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International Journal of Ecology and Environmental Sciences 27: 13-21, 2001
International Scientific Publications, New Delhi

Diversity and Dominance of Liverworts of Chopta-Tunganath in the Garhwal Himalaya

Hans Raj Negi

ABSTRACT

A total of 369 colonies of terricolous (soil-borne) liverworts from 13 plots of 50 m 10 m dimensions, distributed across five macrohabitat (vegetation) types along the gradients of disturbance and elevation (1400 -3700 m) in Chopta-Tunganath landscape of Garhwal Himalaya, yielded 13 families with 15 genera and 19 species. While Scapania verrucosa, Plagiochila ferruginea and Pellia endiviifolia have emerged as the most dominant species, Jungermannia crenulata and Apometzgeria pubescens exhibited as the least dominant (rare) members of the community of liverworts. While rarefaction method was used to compare the macrohabitats with respect to the richness (alpha-diversity) of liverwort flora, change of composition of diversity across the plots (beta-diversity) was measured employing the Jaccard's index of similarity. Regression models were used to interpret the data on the reliability of using higher taxon ranks such as the genera for predicting the species diversity. Simulations were carried out based on randomization process, so as to ensure if the observed complementarity relationships across the taxonomic hierarchies were by chance alone. Amongst the macrohabitats, higher altitude (3400 m3700 m) grasslands and high altitude (2900 m3200 m) mixed forests with dominant tree species of Rhododendron turned out to have the highest numbers of species, genera and families of liverworts followed by middle altitude (2500 m2800 m) Quercus forest, lower altitude (1500 m) Quercus forest and then the paddy fields at 1400 m above mean sea level. Significantly positive relationships between species, genus and family level alpha as well as beta diversities imply that higher taxonomic ranks such as genera and families may be used as surrogates of species for the time and cost-effective long term periodic monitoring of bio-diversity of liverworts. While unregulated local land use practices such as agriculture, deforestation, fire and tourism activities may adversely affect the liverwort communities, traditionally regulated seasonal livestock grazing in the alpine pastures seem to have no marked impact.

Key Words: Alpha-diversity, Beta-diversity, Liverworts, Livestock grazing, Macrohabitats, Rarefaction, Taxon rank surrogacy, Garhwal Himalaya.