Phu Kradueng plateau is the table-top mountain whose altitude ranges from 1,100m to 1,350m and harbors the large area of lower montane coniferous forest and lesser area of lower montane rain forest with many waterfalls. Sporadic floristic exploration has been made for as long as 60 years but no more than 60 species of orchids had ever recorded. Thus, the intensive orchid exploration in Phu Kradueng plateau was conducted from October, 2014 to February, 2016. Together with herbarium specimens and orchid’s census data, it was suggested that as many as 111 species of orchids should have been found on the plateau. Thus far, however, only 78 species had been recorded, and as many as 33 species still have not been seen in this study. Possible causes include illegal smuggling of wild orchids, habitat losses and changes caused by severe wild fires and climate changes.
