growth and wood characteristics of acacia mangium grown in kerala

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Table 22. Sawn timber recovery (%)20.7212 0.4413 61.230.1938 0.1560 80.540.0780 0.0281 36.050.0226 0.0036 15.9Mean 0.2326 0.1363 45.9120.7 132.1 54.8ICV(%) 46.3 43.4 4.5Pooled mean recovery %= 44.5I CV(%) = 43.0 I4.4.8. Observations on biodegradationEven though detailed studies on the biodegradation of this wood are notcarried out in the present study, samples of heartwood and sapwood wereexposed to outdoor conditions for about more than six months to observetheir performance. Termites were found to attack the heartwood (Fig. 4b).The sapwood was found attacked by insect borers. More severe fungalproblems like, sapstain or decay were not found. Mangium timber is generallyregarded as non-durable (Awang and Taylor, 1993). Hence it is advisable totreat the timber with preservative chemical.44
5. CONCLUSIONScacia mangium has been planted in most districts of Kerala in privateAfarms either in conjunction with other farm crops or as pure plantationsof varying sizes. In forest land this has not been raised as an importantspecies.The tree grows continuously throughout the year and the growth rate isrelated to soil moisture. The growth rate varies widely with locality. Meanannual diameter at breast height (DBH) increment varies between 3.6-5.7 cmand the mean annual height increment between 1.8-6.1 m.A relationship between diameter and tree height is arrived at, which can beused to predict the height of trees from DBH values. The relationship is:Log (Height) = 0.708 + 0.716 Log (DBH)The mean GBH is in the range of 18 cm at the age of 1 year to 11 1 cm at theage of 10 years. The MAI in GBH is around 11 cm at the age of 10 years andthe MAI in height at this age is around 2.6 m. The mean height growth vanedfrom 3.8-9.1 m at the age of 1 year to 33.8 m at the age of 12 years. The MAIin GBH and height growth shows that the species is fast growing in good sitesand slow growing in poor infertile sites.The wood is light, the average basic density is around 500 kg/m 3 . The barkproportion is found around 13- 14% by volume and 10- 1 1% by weight. Barkis found heavier than wood. All these properties are more or less in the samerange as those reported for other common Kerala grown timbers. The effectiveheartwood content, excluding its soft core was found to be around 50%. Thecentral core portion which occupies comparatively larger extent (7- 14% of thewood volume) was found to contain reaction wood, often getting detachedfrom the rest of the wood while drying. As inclusion of such portion of woodis undesirable for many utilisation purposes, mean sawn timber recoveryobtained is only around 45%. The wood exhibits only normal shrinkage andis fairly stable when compared with other species growing in Kerala. Thetimber possesses moderate strength properties. However, for comparisonpurpose, the timber from 8-year-old trees is found inferior to rubber wood inits strength properties. These points with regard to the wood properties maybe carefully considered while planning for its extensive or large scale plantationprogrammes. Except in the case of its growth, it appears to be not at alla ‘wonder wood, as claimed by many of the private sector planting organisations.45
Page 1 and 2: KFRI Research Report 174GROWTH AND
Page 3 and 4: ABSTRACTcacia mangium in the recent
Page 5 and 6: 1. INTRODUCTIONcacia mangium is a p
Page 7 and 8: A. mangium is a species of the humi
Page 9 and 10: and Lim (1993) studied the wood spe
Page 11 and 12: 2.3.3. The problem of heart-rotProg
Page 13 and 14: (1990) and Rahim et al (199 1). Met
Page 15 and 16: 11. Pattom2. Pukappurakunnu3. Manth
Page 17 and 18: components such as phyllodes. stem
Page 19 and 20: directions and the distance between
Page 21 and 22: Table 3. District-wise details of A
Page 23 and 24: Table 5. Diameter growth and estima
Page 25 and 26: 4.3. BIOMASS MEASUREMENTRatio of gr
Page 27 and 28: only in the recent years and hence
Page 29 and 30: significant. However, values obtain
Page 31 and 32: 13.6ITree No.Bark % by volumeHeight
Page 33 and 34: Table 12. Variation of bark thickne
Page 35 and 36: Table 13. Variation of heartwood pe
Page 37 and 38: I----Tangential (G-OD) 8yearTangent
Page 39 and 40: Table 15. Physical properties of br
Page 41 and 42: Table 17. Air-dry to oven-dry shrin
Page 43 and 44: Table 19. Mean values of shrinkage
Page 45: Table 20. Variation of mechanical p
Page 49 and 50: 7. REFERENCESAlloysius, D. 1989. Pu
Page 51 and 52: Kaber. M.F.. Bhattacharjee. D.K.. S
Page 53 and 54: Peh. T. B.. Khoo, K.C. and Lee, T.W
Page 55 and 56: Tomimura. Y., Khoo. K.C. and Suzuki
Page 57 and 58: Appendix 2. District-wise number of
Page 59 and 60: Appendix 3 contd ....measurementsee
Page 61: Appendix 5Simple linear regression

growth and wood characteristics of acacia mangium grown in kerala

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