Floristic composition and species diversity at Gunung Inas forest reserve, Kedah, Peninsular Malaysia

Abstract

Monoculture plantations such as Musang King durian farms on a big scale become a controversial issue due to its potential devastating impact to the diversity of forest reserves at some areas in Kedah including Gunung Inas Forest Reserve. This study intended to determine the floristic composition and species diversity at Gunung Inas Forest Reserve (GIFR), Kedah. Three plots of 70 m x 25 m covering 0.53 ha were established at GIFR. Each tree with diameter at breast height of 5 cm and above in the study plots were tagged, measured and identified up to species level. Voucher specimens were then taken for further identification purposes. The floristic composition of GIFR consists of 53 individuals represented by 16 species from 12 families. Anacardiaceae was the most speciose family with four species recorded. The most dominant species was Swintonia schwenkii (Anacardiaceae) with 14 tree individuals. S. schwenkii (Anacardiaceae) was considered to have an absolute dominance at the study site with Important Value Index (IVi) of 12.48%, meanwhile Myrtaceae recorded 20.87% of IVi, reflecting this family to be relatively dominant than other families. GIFR recorded moderate Shannon-Weiner Diversity index of H’ = 2.66 (H’max = 2.77) and Margalef’s Richness Index of DMG = 8.7. High Evenness Index of 0.71 portrayed that the tree species are almost equally abundant at the study area. The total tree biomass in the GIFR was estimated at 76.26 t/ha, contributed by 66.04 t/ha of above ground biomass and 10.22 t/ha below ground biomass. Data and information from this study can serve as a guideline for future ecological research and particularly in planning conservation efforts to ensure the biodiversity and sustainability of forests for future generations.