Information on Forest Science and Technology Number 2 2000

Summaries of papers in the bulletin; for more information contact

Major achievements in natural forest research in Vietnam and directions for future research

(Do Dinh Sam)

This paper outlines the main studies that have been carried out on natural forests in Vietnam, especially forest vegetation classification studies on pine forest: Pinus keysia and deciduous forests of Dipterocarpaceae, structure of broadleaved evergreen forest, a forest cutting (selection) system, natural regeneration and forest enrichment.

The paper also discusses formulation of Ministry silvicultural guidelines based on these results. The direction of research in natural forests focuses on secondary forests and sustainable forest management.

The role of bamboo in the plan for 5 million ha of new forest

(Nguyen Tu Uong)

Bamboo has many uses. It occurs in natural forests and is planted as part of forest plantations. The species Neohouzeaua dulloa (Gamble) A. Cam., Indosasa augustata McClure, Dendrocalamus sericeus Munro, Bambusa procera, A. Chev. and A. Cam., should be protected and tended if they are found in restored forests. Depending on the purpose of the plantation, suitable species can be selected from the following: Bambusa stenostachya Hack, Dendrocalamus membranaceus Munro, Phyllostachys pubescens Mazel ex H. de Lehaie, Sinocalamus latiflorus (Munro) McClure, Dendrocalamus asper (Schet. F.) Back. Ex Heyne and some other exotic bamboo species can also be selected for shoot production.

Zoning of potential flash floods in the Central Highlands and Binh Dinh provinces

(Vo Dai Hai)

Flash floods occur suddenly, last for a short time and cause massive destruction. In Vietnam, flash flooding is a natural disaster that requires urgent preventive measures to limit the damage caused. The likelihood of flash flooding occurring in certain areas is determined by analysing the factors that cause flash flooding and overlaying maps of these factors with the aid of GIS. A map has been constructed of the potential occurrence of flash floods in Central Highlands provinces and Binh Dinh.

Results of a gene-ecological survey on four rare dipterocarp species in coastal sandy areas

(Nguyen Hoang Nghia)

According to surveys, of the 40 dipterocarp species, four play an important role in rehabilitation of forest ecosystems on sandy soil. These are Dipterocarpaceae chartaceus, Shorea roxburghii, Shorea falcata and Hopea cordata. Shorea falcata was found in only two areas: 7 individuals in Xuan Hoa (Phu Yen province) and 6 with some coppice trees in Cam Hai Dong (Khanh Hoa). Hopea cordata trees were discovered in Cam Hai Dong. In situ and ex situ conservation areas have been planned for the four species.

Preliminary surveys of pine wilt nematode disease in Lam Dong province

(Pham Quang Thu and Akiomi Yamane)

Pine (Pinus kesiya) plantations are of major economic, social and environmental importance to Dalat city in particular and in Lam Dong province in general. Pine wilt symptoms and dead trees are found at pine plantations in various locations. The results of previous research showed that the cause of the disease was not clearly identified. A systematic survey was needed to identify the nematode and its vector, the sawyer beetle and to evaluate the incidence and severity of the disease.

The trees’ health status was evaluated by estimating the amount of oleoresin exudation by punching holes in the pine stems in typical 400m2 plots. Nematodes were extracted from wood samples for identification, which revealed the nematode was Bursaphelenchus sp.

Nematode density varied at different locations, the highest density at K’Long K’Lanh and Cam Ly. The disease incidences were 36.5% and 46.4% in Lang Bian and Tuyen Lam, respectively. Sawyer beetle emerged from wood log samples collected in infected plantations. Based on their morphological characteristics, they were classified as Japanese sawyer beetles (Monochamus alternatus). They had two periods of emergence: the first from the end of March to mid April and the second from the end of September to early October.

Effectiveness of bamboo preservation with wood preservatives PBB and CMM

(Nguyen Thi Bich Ngoc)

After harvest, bamboo culms are easily attacked by insects and fungi. Wood preservatives PBB and CMM were tested for their effectiveness in preservation against fungi and termites using a treatment process developed by the Division for Forest Products Preservation. Results of the test allow determination of the rate for each preservative and its respective treatment method to ensure effectiveness in bamboo preservation.

Some features of the mechanization for afforestation in the acid sulphate soil region in the Mekong River Delta

(Nguyen Quang Trung)

Acid sulfate soils represent one-third of the total 4 million hectares of land in the Mekong River Delta. Preparation of land for afforestation on acid sulfate soils requires specific methods and is important for the establishment of high-quality forest plantations.

This is a very hard job, which is mainly being carried out using hand labour, except in a few cases where mechanization is being applied. The use of machines for vegetation treatment gives better results than hand labour, in terms of both quality and economic efficiency.

In the construction of raised beds for planting Melaleuca leucadendron the use of machines is much more effective than hand labour but more attention is needed in selecting the machines that suit soil characteristics in this region. Tools for land preparation which satisfy the requirements of silvicultural techniques and at the same time attain high economic efficiency are also required.

Mechanisms and policy approaches for production of composite board and special forest products

(Vo Nguyen Huan)

Promoting processing and consumption of forest products is an important role of the Forestry branch. Efficient processing and greater consumption of new forest products creates employment and gradual improvement in the living standards of forest labourers.

In this paper, the author suggests some mechanisms and policy approaches to promote the production of composite board and special forest products. This is a contribution to the 2001—2005 plan for forest commodities development of the Ministry of Agriculture and Rural Development.

Social forestry approaches to meet fuelwood demand

(Nguyen Thi Lai)

Wood is an important fuel source in rural areas. Consumption and forecast data highlight an imbalance between supply and demand. A solution to this problem which does not have detrimental effects in other areas is needed. Social forestry with suitable models and approaches is strategically important to solve the problem of fuelwood now and in the future.

Diversified production in development of the Vietnamese rural economy

(Nguyen Ngoc Quang)

In Vietnam, the concept of ‘diversified production’ is still relatively new and much discussion is needed to define it accurately. Some researchers have advanced their own ideas about the term. In recent years, especially after the dissemination of Resolution 5 of the III Party Congress, diversification of the rural economy is frequently mentioned. Is there any contradiction between the terms ‘diversification’, ‘centralization’ and ‘specialization’ and does ‘diversification’ mean ‘diffusion’?

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