Diversity and distribution of Rubiaceae at Bukit Panau, Tanah Merah, Kelantan

Rubiaceae is a family of flowering plants, commonly knownfor economically important members such as Coffea arabica (coffee) and Gardenia jasminoides (ornamental plant) that highlight the importance of the family. It consists of terrestrial trees, shrubs, lianas, or herbs that can be identified by simple, opposite leaves with interpetiolar stipules and actinomorphic sympetalous flowers. This study focused on the distribution and diversity of Rubiaceae species in Bukit Panau, Kelantan. A total of 292 individuals of six Rubiaceae species were identified, with Ixora chinensis being the most dominant, constituting over two thirds of the population. Other species, including Ixora coccinea, Chassalia curviflora, Chassalia corallioides, Gaertnera junghuhniana, and Timonius flavescens, were found in smaller numbers. The distribution pattern showed that I. chinensis was concentrated at lower elevations, while other species were mostly found at higher elevations. Diversity analysis using Shannon-Wiener and Simpson indices revealed low to moderate species diversity, largely due to the dominance of one species. The Shannon Index value was calculated at 0.485, indicating a moderate level of diversity. The Simpson Index value was 0.4896, with a corresponding Dominance Index of 0.5104, indicating moderate species dominance. This finding suggests that environmental factors and species competition influence species abundance and distribution. The study emphasizes the need for continuous monitoring and conservation efforts to maintain the balance of biodiversity. It also recommends expanding future research to include more areas and detailed studies of lesser-known species to support effective conservation planning.