Viet Nam Journal of Forest Science Number 4-2008

1. RESEARCH AND DETERMINE PLANTING REGION FOR E.UROPHYLLA WITH THE PURPOSE OF SUPPLYING BIG-SIZED TIMBER IN THE NORTH Central REGION OF VIETNAM

Nguyen Thanh Son, Dang Van Thuyet

Forest Science Institute of Vietnam

SUMMARY

The objective of this research is to identify the planting region for E. urophylla in North Central Vietnam suitable for supplying large timber. Groups of factors have been considered in order to determine a planting region for E. urophylla including the climate, soil, and topography that is suitable for the ecological character of the species. In the entire North Central area of Vietnam, the most suitable planting area covers 977,605ha (19.0%), the less suitable planting area is 1,827,765ha (35.6%) and the least suitable planting area is 2,327,948 (45.3%).

Key words: Determining planting region, E. urophylla, the North Central Vietnam. 

2. Characteristics of Dendrocalamus membranaceus Munro Plantations in the northern provinces of vietnam

Hoang Van Thang

Silviculture Techniques Research DivisionForest Science Institute of Vietnam

SUMMARY

Investigations into Dendrocalamus membranaceus Munro plantations in Thanh Hoa, Hoa Binh and Phu Tho provinces showed that all Dendrocalamus membranaceus Munro plantations are pure. Besides planting pure stands, Dendrocalamus membranaceus Munro was planted mixed with native broad-leaved species. However, in these plantations, the native broad-leaved species were planted once the Dendrocalamus membranaceus Munro was 10-12 years of age. In general all native broad-leaved species had a high survival rate and good growth.  Diameter at breast height of  Dendrocalamus membranaceus Munro was 4,9-8,4cm on plants 10,2-14,2m high. Compared with other planting methods, mixed plantings with Dendrocalamus membranaceus Munro showed showed good growth of the native broad-leaved species. A number of diseases are common to Dendrocalamus membranaceus Munro, such as withches broom, beetles and culm purple blotch. The percentage of diseased canes in pure Dendrocalamus membranaceus Munro plantations was 12,2-52,6%, while in mixed plantings it was 3,5-26,4%. Pure Dendrocalamus membranaceus Munro plantations with long rotation lengths resulted in decreasing soil fertility, while mixed plantations minimized the decrease in soil fertility. In Dendrocalamus membranaceus Munro plantations with a short rotation, there were no clear results relating to a decrease in soil fertility were found.

Keywords: Plantation of Dendrocalamus membranaceus Munro, growth, disease, effects on soil fertility

3. The Results of Experimental Model establish on Regenerate promotion at Lau Bai, Hoa Binh Province

Nguyen Quang Khai

Silvicultural Techniques Research DivisionForest Science Institute of Viet nam

Summary           

Project for the Rehabilitation of Natural Forest in Degraded Watershed Area in the North of Vietnam (RENFODA-JICA) was carried out at the twenty communes of the Hoa Binh lake area, the aim of the project to determine the technical measures for  forest rehabilitation. With the silvicutural technicque measures to make the lines and gaps, it has direct seed sowing of broad leaf native tree species. After four year the rerults shows that: To apply technical measures by making the lines and gaps for natural regenerate promotion, suplementary seed sowing Erythrophloeumfordii, Peltophorum pterocarpum and Ormosia balansae species. First rerults both of three kind of seeds has higth germinate rates, the seedlings  has good growing, in there the Erythrophloeumfordii are most prospects and second Ormosia balansae. But the Peltophorum pterocarpum have to research more on tending and regulating the leaf canopy in the seed sowing lines for seedling has good sunligth to good for growing and higth alive rates. Additional have to give tending the natural regenerate seedlings avilable in the lines or gaps to promote of degraded secondary forest rehabilitation process in Watershed Area of Hoa Binh lake are necessary.

Keywords: Lau Bai, gaps, lines, promotion regenerate.   

4. Effect of shading on Lithocarpus ducampii seedlings at nursery stage

Ha Thi Hien

Research Center for Forest Ecology and EnvironmentForest Science Institute of Vietnam

Summary   

Lithocarpus ducampii (H. et A. Camus) A. Camus, belonging to Fagaceae family, is a valuable woody species. The demand to use indigenous species in plantations is high; therefore it is necessary to undertake in-depth study to develop scientific-based technical guidelines for plantations, of which appropriate shading at the nursery stage is an important step. Shading helps to reduce temperature, and increase soil and air moisture. Different shading levels have a direct affect on seedling survival rate. Lithocarpus ducampii at 0-1 year old have 100 % survival rate with 75% shading from direct light, while trees at 1-2 years old have 98.98-100% survival rate with 50-75% shading. Shading also affects seedling’s height and diameter. The most appropriate shading for 0-1 year old Lithocarpus ducampii is 75%; while 50% is best for 1-2 year old seedlings. Water content in the biomass of 0-1 year old trees is maximum at 75% shading; while in 1-2 years seedlings water content is maximum at 50% shading.

Keywords: Shading ratio, Lithocarpus ducampii  

5. SOME SILVICULTURECHARACTERISTICS OF PARASHOREA CHINENSIS WANG HSIE IN XUAN SON NATIONAL PARK – PHU THO PROVINCE                                                             

Doan Dinh Tam

Research Center for Forest Ecology and EnvironmentForest Science Institute of Vietnam

SUMMARY           

Parashorea chinensis Wang Hsie is giant tree and has economic and high biological value. Parashorea chinensis is listed in the Red book of Vietnam as it is in danger of extinction and needs preservation. Parashorea chinensis has small ecology amplitude, suitable for feralit soil types which are yellow or red yellow. It can live in forest stands and in that ecological system they can have roles off site. Currently, Parashorea chinensis is being exploited and very little remains in natural forest. Where it does occur naturally it usually grows with other species such as Daracotomelum duperreanum pierre, Cinamomum parthenoxylum, Machilus bonii, and Syzygium malayanum (Gagnep) Merr. It is highly discerning with regards soil and is sensitive to land affected by carbonate calcium. In nature, it doesn’t live on denuded hill and waste lands, or on degraded soil.

Keywords: Parashorea chinensis Wang Hsie, composition structure, regeneration characteristics, Xuan Son National Park

6. Discriminant function application in tree growth classification of Teak plantations in Kamgpong Cham province – Cambodia

Le Meng Seang

SUMMARY  

This paper presents results of growth classification for individuals in Teak plantations from 6 to 18 years of ages which is based on the discriminant functions. The four variables used for tree growth classification include tree diameter at breast height, tree height, trunk height under the biggest living branch and age of forest. A total of 1.647 trees were used for tree growth classification of which 697, 410 and 540 trees respectively were 6, 12 and 18 years of ages. The results show that the discriminant functions with four variables (tree diameter at breast height, tree height, trunk height under the biggest living branch and age of forest) can be used for tree growth grading purposes.

Keywords: Discriminant functions, Teaktona grandis, tree growth classification 

7. Results of research into harvesting, preservation, treatment and sowing of Altingia siamensis seed in the northwest

Pham Quang Tuyen

Silviculture Techniques Research DivisionForest Science Institute of Vietnam

SUMMARY  

Alitngia siamensis is a multipurpose native tree species used for timber and medicinal purposes. Its seeds should be harvested in December when the fruit begins ripening, and changes from a blue-grey color to dark-grey. If we preserve its seeds in the fridge for five months, it will loose its germination capacity. Seeds of A.siamensis treated at a temperature of 400C for 8 hours have the highest sprout rate. Seedlings grown in the nursery for four months grow best when grown in a mix of 90% scattered hummus, 7% completely decomposed compost muck and 3% phosphate. The saplings grow best when they have 50% cover.

Keywords: Alitngia siamensis, preserve seed, Northwest

8. Experiment on some technical methods for intensive cultivation of Luong (Dendrocalamus membranaceus Munro) forest and combination of farming cultivation on bare land in Kha Cuu community, Thanh Son district, Phu Tho province

Bui Thanh Hang

Nguyen Van Thinh

Silviculture Techniques Research Division

Forest Science Institute of Vietnam

SUMMARY

 

Results of experiments on some technical methods for intensive cultivation of Luong (Dendrocalamus membranaceus Munro) forest using four experimental formulae of fertilizer showed a formula consisting of 1kg NPK fertilizer with 10kg animal fertilizer actively affected the height and stems of Luong. In experiments using AMS matter for maintaining moisture it was found that using 10g of matter on a Luong stump increased the height of Luong by 0.4m compared with the controls. The height of Luong was 0.6 m greater using a formula of 0.5kg NPK with 20g AMS/stump than when using formula of 0.5kg NPK fertilizer with 10g AMS. On 1ha of bare land improved at the outset, the combination of Luong and Cassava resulted in increased coverage and income of 10.977.000 VND/year in the first 2 years.

Key words: Kha Cuu Commune, AMS moisture matter, intensive cultivation, Luong, bamboo. 

9. effect of aqueous extracts from leaves, roots and decomposed litter falls of Hybrid acacia to germination of Machilus odoratissima, Pterocarpus macrocarpus and Lithocarpus ducampii seeds  

Ha Thi Mung, Pham Ngoc Thanh

Research Center for Forest Ecology and Environment

Le Quoc Huy

Forest Biology Technology Center                                                                

Forest Science Institute of Vietnam  

Summary

The study results showed that among three aqueous extracts from leaves, roots and decomposed litter falls of Hybrid acacia (A. auriculiformis + A. mangium), the leaf extract had strongest allolepathic effects to the germination rate of studied seeds. Thirty percent concentration of leaf extracts significantly reduced the germination of Machilus odoratissima and Pterocarpus macrocarpus seeds by 30% and 27,7% respectively as compared to that of the control. With Lithocarpus ducampii, at 20% and 30% concentration of the leaf extract, it reduced its seed germination down to 24,7% and 28,7%  respectively as compared to that of the control (p=0,95). The aqueous extracts from root parts could reduce only the germination rate of Pterocarpus macrocarpus seed at a high concentration of 30% (16,4% reduced) and Lithocarpus ducampii seed at 20% and 30% concentrations (22,7% & 27,4% reduced respectively as compared to the control). The aqueous extract from decomposed litter falls had no significant allolepathic effects at all as compared to the control. Similarly to the germination rate, the leaf extract of Hybrid acacia had highest allolepathic effects on the germination speed of studied seeds, of which, Lithocarpus ducampii seed was the most significantly reduced of the three studied seeds as compared to the control (p=0,95).

Keywords: allelopathic effect, Hybrid acacia, Machilus odoratissima, Pterocarpus macrocarpus, Lithocarpus ducampii, aqueous extract.

10. Ecological survey on the habitat of yellow Camellia species at Ba Vi (HaTay) and Son Dong (Bac Giang)            

Ngo Quang De, Ngo Quang Hung

Le Sy Doanh

Vietnam Forestry University

SUMMARY  

Ba Vi yellow Camellia and Son Dong yellow Camellia are distributed in poor secondary forests, with a canopy cover of 0,5 – 0,6 at Ba Vi and 0,5 – 0,65 at Son Dong. They occur at an altitude of 500m above sea level at Ba Vi and 300 – 350m above sea level at Son Dong. Six inventory  plots showed Ba Vi yellow Camellia often grows with species such as Scheffera heptaphylla, Malotus paniculatus, and Engelhardtia sp, and Son Dong yellow Camellia grows with Machilus sp, Erythrophloeum fordii Oliv., Knema pierei, and Canarium album. Ground cover vegetation includes species such as Breynia fruticosa, Macaranga bracteata, Aporosa sp and Ma Mit. Annual temperatures are 22,5oC at Son Dong and 23,4oC at Ba Vi. The annual average temperatures during the coldest month (January) are 14,9oC and 15,7oC respectively, and the annual average temperatures during the hottest month (July) are 28,1oC and 29,1oC. Annual rain fall is 1560mm and 2188mm at Son Dong and Ba Vi respectively. Both yellow Camellias grow along streams, in sabulous or fine argillaceous soil; where the soil horizon is from 60 cm (Ba Vi) to 80cm (Son Dong), with brown and grey soil, and clear layers.   

Keywords: yellow Camellia, habitat

11. The results of up-land cultivation survey and identifying the roles of shifting cultivation in social economic context of in the North mountainS of Vietnam

Hoang Lien Son

Bui Thi Hai Nhung

Forestry Economics Research DivisionForest Science Institute of Vietnam

Summary

The results of an up-land cultivation survey and identifying the roles of shifting cultivation in a social economic context in Son La, Lao Cai, Cao Bang and Ha Giang provinces show that the advantage and potential of these regions have not been properly used; there are disadvantages and poor infrastructure including technical aspects; low productivity of agricultural crops; and unsustainable up-land cultivation. These are causes and consequences of increasing poverty and alleviation of mountainous rural areas. However, beneficial shifting cultivation is the main income source of local people and contributes from 15 to 56 percent to the total gross income per household.

Keywords: up-land cultivation, shifting cultivation      

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