Investigation of distribution of the orchidaceae in Cat Tien National Park

Abstract

During investigating the distribution of the species of Orchidaceae in Cat Tien National Park in a range of 39.627 hectares, 36 species of 21 genera have been identified, of which 4 species could be found in Plant Red Data Book of Viet Nam such as: Dendrobium bilobulatum Seidenf. at EN category, while Dendrobium farmeri Paxt, Dendrobium draconis Reichb. and Nervilia aragoana Gaudich at VU category. The survey also showed that these orchid species growing in an altitude between 100 and 200 meters above sea level, and they were mostly distributed from 135 to 175 meters. The light intensity, temperature and humidity measured below the canopy of the Orchidaceae were 1.000 lux, 23 - 34oC and 55 - 95%, respectively. Orchid plants usually grow in broad- leaved evergreen forests with high diversity of plant species while temperature and moisture less changed.