DIVERSITY OF FOREST TREE SPECIES IN NATURE FORESTS, BA CHE DISTRICT, QUANG NINH PROVINCE

Abstract

Ba Che, a mountainous district of Quang Ninh Province, has a total natural forest area of 12,383.15 ha including 4,980.41 ha of protection forest and 7,402.74 ha of production forest. Information on tree species diversity is becoming important for biodiversity protection program and forest resource management in Ba Che District. Temporary plots of 1,000 m² each (33.3 m ´ 30 m) were used to collect field data. Totally, 42 plots were collected including eight in protection forest and 34 in production forest. The results indicated that 190 tree species were recorded with a total of 2,320 individuals. Engelhardtia chrysolepis Hance, Aporosa dioica (Roxb.) Muell.-Arg, Cratoxylon cochinchinensis (Lour.) Blume, and Wendlandia tinctoria (Roxb.) DC were four most abundant species with more than 100 individuals each. Tree species diversity was significantly different between protection and production forests. Species number was 20 per plot in protection forest, significantly higher than that in production forest; Shannon index in protection forest was 2.68 higher than that in production forest. Meanwhile, Evenness index in production forest (0.15) was higher than that in protection forest. There was no significant difference on biodiversity between ≥ 200 m elevation zone and < 200 m elevation zone in protection forest. Conversely, it was significantly different between two elevation zones in production forest; ≥ 200 m elevation zone had mean of 24 species per plot and Shannon index of 2.66, higher than that in < 200 m elevation zone. The research indicated that there were significant differences on tree species diversity between protection and production forests, and between two elevation zones. The differences resulted from management activities applied in these forests. The research suggests that management activities must be accelerated to production forest to more benefit forest owners, protect biodiversity, and contribute to environment protection.