New species of mycoheterotrophs discovered in KBFSC

Tropical rainforests are famous for their enormous tree species richness. Indeed, at the first glance, it seems that with numerous epiphytes their whole diversity is concentrated in the canopy and there is nothing worth attention of a botanist at the ground. However, at closer inspection, there are dozens of herbaceous species growing on the forest floor, some of them yet unknown to science. Among them, tiny achlorophyllous plants nourished by symbiotic fungi, called mycoheterotrophs, are of particular interest in recent years. These plants are both directly and indirectly heavily dependent on co-existence with a number of organisms, which may be the reason why they are often restricted to primary undisturbed tropical rainforests.

In January, researchers from Palacký University in Olomouc, the Czech Republic, Martin Dančák and Michal Hroneš in collaboration with Dr Rahayu Sukmaria Sukri and Dr Faizah Metali from UBD's Faculty of Science spent several days in Kuala Belalong Field Studies Centre (KBFSC) studying biodiversity of mycoheterotrophic plants of the lowland dipterocarp forest. Two UBD graduate students Salwana Jaafar and Dk Nur Amal Nazira Pg Zaman were also involved in the fieldwork. This collaborative project started in 2013 and so far resulted in discovery and description of three new species from the genus Thismia which has never been known to occur in Brunei Darussalam before.

However, the spotlight was not on Thismia alone but also other tiny plants were of great interest. One of them was Epirixanthes whose five species occur in Borneo rainforests, and four of them were confirmed to occur in Kuala Belalong, including two species so far not known from the country, i.e. Epirixanthes papuanaand E. kinabaluensis. Another hidden jewel of Temburong rainforest is the genus Sciaphila. These delicate almost invisible plants with minute flowers are easily overlooked in the field. The researchers found four species, and like in the Epirixanthes, two of them are new for the country. Among other mycoheterotrophic plants found in Kuala Belalong are some species of orchids and species of the family Burmanniaceae. Altogether 20 species of 11 genera in five families were confirmed to occur in Kuala Belalong.

As it seems that the topography is among the main environmental drivers of the herbaceous diversity in Kuala Belalong the future research will be focused on stream ravines. These habitats are particularly rich in herbaceous plants and it seems that almost each of them hosts a unique assemblage of species.

The findings strongly endorse the floristic and conservational significance of this area and further highlights the importance of KBFSC as a key research facility for studying biodiversity of Bornean rainforest. The high diversity of mycoheterotrohic plants also confirm that the Temburong forests undoubtedly belong to the most notable examples of primary lowland rainforest of Borneo and the whole of South-East Asia.

The establishment of the Kuala Belalong Field Studies Centre (KBFSC) in the early 1990s was to generate, describe and disseminate knowledge in Science and Education related to the vast diversity of Brunei's tropical rainforests, including all the varied life forms and ecosystem processes. Given that Brunei Darussalam houses the most diverse and species-rich forests on Earth, scientists who have been to KBFSC have indicated that there are still a number of plant and animal species waiting to be discovered in Belalong forest.

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