Forest Structure and Tree Species Diversity along an Altitudinal Gradient in Doi Inthanon National Park, Northern Thailand

Abstract

A study on forest vegetation along an altitudinal gradient was conducted in Doi Inthanon National Park, Chiangmai, Thailand. The purpose of the study was to elucidate how community characteristics change from lowland to mountain vegetation in the tropical monsoon climatic zone in mainland Southeast Asia by using floristic composition and species abundance data collected from forty five plots at different altitudes and forest types.Community classification by cluster analysis suggested 45 sample stands to be classified floristically into three forest zones along an altitudinal gradient: (1) Tree density and basal area increases with rising altitude. Diversity of trees sharply increases from the lowland zone to an altitude of 1,800 m asl and gradually decreases at an altitude above 1,800 m asl shown by low species richness indices at high altitudes. In contrast, evenness indices were not greatly different along the altitudinal gradient.Key words: altitudinal gradient, cluster analysis, diversity, dominance, forest vegetation composition Tropical forests are the most species-rich and structurally complex plant communities on the earth

Diversity increases with elevation: empidine dance flies (Diptera, Empididae) challenge a predominant pattern

“…The rainfall profiles indicate that in March there is almost the same rainfall quantity at all altitudes, but the same cannot be said for temperature (Teejuntuk et al . ). Precipitation is a constant abiotic factor along the elevational gradient, at this specific time of year.…”

“…A strong seasonality is observed on Doi Inthanon: a dry season from December to March (no rainfall, an average of 20°C at low elevations and 10°C at high elevations), and a wet season from April to November (extensive rainfall particularly at high elevations, 25°C at low elevations, 10–15°C at summit) (Bedos , Teejuntuk et al . , Plant et al . ).…”

“…Climatic seasonality is strongly marked on Doi Inthanon, Thailand (Bedos , Teejuntuk et al . ) so that this mountain presents a good model to evaluate the potential impact of the alternation between the rainy and dry season on phenology of taxa, especially insects that show pronounced intra‐annual variations in term of abundance and species richness (Wolda ). To incorporate the seasonal dimension, we used the entomological material from two exceptional Doi Inthanon ‘inventory projects,’ each involving sampling throughout an entire year, allowing us to test the intra‐annual variability of diversity and how diversity is shaped by altitude.…”

Intra- and interspecific variation in wood density and fine-scale spatial distribution of stand-level wood density in a northern Thai tropical montane forest

“…The montane zone is further divided into lower and upper montane forests at approximately 1800 m asl (Santisuk 1988). Tree species diversity increases with elevation up to around 1800 m, and then decreases toward the summit (Teejuntuk et al 2002).…”

Altitudinal Effect on Diversity and Distribution of Araceae in Doi Suthep-Pui National Park, Chiang Mai Province in Thailand

“…This result showed that the altitudinal zone was one of the main effects on the variation in Araceae species. Many researches reported about the effect of altitudinal gradients factor could determine the distribution of many plant families in Doi Inthanon National Park [30,31] and Doi Suthep-Pui National Park [32,33]. In South Korea on the ridge of the Baekdudaegan Mountains [34] and in China at Gauncen Mountain [35], the latitude and altitude had effects on plant species richness, diversity and community and different species were also found in Malaysia [36] and Brazil [37].…”