Species diversity of plants in Pha Dum community forest, Na Duang district, Loei province

Abstract

      This research aimed to investigate the plant diversity within the Pha Dum community forest, located in Na Duang District, Loei Province. A total of 14 sampling plots, each measuring 20x20 m, were utilized to assess the diversity of trees, while a 5x5 m sampling plot was employed to examine understory plant diversity. The results revealed a rich variety of plant life, encompassing 29 families, 41 genera, and 45 species. Notably, the Rubiaceae stood out with 7 species, closely followed by the Dipterocarpaceae with 4 species. Among the tree species, Shorea obtusa Wall. ex Blume exhibited the highest Important Value Index (IVI) at 150.160, while Dipterocarpus obtusifolius Teijsm. ex Miq. followed with an IVI of 43.442. Furthermore, in the category of understory plants, Vietnamosasa pusilla (A.Chev. & A.Camus) T.Q. Nguyen had the highest importance value index (IVI) of 52.709, with Fimbristylis dichotoma (L.) Vahl following at 13.881. The species diversity index (H’) for trees and understory plants was calculated to be 3.034 and 2.645, respectively. The evenness value (J) was 0.996 for trees and 0.832 for understory plants, while the diversity value (D) were 7.531 and 7.454, respectively. It is noteworthy to mention that Gardenia sootepensis Hutch. was identified as a rare species within Thailand, and Scleropyrum pentandrum (Dennst.) Mabb. was identified as a globally rare species.