Plant Community at Thachang Official Community Forest (Chaipattana Foundation) Chanthaburi Province

Abstract

Background and Objectives : Chanthaburi is one of the economically significant provinces in the eastern region, particularly in agriculture, gem trading, and tourism. This has led to a large resident and floating population, resulting in urban congestion. However, it has been found that within the city district, which is the center of business and residence, there are community forests interspersed in the area, Thachang Community Forest (The Chaipattana Foundation) is an urban forest that plays an important role in human health and well-being. The problem arises from urban community expansion that is not in harmony with green spaces, which are essential for a high-quality urban life. This forest serves as the lungs of the city for the community, helping to reduce air pollution, sequester carbon, filter PM 2.5 dust, act as a reservoir for excess rainwater during the rainy season, and serve as a source for learning about local plant species. The objectives of this study were to analyze the species composition and forest structure, with the aim of developing a conservation plan and restoring degraded forest areas.

Methodology : This study examine plant communities in the Thachang Community Forest (The Chaipattana Foundation), which was formerly an abandoned rubber plantation, covering an area of approximately 18 rai, located in Tha Chang Subdistrict, Mueang District, Chanthaburi Province. The general characteristics are lowland plains interspersed with small freshwater swamp. Three permanent plots, each 20 x 50 meters, with each plot further divided into 30 sub-plots of 10 x 10 meters, were established in the study area. All trees with circumference of at least 14 cm were tagged, measured, and identified the types of plants found in the plot according to the Flora of Thailand. The scientific name were checked online from The Plant List. (http://www.theplantlist.org/). The importance value index, species diversity index, similarity and plant density were analysed. The implementation period was from November 2022 to September 2023.

Main Results : The results showed a total of 31 families, 35 genera, 45 species, and 4 unknown species. Fifteen species were classified as Restricted Wood type A including Vatica harmandiana Pierre, Garcinia speciosa Wall, Parkia speciosa Hassk, Anisoptera costata Korth, Parinari anamense Hance, Nephelium hypoleucum Kurz, Syzygium thorelii (Gagnep.) Merr. & L.M. Perry, Peltophorum dasyrrhachis (Miq.) Kurz, Cratoxylum formosum (Jack) Dyer, Dalbergia cochinchinensis Pierre, Diospyros ferrea (Willd.) Bakh., Lithocarpus annamensis  A. Camus, Vitex pinnata L., Dillenia ovata Wall. ex Hook. f. & Thomson and Diospyros venosa Wall. ex A. DC. The tree layers were divided by height in the vertical direction into three levels: the upper canopy (20-23 meters), which includes Dipterocarpaceae species such as Anisoptera costata Korth. and Dipterocarpus baudii Korth. Below that is the understory (14-18 meters), which includes Vatica harmandiana, Parinari anamense, Artocarpus lakoocha Roxb., Diospyros venosa, Vitex pinnata, Knema globularia (Lam.) Warb., Garcinia cowa Roxb. ex Choisy, Acronychia pedunculata (L.) Mig., Garcinia speciosa Wall., Diospyros ferrea, Elaeocarpus robustus Roxb., Aporosa microstachya (Tul.) Mull.Arg., Peltophorum dasyrrhachis, Family Myrtaceae and Syzygium spp. The lower layer plants include Memecylon pauciflorum Blume, Melientha suavis Pierre and Melodorum fruticosum Lour. The replacement of tree species in the research area is complete at all levels, and the ground has accumulated organic matter from the shedding of leaves of certain deciduous trees (such as Hevea brasiliensis, Dalbergia cochinchinensis, Vatica harmandiana and Lagerstroemia duperreana). Some areas of the forest have characteristics of small freshwater swamps, thus supporting a community of peat swamp plants, including Calophyllum calaba, Syzygium thorelii and Ixora lobbii. Based on the importance value index (IVI), the dominant species were Hevea brasiliensis, Vatica harmandiana, Aporosa microstachya, Nephelium hypoleucum and Anisoptera costata, with IVI values of 79.17%, 42.24%, 21.46%, 20.1% and 13.25%, respectively. The species diversity index (H^/) was 2.84 with 63.62% of similarity value. While the tree density was 216 individual per Rai. The rubber trees have a total basal area of 152.39 square meters, indicating that the rubber trees in the area are large and dense, which slow down forest recovery by competing for growth factors. However, the survey found a small number of rubber tree saplings, possibly due to the lower competitive ability of rubber tree saplings compared to the saplings of local plants such as Vatica harmandiana, Aporosa microstachya, Nephelium hypoleucum, Lagerstroemia duperreana, Cratoxylum formosum, Calophyllum calaba  and Melientha suavis, among others.

Conclusions  : It was concluded that Thachang Community Forest is undergoing natural regeneration, with a diverse range of local plants thriving. The prominent species is Vatica harmandiana. The variety of plants found, such as Aporosa microstachya, Nephelium hypoleucum, Anisoptera costata, Cratoxylum formosum, Calophyllum calaba, Lithocarpus annamensis, Elaeocarpus robustus, Melodorum fruticosum and Melientha suavis will lead to the selection of species for planting alongside rubber trees, which continue to grow well in the area, to shorten the forest restoration period. This approach also serves as a guideline for managing the area to conserve local plants and improve the surroundings for the community’s recreational benefits.