Nguyen Cong Doi INTRODUCTION The questions is after exploiting the first rotation Styrax tonkinensis forests, can new Styrax forests be established? and by what techniques? Research was carried out at Yen Bai province from 1971. Ten -twelve year old Styrax tonkinensis plantation forests having average heights of 18-22m, average diameter of 17-18cm (D1.3) total production of 50-100m3 were selected for study. There was vegetation including shrubs, Saccharum arundinaceum, Miscanthus … [Read more...]

Doan Bong Nguyen Quang Khai INTRODUCTION Economic benefits require the establishment of Styrax tonkinensis plantations on a relatively concentrated and large scale to supply raw material for the paper industry. There are many types of planting soils. The old technical procedures for planting Styrax tonkinensis could not meet requirement. Therefore a complementary study in some technical aspects must be carried out to solve the three following problems: . Prolong the planting … [Read more...]

Vu Dinh Phuong Nguyen Quang Hung INTRODUCTION To serve the management of Styrax tonkinensis forest with a complete basis, the Research Subject aimed to solve the following problems: * Establish a volume table to calculate forest production * Establish a table of soil classes * Determine the age of quantity and technological maturity of a stand * Determine the rules of growth of crown diameter, height; breast-height diameter and height of stems and stand METHODS … [Read more...]

Hoang Xuan Ty Nguyen Duc Minh INTRODUCTION In order to plant Styrax tonkinensis on a large scale, to achieve high productivity and long-term management and to ensure raw material supply for industry, the three following problems relating to the field of pedology must be solved, * Determination of the requirement of Stryrax trees on soil, to serve as a basis for planning and designing work. * Formation of site classification for planting Styrax which can serve to determine … [Read more...]

Doan Van Nhung Nguyen Huu Dong Nguyen Quang Tang INTRODUCTION The yearly requirement for Styrax tonkinensis seeds is very high. In order to meet this requirement, on one hand, seed stands must be established, which can meet requirements in productivity and stable yield so that seed collection can be implemented concentratedly in one area and suitable collecting techniques can also be applied. On the other hand, suitable storing techniques must be used to maintain germination … [Read more...]

Bui Nganh Nguyen Ngoc Dich INTRODUCTION Investigation on the changing of some micro-climatic factors in the forest to serve forest regeneration work was carried out by using an obsis station to collect data according to procedures from the Meteological Department. There was one station placed in mixed broadleaved forest with shading of 0.7-0.8, and one station placed in an open area at Nuitien. RESULTS 1. Changing of the temperature regime in the forest - Due to the … [Read more...]

Tran Nguyen Giang Nguyen Dinh Huong INTRODUCTION The forest selected for research is the forest at Huulung (Langson province) which was exploited many times by selective cutting and only crooked trees belonging to Phoebe sp. (Machilus sp.), Gironniera subaequalis, Canarium sp., Erythrophoeum fordii, Pithecolobium clyperia, Pterosperum heterophyllum, Trema sp. and bamboos have been left. Naturally regenerated trees are found in very low number andare weak and irregularly distributed. … [Read more...]

Nguyen Vi Pham Dinh Tam INTRODUCTION Songhieu forest area has missed the exploitation process for large-sized timber. Because there was no need to consume small-sized wood, the remaining forest was not greatly destroyed and could maintain its environment, but it was poor in tree species with high economic value. The problem is how to increase the value of this poor forest? In order to solve this problem, we must find highly valuable tree species with suitable silvicultural … [Read more...]

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Nguyen Anh Tiep INTRODUCTION Within poor, depleted, secondary forest types to be rehabilitated and improved, there is a forest type which has been affected by burning many times for agriculture cultivation, so that the soil is degraded, the surface soil layer is thin and dry and vegetation contains Neohouzeaua dullosa, bamboos, climbing plants and shrubs. In many production organizations, such areas were left because of the difficulty of vegetation treatment. The problem is that in … [Read more...]