Vietnam Journal of Forest Science Number 2-2008

1. Characteristics and keys for identification of genera of Bambusinae Subtribe recorded in Vietnam 

Tran Van Tien, Nguyen Hoang Nghia

Forest Science Institute of Vietnam 

Summary 

Eight genera of Bambusinae subtribe in Vietnam which were found during the field surveys during 2003-2006 are: Bambusa, Bonia, Dendrocalamus, Gigantochloa, Kinabaluchloa, Maclurochloa, Melocalamus and Thyrsostachys. Based on flower structure ß 37 species ß 5 genera and morphological characteristics of other species, 8 bamboo genera of Bambusinae substribe were described and identified. The identification keys was also established by using simple sets of characters of the vegetative parts and characters of the flowers which can be very useful for identifying 8 genera of Bambusinae subtribe found in Vietnam. 

Keywords: Subtribe Bambusinae, description, keys for genus identification

2. Micro-level land classification for Acacia mangium at the Central region

Nguyen Van Thang, Ngo Dinh Que

Research Center for Forest Ecology and Environment

Forest Science  Institute of Vietnam

Summary

In the frame work of project “Land classification and evaluation for plantation forest at priority region, 2006-2009”, influence of site condition on growth rate of Acacia mangium was investigated employing quantitative approach. The result showed that 3 most important factors affected Acacia mangium‘s yield are: soil depth, total humus, and available P2O5. Based on this result, a micro-level land classification matrix was developed for Acacia mangium at the Central region.

Keywords: land evaluation, forest land, Acacia mangium

3. Scientific basis to indentification wood volume under the branches of Erythrophloeum fordii and Vatica odorata var tonkinensis 

Pham The Anh

Vietnam Forestry University

Summary

Based on the data collected from 201 lelled trees, using the common research methods applied in forest inventory, we did find and established some structure models of shape and dimension for the main stems right below the branches for Erythrophloeum fordii and Vatica odorata var tonkinensis. Thenceforward, 3 methods for inventorying the total stem wood volume under the branches were proposed, resulting in some initial experimental finding meeting the actual needs of the presnt forestry inventory.

Keywords: Erythrophloeum fordii, Vatica odorata var tonkinensis, wood volume

4. Estimating the amount of potential plane of erosion and the problem of fountain head gradation in the area of Son La Power Pool

Nguyen Huu Tan

Hong Duc University – Thanh Hoa 

SUMMARY           

The article has estimated the amount of potential plane of erosion and the problem of fountain head gradation in the area of Son La Power Pool. On the basis of the equation of erosion by Wischmeier and Smith D.D (1978) and the correction plate of erosion coefficient by Nguyen Trong Ha, we have estimated the amount of plane erosion, wich help us to build up a table of erosion coefficient, a gradation map and a distribution map of erosion; to forecast the amount of plane erosion and the percentage (%) of correlative fountain head gradation (not very important, important, very important) in the area of Son La Power Pool,

Keywords: Watershed classification, vegetation, headwater protection forest.

5. The inutial research on reasons for the broken stem phenomenon of Hybrid Acacia trees at Ham Yen station, Tuyen Quang province 

Tran Thi Quyen, Ngo The Long, Phung Dinh Trung

Hung Vuong University 

Summary

Hybrid acacia is a fast growing tree and suits the many ecological conditions of Viet Nam. In recent years, there is a phenomenon of broken stems of hybrid acacia trees starting with 4 year old trees and continuing through maturity. The initial research on the reasons for this phenomenon of broken tree stems at Ham Yen station shows the following: The wider trees have crown diameters (Dt) and their broken stem capacities are higher. Also if the branches are bigger, their broken stem capacities are found to be higher. The factors of diameter at breast height (D1.3) and total tree height (Hvn) also influence these capacities. The higher the breast height D1.3 and tree total height (Hvn), the broken stem capacities are shorter. The deep reasons of the phenomenon of broken stems are due to the fact that hybrid acacia trees grow so fast, especially the growth of crown diameter that makes tree develop unproportionally. However, the direct reason is due to windstorms.

Keywords: Compared tree, probability, Logistic regression model, growth.

6. Use of tree green belt for forest fire prevention in Binh Dinh province

Nguyen Dinh Thanh

Binh Dinh Forest Protection Department

Tree Green belt is a common method for forest fire prevention which is used widely all over the world. In this study we use a combination of method such as survey, interview, analysis of leaf and bark component to select the most suitable species for green belt formation.

Keywords: forest fire prevention, green belt, Binh Dinh province

7. Study on building up a Sa nhan tim (Amomum longiligulare) model at Son Hoa district, Phu Yen province

Nguyen Thanh Phuong

Southern coastal central agricultural science institute

Summary           

A. longiligulare is grown in the 3 year old acacia auriculiformis forest (0,3-0,4 shade) and secondary natural forest shade (0,5-0,6 shade) developing well. After 8 months, Its fruits are formed and the first year dry productivity is 13,2 kg/ha (in acacia forest shade) and 5,0 kg/ha (in natural forest shade). The second year dry productivity is 45,1 kg/ha (in acacia shade) and 14,6 kg/ha (in natural shade). A. longiligulare plant grown in commercial coffee and home garden shade develops very well, forming flower and havesting fruit after 30 months. A. longiligulare in the highland Van Hoa, Son Hoa, Phu Yen is havested 2 crops/year: summer-winter crop (May – August) and autumn-winter crop (September – December). After 2 years of growing, it has reached return 4.664.000 dong/ha (in acacia shade) and 1.712.000 dong/ha (in natural forest shade). The next years, the income will increase 2,25-3,96 times (in acacia shade) and 4,73-8,46 times (in natural forest shade) than the second beginning years.

Keywords: Amomum longiligulare, Phu Yen province

8. Assessment on growth and social economic effects of Acacia Hybrid plantation for paper material at Dak Nong and Dak Lak provinces

Dang Van Dung

Dak Lak Paper matrial Enterprise Acacia hybrid in the study area (Cu K’Roa commune, M’Drak district, Dak Lak province; & Dak Ro commune, Krong No district; & Quang Khe commune , Dak Glong district, Dak Nong province) have high growth rate of  21,39 – 30,77 m3/ha/year. After six years, the average volume is 128,36 – 184,66m3/ha equivalence to gross value of 14.832.098 – 32.124.063 VND/ha. In addition to the economical benefit, Acacia hybrid also contribute to increase forest coverage, erosion protection, create job and raise livelihood of local people. Acacia hybrid plantation have a high cost / benefit ratio and fast return on investment.

Keywords: Acacia hybrid, Dack Lak province, Dak Nong province  

9. Canarium seedlings in nursery

Pham Duc Tuan

Forestry Department

Nguyen Quoc Tuan

Vietnam Forestry University

Summary

Canarium album species is a multipurpose tree and it has been planted a lot in Vietnam. However, the root system of Canarium seedlings is always developed not well. This is one of reasons causing the low survival rate of seedlings after planted. So the improvement for root system of Canarium seedlings is necessary in deed.Experiment consists 3 tests (CT1, CT2, CT3), each including 3 random blocks with enough quantity (>30):CT1- cutting sprout shoot of root, remainder is 0.5 cm longCT2- cutting sprout shoot of root, remainder is 1.0 cm longCT3- no cutting (control)The results show that no differences between CT1 and CT2, but CT3 is much different in deed. In CT3 there is only one tap-root and a few lateral roots. Meanwhile, in CT1 and CT2 the main roots growing in a bunch and there are a lot of lateral roots and specially rootlets are much more than 6 times in comparison with CT3.The results also show that after 4 months planted, the survival of Canarium seedlings with 12 months old from CT1 is much higher (100%) than from CT3 (60%). These results affirm that the measure to cut sprout shoot of root has created the well developed root system of Canarium seedlings, this contributed to improve the quality of Canarium seedlings.

10. The economic essence of forestry production and the objective indispensability of land accumulation process

Tran Van Con

Silvicultural Research Division Forest Science Institute of Vietnam

Summary

The paper analyses the economic essence of forests and the special feature of the forestry production process in a market economy under management of the Government with socialistic orientation to point out the objective indispensability of land accumulation for the forestry production. The economic essence of forest as production object is expressed in three characters: (i) It is both the material and the object of the production; (ii) Its use value is collective and multifunctional; and (iii) Its use value is potential, that means its benefit does not only in the use values of forest products and its services but also in the regeneration capacity of all of those. The special feature of the forestry production process is the combination of the both processes, the biological reproduction with long term rotation and the economic reproduction with annual period. Thus, object of forestry production is not tree, number of trees or stand, number of stands but an entire forest ecosystem as a Forest Management Unit which is large enough in area to have a spatial and time structure to optimally the combination of the both biological and economic reproduction. Forest allocation to households, individuals, communities and non government organizations is necessary for decentralization of the state forestry characterized as the system of administrative subsidies with very low efficiency to a social forestry to provide equal livelihood opportunities and so attracting all stockholders participating in forestry production. This decentralization process has disadvantage of the fragmentation of forest lands not suitable for the intensive production and management. Thus the accumulation of forest lands is an objective indispensability to transfer the fragment, small forest economy to a sustainable, multifunctional forest economy.   

Keywords: economic essence of forest ecosystem, special feature of forestry production, accumulation of forest lands. 

11. Forest Land Evaluation System FOLES

Hoang Viet Anh, Ngo Dinh Que

Research Center for Forest Ecology and Environment

Forest Science  Institute of Vietnam

Summary

FOLES (Forest Land Evaluation System) was developed based on the site mapping method as the result of the project “Forest land classification of important plantation species”. The software was developed on AcrEngine ESRI technology. Three main groups of function are: forest land evaluation; tree suitability assessment & yield estimation; and cost/benefit prediction. FOLES have been tested with field data for several ecological zone in Vietnam. The result show that: FOLES give high accuracy in land valuation and yield prediction; user friendly interface; can run stably in low configuration computer Pentium II and above.

Keywords: FOLES 

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