The potential sawlog production of acacia plantations in Binh Dinh and Phu Yen

Abstract

If requirement of diameter at breast height (DBH) for sawlog is greater
than 18 cm, almost Acacia hybrid plantation within 6 - 10 year - old in
Binh Dinh and Phu Yen province cannot meet this requirement; DBH,
standing volume and MAI of the poorest and fastes growth rate
plantations were 9.18 and 16.67 cm, 57.96 and 133.51 m3/ha, and 9.06 and 19.07 m3/ha/year, respectively. For Acacia mangium, there are only two
plantations which were 10 year - old in Binh Dinh province having DBH,
standing volume and MAI of 23.38 cm, 231.88 m3/ha and 23.19 m3/ha/year,
respectively. There was a 20 year - old plantation in Phu Yen province which had DBH, standing volume and MAI of 35.63 cm, 305.03 m3/ha and 15.25 m3 /ha/year, respectively. For Acacia auriculiformis, there were four single  species plantations (pure A. auriculiformis) and a mixed -species plantation (A. auriculiformis + Hopea odorata); one of them was 14 year - old and the others were 20 - 21 year - old. However, only one 20 year - old single - species plantation and the 21 year - old mixed - species plantation which have timber that can be used for sawlog; DBH, standing volume and MAI of 21.39 and 24.99 cm, 198.27 and 224.89 m3/ha and 9.44 and 11.24 m3/ha/year, respectively. DBH, standing volume and MAI of the other plantations were 14.61 - 16.85 cm, 93.36 - 156.06 m3/ha, and 6.67 - 7.43 m3/ha/year. DBH growth in almost plantation were low. Further intervention by silviculture techniques should be applied, so timber of these plantations can be used for sawlog in the next 5 - 7 years.