Threats to Epiphytic Orchids in Joypur Forest Range, Bankura, West Bengal, India

Abstract

Epiphytic orchids are generally found in subtropical forests, they can also be found in tropical dry deciduous forests. However, their phorophyte preferences is largely dependent on the diversity of tree species in forest ecosystem. The aims of this present study to assess the diversity of tree species in Joypur Forest Range of Bankura district, with a focus on the density of host plants for significant epiphytic orchids. We recorded a total of 39 tree species belonging to 22 families, and also identified 06 species of epiphytic orchids. The highest Important value Index (IVI value-58.09) was recorded for the dominant tree species Shorea robusta Gaertn., associated with Semecarpus anacardium L.f. (29.00), and Croton persimilis Müll. Arg. (14.33). Diversity index (H'), Dominance index(cd) and Evenness index(E) were calculated from total sample. The value of the indices is 1.58, 0.06 and 0.204 respectively. Along with calculating the Importance Value Index (IVI) of the dominant tree species, we also calculated the IVI of the orchid host tree species and determined their density per hectare of forest area. The present investigation suggests that the reduced density of orchid host trees in the forest area could be a threat to the survival of epiphytic orchids. Therefore, additional research is needed to investigate the factors affecting the survival of epiphytic orchids, including fungal diversity and host tree bark ecology, in order to develop and implement effective conservation management plans for the Joypur Forest.