Pteridophytes of Nubri Valley, Manaslu Conservation Area, Central Nepal

Abstract

his study is an inventory based research work carried out in Nubri valley of Manaslu Conservation Area (MCA), Central Nepal. A total of 105 species of Pteridophytes was collected belonging to 45 genera and 20 families. Out of 105 species of pteridophytes two species viz. Selaginella vardei Lev. and Athyrium contingens Ching are new records for Nepal. Based on the number of taxa belonging to particular rank Polypodiaceae and Dryopteris are the largest family and genera respectively with 8 and 12 taxa. On the basis of habitat, majority of the species are terrestrial (65) followed by epiphytic (28) and lithophytic (34). Similarly, a few species are also recorded growing in more than one particular habitat as 16 species growing in both epiphytic and lithophytic conditions. Similarly, one species as epiphytic as well as terrestrial whereas only four species growing in terrestrial and lithophytic habitats. All together there are some 8 distinct forest types, 1 cropland and 1 meadow in the present study. The species show quite distinct relationship with each other based on these forest types. The species are differentiated into 5 distinct main clades. Almost all of the species of cropland are quite closer in the dendrogram. However, even being the members of the same genera, the species show not closure relationship with each other due to their associate forest types so they get departed. Similarly, the species limited to a particular forest type are closer whereas the species diversified well in more than one forest types are also linked to the species of other genera having the same type of distribution along various forest types. The study presented here does not show uniform species richness all along the altitudinal gradient. Highest number of species (43) was found between the altitude 2400-2800 m followed by 36 species at 1500-2200 m, likewise 13 species at 3000-3400 m and 10 species at 3600-3800m. The lowest number of four species was found at 4000 m. Similarly, Notholaena himalaica and Onychium contiguum are with highest distribution range almost from 2200-3600 m followed by Lepisorus loriformis and Osmunda claytoniana having the range of 2400-3400 m and 2600-3600 m respectively. Among economically important species, out of total 105 species so far collected 5 species like Diplazium esculentum, Tectaria coadunata, Dryopteris cochleata, Cythea spinulosa and water ball of Nephrolepis cordifolia species have been found widely used as food; 3 as medicine, one of which also being an important good for export; 1 as ornamental and few others like Dennstaedtia appendiculata, Pteridium revolutum, Pteris biaurita, Pteris cretica, Osmunda claytoniana mainly for agriculture composting and animal fodder and litters.