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Research results on forest planting with album Roeusch

Pham Dinh Tam Tran Lam Dong, Nguyen Si Duong FSIV

I. Introduction

Canarium album is a native , 20 – 30m in height, 50 – 70 cm in diameter breast- high, with straight and cylindrical bole, crown is large and green all the year round. C.album is a multi-purpose tree species, much desired by the people. C.album wood is soft and light with fine grain, easily made in to veneer and is usually used as raw material for plywood, ordinary furniture and house construction. C.album resin is used in soap, scent and synthetic paint industries; making electric insulation material and shoe polish. C.album fruit is edible and can be used to make sugared dry confectionary and as foodstuff, cough-curing medicine, detoxifying agent. C.album had been studied by many scientists at home and overseas countries right in early XX century. Researches have been mainly concentrated in main problems: research on biological characteristics of C. album, research on technical measures in planting and research on non-wood products (resin and fruit) exploitation and processing. The research on biological characteristics and non-wood products of C. album are considered relatively successful. The results have been applied for resin and fruit processing for use in light industry, food industry, medicine… and have served as a scientific basis for technical researches later on. As regards silvilcultural technique alone there remain now many problems especially the choosing of planting system, vegetation treatment and choosing support tree species etc… That is why few successful planted C.album on scale of tens of hectares are seen in localities elsewhere: With that reason in view the Ministry of Forestry now the Ministry of Agriculture and Rural Development had approved a research subject on establishing C.album plantations to supply raw material for plywood production (1985 – 1999).

II. Research Methodology and Material

2.1. Research Methodology  Application of empirical ecological research method for field survey and data collection and supplementary survey on basic silvilcultural characteristics of C.album .  Application of field method to lay out experiments techniques on the field.  Experiments are laid out with statistical method and are 3- time replicated.  Calculation and data processing are made with statistical method and computer software commonly used at present.

2.2. Research material Research sites are at three locations: Cau Hai (Phu Tho), Binh Thanh (Hoa BInh) and Ky Son (Hoa Binh).

III. Research results and discussion

3.1. Research on scientific basis for recommendation on silvilcultural measures:

* Survey on demand for and norms of wood as raw material:

Through survey and investigation in some plywood production units in the country and test production of veneer from 20 year old plantation wood in Lac Thuy (Hoa BInh) the research subject was able to compile a table of norms of wood as raw material for plywood such as type size of round wood, size of finished products and 15 norms concerning quality serving the orientation of silvicultural techniques aimed at producing the products in keeping with the raw material requirements. The research subject also confirms that wood from C.album plantation meets the norms of raw material for plywood, the rates of veneer as finished product is 61.2% of which veneer for surface layer accounts for 73.8%. These results show that C.album wood used as raw material for plywood is far better than wood of other native tree species.

* Review and evaluation of existing C.album plantation models.

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The research subject has synthesized and analyzed 25 scientific reports concerning the research on C.album by authors in home country, studied and evaluated 10 C.album plantation models from 2 to 16 years of age in some provinces in the North. Some remarks are as follows: - C.album had been mentioned and studied from early XX century embracing 3 main fields: exploitation and processing of resin, investigation on biological characteristics and planting technique. Researches in the first 2 fields are considered as successful and the results have been much applied in practice. Research in the third field alone has met with many restrictions; research works have not been many and done in a systematic way. No recommendations have been made on the technique to ensure success of the plantations thus few demonstration models are found in the field. In production many localities have planted hundred of hectares of C.album with different systems such as Hoa Binh, Phu Tho, Yen Bai, Tuyen Quang, Thai Nguyen etc… but it can be said that little success has been obtained. The majority of C.album plantations met with failure within the first 3 – 4 years and the remaining had poor growth. The reason was lack of good understanding about important silvicultural characteristics of C.album leading to irrational choice of planting systems, support tree species, tending and vegetation treatment process.

* Supplementary research on basic silvicultural characteristics of C.album.

To serve the research orientation for silvicultural measures at the same time the elaboration of technical procedures for C.album plantation establishment the research subject has carried out supplementary research on basic silvicultural characteristics of C.album at nursery stage. The results show that:

- C.album is a species of wide distribution in North, Central and South and is frequently met in secondary forest with intact forest soil, at elevation from 10m .a.s.l (Ba Ria Vung Tau), (Tan phu – Dong Nai) to 1,000 a.s.l (Tua Chua – Lai Chau).

- The soil in the distribution range of C.album is almost of thick layer, >0.5m, pHkcl varies from 3 to 7, P2O5 < 5mg/ 100g soil, humus varies from 2 to 4.7%. This means that C.album is tolerant to acidic to slightly acidic soil, rather poor in P but humus content must be rather high and soil layer must be deep. - C.album is capable of strong natural regeneration from both seed and coppice. - Level of shading affects growth of seedlings at nursery stage (1 - 2 year old). Shading degree of 25 – 50% is best for the growth of seedlings.

3.2. Research on silvicultural technique

Through studying the experimental models of the previous research subjects on C.album planting and plantation models in production the research subject has drawn attention to the remaining problems at present in the application of silvicultural techniques to create C.album stands of concentrated yield. On the other hand based on the requirements of wood as raw material for plywood, the research subject has concentrated in solving some key problems aimed at creating C.album plantations suitable for industrial wood supply, these are:

- Choice of planting system.

- Choice of support tree species called also for soil covering to support C.album in young forest stage. - Mixed planting system.

Experiments were laid out by the research subject in Lon hamlet, Binh Thanh commune, Hamlet 3, Mong Hoa commune of Ky Son district, Hoa Binh province and at Cau Hai centre, Chan Mong commune, Doan Hung district, Phu Tho province.

3.2.1 Research results on planting system

* Experiments laid out Three experimental formulae were laid out: Total planting together with support trees, row planting and pure planting without support trees (control). The experiments were laid out in Randomized complete Block – RCB, with three replicates. Concrete technical designing is as follow: - Formula 1 (total planting with support trees): Total clearing and removing of vegetation Page 3 of 8

then forest planting design is made. Planting density 1,600 trees/ ha (3 x2m) of which C.album 800 trees/ ha, Acacia mangium 800 trees/ ha. C.album and A.mangium are planted at the same time, mixed in rows, Tephrosia candida is sown between tree rows. Formula 2 (Row planting): Lowering the height of the forest to below 5m, opening pararelle rows 3m in width, 8m apart. Vegetation in the rows is cleared and removed. C.album trees is planted, 2m apart along a line in the middle of the rows.

- Formula 3 (control planting – pure planting without support trees): Clear cutting and removing of the vegetation and then forest planting design is made. Planting density 1,600 trees/ ha (pure C.album) no trees are planted for soil cover.

The experiments were laid out at Binh Thanh (Hoa Binh) in 1996 in the area of rehabilitated forest after the failure of PAM forest plantation; at Cau Hai (Phu Tho) in 1996 after clear cutting of Manglietia glauca; at Ky Son (Hoa BInh) in the area of rehabilitated natural forest after depleted exploitation.

* Results and discussion The research subject has collected data on growth of planted trees in the experimental formulae once a year with to main indices i.e. Doo and Hvn. The data are shown in the table 1 below:

Table, 1. Diameter and height growth of C.album planted in experimental formulae at three locations (measurement made in Nov. 1999).

Formulae Location Planting Indices Total planting Row planting Control year with support trees Doo Hvn Doo Hvn Doo Hvn (cm) (m) (cm) (m) (cm) (m) Ho µ B×nh 1996 Xtb 5.31 3.03 3.42 2.08 3.39 1.88 (B×nh V% 24.85 23.53 27.42 24.07 29.69 30.75 Thanh) Phó Thä 1997 Xtb 3.03 1.85 1.52 0.95 2.79 1.43 (CÇu Hai) V% 28.49 24.57 34.56 40.15 33.08 39.33 Ho µ B×nh 1998 Xtb 1.56 1.2 1.59 1.26 1.56 1.10 (M «ng Ho¸) V% 40.47 35.41 34.03 29.56 34.32 25.18

It is found in the above table that in all the three experimental locations at the young forest stage (1-year old) diameter and height growths of C.album do not yet show any deference but from two years of age onwards the deference among formulae becomes more marked and best diameter and height growth were obtained with formula of total planting with support trees. (see table 2). Let us study carefully the experiments at Binh Thanh (Hoa BInh), the model of highest age (4year old). It can be found that at 12 month old, there is not as yet any difference among the three formulae but later on the formula with support trees becomes far better. As regards 2 formulae of row planting and control till the 4 th the year there is not yet any difference. As regards height, in the first two years there is not yet any difference among the three formulae but after 24 months onwards there begins a differentiation between the 3 formulae. Greatest diameter and height are obtained in formula with support trees (see table 2).

Table 2. Diameter and height growths of C.album planted in forest planting systems in 1996 at Binh Thanh Formulae Age Total planting Row planting Control Doo (cm) Hvn (m) Doo (cm) Hvn (m) Doo (cm) Hvn (m) 12 months 0.6 0.46 0.59 0.48 0.57 0.46 24 months 1.93 0.95 1.31 0.95 1.27 0.88 36 months 3.59 1.95 2.25 1.52 2.20 1.41 48 months 5.31 3.03 3.43 2.08 3.39 1.88 Page 4 of 8

As regards annual increments in the forest plantations planted in 1996 at Binh Thanh we see that in the first year the diameters at tree base in all the three formulae are relatively similar but in the 2 nd year, the formula with support trees is far better while with formulae of row planting and control there is not any difference till the 4 th year. As regards height, from the 2 nd year onwards the formula with support trees is better while there is not as yet any difference in the two remaining formulae.

Table 3. Annual increments of C.album planted in experiments with different systems (plantation planted in 1996 at Binh Thanh).

Formulae Age Total planting with Row planting Control support trees ZDoo ZH (m) ZDoo ZH (m) ZDoo ZH (m) (cm) (cm) (cm) First year 0.6 0.46 0.59 0.48 0.57 0.46 Second year 1.33 0.49 0.72 0.47 0.70 0.42 Third year 1.66 1.00 0.94 0.57 0.93 0.53 Fourth year 1.72 1.08 1.17 0.56 1.19 0.47

Statistic method is used to compare growth between the formulae and it is found that the formula of total planting with support trees is best.

3.2.2 Experiments on using support trees and

* Laying out of experiments The research subject has made use of 4 different tree and species to support C.album in it’s young stage. These are Tephrosia candida, Acacia mangium, Indigofera teysmanii natural vegetation and control. (without soil cover trees or plants). The experiments were 3- time replicated at three different locations: Binh Thanh, Mong Hoa ( HOa BInh), Cau Hai (Phu Tho). Other conditions in each time of laying out the experiment were the same. Data were collected annually with Doo and Hvn.

Vegetation treatment and concrete planting technique are as follows: - In formulae with Tephrosia candida, Acacia mangium and Indigofera teysmanii as support species, the land preparation technique is the same, the vegetation is totally cleared and removed and then forest planting design is made. Planting density is 1,600 trees/ ha (3 x 2m), ball seedlings are used Hvn= 25cm, Doo= 0.45cm. Support species are sown when digging of planting holes is finished. - Formula of natural vegetation as soil cover. All tall trees are cut down, leaving behind weed and regenerated trees below 1m in height; making rows clear of vegetation, equal distance apart, width of a row is 1 m. Planting holes are dug in the middle of the rows, planting density is 1,600 trees/ ha (3 x 2m).

* Results and discussion Data of growth of C.album in formulae of different soil covers were collected annually and the last measurement was made in Nov. 1999. Synthesis of data is shown in the following table 4. Table 4. Growth of C.album in experimental formulae with different soil covers (measurement made in 11/ 1999).

Location Planting Soil cover formulae year Tephrosia Acacia Indigofera Natural Control candida mangium teysmanii vegetation Doo Hvn Doo Hvn Doo Hvn Doo Hvn Doo Hvn B×nh 1996 6.36 3.60 5.31 3.03 4.01 2.65 3.56 2.60 3.39 1.88 Thanh V% (4year 17.5 17.6 24.9 23.5 21.1 20.1 29.3 23.7 29.7 30.8 old) Page 5 of 8

CÇu Hai 1997 3.11 1.85 3.03 1.75 2.88 1.53 2.79 1.43 V% (3year 28.4 24.6 31.8 27.4 25.7 30.7 33.0 39.3 old) Kú S ¬n 1998 1.72 1.45 1.56 1.20 1.49 1.15 1.56 1.10 V% (2year 25.7 24.0 40.5 35.4 40.1 28.7 34.3 25.2 old)

It is shown in table 4 that with the exception of formula with Tephrosia candida as soil cover in the other formulae the diameter and height growths of C.album show no much difference 1 year after planting. But in the second year the control formula (no soil cover) and the formula with natural vegetation as soil cover the growth begins poorer than in other formulae. Three years after planting, soil covering species exert marked effects on growth of C.album. Carefully studying the area planted in 1995, model of height age (4 year old) we see more clearly: - As regards diameter and height growths. Table 5. Growth of C.album in experiments with soil covering species.

Formulae Indices T.candida A.mangium I. teysmanii Natural Control vegetation Doo Hvn Doo Hvn Doo Hvn Doo Hvn Doo Hvn (cm) (m) (cm) (m) (cm) (m) (cm) (m) (cm) (m) 12 0.62 0.49 0.60 0.46 0.58 0.45 0.57 0.47 0.57 0.46 months 24 1.95 1.04 1.93 0.95 1.50 0.95 1.45 0.89 1.27 0.88 months 36 3.57 2.13 3.59 1.95 2.74 1.84 2.24 1.60 2.20 1.41 months 48 6.36 3.60 5.31 3.03 4.01 2.65 3.60 2.60 3.39 1.88 months V% (48 17.15 17.56 24.85 23.53 21.21 20.07 29.25 23.71 29.69 30.75 months)

Through the above table we see that at 12 – month old. growth of Doo is the 5 formulae in the same. After 12 months of age 2 groups are formed, the better group consists of Tephrosia candida and Acacia mangium as soil cover species but from 24 months to 48 months of age formula with T.candida grows far better and next comes the formula with A.mangium. Of the other 3 formulae, the formula with Indigofera steysnenii is a little better. As regards height after 24 months the differentiation is marked, the formula with T.candida is still the poorest (see Table 6). Concerning variation coefficient, the formula with T.candida has smallest variation coefficient, the control formula has greatest variation coefficient. - As regards annual increment:

Table 6. Annual increments of C. album in formulae differing in soil cover species (last measurement was made in 11/ 1999 )

Indices Formulae T.candida A.mangium I.teysmanii Natural Control vegetation Year ZDo ZHn ZDo ZHn ZDo ZHn ZDo ZHn ZDo ZHn (cm) (m) (cm) (m) (cm) (m) (cm) (m) (cm) (m) First year 0.62 0.49 0.60 0.46 0.58 0.45 0.57 0.47 0.57 0.46 Second 1.33 0.55 1.33 0.49 0.92 0.50 0.88 0.42 0.70 0.42 year Third year 1.62 1.09 1.66 1.00 1.24 0.89 0.79 0.71 0.93 0.53 Fourth 2.79 1.47 1.72 1.08 1.27 0.81 1.36 1.00 1.19 0.47 year Average 1.59 0.90 1.33 0.76 1.00 0.66 0.90 0.65 0.85 0.47

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It can be seen through the above table that in the two formulae with T.candida and A.mangium, similar growth rates are obtained in both diameter and height, in a year growth rates are markedly higher than in the previous year. In the fourth year there is a somewhat stand-still especially the tree height. This may be due to the crown of Indigofera steymanii overshading C.album thus affecting height growth of the latter. In control formula absence of shading (total opening) also obviously has effect on height growth of C. album . Comparison made in a statistic way of C.album diameter and height growths between the formulae shows that total planting with T.candida serving as soil cover and mixed planting with A.mangium are better than other formulae. In the remaining formulae difference in growth is not yet obvious.

3.2.3 As regards mixed planting system

* Laying out of experiments The research subject has laid out mixed planting of C.album with Peltophorum ferugineum and A.mangium in two locations: Cau Hai (Phu Tho) and Mong Hoa (Hoa Binh). Concrete formulae are as follows: - C.album + A.mangium (in rows) - C.album + P. ferrugineum (in rows) (A.mangium and Peltophorum ferrugineum are mixed in a row).

* Results and discussion Table 7. Tree growth in mixed planting systems planted in 1997 (Measurement made in Nov. 1999).

Formula C.album + P.ferrugineum C..album + A.mangium C.album + (A.mangium + P.ferrugineum ) Tree species Doo Hvn Dt Doo Hvn Dt Doo Hvn Dt Cambium 3..20 1.87 0.80 3.03 1.85 0.75 3.11 1.75 0.85 P.ferrugineum 3.36 2.05 1.02 3.20 2.10 1.05 A.mangium 4.80 2.86 2.25 5.10 3.05 2.30

Through the above table it is seen that in formula C.album + P.ferrugineum, height growths of the two species do not remarkably differ from each other, from 0.1m to 0.35m Crowns of these two species do not yet touch each other and they thus still exert mutual benefit. On the other hand, growth rates of the two species are equal. Thus this formula may in the future be better formula. In the two remaining formulae, height of A.mangium presently already surpasses that of C.album from 1 to 1.2m. Crowns of A.mangium do not yet over shade the top of C.album trees and thus do not yet effect the growth of the latter. But in 1 or 2 years to come, A.mangium will grow fast and over shade the top of C.album trees and the latter will grow poorer. Therefore with these 2 formulae in the time to come A.mangium must receive strong treatment so that C.album might continue its good growth. Studying tree growth among the formulae, the research subject has come to some remarks as follows: - Growth of planted trees in the models is at present normal. - Growth of C.album in the experiment does not as yet suffer any effect. Through studying however it is found that in the two formulae C.album + ( A.mangium + ferrugineum ) and C.album + A.mangium crowns will be a threat to the growth of C.album .

IV. Conclusions and recommendation

4.1. Conclusions Through implementation of the research subject and the results obtained, some conclusions are drawn as follows: 1. Based on the norms of the wood as raw material presently applied by the plywood production units the wood harvested from C.album plantations is up to the standard as plywood raw material. Thus the planting of C.album to supply raw material for plywood production is feasible. 2. Through survey, study and evaluation of C.album plantation models in production it is found that many localities do have the need to plant C.album aimed at various purposes but the establishment of C.album plantations has not been much a success due to unsuitable choise of planting systems and concrete technical measures to manage the plantations in their young stage. 3. C.album is capable of regeneration from seed and coppice. Younger trees have stronger coppice capability. Page 7 of 8

4. At nursery stage C.album requires 25 – 50% shading. 5. Planting system does affect C.album plantation in young stage. Through comparison it is found that the system of total planting with support trees at early stage proves to be suitable for C.album growth. 6. In early stage (4 – 5 years of age) C.album requires support trees as soil cover for its growth. Suitable soil covering species are Tephrosia candida , Acacia mangium. There must be regulation of soil covering trees so that they do not overshade C.album . 7. In early stage (3 – 4 years of age) mixed planting system does not affect C.album growth. However preliminary observation reveals that C.album can be mixed with other native species that have similar growth rate (especially height growth) to C.album such as Peltophorum ferrugineum

4.2. Recommendation Due to limited budget and the time for the research has not been long (field implementation has lasted only 4 years) thus some problems have not fully been solved by the research subject and the research must be continued in next programmes. With the results obtained however the research subject has some recommendations as follows:

* As regards scientific matter: - Allowing the continued tending and monitoring of the experimental models in more 2 – 3 years to have fuller data for comparison. - Research is carried out to select good provenances of fast growth and high resistance to pest insect and diseases. - Research on control measures of shoot borers of C.album, one of the factors seriously affecting the growth of C.album plantation at young stage. - Research on vegetative propagation (mainly by grafts) serving forest planting for dual-purpose: fruit and wood.

* As regards technology transfer: - Research results obtained by the research subject are scientifically well-based, the experimental models in the field are highly promising and feasible elsewhere. These are proposed to be recognized as scientific and technical advances so that they are soon applied in production. - Widely promulgating technical procedures for C.album plantation establishment in regions suitable and intended to plant with this species. - Establishing some demonstration models in some different ecological zones with two promising formulae: total planting with T.candida as support species for soil cover and C.album and A.mangium mixed planting (A.mangium as support species) for timely serving the programme for planting new 5 million hectares of forest.

References:

1. Duong Huu Thach. – Forestry Review, 1975.

2. Nguyen Van Sac. Planting Canarium album under forest canopy – Forestry Review no. 1963.

3. Le Canh Huyen. Measures for Canarium album planting, Forest Research Institute 1/ 1962.

4. Agricultural Publishing House, 1994. Technique of Canarium album sowing and planting.

5. Nguyen Van Le, Luu Pham Hoanh. Results of research on Canarium album planting technique in Huu Lung, Lang Son. Information Service, Ministry of Foretry, 1985.

6. Nguyen Dinh Hanh. Control measures for shoot borers of Canarium album – Forestry Review no 5/ 1965.

7. Dang Van A. Results of research on control of shoot borers. Forestry Review, 1998. Page 8 of 8

8. Trieu Hung. Results of survey on Canarium album ecology. Scientific Report. Forestry Colleege, 1992.

9. Nguyen Xuan Quat. Final Report of research subject 04A. 00.06.

10. Pham Dinh Tam, Tran Lam Dong. Canarium album cultivation. Forest Scientific and Technical Information no 1, 1998. Forest Science Institute of Vietnam.

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