Nature Conservation Research: Заповедная наука (Oct 2020)
Wild orchid diversity of highland forest in the Heart of Borneo: Long Banga and Tama Abu, Sarawak
Abstract
The Heart of Borneo (HoB) initiative facilitates conservation and environment protection while enhancing sustainable development that safeguards the welfare of natural resources and inhabitants of the island. The HoB research expeditions conducted in the Long Banga and Tama Abu were aimed to document the highland orchid species inhabited in one of the largest remaining transboundary rainforests in the world, which are racing dissolution from their habitat. Thus the resolution for their conservation in situ and ex situ could be drafted meritoriously. The research expeditions in the protected transboundary forest areas revealed a total of 206 species and 59 genera. A total of 118 species of 46 genera were recorded during the HoB Long Banga 2016 expedition, while 117 species in 46 genera were found from the HoB Tama Abu 2017 expedition. Roughly 70% of the species documented were epiphytes. A few of them were mycoheterotrophs, such as Aphyllorchis pallida, Cystorchis aphylla, and Tropidia saprophytica, and several «jewel» orchids, including Cystorchis stenoglossa and Macodes petola. Astonishingly, we discovered a number of endemic and newly recorded orchid species for Borneo. In Long Banga, the riverine forests are home to a higher number of orchids than the inland forests, owing to the presence of host trees with a spreading crown structure and moist bark texture suited epiphyte colonisation. In addition, the riverine forests are banked by a swampy alluvial vegetation that encourage the terrestrial species to grow in. Sites of the inland forests were seen disturbed with wide canopy gaps lacking of the emergent layer. Contrarily, in Tama Abu, the inland forest perceived as the more preferable habitats for orchids to thrive in as it was an undisturbed forested belt. In addition, they had a higher humidity essential for the orchid growth. It was not surprisingly, that a high abundance of orchid species was encountered in the undisturbed inland hill forest roofed with dense tree canopy cover. The hills transitioned into a montane vegetation with a lower number of species. This parameter peaked in a mossy forest, a distinct habitat harbouring endemic and rare species. In addition, ten endemic species are assessed as EN B2b(iii). Herewith, our discovery infers the need for a continuous biodiversity monitoring and conservation assessment to maintain orchid species survival and to reveal the accurate species richness within the highland habitats of Sarawak. Additionally, underlined herein is the need for establishment of an arboretum or a conservation centre for orchids to accommodate the botanical study.
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