Floristic composition of tree diversity in mixed broad - needle leaf forest communities in bidoup-nuiba National Park, Lamdong province, Vietnam

This study investigated six types of mixed broad - needle leaf forest communities, which had domination on %IV of the conifers (including: Pinus. krempfii, Pinus dalatensis, Fokienia hodginsii, Keteleeria evelyniana) in Bidoup - Nuiba National Park, Lamdong province, Vietnam. Structural, regenerational characteristics and floristic composition of tree diversity were in twelve representative 50 x 50 m plots, each stand was two plots. The study enumerated total of 145 high tree species (diameter at breast height - dbh > 10 cm), belonging to 86 genera, 45 families. The mean density was 894 trees ha⁻¹, Shanon-Wiener index (He) ranged from 3.42 to 3.92. The conifers were dominance species in high trees, with composition coefficient up to 25.4%, but not in regenerated trees. The conifers' regeneration ability in the sites were poor, the mean density of small regeneration trees (about 1.2%) was much lower when compared to whole communities. Sorensen's similarity index (SI) between tree classes ranged from 0.38 to 0.67. Species richness, density and basal area of the communities decreased with increasing dbh class and contributed mainly about in <30 cm dbh class.