抄録
The present state of the forest vegetation was surveyed in the Ba Vi National Park situated approximately 50 km west of Hanoi. The Ba Vi mountains including the National Park is located about 21° in north latitude, and have much rain fall of about 2000 mm/yr. Well-preserved sub-tropical forests are remained from the summit area (over 1200 m) to 800 m in altitude. From 600 m to 400 m in altitude, sub-tropical forests are degraded by severe selective cuttings, and most of the stands are invaded by much creeping bamboo. In the area bellow 400 m in the National Park, only small fragments of low montane tropical rain forests are remained. Conifer species such as Calocedrus macrolepis, Fokienia hodginsii and two species of Podocarpus are distributed on rocky ridges and upper slope near the two peaks, Dinh Ngoc Hoa and Den Thuong. Sub-tropical ever green forests widely spread on upper part, over 800 m, of the mountains. Forest stands which are mainly composed of some Fagaceae species, and often accompanied with Arundinaria baviensis, establish above 1200 m in altitude. The Fagaceae species and the Lauraceae species are not only distributed widely, but also dominated in the sub-tropical forests from 1200 m to 800 m in altitude. It is found out that species compositions of these forests become more complex as lower in altitude. Results of soil observation suggested that the area has low nutrient and shallow soil because of heavy rain fall and steep slope.
