Page 1 of 8 Research results on forest planting with Canarium album Roeusch Pham Dinh Tam Tran Lam Dong, Nguyen Si Duong FSIV I. Introduction Canarium album is a native tree species, 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. Page 2 of 8 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 Vietnam 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 trees 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.