Lichen diversity in the Eastern Himalaya biodiversity hotspot region, India

Eastern Himalaya, a part of the Himalaya biodiversity hotspot region has been assessed for its lichen diversity, based on the own collections, identifications, field observations and published literature. Out of ca 2540 species so far, known from India, 1047 species,1 sub species and 4 varieties distributed in 592 crustose, 321 foliose, 125 fruticose and 9 squamulose growth forms under 212 genera and 63 families, occurring as corticolous, saxicolous, terricolous, foliicolous, and muscicolous constitute c. 41.22 % of the total lichen diversity of the country. The lichen vegetation is recognized into four major types and discussed under (i) tropical lichen vegetation (ii) sub tropical lichen vegetation (iii) temperate lichen vegetation and (iv) subalpine and alpine lichen vegetation. A comparative statistics of diversity of species under dominant families and genera at India and Eastern Himalaya level is given. The region is also active centre of speciation and represented by 107 endemic species including many point endemics. It is pointed out that this rich diversity of lichens is under threat due to various biotic activities. Therefore, conservation measures concerning rich lichen diversity in brief are also discussed. It is also suggested that unexplored high altitude areas are required to be explored thoroughly for getting complete knowledge of the lichen diversity of the region and finally its utilization for the welfare of human beings.