Keywords :
Detrended correspondence analysis (DCA),
Ecological niche,
Forestry research and training station,
Generalized linear model (GLM),
Geoinformatics system
บทคัดย่อ :
Understanding tree distributions in the context of ecological niches is critical to
conserving and restoring sensitive forest communities, such as dry evergreen forest
(DEF). This study determined the distributions of dominant tree species in relation to
environmental factors in a recovering DEF. In 2016, a 3 ha permanent plot (150 m x 200
m) was set up in lowland DEF on the Wang Nam Khiao Forestry Research and Training
Station, northeastern Thailand. Each tree with diameter at breast height (DBH) >= 2 cm
was tagged and identified, and its DBH and position (X, Y) were recorded. Topographic
factors and soil properties were selected as important environmental variables. The tree
distribution in the plot was analyzed using detrended correspondence analysis (DCA)
and generalized linear model (GLM) methods. DCA indicated that tree distribution
was strongly influenced by the topographic gradient, which affected the soil bulk density
(p < 0.05). Using the DCA diagram, two forest communities were identified; the first
was distributed in areas of high elevation and steep slopes, while the second was
characterized by high soil bulk density, which was mostly found in low-lying plateau
areas, particularly near the stream bank. The GLM results showed that the native species,
Walsura pinnata, was mostly in low-relief areas along the stream (p < 0.05), likely
to minimize water stress. In contrast, Hydnocarpus ilicifolia and Streblus ilicifolius
generally occupied ridge areas (p < 0.05). The results indicated that ecological niches
varied among species, following environmental patterns. These findings can be applied
to restoration programs, allowing suitable species to be selected for planting based
on their niches.
เอกสารอ้างอิง :
Marod, D., Phumphuang, W. and Wachrinrat, C., 2021. Effect of environmental gradients on tree distribution in lowland dry evergreen forest, northeastern Thailand. Agriculture and Natural Resources, 55(5), pp.795-805.
