TREE SPECIES DIVERSITY IN PHRA THAT SI MUEANG PONG AREA, CHIANG MAI PROVINCE, THAILAND

Article Highlights
- Rich tree diversity found in Phra That Si Mueang Pong area.
- Endangered species identified, promoting conservation efforts.
- Unique plant distribution influenced by land use and water proximity.
- Potential for ecotourism and environmental education in the region.
- Study provides foundational data for future ecological research.

Abstract
This research conducted a survey of perennial flora in ten subplots along the pathway leading to Phra That Si Mueang Pong, identifying a total of 30 species representing 20 families, 28 genera.  Dominant species included Lagerstroemia duperreana var. duperreana, Shorea siamensis, Pterocarpus macrocarpus, Tectona grandis, and Vitex canescens. Families with the highest species number were Fabaceae, Lamiaceae, Combretaceae, and Malvaceae. The study revealed the presence of both common and rare plant species in the area, with differences in species distribution between plots 1-5 and 6-10. Plots 6-10, near the Mae Tha Chang River, displayed higher biodiversity, correlating with the biodiversity index. The dominant species, based on the importance value index (IVI), were Pterocarpus macrocarpus, Lagerstroemia duperreana, Tectona grandis, Shorea siamensis, and Millettia brandisiana, respectively. Two species, Pterocarpus macrocarpus and Tectona grandis, were classified as endangered. The soil analysis indicated slightly acidic pH and relatively low moisture content, with significant differences between plots 1-5 and 6-10. The study suggests the potential for ecotourism and environmental learning centers in the Chiang Mai province cultural tourism destination, emphasizing the rich biodiversity and ecological value of the mixed deciduous and dry dipterocarp forest ecosystems.

INTRODUCTION

Exploration of biological diversity and utilization of plant resources in Thailand has been an ongoing effort, encompassing both areas of base surveys and specific group-focused investigations(Sudchaleaw et al., 2023);(Boonma et al., 2023);(Panyadee et al., 2023);(Ragsasilp et al., 2022);(Pansumrit et al., 2022);(Sutjaritjai et al., 2022);(Saensouk et al., 2021). This research unveiled that biological diversity of plant species, varying across different regions, consistently generates new knowledge and insights. While studies on plant diversity in ecotourism areas in Thailand have provided limited information, most research has focused on national parks, such as Doi Inthanon National Park, Phu Kradueng National Park, Khao Yai National Park, and Kaeng Krachan National Park.

Chiang Mai Province, located in the northern region of Thailand, has a tropical monsoon climate. The average temperature ranges from 22.3^oC to 34.4^oC, with annual rainfall of 972.1 mm(Center, 2020). With its mountainous terrain, there are many cultural tourist attractions situated on various mountains outside the boundaries of national parks. With a well-preserved environmental system, these factors make it feasible to promote sustainable ecotourism destinations in the future, facilitating easier access for visitors.

Phra That Si Mueang Pong, also known as the White Pagoda, stands as a prominent cultural and ecological tourist destination within the province of Chiang Mai. It is situated on the summit within the Aranyawat Temple in Hang Dong District, Chiang Mai, Thailand.

There are two routes to reach Phra That Si Mueang Pong, i.e., one involves climbing the stairs, while the other allows for driving up the road. The ascent via the staircase serves as an ecotourism route, winding through mixed deciduous forest and dry dipterocarp forest. During the climb to Phra That Si Mueang Pong, both sides of the staircase are influenced by significant factors contributing to plant diversity. One side is situated near the Mae Tha Chang River, while the other side borders an agricultural area, resulting in distinct variations in plant diversity.

Therefore, this study investigated the diversity of tree species along the ascent to Phra That Si Mueang Pong in the ecotourism area, encompassing detailed analyses of biodiversity index and importance value index. The findings from this study were expected to benefit the local community, tourists, as well as educational institutions in the vicinity to utilize the area for studying ecotourism, focusing on the diversity of tree species. Additionally, this research provided foundational information for future studies in various research areas.

MATERIALS AND METHODS

Study Area

The study area was located surrounding Phra That Si Mueang Pong in Hang Dong District, Chiang Mai, Thailand. The geographical features comprised a mountainous terrain consisting of deciduous forest and dry dipterocarp forest, with elevations ranging from 350 to 450 meters above sea level (masl).

Data Collection

Plant diversity data were collected from 2019 to 2020 within a permanent sample plot measuring 200 x 200 m². The quadrat method, specifically employing 10 x 10 m²subplots, was utilized for the systematic sampling of plant species. Along the ascent to Phra That Si Mueang Pong, a total of ten subplots were established, with five plots positioned on the side adjacent to the agricultural area, while the remaining five plots were situated on the side bordering the Mae Tha Chang River (Figure 1).

In each subplot, the circumference of tree trunks with a diameter greater than or equal to 15 cm was measured at a height of 1.30 m. Subsequently, the measured trees were tagged with number tapes, which also included information on the species, such as local name, common name, scientific name, and family of the perennial tree. Data on tree species were gathered through consultation with experts and relevant literature(Chayamarit & Chamchumroon, 2016). Additionally, the status of trees was assessed based on the IUCN red list of threatened species(Source Title, 2024).

Physical and chemical parameters of the soil were analyzed, including soil pH content and water content. Soil pH was determined using the Soil-H₂O system(F.A.O., 2021), while soil water content was calculated as a percentage based on oven-dried soil weight according to FAO (2023) as follows:

W% =\( \documentclass{article} \usepackage{amsmath} \begin{document} \displaystyle \text{\ \ \ }\frac{M_{\text{cms}} - \ M_{\text{cds}}}{M_{\text{cds}} - M_{c}}\ \times 100 \end{document} \)\( \documentclass{article} \usepackage{amsmath} \begin{document} \displaystyle \text{\ \ \ }\frac{M_{\text{cms}} - \ M_{\text{cds}}}{M_{\text{cds}} - M_{c}}\ \times 100 \end{document} \)

where:

W = soil water content expressed in units of percentage (%)

M_cms= mass of container and moist soil (g)

M_cds= mass of container and oven dry sample (g)

M_c= mass of container (g)

Data Analysis

Data obtained from the field survey were analyzed to determine the Importance Value Index (IVI). This calculation involved assessing the Relative Density (RD), Relative Frequency (RF), and Relative Dominance (RDo), following the methodology outlined by Ismail et al. (2017). In addition, species diversity index (H’) and evenness value (E) of tree species were determined and calculated following the Shannon’s Diversity Index(Odum & Barrett, 2004).

The baseline statistics used were the mean±standard deviation. One-way analysis of variance (ANOVA) was performed using the Statistical Package for the Social Sciences (SPSS) software program. To further analyze the results, Duncan’s new multiple tests was performed at a significant level of 5%.

Figure 1.Aerial photograph of Phra That Si Mueang Pong (a) and the

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