 Altitudes range from in the south-eastern Terai to at Sagarmatha within a short horizontal span.This extreme altitudinal gradient has resulted in 11 bio-climatic zones ranging from lower tropical below to nival above in the High Himalayas, encompassing nine terrestrial ecoregions with 36 vegetation types.Botanists recorded 1,120 species of non-flowering plants and 5,160 species of flowering plants.