Research on some intensive planting techniques of growing Lithocarpus ducampii A. Camus forest for larger size timber in phu tho province

Abstract

The research result of some intensive planting techniques of growing Lithocarpus ducampii in Phu Tho province contribute to supplementing scientific basis for afforestation to provide large size timber to serve the forestry sector restructuring project. At 40 months old fertilizing experiment formula, the survival rate of model is from 90.91 - 94.95%. The average growth of top dressing NPK formula is biggest with D0 = 4.59 cm, Hvn = 459.1 cm. Average growth in diameter at a rapid growth rate is 1.16 cm/year. The rate of good quality trees range from 74.5 - 87.9%, medium quality trees range from 12.1 - 15.5%, and bad quality trees range from 0.0 - 12.3%. At 30 months old density experiment, the survival rate of the density model is from 92.1 to 92.9%. The average growth of stump diameter in the formulas reached D0 = 2.93 cm, Hvn = 266.2 cm. The average growth in diameter at a rapid growth rate is 1,11 cm/year. The rate of good quality trees range from 80.3 - 82.2%, medium quality trees range from 10.5 - 14.6%, and bad quality trees range from 5.1 - 7.2%. At 20 months old seedling standard experiment, the survival rate is from 91.9 - 92.9%. The average growth of stump diameter in the 18 months old seedling standard formulas has biggest average growth rate with D0 = 2.95 cm, Hvn = 268.5 cm. The average growth in diameter at a rapid growth rate is D = 1.06 cm/year. The rate of good quality trees range from 79.4 - 81.3%, medium quality trees range from 12.1 - 14.1%, and bad quality trees range from 5.4 - 6.6%