Maximising growth and sawlog production from Acacia hybrid plantations in Vietnam
- 62 Downloads
Management options to optimise sawlog production from Acacia hybrid (A. mangium × A. auriculiformis) combining thinning and fertiliser treatments were applied at six sites of varying resource availability across Vietnam. Stockings at planting varying from 2000 to 1111 trees ha−1 were thinned from 1333 to 450 trees ha−1 (representing 27–54% thinning %) at ages 2.0–5.6 years. Tree diameter (DBH) responses to thinning were greater in the south than in the north and south central regions. Application of fertiliser at thinning increased DBH and stand volume (SV), compared with the unfertilised treatment, regardless of thinning treatment. Early thinning (at age 2–3.6 years) to 450 or 600 trees ha−1 resulted in the greatest DBH for all diameter classes with a greater proportion of larger diameter logs. The 3-PG process-based model was applied to predict DBH and SV for all silvicultural treatments and ages. When thinning is conducted at 2–3.6 years after planting, the modelling showed that for medium and large-diameter sawlogs, the optimum rotation length is at least 5–7 years in the south and south central coast and 6–10 years in northern Vietnam.
KeywordsAcacias Productivity Sawlogs Silvicultural practices 3-PG model
This study was part of a Ph.D. research program funded by an Australian Centre for International Agricultural Research (ACIAR) John Allwright Fellowship. Substantial support for this research was provided by the ACIAR funded project FST/2006/087. We acknowledge, with thanks, permission given by the ACIAR project FST/2006/087 and Forest Science Institute of South Vietnam to collect analyse and publish this data. We thank our colleagues from the Vietnamese Academy of Forest Sciences and Ba Vi station for assistance with sampling and the maintenance of the field experiments at Ba Vi. We are grateful to Dr Vu Dinh Huong for providing soil and growth data of central and south sites. Thanks to Drs Daniel Mendham, Chris Harwood and two anonymous reviewers for valuable comments on an earlier draft of the manuscript.
- Beadle C, Ottenschlaeger M, Dung PT, Caroline M, Huong VD, Dat KT, Daniel M, Harwood C, Morag G (2013a) Optimising silvicultural management and productivity of high-quality acacia plantations, especially for sawlogs. Australian Centre for International Agricultural Research, Canberra, p 123Google Scholar
- Beadle C, Trieu DT, Harwood CE (2013b) Thinning increased saw-log values in fast growing plantations of Acacia hybrid in Vietnam. J Trop For Sci 25:42–51Google Scholar
- Beadle C, Ottenschlaeger M, Dung PT, Cao TT, Dat KT, Bon PV, Harwood C (2015) Extending silvicultural knowledge on sawlog production from Acacia plantations. Australian Centre for International Agricultural Research, Canberra, p 61Google Scholar
- Binh NT (2003) Yield table of monocultural Acacia hybrid plantations. Forestry University of Vietnam, Ha Noi, p 53Google Scholar
- Dung PT, Dat KT, Quang LT, Bon PV, Huong VD (2012) Research on technical measures to protect and improve soil fertility for enhancing productivity of eucalypt and acacia plantations in successive rotations. Scientific Report. Ho Chi Minh, Vietnam, p. 138.Google Scholar
- Gerrand AM, Neilsen WA, Medhurst JL (1997) Thinning and pruning eucalypt plantations for sawlog production in Tasmania. Tasforests 9:15–33Google Scholar
- Harwood CE, Nambiar EKS (2014) Productivity of acacia and eucalypt plantations in South-east Asia. 2. Trends and variations. Int For Rev 16:249–260Google Scholar
- Lap VT (1999) Natural geography of Vietnam. Education Publishing House, Ha NoiGoogle Scholar
- MARD (2015) Approval for action strategy to improve productivity, quality and value of commercial plantation during period 2014–2020. Ministry of Agriculture and Rural Development, HanoiGoogle Scholar
- Son NH, Quat NX, Nam DH (2006) Planting techniques of tree species for raw materials. Statistic Publishing House, Hanoi, p 128Google Scholar
- VNFOREST (2018) Statistical report of total areas and yields of plantations by forest type and planted species in Vietnam up to 6/2018. Department of Forest Development, Vietnam Administration of Forestry, Ha NoiGoogle Scholar