Species composition, morphological variation, and host preferences of epiphytic bryophytes in dominant forest types in central Himalaya

Bryophytes are the second largest group of land plants constituting an essential part of the forest ecosystem. Only limited studies have been carried out on the epiphytic bryophytes of the Himalayan region. The present study was done to assess the species composition, morphological variation, and host preferences of epiphytic bryophytes on the stem bark of four dominant phorophytes namely; Quercus leucotrichophora A.Camus, Quercus floribunda Lindl. ex A.Camus, Quercus semecarpifolia Sm. and Pinus excelsa Wall. in their respective forest sites i.e. Kailakhan (1845–1950 m), Lands’ End (2000–2230 m), Naina Peak (2400–2600 m) and Sigri (2100–2450 m), respectively. The effect of tree canopy and substrate on the epiphytic bryophytes was also analyzed. Fifty-nine bryophyte species were recorded in all phorophytes belonging to 44 genera, 25 families, and nine orders. The maximum number of species belonged to the family Brachytheciaceae (seven) followed by Thuidiaceae (six). Three morphological forms (acrocarpous mosses, pleurocarpous mosses, and leafy liverworts) and five growth forms (tuft, mat, turf, pendant, and weft) were found in collected bryophyte species. Species richness varied from 23 on Q. leucotrichophora to 40 on P. excelsa . A maximum (of 32) species were reported from girth class D ( P. excelsa ) and a minimum (of nine) from girth class A ( Q. floribunda ). Tree bark pH and moisture content were found significant factors for the distribution of epiphytic bryophytes in forests. On the basis of regression analysis, Bark pH contributed to 8.64% of species richness, while moisture contributed 21.67% to species of the epiphytic bryophytes. The present study will be highly useful in assessing conservation status and predicting the effect of changing abiotic factors on bryophyte distribution and productivity.