Abstract:

The sample plot investigation and stem analysis were conducted in order to study growth rhythm of 30-year-old Manglietia hainanensis and to analyze the relationship between the growth and site environments. The resuits indicated that:(1) Manglietia hainanensis, an indigenous timber tree species, grew quickly, and its annual increment of tree height, stem basal and breast height diameter, and tree volume had many peaks. (2) The time with high peak of annual growth increment of breast height diameter was the llth year after planting, it was ahead of the time of tree height growth peak. (3)In the early 8 years of growth, the tree volume growth was extremely slow with annual growth increment less than 0.0009m³, then the annual increment became quickly, and the first high peak value(0.00868 m³)appeared in the 17th year. (4)In the view of mean annual increment, the change of stem basal diameter icrement was quite, the increment of breast height diameter was going up steadily from 0.1 to 0.59 cm/a in the early 14 years and then descended extremently slowly, the tree height increment presented ascendant tendency in the early 19 years and then declined slightly, the tree volume increment continuously increased along with age increase. (5) The difference in soil moisture, soil fertility and other environment conditions of different slope position caused the distinct growth of Mangtietia hainanensis, the tree height and breast height diameter in down slope site were larger 37.5% and 29.1% respectively than these in upper slope site. (6) The change tendency of annual growth increment of tree height, stem basal and breast height diameter was in accord with that of the rain/evaporation rate(R/E)in this area.

Key words: Jianfengling, Manglietia hainanensis, Growth rhythm