Habitat Ecology of Epiphytic & Terrestrial Orchids in Langchenphu, Jomotsangkha Wildlife Sanctuary, Bhutan

Abstract

Orchids are the largest and diverse families of flowering plants. Orchids are found growing mostly in tropical climates affecting various communities socio-economically. Among many protected areas in Bhutan, Jomotshangkha Wildlife Sanctuary (JWS) is the least explored in terms of flora and fauna. The study was carried out to assess diversity, host tree preferences and to determine the growth zone of epiphytic orchids along the altitudinal gradient in Langchenphu gewog in JWS. Transect technique was used in which three trails transect were laid out with 10 sampling plots in each transect. Plots size of 20 m × 20 m along the altitudinal gradients were established maintaining an altitudinal interval of 100 meters between each sample plot. A total of 42 species of epiphytic orchids from 20 genera was recorded of23 host tree species under 15 families were recorded. A significant correlation between diversity of orchid and altitude was observed (r = .927, p < .05). Myrtaceae and Theaceae were the most preferred host tree families (14%) followed by Bignoniaceae (13%) and others respectively. The Study concludes that 57% of total species encountered prefers higher canopy & on a tree with rough bark, Pearson chi-square test (X2(1) = 4.7, p< .05) showed a significant difference between trunk, branches, and canopy. Many epiphytic orchids prefer dense canopy (n = 73, 47%) and living trees (99%). Future studies should be focused more on the flowering season for obtaining better information on orchid diversity in the study area.

Diversity and Habitat Preferences of Orchids in Tarakan Forest

“…Epiphytic orchids generally attach to parts of the tree that are exposed to direct sunlight with temperatures, humidity, and nutrients that are following the orchid's physiology (Baiduri & Fitriani, 2019). Some types of orchids can only live on certain trees (Choden et al, 2021), so the presence of trees (hosts) for orchids will also strongly affect the diversity of orchid species in ecosystem. The data above shows that the 4 epiphytic orchid species found are in 33-49 masl altitude range.…”

“…Altitude is one of the main factors affecting the distribution of epiphytic orchids. Choden et al, (2021) reported that the diversity of epiphytic orchids in the lowlands was much less because the area was mostly covered by settlements and had less vegetation cover. This is in accordance with the location of the forest in the orchid garden area which is not far from the beach or at a low-medium altitude.…”