Wood properties of teak (<Emphasis Type="Italic">Tectona grandis</Emphasis>) from a mature unmanaged stand in East Timor

The wood quality from 50- to 70-year-old Tectona grandis trees from an unmanaged forest in East Timor was assessed. The aim was to evaluate teak in mature stands that had undergone uncontrolled disturbances, e.g., fire and local community usage. Heartwood represented 91% of the tree radius at a height of 1.7 m, and sapwood contained on average nine rings. The mean ring width showed within-tree and between-tree variability. The chemical compositions of heartwood and sapwood were similar. Within-tree chemical variation occurred only in terms of extractives, which increased from the pith (8.3%) to the heartwood-sapwood transition (12.7%) and decreased in the sapwood (9.2%). Overall, the wood properties of teak from a unmanaged forest in East Timor were comparable to those reported for plantation teaks of other origin: 607 kg/m³ basic density, 3.5% and 5.2% radial and tangential shrinkage, 141 N/mm² modulus of rupture, 10684 N/mm² modulus of elasticity, and 50 N/mm² maximum crushing strength in compression parallel to the grain. Disturbances on individual tree growth arising from the unmanaged status of the stand were evidenced by higher within-tree variability of ring width. However, the longitudinal and radial variations of wood density and mechanical properties were of low magnitude and in a degree that did not negatively impact on timber quality.     

Diversity and genetic structure of teak (<Emphasis Type="Italic">Tectona grandis</Emphasis> L.f) in its natural range using DNA microsatellite markers

Teak (Tectona grandis L.f.) is considered to be an extraordinarily durable building timber with a worldwide reputation. Its widespread use has entailed the over-exploitation of natural forests and a large reduction in natural diversity. Fifteen microsatellite markers were used to study the genetic variability and structure of 166 teak trees distributed over the whole natural area of teak. Analysis showed that in the teak natural area there were four main centers of genetic variability. Two clusters were in India and could be considered as main centers of genetic diversity in teak. The third cluster mainly consisting of populations in Thailand and Laos was genetically very distinct from the Indian populations but presented only half as much allelic variability. A fourth cluster from Central Laos showed even less genetic variability. The use of SSR markers for conservation of teak forest diversity is discussed.     

Grouping of <Emphasis Type="Italic">Tectona grandis</Emphasis> (L.f.) clones using wood color and stiffness

Commercial Tectona grandis plantations using clones have attracted considerable interest for lumber production in tropical regions where small areas are frequent. However, studies on wood properties are limited. Therefore, the purpose of this study is to group clones with similar wood color characteristics using the CIELab system, and mechanical resistance by dynamic stiffness (Ed) in order to obtain different types of clones for different climate and edaphic conditions. It was found that lightness (L*), yellowness (b*), redness (a*), and Ed are similar to those found for other plantation trees. These wood characteristics are significantly influenced by clone and site. Variance due to clone and site went from 31 to 53% and from 2.95 to 24.22%, respectively. Another source of variance was distance from pith, with the exception of parameter b*, which was not affected. Finally, clones were grouped (using multivariate analysis) according to color and mechanical resistance. This analysis established 4 groups by color and 5 groups by Ed. Clone clustering will allow us to choose or use clones with similar wood properties according to site and environmental conditions increasing area production and wood quality uniformity.     

Provenance effect on the ring structure of teak (<Emphasis Type="Italic">Tectona grandis</Emphasis> L.f.) wood by X-ray microdensitometry

• Context  

Teak (Tectona grandis L.f.) is a tropical timber which is appreciated worldwide and has been planted into many regions of the tropics. It is essential to obtain information about provenance variation of basic wood properties in order to preserve the wood quality of end-products derived from future plantations. Figuring is one of the wood characteristics valued for panelling and furniture and it is an important parameter to evaluate the quality of teak wood. The ring structure affects within-ring and between-ring colour variation and, therefore, the figure of wood and the related aesthetical aspects.     

Permeability of <Emphasis Type="Italic">Tectona grandis</Emphasis> L. as affected by wood structure

This experiment describes some anatomical features of Tectona grandis L. relating to the variation of liquid permeability in radial and longitudinal directions. Safranine aqueous solution was used to measure the permeability for its brilliant color and staining properties. Even in presence of abundant rays, penetration depth of liquid in radial direction was found very low in comparison with axial flow. Herein ray length and perimeter of cross-sectional area, interparenchymatous pit number and diameter determined the radial permeability. On the other hand, vessel length and diameter, intervessel pit size, and fiber length affected the longitudinal flow of liquids. Following a go-stop-go cycle, penetration speed of liquid decreased over time.     

Teak (<Emphasis Type="Italic">Tectona grandis</Emphasis> L.) tree growth,stem quality and health in coppiced plantations in Java,Indonesia

Coppicing is an alternative reforestation tool for teak in the tropics, substantially reducing regeneration time/costs and associated demands for labor and seed when available. Growth rates of coppiced material are rapid in most situations, but stem/wood quality is a frequent concern. We compared coppiced teak plantations to paired seed-origin plantations, at ages 3, 8, and 13 years, on Forest State Corporation managed land located in Java, Indonesia. Teak trees were evaluated for height, diameter, lower-bole straightness, and presence of disease in both plantation types and at three ages. Mean height and diameter of trees in coppiced plantations were both significantly greater than that in their paired seed-origin plantations at all three ages. Furthermore, heights and diameters in coppiced plantations were higher than expected based on established growth tables for Java. Coppiced plantations were less symptomatic of disease than seed-origin plantations, which promises better wood production and quality. Lower-bole stems in coppiced plantations developed less straight than those in seed-origin plantations, but these deviations faded with time and will likely become insignificant within a 60-year rotation. Based on these results from existing coppiced plantations in Java, coppiced plantations can make a major contribution to teak production in Indonesia.     

Growth and mineral nutrient analysis of teak (<Emphasis Type="Italic">Tectona grandis</Emphasis>) grown on acidic soils in south China

Teak (Tectona grandis L.f.) is widely planted in the world due to its high market demand, economic, ecological and social value. Its plantations have mostly been established and expanded into sites that are acidic to severely acidic in southern China. But, there are no available and specific evidence-based nutrient management techniques. To better recognize and understand the relationship between teak tree growth and nutrient content in the foliage and soil and establish nutrient norms are critical to optimally manage these young plantations. We studied the foliar nutrient and soil chemistry in 19 representative teak plantations aged 5–8 years. Regression analysis indicated that the mean annual increment of teak volume was linearly and positively correlated with foliar N, Ca, Fe and B concentrations, with soil base saturation percentage, available P and Zn concentrations, and negatively correlated with soil Al concentration. Only if the Ca and Mg contents in soil were enhanced, could the increase in soil base saturation percentage benefit teak growth. A revised classification of low-and high-yielding stands was established by using a sorting method of principal components over 6 foliar macro and 8 micro elements in a Diagnosis and Recommendation Integrated System (DRIS). Specific DRIS norms for teak plantations in acid soils were derived. The nutrient balance of N, P, K Ca, Mg, Zn, B with Fe or Al, Ca with Mg, and Fe with Al provided a key to promote the growth of teak in acid soils. Meanwhile, soil Zn was also found as a primary trace element that affected teak growth in this study.     

Litterfall,decomposition and nutrient release of <Emphasis Type="Italic">Shorea robusta</Emphasis> and <Emphasis Type="Italic">Tectona grandis</Emphasis> in a sub-tropical forest of West Bengal,Eastern India

We studied leaf litter fall, decomposition and nutrient release patterns of Shorea robusta and Tectona grandis by using a litter bag technique to better understand the release pattern of nutrients to soil from leaf litter. Annual litterfall varied from 13.40 ± 2.56 t ha^?1 a^?1 for S. robusta to 11.03 ± 3.72 t ha^?1 a^?1 for T. grandis and the decay constant (k) of decomposed leaf litter was distinctly higher for T. grandis (2.70 ± 0.50 a^?1) compared to S. robusta (2.41 ± 0.30 a^?1). Biomass loss was positively correlated with the initial litter C, WSC, C/N and ash content in S. robusta and N, P and K concentration for T. grandis. Biomass was negatively correlated with lignin and L/N ratio for S. robusta and L, WSC, L/N and C/N ratio for T. grandis (P < 0.01). Nutrient use efficiency (NUE) and nutrient accumulation index (NAI) of S. robusta was higher than for T. grandis. The retranslocation of bioelements from senescent leaves ranked as P > N > K. Annual N, P and K input to soil through litterfall differed significantly between the two species in the following order: N>K>P. S. robusta was superior in terms of K and P return and T. grandis was superior in terms of N return. The two tree species showed a similar patterns of nutrient release (K > P > N) during decomposition of their leaf litter. Nutrients of N, K and P were the primary limiting nutrients returned to soil through litterfall with important roles in soil fertility and forest productivity.     

Diversity of arbuscular mycorrhizal fungi in <Emphasis Type="Italic">Tectona grandis</Emphasis> Linn.f. plantations and their effects on growth of micropropagated plantlets

Regeneration of stands of valuable tropical hardwood tree species for sustainable harvest requires production of seedlings with high probabilities of survival. One way to enhance the vigor of plants for outplanting is pre-colonization of roots by arbuscular mycorrhizal (AM) fungi. We pursued the strategy that the most promising AM fungus candidates for inoculation would be those associated with the tree of interest in the field. AM fungus communities were assessed in five plantations of Tectona grandis Linn.f. A total of 18 AM fungal morphotypes were found, representing four families: Glomeraceae (49.6%), Acaulosporaceae (24.9%), Claroideoglomeraceae (20.8%), and Gigasporaceae (4.8%). AM fungus spore density was negatively correlated with soil organic carbon. Some of these AM fungi, plus Rhizophagus irregularis, were established in pot culture and in vitro with transformed carrot roots, and subsequently used to inoculate micropropagated plantlets of T. grandis. Tectona grandis plantlets inoculated in vitro were successfully colonized by all AM fungi studied. Plants inoculated with Funneliformis mosseae were taller than uninoculated plants. Tectona grandis plantlets inoculated with the AM fungus Claroideoglomus etunicatum PBT03 were taller than uninoculated controls in ex vitro experiments. This study provides early insight for the targeted use of the AM symbiosis in production of important tree species in future greenhouse studies and reforestation.     

Estimation and economic evaluation of aboveground carbon storage of <Emphasis Type="Italic">Tectona grandis</Emphasis> plantations in Western Panama

Tropical tree plantations may play an important role in mitigating CO₂ emissions through their potential to capture and sequester carbon from the atmosphere. The Clean Development Mechanism (CDM) as well as voluntary initiatives provide economic incentives for afforestation and reforestation efforts through the generation and sale of carbon credits. The objectives of our study were to measure the carbon (C) storage potential of 1, 2 and 10-years old Tectona grandis plantations in the province of Chiriquí, Western Panama and to calculate the monetary value of aboveground C storage if sold as Certified Emission Reduction (CER) carbon credits. The average aboveground C storage ranged from 2.9 Mg C ha⁻¹ in the 1-year-old plantations to 40.7 Mg C ha⁻¹ in the 10-year-old plantations. Using regression analysis we estimated the potential aboveground C storage of the teak plantation over a 20 year rotation period. The CO₂-storage over this period amounted to 191.1 Mg CO₂ ha⁻¹. The discounted revenues that could be obtained by issuance of carbon credits during a 20 year rotation period were about US$460 for temporary CER and US$560 for long-term CER, and thus, contribute to a minor extent (1%) to overall revenues, only.     

Genetic variation in traits affecting sawn timber recovery in plantation-grown <Emphasis Type="Italic">Eucalyptus nitens</Emphasis>

• Introduction   

There is increasing interest in managing Eucalyptus nitens plantations for sawn timber production.     

Phenotypic variation of baobab (<Emphasis Type="Italic">Adansonia digitata</Emphasis> L.) fruit traits in Mali

We analyzed the phenotypic variation of baobab (Adansonia digitata L.) fruits from Mali to define the domestication potential of this species. 269 trees, selected from 10 provenances distributed along a rainfall gradient, were characterized. Five fruits were sampled from each tree. Total individual fruit weight was partitioned into shell, pulp, and seed weight. Ratios were calculated between pulp + seed and total weight, and between pulp and seed weight. For all the measured fruit traits, we detected significant differences between provenances, as well as between trees from the same provenance. Assuming that the measured traits are under genetic control, the latter facts indicate that there are considerable opportunities for tree selection on a local scale. However, candidate plus trees with specific properties, e.g., extremely high pulp or seed weight, were found only in some locations. Mean pulp yield per fruit might be considerably increased by selecting the 5% trees with the highest pulp weight (mean: 45 ± 1 g, best 5%: >100 g). The same might be true for seed production (mean: 71 ± 2 g, best 5%: >150 g). Also the ratio between pulp and seed weight can be an important fruit characteristic for selection: in fruits with a low ratio, relatively more pulp sticks to the seeds when separating the two fruit parts by grinding, and thus more pulp will be lost for further processing. We identified several trees with a high pulp weight combined with a high ratio between pulp and seed weight. It is concluded that there is considerable phenotypic variability in traits of baobab fruit in Mali, offering opportunities for cultivar selection.     

Genetic variation of natural durability traits in <Emphasis Type="Italic">Eucalyptus cladocalyx</Emphasis> (sugar gum)

• Introduction  

We present a study on genetic variation in natural durability traits of young-aged Eucalyptus cladocalyx, a species adapted to temperate, low rainfall regions. Our motivation was the production of naturally durable posts for applications such as vine trellises, a sector dominated by heavy metal preservative-treated wood in some of the world’s main wine-producing countries.     

Regeneration dynamics of planted seedling-origin aspen (<Emphasis Type="Italic">Populus tremuloides</Emphasis> Michx.)

Aspen (Populus tremuloides Michx.) is a foundational tree species of the North American boreal forest. After disturbance, clonal aspen stands quickly achieve canopy closure by sending up numerous clonal shoots (root suckers) from their lateral root system. Controlled aboveground disturbance will commonly induce prolific root suckering and thereby increase stem density in clonal aspen stands, but it is unclear if increases in stem density will be observed in planted seedling-origin aspen stands. The objectives of this study were to determine (1) overall root suckering response of planted aspen to aboveground disturbance; (2) if different cut heights of the stem or infliction of root damage impact the number of root suckers produced. We found that planted aspen regenerated readily after disturbance, averaging five root suckers per cut tree. However, individual response was highly variable, ranging from zero to 29 root suckers per root system. Of the cut trees, 75% produced at least one root sucker and 60% produced at least one stump sprout. Cutting trees close to the soil surface produced more root suckers than leaving a 25 cm stump. While root system size (mass and length) was well correlated with aboveground measures of planted aspen, root suckering was not related to root system size. As a result of increased forest reclamation efforts in the boreal forest region the planting of aspen has become a more common practice, necessitating a better understanding of the regeneration dynamics and root suckering potential of these planted and seedling-origin aspen forests.     

Assessment of crown woody biomass in <Emphasis Type="Italic">Eucalyptus grandis</Emphasis> and <Emphasis Type="Italic">E. globulus</Emphasis> plantations

Young trees were harvested to explore non-destructive methodologies to estimate live branch dry weights in young fast-growing Eucalyptus species under different spacing and fertilizer treatments. Branch growth can vary with silvicultural management such as spacing, fertilizing and thinning, and over relatively short periods in response to environmental conditions. Many published regressions based on standard measurements of height and diameter are site, age and treatment specific. The aim of this study was to improve our capacity to predict woody crown dry weight, based on stem measurements, and to minimize (or eliminate) treatment effects on the resulting model. In young trees, branches are temporary support structures for foliage and are often discarded as the base of the green crown rises. As temporary structures they represent an investment of biomass and nutrient elements, and are subject to selection pressures to maximize the return on investment by the tree. Trees were harvested from existing plantation experiments located in south-eastern Queensland for E. grandis W. Hill ex Maiden (ranging from 0.28 to 15.85 m in height, to 5 years old) and south-western Australia for E. globulus Labill. (0.10–34.4 m in height, to 10.2 years) in order to examine the impact of spacing, nitrogen and phosphorus fertilization on early growth. Relationships to estimate crown woody biomass from non-destructive measurements were developed, and these relationships tended to have different slopes and intercepts for trees with predominantly juvenile foliage and those with intermediate or adult foliage. Dry weight of whole-crown live branch wood (W_branch) was related to heights and/or diameter at breast height (D_BH), but the regressions parameters were different, depending on treatment. The relationships became more generic (i.e. less dependent on treatment effects) between W_branch and stem sectional area at the height of the base of the green crown (SA_CB), consistent with the pipe model theory (R² > 0.91 for the two species for trees with intermediate/adult leaves). However, W_branch was more closely related again to the stem volume above the base of the green crown and treatment effects were not significant (V_Con,gc, R² > 0.93). Branches exit the stem below the green crown, and for E. grandis the best relationship was on stem volume above the lowest live branch (V_Con,llb, R² 0.94). Limited sampling from four other species with similar or contrasting crown characteristics indicated that the relationship could be applied quite generally. Individual E. grandis branch woody dry weight was closely related to the conical volume of the main (first order) branch (V_con,br, R² 0.98₎. The whole crown equivalent, branch woody dry weight plus stem dry weight above the lowest live branch, was also closely related to the stem volume within the woody crown (V_Con,llb, R² 0.97–0.99). While the slope of this relationship was still significantly different between trees with juvenile and intermediate/adult foliage, it had a similar form, suggesting that trees with juvenile foliage allocated a different proportion of their woody biomass within the crown to branches than older trees.     

Genetic correlations between wood quality traits of <Emphasis Type="Italic">Pinus pinaster</Emphasis> Ait

• ? It is essential to understand how characteristics are related to each other in breeding programmes to select wood properties, in order to avoid that, in selecting for one trait, we are negatively affecting another. Moreover, measuring wood properties is time consuming and expensive.
• ? This study assesses genetic and phenotypic correlations between wood density components and spiral grain of 46 half-sib families of Pinus pinaster in seventeen-year-old trees.
• ? Results showed that genetic correlations for all wood density components were higher than corresponding phenotypic correlations. Furthermore, all wood density components were highly genetically correlated with ring density, and also closely associated among themselves. Results showed a higher genetic correlation of ring density with earlywood density (r _g = 0.96) than with latewood density r _g = 0.79). A moderate to high positive genetic correlation was found between spiral grain and wood density characteristics (0.29–0.61).
• ? We conclude that ring density (overall wood density) can be improved by increasing either earlywood density, latewood percent, or both of these traits, and spiral grain can be modify in future plantations.

     

Discrimination of infested cotton squares by females of <Emphasis Type="Italic">Anthonomus grandis</Emphasis>

The avoidance of infested squares of Gossypium hirsutum as oviposition substrate by females of Anthonomus grandis was studied following two approaches. First, the preference for oviposition in infested versus non-infested squares was studied in laboratory. Second, the distribution of ovipositions by A. grandis in nature was analyzed in cotton plots from Argentina. In addition, the consequences of multiple ovipositions were assessed in terms of emergence rate, adult weight and sex ratio. In the laboratory, the number of ovipositions was significantly higher in non-infested than in infested squares. Likewise, females were found to reject infested squares more frequently than non-infested squares. In the field, oviposition pattern fitted a uniform distribution for squares collected from the ground, while the distribution in squares sampled from the plant fitted random and uniform distributions. This suggests that oviposition decisions could be dynamic and change with the infestation conditions. Multiple ovipositions resulted in the elimination of competing larvae between L1 and L2 instars. The weight of the individual that develops to the adult stage was negatively affected by the level of larval competition, and the sex ratio deviated toward females. Our results suggest that females of A. grandis tend to avoid already infested squares. This behavior would allow reducing the levels of intraspecific competition, which we also found can seriously affect the development of their progeny. A deeper knowledge of the oviposition behavior of A. grandis could contribute to developing control methods against this important cotton pest.     

Genetic variation in heartwood properties and growth traits of <Emphasis Type="Italic">Eucalyptus bosistoana</Emphasis>

Forty-one E. bosistoana families were evaluated for the production of heartwood quantity and quality in two sites. High estimated heritabilities of heartwood diameter (HWD) were found in both sites (0.66 and 0.71). The estimated heritabilities of extractives content (EC) were lower with 0.16 and 0.25. Weak genetic correlations between HWD and EC were found in one site, but highly negative (??0.86) genetic correlations were observed in the other. The G?×?E interaction had no significant influence on growth traits but a small-level influence on the EC. Five families were selected for tree breeding as they produced both large HWD and high EC in both sites. It was suggested that genetic breeding selection could improve the heartwood quantity and quality of E. bosistoana plantations.     

Genetic parameters of growth,straightness and wood chemistry traits in <Emphasis Type="Italic">Pinus pinaster</Emphasis>

Introduction   

Tree breeding is giving an increasing attention to wood properties in order to better fit the requirements of the saw, board, pulp and paper industries. In particular, it has been reported that lignin and cellulose content display moderate to high heritabilities making them prime candidates for genetic improvement of wood chemistry. Moreover, these traits have been shown to be negatively correlated at both phenotypic and genetic levels. However, they have generally been evaluated against a narrow genetic background, and little is known about their correlations with mandatory selection criteria such as growth and straightness.     

Recessive inheritance of morphological characteristics of utsukushimatsu,<Emphasis Type="Italic">Pinus densiflora</Emphasis> f.<Emphasis Type="Italic">umbraculifera</Emphasis>

Pinus densiflora f.umbraculifera, commonly known as utsukushimatsu, is a distinctively shaped form of Japanese red pine whose growth is restricted to a forest stand in Shiga Prefecture, Japan. The inheritance mode of morphological characteristics of utsukushimatsu was studied to preserve the genetic resource of this pine. As previously reported, F₁ trees grown from open-pollinated seeds harvested from trees inhabiting the native stand showed two phenotypes: one resembling utsukushimatsu, which produces multiple trunks, and the other resembling normalP. densiflora, which produces one or a few trunks. In the present study, controlled pollination was carried out using F₁ and normalP. densiflora trees. Segregation ratios of the two phenotypes observed in the F₂ population showed that the morphological characteristics of utsukushimatsu are inherited recessively. This suggests that the mutation of one gene or a few closely linked genes controls the morphological characteristics of utsukushimatsu. Since multiple trunk formation of utsukushimatsu might be related to a loss of lateral bud inhibition, it follows that a simple gene mutation breaks apical dominance inP. densiflora.