Tree improvement programmes benefit from measured data for multiple phenotypes in order to potent... more Tree improvement programmes benefit from measured data for multiple phenotypes in order to potentially gain maximum genetic leverage for selection. Diameter at breast height, tree height and tree form have traditionally dominated the measured phenotype due to their ease of measurement, and the fact that logs are traded by volume. More complex traits, including those that potentially offer economic benefit in terms of quality and end-product performance such as strength and stiffness, are more difficult to measure in standing trees and are frequently overlooked. These traits are therefore in need of rapid methods of assessment. Tree improvement of Eucalyptus pellita in Malaysian Borneo for solid wood and veneer product utilisation is one such example of where selection for improved stiffness is desirable. Genetic trials of E. pellita were assessed using acoustic velocity measurements at several intervention points, including the standing tree, fallen stem, logs and boards, along with...
Leucaena leucocephala (Lam) de Wit is a fast-growing tree species often used as lead (shade) tree... more Leucaena leucocephala (Lam) de Wit is a fast-growing tree species often used as lead (shade) tree that can be cultivated in Malaysia. This species has potential as an alternative resource for the Malaysian furniture and panel board industries in the coming years because of a shortage of the current frequently used raw material (rubberwood). A study on growth performance and potential as particleboard resource material was done. In terms of growth performance, the preliminary study indicated that Leucaena trees grew at a rate of 44% from the first month to the forth month and 43% from 6 to 12 months. As for particleboard manufacturing, Leucaena: Rubberwood admixture bound with urea formaldehyde (8%, 10%, and 12% resin content) to a density of 700 kg/m3, showed promise of usability when all boards pass the Type P2 board requirement of EN312:2010. In general, L. leucocephala wood is a potential raw material for the manufacture of wood composites.
ABSTRACT Plantation-grown Eucalyptus pellita in Sabah, Malaysia, was analysed for compression and... more ABSTRACT Plantation-grown Eucalyptus pellita in Sabah, Malaysia, was analysed for compression and flexural properties to assess the potential for solid-timber and engineered wood product end uses. It is necessary to consider not only the volume of wood produced in a plantation but also the wood quality, particularly those aspects important for end-product performance. Tree volume is readily measured from height and diameter at breast height using appropriate form factors. This paper discusses the compression, strength and stiffness of E. pellita compared with tropical hardwood species, and variation within trees and at different ages (7–23 years). Small clearwood test samples obtained from radial positions within log heights were subjected to analysis of compression parallel to grain and three-point bending according to ISO 13061-4, 2014. Results indicate that plantation-grown E. pellita in the tropics has potential for structural-use applications. The average basic density across the trials was 658 kg m−3, while the bending strength for all trials was in the range of 11.7–15.5 GPa for modulus of elasticity and 96.3−120.1 MPa for modulus of rupture, and the compression strength parallel to grain ranged from 52.3 to 67.8 MPa. Mean mechanical strength increased from pith to bark and from the butt log to the top log. Because the wood-processing sector in Malaysia is transitioning from reliance on a harvest of mixed tropical hardwood towards plantation-grown species, these results indicate that plantation-grown E. pellita meets the structural requirements of strength and stiffness.
Eucalyptus pellita F. Muell. has become an important tree species in the forest plantations of SE... more Eucalyptus pellita F. Muell. has become an important tree species in the forest plantations of SE Asia, and in Malaysian Borneo in particular, to replace thousands of hectares of Acacia mangium Willd. which has suffered significant loss caused by Ceratocystis manginecans infection in Sabah, Malaysia. Since its first introduction at a commercial scale in 2012, E. pellita has been planted in many areas in the region. The species replacement requires new silvicultural practices to induce the adaptability of E. pellita to grow in the region and this includes relevant research to optimise such regimes as planting distance, pruning, weeding practices and nutrition regimes. In this present study, the nutritional status of the foliage was investigated with the aim to develop near infrared spectroscopic calibrations that can be used to monitor and quantify nutrient status, particularly total foliar nitrogen (N) and phosphorus (P) in the field. Spectra acquired on fresh foliage in situ on the...
The magnitude of spatial dependence on teak tree growth was examined based on a teak plantation m... more The magnitude of spatial dependence on teak tree growth was examined based on a teak plantation managed by the research and development team at Sabah Softwood Berhad, Brumas camp, Tawau, Sabah, Malaysia. A sample of 432 and 445 georeferenced individual tree points specific to Solomon Island-derived clones that were 6 and 7 years old, respectively, were analyzed, as previous findings showed that this was the genotype that thrived the most. This study aims to show that spatial dependence exists in the 6- and 7-year-old teak tree blocks of the plantation and that there are changes in the magnitude of spatial dependence when it is analyzed as a continuous plot. Moran’s I values and Moran scatterplots as well as semivariograms and thematic maps were used to satisfy the hypothesis regarding the relationship between spatial dependence and the growth of the physical parameters: the diameter at breast height (DBH), height, and the volume of the teak tree. The Moran’s I values that were calcu...
Fifteen clones of teak (Tectona grandis) produced by micropropagation from 0.5 to more than 60 yr... more Fifteen clones of teak (Tectona grandis) produced by micropropagation from 0.5 to more than 60 yr-old selected ortets were established in a clonal test in Sabah (East Malaysia) under 2500 mm of annual rainfall to compare their growth performances during the first 7 years of development. Field establishment was good with average mortality less than 10%. The clones developed rapidly true-to-type with significant between-clone differences in growth. Ranges of clone means were 13.6 to 19.3 m in height, 16.3 to 23.4 cm in diameter at breast height (DBH) and 129 to 264 dm3 in volume. Broad sense heritability estimates for these growth traits were lower overall for single trees (H2i) than for clone means (H2c) (H2i ≤ 0.257 vs H2c ≤ 0.634 for height, H2i ≤ 0.120 vs H2c ≤ 0.383 for DBH and H2i ≤ 0.125 vs H2c ≤ 0.364 for volume). The highest genetic gain that could be expected from the best three clones out of the fifteen compared was at age 2 for height (+0.66 m, or +11.7%), and age 3 for DB...
Southern Forests: a Journal of Forest Science, 2015
A dramatic rise in the incidence of a serious canker and wilt disease of Acacia mangium has led t... more A dramatic rise in the incidence of a serious canker and wilt disease of Acacia mangium has led to the replacement of thousands of hectares of plantation forests in eastern Sabah. A disease screening program was initiated to evaluate levels of disease resistance and tolerance to the causative fungus, Ceratocystis acaciivora, in an A. mangium breeding population. Resistance was evaluated as the presence or absence of external symptoms in two open-pollinated progeny trials. In addition, tolerance was evaluated in one of these trials by measuring the size of lesions produced following a controlled inoculation with C. acaciivora. Heritability estimates were low to moderate for growth traits but were close to zero for the range of traits used to evaluate Ceratocystis resistance and tolerance. Nevertheless, significant differences were found among the three sources (families from the local land race, Queensland and Papua New Guinea origins, all selected in progeny trials in Sabah) and among populations within these sources for many of the traits used to assess damage by the pathogen. Significant differences in lesion length among sources were evident, but no differences among populations within sources were found. Differences among sources and populations would have been reduced as seed was sourced from a progeny within provenance trial where hybridisation among origins and populations would have occurred. Results of this study suggest that modest genetic improvement may be realised from selecting among populations and sources for resistance and tolerance to this pathogen. However, the lack of additive genetic variation will make the development of resistant breeds challenging.
... The ever increasing need for teak timber has therefore resulted in large scale plantations be... more ... The ever increasing need for teak timber has therefore resulted in large scale plantations beyond its native countries in Asia (Indonesia, Malaysia ... The seedlings were planted by the ICSB's Plant Improvement and Seed Production (PISP) unit as a demonstrational plot in Lua-...
In the context of an increasing utilization of the interspecific hybrid Acacia mangium × A. auric... more In the context of an increasing utilization of the interspecific hybrid Acacia mangium × A. auriculiformis as a plantation tree in the tropical humid zone, its symbiotic characterization was carried out in comparison with that of its two parental species. Rhizobium strains of diverse geographical origins were isolated from root nodules of the hybrid and its parents. Almost all Acacia hybrid isolates were fast growing on yeast extract-mannitol medium, in contrast to those isolated from both parental species, which were mostly slow growing. The rhizobium strains were characterized through partial sequencing of the rRNA operon. In the phylogenetic tree, almost all strains isolated from the hybrid were grouped together in a clade close to Bradyrhizobium japonicum , while all strains isolated from both parental species were close to Bradyrhizobium elkanii . Inoculation experiments performed under in vitro or greenhouse conditions showed that all strains were infective with their original...
Acacia mangium x A. auriculiformis is a promising hybrid for tree plantations. It can, however, o... more Acacia mangium x A. auriculiformis is a promising hybrid for tree plantations. It can, however, only be propagated vegetatively, and there is currently a lack of available plant material and expertise concerning its clonal propagation. The authors combined conventional and in vitro propagation methods and demonstrated that largescale reforestation is possible with this hybrid. (Resume d'auteur)
Fast-growth plantation forestry is relatively new in many Southeast Asian countries, and there is... more Fast-growth plantation forestry is relatively new in many Southeast Asian countries, and there is a clear need for monitoring and assessment of plantation forest soils in this region. In this study, we used miniature plots to estimate and explain site productivity for three widely planted hardwood tree species: Acacia mangium, Falcataria moluccana and Eucalyptus pellita. Miniature plots investigate forest productivity by carrying out very small-scale, short-term experimental studies and treating the results as analogous to what would occur in an operational-scale forest stand over a normal rotation. Miniature plots were established in three separate compartments of a tropical forest plantation in southeastern Sabah, Malaysia. Plots included the three species of interest, each with a fertilised and unfertilised subplot. Assessments were made of site and soil factors including soil profile properties and laboratory analysis of soil carbon, nitrogen, phosphorus (total and available) an...
Tree improvement programmes benefit from measured data for multiple phenotypes in order to potent... more Tree improvement programmes benefit from measured data for multiple phenotypes in order to potentially gain maximum genetic leverage for selection. Diameter at breast height, tree height and tree form have traditionally dominated the measured phenotype due to their ease of measurement, and the fact that logs are traded by volume. More complex traits, including those that potentially offer economic benefit in terms of quality and end-product performance such as strength and stiffness, are more difficult to measure in standing trees and are frequently overlooked. These traits are therefore in need of rapid methods of assessment. Tree improvement of Eucalyptus pellita in Malaysian Borneo for solid wood and veneer product utilisation is one such example of where selection for improved stiffness is desirable. Genetic trials of E. pellita were assessed using acoustic velocity measurements at several intervention points, including the standing tree, fallen stem, logs and boards, along with...
Leucaena leucocephala (Lam) de Wit is a fast-growing tree species often used as lead (shade) tree... more Leucaena leucocephala (Lam) de Wit is a fast-growing tree species often used as lead (shade) tree that can be cultivated in Malaysia. This species has potential as an alternative resource for the Malaysian furniture and panel board industries in the coming years because of a shortage of the current frequently used raw material (rubberwood). A study on growth performance and potential as particleboard resource material was done. In terms of growth performance, the preliminary study indicated that Leucaena trees grew at a rate of 44% from the first month to the forth month and 43% from 6 to 12 months. As for particleboard manufacturing, Leucaena: Rubberwood admixture bound with urea formaldehyde (8%, 10%, and 12% resin content) to a density of 700 kg/m3, showed promise of usability when all boards pass the Type P2 board requirement of EN312:2010. In general, L. leucocephala wood is a potential raw material for the manufacture of wood composites.
ABSTRACT Plantation-grown Eucalyptus pellita in Sabah, Malaysia, was analysed for compression and... more ABSTRACT Plantation-grown Eucalyptus pellita in Sabah, Malaysia, was analysed for compression and flexural properties to assess the potential for solid-timber and engineered wood product end uses. It is necessary to consider not only the volume of wood produced in a plantation but also the wood quality, particularly those aspects important for end-product performance. Tree volume is readily measured from height and diameter at breast height using appropriate form factors. This paper discusses the compression, strength and stiffness of E. pellita compared with tropical hardwood species, and variation within trees and at different ages (7–23 years). Small clearwood test samples obtained from radial positions within log heights were subjected to analysis of compression parallel to grain and three-point bending according to ISO 13061-4, 2014. Results indicate that plantation-grown E. pellita in the tropics has potential for structural-use applications. The average basic density across the trials was 658 kg m−3, while the bending strength for all trials was in the range of 11.7–15.5 GPa for modulus of elasticity and 96.3−120.1 MPa for modulus of rupture, and the compression strength parallel to grain ranged from 52.3 to 67.8 MPa. Mean mechanical strength increased from pith to bark and from the butt log to the top log. Because the wood-processing sector in Malaysia is transitioning from reliance on a harvest of mixed tropical hardwood towards plantation-grown species, these results indicate that plantation-grown E. pellita meets the structural requirements of strength and stiffness.
Eucalyptus pellita F. Muell. has become an important tree species in the forest plantations of SE... more Eucalyptus pellita F. Muell. has become an important tree species in the forest plantations of SE Asia, and in Malaysian Borneo in particular, to replace thousands of hectares of Acacia mangium Willd. which has suffered significant loss caused by Ceratocystis manginecans infection in Sabah, Malaysia. Since its first introduction at a commercial scale in 2012, E. pellita has been planted in many areas in the region. The species replacement requires new silvicultural practices to induce the adaptability of E. pellita to grow in the region and this includes relevant research to optimise such regimes as planting distance, pruning, weeding practices and nutrition regimes. In this present study, the nutritional status of the foliage was investigated with the aim to develop near infrared spectroscopic calibrations that can be used to monitor and quantify nutrient status, particularly total foliar nitrogen (N) and phosphorus (P) in the field. Spectra acquired on fresh foliage in situ on the...
The magnitude of spatial dependence on teak tree growth was examined based on a teak plantation m... more The magnitude of spatial dependence on teak tree growth was examined based on a teak plantation managed by the research and development team at Sabah Softwood Berhad, Brumas camp, Tawau, Sabah, Malaysia. A sample of 432 and 445 georeferenced individual tree points specific to Solomon Island-derived clones that were 6 and 7 years old, respectively, were analyzed, as previous findings showed that this was the genotype that thrived the most. This study aims to show that spatial dependence exists in the 6- and 7-year-old teak tree blocks of the plantation and that there are changes in the magnitude of spatial dependence when it is analyzed as a continuous plot. Moran’s I values and Moran scatterplots as well as semivariograms and thematic maps were used to satisfy the hypothesis regarding the relationship between spatial dependence and the growth of the physical parameters: the diameter at breast height (DBH), height, and the volume of the teak tree. The Moran’s I values that were calcu...
Fifteen clones of teak (Tectona grandis) produced by micropropagation from 0.5 to more than 60 yr... more Fifteen clones of teak (Tectona grandis) produced by micropropagation from 0.5 to more than 60 yr-old selected ortets were established in a clonal test in Sabah (East Malaysia) under 2500 mm of annual rainfall to compare their growth performances during the first 7 years of development. Field establishment was good with average mortality less than 10%. The clones developed rapidly true-to-type with significant between-clone differences in growth. Ranges of clone means were 13.6 to 19.3 m in height, 16.3 to 23.4 cm in diameter at breast height (DBH) and 129 to 264 dm3 in volume. Broad sense heritability estimates for these growth traits were lower overall for single trees (H2i) than for clone means (H2c) (H2i ≤ 0.257 vs H2c ≤ 0.634 for height, H2i ≤ 0.120 vs H2c ≤ 0.383 for DBH and H2i ≤ 0.125 vs H2c ≤ 0.364 for volume). The highest genetic gain that could be expected from the best three clones out of the fifteen compared was at age 2 for height (+0.66 m, or +11.7%), and age 3 for DB...
Southern Forests: a Journal of Forest Science, 2015
A dramatic rise in the incidence of a serious canker and wilt disease of Acacia mangium has led t... more A dramatic rise in the incidence of a serious canker and wilt disease of Acacia mangium has led to the replacement of thousands of hectares of plantation forests in eastern Sabah. A disease screening program was initiated to evaluate levels of disease resistance and tolerance to the causative fungus, Ceratocystis acaciivora, in an A. mangium breeding population. Resistance was evaluated as the presence or absence of external symptoms in two open-pollinated progeny trials. In addition, tolerance was evaluated in one of these trials by measuring the size of lesions produced following a controlled inoculation with C. acaciivora. Heritability estimates were low to moderate for growth traits but were close to zero for the range of traits used to evaluate Ceratocystis resistance and tolerance. Nevertheless, significant differences were found among the three sources (families from the local land race, Queensland and Papua New Guinea origins, all selected in progeny trials in Sabah) and among populations within these sources for many of the traits used to assess damage by the pathogen. Significant differences in lesion length among sources were evident, but no differences among populations within sources were found. Differences among sources and populations would have been reduced as seed was sourced from a progeny within provenance trial where hybridisation among origins and populations would have occurred. Results of this study suggest that modest genetic improvement may be realised from selecting among populations and sources for resistance and tolerance to this pathogen. However, the lack of additive genetic variation will make the development of resistant breeds challenging.
... The ever increasing need for teak timber has therefore resulted in large scale plantations be... more ... The ever increasing need for teak timber has therefore resulted in large scale plantations beyond its native countries in Asia (Indonesia, Malaysia ... The seedlings were planted by the ICSB's Plant Improvement and Seed Production (PISP) unit as a demonstrational plot in Lua-...
In the context of an increasing utilization of the interspecific hybrid Acacia mangium × A. auric... more In the context of an increasing utilization of the interspecific hybrid Acacia mangium × A. auriculiformis as a plantation tree in the tropical humid zone, its symbiotic characterization was carried out in comparison with that of its two parental species. Rhizobium strains of diverse geographical origins were isolated from root nodules of the hybrid and its parents. Almost all Acacia hybrid isolates were fast growing on yeast extract-mannitol medium, in contrast to those isolated from both parental species, which were mostly slow growing. The rhizobium strains were characterized through partial sequencing of the rRNA operon. In the phylogenetic tree, almost all strains isolated from the hybrid were grouped together in a clade close to Bradyrhizobium japonicum , while all strains isolated from both parental species were close to Bradyrhizobium elkanii . Inoculation experiments performed under in vitro or greenhouse conditions showed that all strains were infective with their original...
Acacia mangium x A. auriculiformis is a promising hybrid for tree plantations. It can, however, o... more Acacia mangium x A. auriculiformis is a promising hybrid for tree plantations. It can, however, only be propagated vegetatively, and there is currently a lack of available plant material and expertise concerning its clonal propagation. The authors combined conventional and in vitro propagation methods and demonstrated that largescale reforestation is possible with this hybrid. (Resume d'auteur)
Fast-growth plantation forestry is relatively new in many Southeast Asian countries, and there is... more Fast-growth plantation forestry is relatively new in many Southeast Asian countries, and there is a clear need for monitoring and assessment of plantation forest soils in this region. In this study, we used miniature plots to estimate and explain site productivity for three widely planted hardwood tree species: Acacia mangium, Falcataria moluccana and Eucalyptus pellita. Miniature plots investigate forest productivity by carrying out very small-scale, short-term experimental studies and treating the results as analogous to what would occur in an operational-scale forest stand over a normal rotation. Miniature plots were established in three separate compartments of a tropical forest plantation in southeastern Sabah, Malaysia. Plots included the three species of interest, each with a fertilised and unfertilised subplot. Assessments were made of site and soil factors including soil profile properties and laboratory analysis of soil carbon, nitrogen, phosphorus (total and available) an...
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