印度西高止山脈莫都馬賴野生動物保護區內熱帶森林之植物組成與評估量化後的林分結構

Quantitative Structure and Composition of Tropical Forests of Mudumalai Wildlife Sanctuary, Western Ghats, India

本研究主要探討位於印度西高止山脈（Western Ghats of India）莫都馬賴野生動物保護區（Mudumalai Wildlife Sanctuary）內熱帶森林之植物組成與評估量化後的林分結構。林分結構的量化是透過胸高樹圍（G.B.H., Girth Breast Height）與樹高分級的方式進行。分析計算當地156個樹種之重要值（IVI, Importance Value Index）、Shannon指數（Shannon-Weiner index）、辛普森指數（Simpson index）、Margalef物種豐富度指數（Margalef Species Richness Index）與均勻度指數（Pielou index）。結果顯示林分密度的範圍介於每公頃112-406.8棵，平均林分胸高斷面積為26.25 m2/ha。物種歧異度方面，Shannon指數範圍介於3.94-4.90之間，辛普森優勢度指數範圍介於0.86-0.94之間。Margalef物種豐富度指數範圍則在4.61-8.31之間。關於林分結構量化方面，約65.4%及36.4%的林木屬於胸高樹圍徑級30-60 cm。在樹高分級部份，約28.7%的林木高度介於20-25 m之間；24.4%的林木高度介於15-20 m之間；僅有3.37%的林木高度大於30 m。

The present study deals with the assessment of quantitative structure and floristic composition of tropical forests of Mudumalai Wildlife Sanctuary, Western Ghats, India. Forest structure was analyzed across girth classes and height intervals. Altogether 156 tree species were analyzed. Vegetation type-wise Importance Value Index, Shannon-Weiner index, Simpson index, Margalef’s index and Pielou Index were calculated. The tree stand density varies from 112-406.8 ha-1 with the average basal area of 26.25m2/ha-1. Shannon-Weiner Index (H') ranges from 3.94-4.90. The Simpson Index of dominance varies from 0.86-0.94. The Margalef Species Richness Index varies from 4.61-8.31.The population density of tree species across girth class intervals shows that 65.4% and 36.4% of individuals belong to 30-60 cm gbh. Tree distribution by height class intervals shows that around 28.7% of individuals are in the height class of 20-25m, followed by 24.4% in the height of 15-20m, whereas 3.37% of individuals are in the height class of >30m.