Ecological comparison of vegetation structure and avifauna on burned and unburned areas of mixed deciduous forest at Doi Suthep-Pui National Park, Chiengmai, Thailand

The results showed a high similarity of floristic composition in tree layer of the two areas, index of similarity was 83%. The total of 43 and 49 species were found in burned and unburned areas, respectively. In shrub layer, there was an equal species richness of 31 species but an obvious difference in species composition indicated by a low index of similarity of 68%. The greatest difference in species composition as well as richness was found in herb layer. The index of similarity was only 57%, while the total number of species were 42 and 25 species in burned and unburned areas, respectively. A nearly equality of the minimal sampling areas for the study emphasizing on species composition of the two areas was found. Such areas were 510 m2 and 5167600 m2 for burned and unburned areas, respectively. There was no remarkable difference in dominant species in tree layers of the two areas. On the other hand, dominant species in shrub as well as herb layers were greatly different. However, there were 4 species that dominated in both areas, namely; Tectona grandis, Lagerstroemia balansae, Lygodium japonicum, and Cratoxylum sumatranum. The number of seedlings in burned area was much greater than those in unburned area. The densities of sapling and tree in burned area were 2123 and 1650 trees/ha, respectively, whereas the corresponding densities in unburned area were 3099 and 2675 trees/ha. The profile diagram of the two areas showed no difference in the average stature of forest as well as the layer classification. On the other hand, the percentage of crown cover in unburned area was higher than those in burned area. Avifauna showed a slight preference for unburned area, but it was not significant. There was an obvious difference in species composition; the index of similarity was only