Unique Southeast Asian peat swamp forest habitats have relatively few distinctive plant species

The peat swamp forests of Southeast Asia are often described as having a unique biodiversity. While these waterlogged and nutrient-poor habitats are indeed unique and include a distinct fauna (especially fish), the peat swamp forest flora is much less distinct and shares a surprisingly large number of species with other habitats. Out of 1,441 species of higher plants found in Southeast Asian swamps (from Thailand to Papua), 1,337 are found in the lowlands (< 300 m a.s.l.). Of these 1,337 species, 216 (16.2 %) occur mainly in lowland swamps, 75 (5.7 %) are shared with freshwater swamps and riparian habitats, 49 (3.7 %) are shared with heath forests, 7 (0.5 %) are shared with montane ecosystems, and 86 (6.5 %) are shared with a range of other lowland habitats. Of the 216 species (16.2 %) that occur in lowland swamps, 120 (9.2 %) are restricted to this habitat (which includes freshwater swamps), and 45 (3.4 %) are restricted to lowland peat swamp forests. Thus, more than 80 % (1,152 species) of the known peat swamp forest flora is common to a wide range of habitats, while 12.4 % (166 species) is composed of opportunistic pioneer or secondary forest species.