibited the highest GP (90.22 ± 3.38%), GE (84.11 ± 4.20), and GV (11.21 ± 1.38), while Kotgarh division recorded lower values. About 90% of sites had tree densities exceeding 300 Ind ha⁻¹. Maximum natural regeneration was observed at altitudes of 2000–2500 m, on slopes of 10–40°, and on northern aspects. These findings indicate that Shimla district supports a robust population of R. arboreum with good natural regeneration. The results provide essential baseline data for the development of effective management and conservation strategies to mitigate threats from habitat loss, deforestation, grazing, climate change, and invasive species.