Relationship between the Survival Rate and Characteristics of Melaleuca cajuputi Powell after a Forest Fire in the Kuan Kreng Peat Swamp Forest, Nakhon Si Thammarat Province
Preechaya Naknongnuch and Kobsak Wanthongchai
We studied the relationship between survival rate and characteristics of Melaleuca cajuputi Powell after forest fire as fire can affect plant community tremendously, including plants adaptation to fire, such as M. cajuputi. The study aimed to determine the percentage mortality of M. cajuputi after the fire incident. Nine 20 m ? 20 m size sample plots were conducted in the burned area. Characteristics of M. cajuputi such as growth, height, height of scorch, bark thickness, and coppicing ability of new shoot were determined.
The results showed a significant difference between the densities of M. cajuputi before and after the fire. The pre-fire tree density was 688.87 trees/ha, while the density after the fire was 550 trees/ha. The average mortality was 21.27 % with the highest mortality rate being 40.0 % and the lowest being 2.78 %. We concluded that the forest fire resulted in mortality and a reduced density of M. cajuputi. Bark thicknesses of dead trees and those which survived were significantly different (p?0.01). Moreover, bark thickness was positively related to the new shoot coppiced from the stem (coppicing ability) (r=0.324), and tree height (r=0.370) as the bark serves an insulator protecting the tree from fire. The scorch ratio on the stem was negatively related to the coppicing ability (r=-0.134). Hence, large trees had a higher tendency of survival than smaller trees. Bark thickness and scorch ratio on the stem are significant factors that can determine tree survival. This finding suggested that M. catujupi can survive after the fire and forest restoration for peat swamp forest where M. catujupi dominated the area depends on tree size and fire severity that damage to the tree.