This study examined diversity and abundance of wild orchids at five nature trails.
Khao Nan National Park.Nakhon Si Thammarat Province.peninsula of Thailand.Five nature trails were Bua ChakYai.Huai Lak. Thaton-Yodnum. Sanyen. and Thaton-1400m Peak. Data and specimens were collected from January to December 2007. From the study.41 genera with 58 species of wild orchids were found along these five nature trails.Wild orchids were classified based on habitat types.35 epiphytic orchids.15 terrestrial orchids.2 lithophytic orchids. Six species of orchids were found in more than one habits.Comparing between the number of wild orchid species and its abundance among five nature trails at Khao Nan National Park.It was found that Sanyen Nature Trail had the highest wild orchid species richness.abundance and biodiversity indax with a total of 30 wild orchid species.697 wild orchid individuals and Shannon-Weiner lndax of 4.46.