Moss-associated diatoms from Malaysian montane cloud forest with a description of two new species

Although tropical montane cloud forests (TMCFs) occupy less than half of a percent of the Earth's land surface, they are the most species-rich and species-dense ecosystems worldwide. Despite numerous studies on various organisms in this environment, diatoms remain a group that is practically unknown. Our work focused on samples of terrestrial bryophytes collected from various substrata at a single site in the Malaysian cloud forest. Despite originating from only one site, the samples contained a high diversity of diatom species and represented a wide range in pH (3.6-6.3). In our study, 62 diatom taxa were observed (8-24 per sample), of which 19 could not be identified with certainty, and were referred to established taxa of similar morphology (as cf. or aff.). Among these however, two species are described as new on the basis of their unique valve morphology: Geissleria bryophila sp. nov. and Eunotia brinchangiana sp. nov.