Abstract Understanding the regional diversity of epiphytic bryophytes along elevation gradients is crucial for assessing forest ecosystems, particularly in areas vulnerable to climate change. The study aimed to compare the composition and richness of epiphytic bryophytes colonising on basal trunks of Cryptomeria japonica , a predominant conifer in the Darjeeling hills, across different altitude zones, and to assess the underlying macroclimatic factors driving such variations. The field surveys were performed at nine elevation zones of Darjeeling between 1450 and 2250 m above sea level. Bryophytes belonging to 37 genera, primarily from Dicranales and Hypnales, were recorded. Diversity profiles reflected low evenness, with Syrrhopodon confertus emerging as the dominant moss in the community. Species richness displayed a multimodal pattern along the altitudinal gradient. The trend exhibited an initial hump peaking at 1550 m and a subsequent rise of richness above 2150 m. About 43.24% of species were confined to a single altitude zone, signifying a narrow range of occurrence. The epiphyte compositions of 1450, 1550 and 2250 m were distinct compared to the other elevation zones. Furthermore, statistical evaluation predicted the influence of climatic parameters such as precipitation, temperature stability and solar radiation on bryophyte assemblage. Therefore, the outcome provides a broad overview of the distribution of bryophytes at managed conifer forests and underscores the significance of elevation-specific climatic conditions in shaping bryophyte diversity, which can be useful for designing their effective conservation strategies.
Projjwal Chandra Lama (2025) studied this question.