Diversity of Woody Plants in Dak Nong's Natural Forests, Vietnam
Nguyen Thi Thanh Huong*, Nguyen Duc Dinh and Nguyen The Hien
Faculty of Agriculture and Forestry, Tay Nguyen University, No. 567 Le Duan Str., Buonmathuot City, Daklak province, Vietnam
*Corresponding Author: Nguyen Thi Thanh Huong, Faculty of Agriculture and Forestry, Tay Nguyen University, No. 567 Le Duan Str., Buonmathuot City, Daklak province, Vietnam.
Published: August 05, 2024
Abstract
The objective of this study is to quantify the species composition and diversity of woody plant species (WPS) measured from six natural forests in Dak Nong province, which are managed in different ways. Additionally, the changes in WPS diversity according to topographic gradients (e.g., elevation and slope) were examined. The Hill number was applied to quantify the diversity of the WPS. The Jaccard coefficient and non-metric multidimensional scaling were used to compare the WPS among the forests. A total of 518 species representing 76 families were recorded in 181 sample plots (30m x 30m). The Fagaceae family is the most dominant in the forest with 45 species, followed by Lauraceae (40 species) and Euphorbiaceae (31 species). The lowest Hill number value was found in Dak R’Mang - Protection Forest Management Board (PFMB), whereas the highest value was observed in Nam Cat Tien PFMB and Ta Dung National Park (NP). The composition of the WPS varies among different forests and elevation gradients. Dak R’Mang PFMB presents the most significant difference in the diversity of woody species. A unimodal trend was found between tree species diversity and elevation gradients, which is consistent with natural expectations. Specifically, the diversity indices showed a trend of decreasing from H1 to H3 (<600m a.s.l (H1); 600 - 800m a.s.l (H2); 800 -1000m a.s.l) and increasing at higher elevations. The highest diversity index value was found at H6 (≥1400m a.s.l). This implies that species diversity may be influenced by human activities during the forest use history as well as microclimates.
Keywords: Woody plant species; diversity indices; elevational gradients; slope gradients
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