Preliminary notes on distribution of Himalayan plant elements: A case study from Eastern Bhutan

摘要

Vascular plant species composition surveys in the lower montane vegetation of "Korila" forest, Mongar, Eastern Bhutan, identified 124 species, which constitutes an important component of the vegetation. Findings revealed that majority of the species were herbs including pteridophytes (ferns and lycophytes) (48.3%), followed by trees (23.4%), shrubs (20.9%), small trees (4.8%), (4.8%), and climbers/creepers (2.4%). Plant species composition and the vegetation analysis showed that the vegetation falls in lower montane broad-leaf forest type containing Castanopsis spp. and Quercus spp. (Fagaceae). A vegetation comparison study of the area with lower montane forest in South-East Asia through literature revealed that the true Himalayan element distribution range ended in the North of Thailand where the Himalayan range ends. But surprisingly, the study found that some Himalayan elements could extend their southernmost distribution until North of the Peninsular Malaysia. Thus, it can be concluded that the Himalayan range had formed an important corridor.