The Study of Riparian Forest Structure in Mun River Basin

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Kwanjai Khammongkol
Yongyut Trisurat
Prateep Duengkae
Sarawood Sungkaew

Abstract

The main objectives of this study were to 1) investigate the vegetation structure, species composition, density, dominance, similarity and diversity, and 2) study the relationships between environmental factors and vegetation. The study was conducted during October 2011 to September 2012. A total of 9 stands (threes temporary 30x30 m. sample plots per stand) was investigated. An Agglomerative Cluster Analysis of Relative Sorensen Distance and Ward’s Linkage Methods were used to classify stands for dominance types based on the Importance Value Index of tree species. An Ordination Analysis of Canonical Correspondence Analysis (CCA) was also performed to find out how species relate to their environments.


The results showed that, there were 6,009 trees (2,473 trees/ha) of 85 families, 272 genera and 398 species in the total of 9 stands. The first 3 dominant families, based on the Importance Value Index, were Fabaceae, Phyllanthaceae and Dipterocarpaceae, respectively. Four types of stands were recognized by this study, they are; Lagerstroemia floribunda type (LAGF), Dipterocarpus obtusifolius type (DIPO), Mallotus thorelii type (MALT) and Streblus asper type (STRA). The results indicated that the Streblus asper type tended to restrict to the high soil pH, short flooding duration (7-15 days) and was usually found in the upper river basin. The presence of the Lagerstroemia floribunda type, Mallotus thorelii type and Dipterocarpus obtusifolius type were found in the middle and lower river basin on soils with clay sediment. Mallotus thorelii type tended to occur in the place with high organic matter in soils and long flooding duration (45-60 days). The vertical structure of riparian forest could be categorized into three layers as follows; upper canopy, sub canopy and undergrowth. The species diversity value, based on the Shannon-Wiener’s index was found the highest in Lagerstroemia floribunda type (4.07) while the lowest was in Mallotus thorelii type (2.16). The highest similarity was found between Lagerstroemia floribunda type and Dipterocarpus obtusifolius type (32.75%) whereas the lowest was between Dipterocarpus obtusifolius type and Streblus asper type (12.33%)


 


Keywords:  flood duration, forest structure, Mun river basin, riparian forest, wetlands

Article Details

How to Cite
Khammongkol, K., Trisurat, Y., Duengkae, P., & Sungkaew, S. (2022). The Study of Riparian Forest Structure in Mun River Basin. Thai Journal of Forestry, 32(Supplementrary), 97–109. Retrieved from https://li01.tci-thaijo.org/index.php/tjf/article/view/255486
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Original Articles