In terms of vegetation, habitats and biodiversity (criterion x), Hin Nam No is estimated to be 31% forested, with 20% of dense or mature forest, whereas Phong Nha- Ke Bang is estimated to be 94% forested with 84% of dense or mature forest. Above 700 m elevation, the Phong Nha - Ke Bang side of the plateau supports submontane and tropical moist evergreen forests on limestone karst. The forests in the east of Hin Nam No are the only example of tropical moist evergreen forest on limestone on the Lao PDR side of the plateau. In other areas of Hin Nam No the exposed limestone karst supports a sparse, stunted, open, deciduous forest community of mainly xerophytic species. Hin Nam No generally has lower levels of recorded biodiversity than Phong Nha Ke Bang. For example, Hin Nam No has 452 species of vascular plants, and 377 vertebrate species comprised of 55 mammals, 184 birds, 21 reptiles, 21 amphibians and 96 fish. Corresponding figures for Phong Nha - Ke Bang are 2744 species of vascular plants and 785 vertebrate species comprised of 128 mammals, 314 birds, 117 reptiles, 58 amphibians and 170 fish. However, the 7 primate species recorded for Hin Nam No compare favourably with the 9 primate species recorded for Phong Nha - Ke Bang. lt is unclear to what degree these differences in biodiversity reflect differences in climate or other factors, and how much they may reflect the limited field studies and sampling in Hin Nam No."
Source: UNESCO World Heritage Tentative List
Xe Bang Fai River Cave postcard. I bought both postcards in Laos in Luang Prabang and have them cancelled with stamps in Vientiane General Post Office in 2017.