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Wood quality is related to the characteristics and properties of this material. Understanding the factors that can impact the wood formation is fundamental in the indications for use. The aim of this study was to evaluate the influence of different planting densities on the wood quality and the radial profile on some physical and anatomical characteristics of young trees of Tectona grandis. Nine trees were evaluated in three planting densities: 6 x 2 m; 5 x 2 m; and 4 x 2 m. All trees were subjected to analysis of acoustic tomography, X-ray densitometry, and fiber characterization. Multivariate associations between the variables of interest were evaluated according to the planting spacing and the radial profile by principal component analysis. The results indicated that the wood characteristics of young teak trees are influenced, mainly, by the radial variation (pith-bark).

Background and aims: Teak (Tectona grandis L.f.) is one of the most promising timber species in the tropical and subtropical areas in south China. Arbuscular mycorrhizal (AM) fungi play a crucial role in promoting plant growth, enhancing plant stress resistance and sustaining healthy ecosystem. However, little is known about mycorrhizal status in teak plantations. This study aims to characterize the dynamics of AM fungal communities in the rhizosphere of teak plantations at different ages. Methods: Fine roots and rhizosphere soils in teak plantations at varying ages (22, 35, 45 and 55 years old), and the adjacent native grassland without teak plantation (CK) were assessed for soil properties, root mycorrhizal colonization, and AM fungal communities using amplicon sequencing technology. Results: With the increase of stand ages, AM fungal colonization rates in teak fine root samples and spore density in the rhizosphere were increased linearly; catalase and ammonium nitrogen in the rhizosphere soil were also increased; soil organic carbon, total phosphorous (P), acid phosphatase, available potassium (AK) and available phosphorus (AP) were first increased and then declined at 55 years old stands. In total, 12 and 9 AM fungal genera were detected in the rhizosphere soil and in teak root samples, respectively. The OTUs data revealed that AM fungi presented in the rhizosphere soil and roots were mostly belonged to Glomus. In the rhizosphere soil, the relative abundance of Glomus was first increased and then declined, while Gigaspora and Scutellospora were declined, although the diversity and richness of AM fungi showed no significant variation with stand ages. In roots, the composition of AM fungal community and its diversity did not change with stand ages, whereas the richness was increased with the stand age. The monte carlo permutation test indicated that AK, nitrate nitrogen and C/P ratio largely explained the shift in the composition of AM fungal community in the rhizosphere soil. Conclusion: The results demonstrated that AM fungal communities in the rhizosphere soil and teak roots shifted across plantation ages. These changes were largely attributed to the age-induced variation in soil properties.

This study analyzed the fuel properties of bio-oils produced by catalytic fast pyrolysis of Tectona grandis in a fixed bed reactor at different temperatures (400 – 600°C) and biomass to catalyst (b/c) weight ratios (90/10 – 60/40). Magnesium oxide (MgO) was used as catalyst. The product yields were determined. Bio-oils were characterized with their elemental composition and their Higher Heating Values (HHVs) as well as their basic fuel properties at maximum bio-oil yields conditions, including viscosity, flash point, moisture content, pH value and Conradson Carbon Residue (CCR), were determined and compared with those of non-catalytic pyrolysis bio-oils. The maximum yields of bio-oil at 400, 500 and 600°C were 31.53, 40.87 and 29.30 wt.%, respectively, obtained at b/c ratios of 70/30, 80/20 and 70/30. Catalytic pyrolysis bio-oils possessed higher carbon and hydrogen but lower oxygen and sulphur contents than non-catalytic pyrolysis bio-oils. The HHVs of catalytic pyrolysis bio-oils (40.31 – 42.08 MJ/kg) were higher than those of non-catalytic bio-oils (36.47 – 36.76 MJ/kg). Catalyst reduced the viscosity (at 400 and 500°C), moisture content and CCR (at 400 and 600°C), and increased the pH value of bio-oils (at 400 and 600°C). Catalytic pyrolysis deoxygenates and enhances the fuel properties of bio-oils. Bu çalışmada, farklı sıcaklıklarda (400 – 600°C'de) ve farklı biyokütle/katalizör (b/c) ağırlık oranlarında (90/10 – 60/40) sabit yataklı bir reaktörde Tectona grandis'in katalitik hızlı pirolizi ile üretilen biyo-yağların yakıt özellikleri incelenmiştir. Katalizör olarak magnezyum oksit (MgO) kullanılmıştır ve ürün verimleri belirlenmiştir. Biyo-yağlar karakterize edilmiştir ve element bileşimleri, yüksek ısıtma değerleri, maksimum biyo-yağ verimi koşullarındaki temel yakıt özellikleri, viskozite, parlama noktası, nem içeriği, pH değeri ve Conradson karbon kalıntısı (CCR) değerleri incelenmiştir ve katalitik olmayan piroliz biyo-yağların değerleri ile karşılaştırılmıştır. 400, 500 ve 600°C'de ve 70/30, 80/20 ve 70/30 b/c oranlarında elde edilen ağırlıkça maksimum biyo-yağ verimleri sırasıyla, %31,53, % 40,87 ve % 29,30 olarak bulunmuştur. Katalitik piroliz biyo-yağları, katalitik olmayan piroliz biyo-yağlarından daha yüksek karbon ve hidrojene ancak daha düşük oksijen ve kükürt içeriğine sahip bulunmuştur. Katalitik piroliz biyo- yağlarının Yüksek Isıtma Değerleri (HHV) (40,31 – 42,08 MJ/kg), katalitik olmayan biyo-yağlardan (36,47 – 36,76 MJ/kg) daha yüksek belirlenmiştir. Katalizör, viskoziteyi (400 ve 500°C'de), nem içeriğini ve CCR'yi (400 ve 600°C'de) azaltmıştır ve biyo-yağların pH değerini (400 ve 600°C'de) artırmıştır. Katalitik piroliz, biyo-yağların yakıt özelliklerini geliştirmektedir.

The Tectona grandis L.f. (teak) is an important forest species with high economy value in Asia, Africa, and Latin America. In Latin America, Brazil is one of the countries with the most cultivated areas. The cultivation of teak turns out to be challenging because of its high nutritional demand and the need for seedling production by clonal propagation that includes about 90 days in the nursery phase. The optimization of seedling production is necessary for better results in the nursery and to enhance growth in the field. In this way, the well-known advantage of using microorganisms that promote plant development appears as a potential biotechnological approach to be explored and for the implantation of new areas of wood production. In this study, the inoculation of Bacillus subtilis as plant growth-promoting rhizobacteria (PGPR) was evaluated, and Rhizophagus clarus, an arbuscular mycorrhizal fungus (AMF), and the co-inoculation of these microorganisms in the teak seedling production phase can improve the development of commercial plantations under field conditions. Experiments were carried out under greenhouse and field conditions to evaluate four treatments based on the substrate inoculation of the seedlings. Treatments consisted of a non-inoculated control, PGPR inoculation, AMF inoculation, and PGPR + AMF inoculation. The results of the biometric evaluation of seedlings in the greenhouse showed that there was a significant difference in AMF inoculation and PGPR + AMF inoculation in terms of the specific root length and root density treatments, there was also a positive correlation between these two treatments and the absorption of some nutrients, such as P, N, K, Mg, Cu, Mn, and Zn. This response led to an increase between 4.75 and 11.04% in the field growth rate.

Key message In this study, deep roots of teak tree seem to have acted as a "safety net", allowing trees to maintain their canopy cover longer, thus coping with inter- and intra-seasonal drought. Abstract Most deciduous species of dry monsoon forest, such as teak tree (Tectona grandis Linn F.), establish new foliage slightly before, or at the onset of the rainy season, when the upper soil layers are the driest. This phenomenon suggests that trees rely upon deep water storage to cover their need for the new canopy development. Therefore, we hypothesized that deeper rooted trees may display phenological patterns that confer them physiological advantages with regard to access to water. At an upland location in Northern Laos, we characterized 10 mono-specific teak tree plantations corresponding to micro-environments that differed with regard to soil, slope, elevation, and orientation. We compared the leaf phenology of trees, taking into account their age, diameter at breast height (DBH), and rooting pattern down to 3.5 m depth. With at least 5% of its total fine roots below 2 m, teak trees were found to be deep rooted. There was no correlation between the timing of leaf flushing and rooting depth nor with primary production (assessed on the basis of tree girth increase). Leaf flushing was strongly synchronous with rainfall rather pointing out that its primary determinant is the water status of topsoil and near-surface soil horizons that results from seasonal rainfall, even though the mechanism(s) underlying such a process remain to be clarified. However, deeper rooted teak trees tended to maintain a denser canopy cover over longer periods than trees with shallower rooting systems. This suggests that, deep roots may play a role as a "safety net", i.e., providing improved resilience to inter- and intra-seasonal drought events, but do not influence the timing of the leaf flushing.

The durability of imported timber is a matter of growing concern in the tropical Indian climate, with their refractory nature further adding to the woes with respect to further processing. In the present study, the effect of microwave pre-treatment, exposure time and initial wood moisture content on retention, treatability and cross-sectional anatomical properties of Tectona grandis and Southern yellow pine imported from Ghana and South America were evaluated. Water based preservative copper chrome borate (CCB) of 2 % concentration was used for the study. The experimental study in combination with dip-diffusion method returned with significant improvement in retention of about 5-6 folds more than the control sets in Southern yellow pine and Tectona grandis. Another set of Southern yellow pine and Tectona grandis samples were further treated using a full cell pressure method after microwave, without initial vacuum, which showed similar trends with a 3-4 folds increase in retention over controls. Both experiments returned with significant improvement in the treatability class of Tectona grandis and Southern yellow pine. The anatomical analysis was performed using a light microscope with 5 and 10x magnifications on treated and untreated samples of both Tectona grandis and Southern yellow pine. The outcome of the anatomical study exhibited improvement in vessel diameters in the treated samples of Tectona grandis with a reduction in the degree of occlusion by the presence of tyloses. For Southern yellow pine, checks on micro level and cracks on macro level appeared along with the ray cells and the diameter of the resin canals was substantially expanded which ascertains that microwave pre-treatment ameliorated the flow of fluids in the wood microstructure which improved permeability and resulted in better uptake and penetration.

International audience; Recent methodological advances have opened new perspectives for tropical dendrochonological studies by facilitating the visualization, delimitation, and analyses of tree-rings. One of those improvements was brought by X-ray densitometry, which allows building radial wood density profiles at microscopic scale. Furthermore, recent methods allow for cutting long histological sections to study anatomical variations along the entire radius of trees. These techniques have mainly been applied to low wood-density species from temperate and Mediterranean regions, with only limited applications in the tropics. Here we provide an improved protocol that allows for obtaining long histological sections of tropical woods, apply it to six species with varying wood densities 0.45−0.85 g cm−3 (Eucalyptus grandis, Tectona grandis, Acacia mangium, Cedrela fissilis, Hymenaea courbaril, and Copaifera duckei), and explore potential applications for tree-ring analyses. We provide instructions on core-microtome knife adjustments, procedures for softening and sectioning long histological samples of high wood-density species. We also present a multi-proxy approach that combines X-ray density profiles with the histological sections that improve the characterization and distinction of the various and complex tropical growth rings anatomical markers (fibre zone, marginal parenchyma, and ring porosity). This multi-proxy approach also opens the door for obtaining quantitative anatomy and physical parameters of tropical species with (intra-annual resolution. Our proposed approach is thus not only an additional tool to improve ring-boundary delimitation of tropical species, but it also paves the way to more innovative, borderline approaches in tropical dendrochronology.

Teak Tectona grandis Linn is still used as the main product in the form of wood, while other products, especially environmental services have not received much attention. This study analyzed biomass, carbon stocks and decomposition rate of leaf litter in teak plantations in city forest of Hasanuddin University, Makassar. The individual biomass of teak plants is calculated using the allometric equation Y = 0.11 × ρ × D2.62. Carbon stocks were analyzed using a formulation C = 0.47 × B. The leaf litter decomposition rate is expressed as the ratio of the remaining litter dry weight, with the formulation X = (A − B)/A. The number of teak plants in 5 sample plots were 239 trees with an average stem diameter of 20.6 cm and an average height of 9.02 m. Total biomass in 5 sample plots was 51,712.61 g. Carbon stocks in 5 sample plots was 24,304.92 g. Decomposition rate average of leaf litter of 24.4 g during 60 days incubation. The existence of teak plantations is able to reduce CO2 in the atmosphere by as much as 89,199.06 g CO2 and resulting in a decomposition rate of teak leaf litter 0.4 g per day.

The properties of teak wood, such as natural durability and beautiful color, are closely associated with wood extractives. In order to further understand the performance differences between teak heartwood and sapwood, we analyzed the chemical components of extractives from 12 wood samples using an ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS)-based metabolomics approach. In total, 691 metabolites were identified, and these were classified into 17 different categories. Clustering analysis and principal component analysis of metabolites showed that heartwood samples could be clearly separated from sapwood samples. Differential metabolite analysis revealed that the levels of primary metabolites, including carbohydrates, amino acids, lipids, and nucleotides, were significantly lower in the heartwood than in the sapwood. Conversely, many secondary metabolites, including flavonoids, phenylpropanoids, and quinones, had higher levels in the heartwood than in the sapwood. In addition, we detected 16 specifically expressed secondary metabolites in the heartwood, the presence of which may correlate with the durability and color of teak heartwood. Our study improves the understanding of differential metabolites between sapwood and heartwood of teak, and provides a reference for the study of heartwood formation.

Tectona grandis is a valuable timber species with heartwood that is used worldwide. Most of the previous studies on its heartwood and sapwood have focused on dominant or mean trees, while trees with different social status might show different vertical and horizontal distributions of heartwood and sapwood. Studies on their heartwood and sapwood properties could be conducive to increasing heartwood yield at stand level. In 31-year-old plantations of T. grandis in southwest Guangxi, China, the trees were divided into three groups including dominant, mean and suppressed trees. Stem analysis was conducted for sampled trees in each of these groups to explore the differences in the horizontal and vertical distribution of their heartwood and sapwood. The results indicated that the heartwood radius, heartwood and sapwood areas of T. grandis showed significant differences in horizontal and vertical directions among trees of different social status. Heartwood began to form when xylem radius was 2&ndash, 3 cm, and the heartwood radius ratio tended to be stable when the xylem radius reached about 8 cm. Heartwood radius and area, sapwood area and section heartwood volume all decreased with increasing tree height. The ratios of heartwood radius and area were relatively stable for sections under 50% of tree height. The sapwood width did not vary largely in horizontal and vertical directions among the three social status tree groups, which mainly fluctuated in the range of 1&ndash, 4 cm. The heartwood volume proportions for dominant, mean and suppressed trees were 60%, 55% and 51%, respectively. There was a significant exponential relationship between heartwood volume and diameter at breast height (DBH) regardless of social status. The model HV = 0.000011 &times, DBH2.9787 (R2 = 0.8601) could accurately estimate heartwood volume for all T. grandis with different social statuses at this age. These findings could provide evidence for stand management and high-quality and large-sized timber production of T. grandis.

The objective of this work was to evaluate the productivity and beverage sensory quality of arabica coffee under the influence of tree species cultivated at different spacings. The experiment was set in 2012, in the municipality of Santo Antônio do Amparo, in the state of Minas Gerais, Brazil. A randomized complete block design was carried out with four replicates and seven treatments, as follows: Catuaí Vermelho IAC 99 Coffea arabica in monoculture (3.40x0.65 m); and this cultivar intercropped at two spacings (9.0x13.6 and 18.0x13.6 m) in the coffee row ‒ either with African mahogany (Khaya ivorensis), teak (Tectona grandis), or pink cedar (Acrocarpus fraxinifolius). Three coffee rows were fixed between rows, totaling 13.6 m between the wooded rows. Productivity, sensory analysis (cup test), and content analysis of sensory attributes were evaluated in the 2017 and 2018 crop years. The treatments and years of harvest influenced productivity. The sensory analysis was positive for coffee intercropped with African mahogany and teak, in 2018. Sensory attributes and nuances are modified by the years of harvest. Arabica coffee plants intercropped with African mahogany show a superior productivity, regardless of the spacing between species, as well as a higher sensory quality in the 2018 harvest. Resumo: O objetivo deste trabalho foi avaliar a produtividade e a qualidade sensorial da bebida do café arábica sob a influência de espécies arbóreas cultivadas em diferentes espaçamentos. O ensaio foi instalado em 2012, no município do Santo Antônio do Amparo, no estado de Minas Gerais, Brasil. Um delineamento de blocos ao acaso foi realizado, com quatro repetições e sete tratamentos, conforme a seguir: Coffea arabica Catuaí Vermelho IAC 99 em monocultivo (3,40x0,65 m); e essa cultivar consorciada em dois espaçamentos (9,0x13,6 e 18,0x13,6 m), na linha dos cafeeiros, com mogno-africano (Khaya ivorensis), teca (Tectona grandis), ou cedro-rosa (Acrocarpus fraxinifolius). Nas entrelinhas, foram fixadas três linhas de café, tendo totalizado 13,6 m entre as fileiras arborizadas. A produtividade, a análise sensorial (prova de xícara) e a análise de conteúdo dos atributos sensoriais foram avaliadas nas safras de 2017 e 2018. Os tratamentos e os anos de colheita influenciaram na produtividade. A análise sensorial foi positiva para o consórcio com o mogno-africano e a teca, em 2018. Os atributos sensoriais e as nuances são modificados pelos anos de colheita. Os cafeeiros arábica consorciados com mogno-africano apresentam produtividade superior, independentemente do espaçamento entre as espécies, bem como qualidade sensorial superior na colheita de 2018.

The objective of this work was to evaluate the growth and yield of teak (Tectona grandis) stands at different spacing and in different soil classes. Twelve spacing were evaluated in an Inceptisol and Oxisol, in plots with an area of 1,505 or 1,548 m2, arranged in a completely randomized design with nine replicates. The teak trees were measured at 26, 42, 50, and 78 months of age. Total tree height was less affected by spacing. Mean square diameter was greater in wider spacing, whereas basal area and total volume with bark were greater in closer spacing. An increase in volume with bark per tree was observed with the increase of useful area per plant. For teak trees, growth stagnation happens earlier, the growth rate is higher in closer spacing, and the plants grow more in the Inceptisol than in the Oxisol. Resumo: O objetivo deste trabalho foi avaliar o crescimento e a produção de povoamentos de teca (Tectona grandis) em diferentes espaçamentos e classes de solo. Foram avaliados 12 espaçamentos em Cambissolo e Latossolo, dispostos em parcelas com área de 1.505 ou 1.548 m2, em delineamento inteiramente casualizado, com nove repetições. As plantas de teca foram medidas aos 26, 42, 50 e 78 meses de idade. A altura total das árvores foi menos influenciada pelos espaçamentos. O diâmetro quadrático médio foi superior nos maiores espaçamentos, enquanto a área basal e o volume total com casca foram superiores nos espaçamentos mais adensados. Observou-se aumento do volume com casca por árvore com o aumento da área útil por planta. Em teca, a estagnação do crescimento ocorre mais cedo, a taxa de crescimento é maior nos espaçamentos mais adensados e as plantas crescem mais em Cambissolo do que em Latossolo.

Stem straightness, axis persistence, presence/absence of protuberant buds and epicormics, diameter and height have profound influence on timber quality and volume of teak ( Tectona grandis ). Provenance trials of teak were established in the 1970s in Ghana, as part of the Food and Agriculture Organization (FAO) International Series of Provenance Trials, with the view of selecting teak germplasm for sites with specific environmental conditions. Two field trials were located in dry semi-deciduous (dry) and moist semi-deciduous (moist) ecological zones of Ghana. They consisted of 13 provenances, including four landraces each from Ghana and Indonesia, and two and three provenances from India and Laos, respectively. Trees were assessed at 9, 17 and 28 years to (1) quantify the potential variation in quality and timber volume production, (2) examine possibilities for determining early selection of parameters of superior provenances and (3) select provenances for sites with particular environmental conditions. Production traits were higher on the moist site than the dry site. Mean height was 23.2 and 20.2 m tree −1 , stem cross-sectional area at breast height was 0.0896 and 0.0474 m 2 tree −1 , and stem volume was 0.75 and 0.34 m 3 tree −1 for the moist and dry sites, respectively. Nilambur provenance from moist India had the highest mean stem straightness score of 19% above average, whereas Savannakhet from Laos had the best protuberant bud score with 18% of the trees above average. Indonesian landraces performed better in the dry zone, whereas provenances from India and Laos performed better in the moist zone. Phenotypic correlations between age 9 and 28 years were moderate ( r = 0.54–0.90) to high ( r > 0.90) for production and qualitative characteristics, indicating feasibility of early assessment for identification of superior provenances. Nilambur and Savannakhet II provenances proved to be favourable choices for the moist zone, whereas the Temandsang provenance from Indonesia was found to be the best choice for the dry site. Keywords: axis persistence, epicormics, forestry, landraces, natural range, stem straightness

This work presents a first approach concerning the use of Tectona Grandis tree sawdust (from East Timor) for high activated carbon production, by physical activation with carbon dioxide at different temperatures. The activated carbons (AC) obtained exhibit a well-developed porous structure with a pore size distribution varying from micro to mesopores. Selected AC was successfully evaluated for pesticide removal, specific to 4-chloro-2-methylphenoxyacetic acid, from the liquid phase. The results presented are very promising, allowing to establish that Tectona Grandis sawdust is as an excellent precursor for the basic AC production and allow to expect good performance of theses adsorbents on the removal of a broad range of pollutants. It should also be noted that, this achievement is very relevant for developing countries, such East Timor, where Tectona Grandis sawdust is available and may constitute a source of income creating a handle to the technical and industrial development of this region.

Density management diagrams are valuable tools for managing specific forestspecies. The aim of this study was to obtain a density management diagram for teak (Tectona grandis L.) plantations in the State of Tabasco in Mexico. To achieve this objective, a set of 10 plantations were studied, in which 42 plots were established. Two equations were fitted simultaneously, including one related to the quadratic mean diameter, stand density and dominant height and the other which related the total stand volume to the quadratic mean diameter, stand density and dominant height. The results showed that the diagram had an acceptable predictability, thus indicating its usefulness and accuracy in planning silvicultural interventions. This diagram is a very powerful tool that can enable stakeholders to manage teak plantations in the State of Tabasco. Fil: Minoche, Djhon. Universidad de Valladolid; España Fil: Risio Allione, Lucia Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina Fil: Herrero De Aza, Ceclia. Universidad de Valladolid; España. ECM Environment Engineering; España Fil: Martínez Zurimendi, Pablo. Universidad de Valladolid; España. El Colegio de la Frontera del Sur; México

The main objective of this research was to evaluate the use of unmanned aerial vehicles (UAVs) in estimating the aboveground biomass and carbon, and the dasometric characteristics at three different spacings (2.5 m × 1.0 m, 2.5 m × 2.0 m and 2.5 m × 3.0 m) in a silvopastoral system (SPS) for the biomass production of Tectona grandis. A total of 90 trees were sampled, 63 of which were used to perform a dasometric evaluation (vertical and horizontal) in a spacing test in an SPS, and the rest to evaluate the use of UAVs in estimating the aboveground biomass in the spacing test. The results showed significant differences in average diameter at breast height (dbh) between spacings, and in aboveground biomass per tree. The amount of aboveground biomass and carbon per hectare increases at smaller spacings, but the differences were not statistically significant. A logarithmic model was prepared to estimate the dbh based on the crown diameter from the data collected taken in the field, since estimating this variable by means of UAVs is difficult. Significant differences were found in the aboveground biomass estimated using the field data compared to UAV data. The estimation of the crown diameter of the selected trees, hindered by the canopy closure in the SPS, was not adequate, which could influence the amount of aboveground biomass estimated using UAV data.

We developed a forest planning model integrating two operational scales (single-stand and forest levels) for the optimization of timber production and carbon sequestration in forest teak (Tectona grandis L. f.) plantations. At the stand level, growth and yield simulations using a heuristic thinning optimizer provided a set of near-optimal thinning regimes for individual stands differing on initial spacing and site quality, given biological, silvicultural, and financial constraints. The set of near-optimal thinning regimes obtained were then used as input of the forest-level model, which generated optimal harvest plans for the whole plantation by simultaneously maximizing the net present value of merchantable wood and carbon sequestration. The net amount of carbon captured by the biomass and the emissions produced by decomposition of woody debris and timber products after harvest were estimated. The growth and yield model was based on a system of differential equations incorporating heuristics (genetic algorithms) to optimize age and intensity of thinnings. The full model can handle the optimization of harvest schedules for projects up to 10.000 ha and 200 stands and was tested on a validation dataset including teak plantations from Venezuela and other Latin American countries. Results indicated that regimes favoring carbon sequestration reduce the benefits of timber production, and equal profitability of carbon sequestration and timber production was obtained for carbon prices over 40 $US Gg-1. Sensitivity analysis showed that the proposed model is sensible to variation in growth rates, carbon and timber prices, and production quotas, and barely sensible to harvest and transport costs. The developed model has a modular structure that allows its calibration to incorporate data from a wide range of management regimes for teak and other forest species.

In tropical forest, landscape fragmentation and the consequent degradation of disturbed forests increase the incidence of light and dry hot winds, causing a disturbance on natural regeneration. Under these conditions, lianas (woody vines) development is stimulated instead of other species, which are more suited to mature forest and under less influence of the edge effect. For this, lianas colonization is an important variable for assessing the disturbance level of a forest. In this context, it becomes important to understand the nature of the competitive relationships between hyper-abundant lianas and ring growth of the host trees. Here, we selected trees with occupation or absence of lianas from two tropical species – Pinus caribaea var. hondurensis (Caribbean pine) and Tectona grandis (teak) – localized in a semideciduous forest fragment in southeastern Brazil, aiming to compare growth, climatic response, anatomy (vessels and intra-annual density fluctuations), wood density and carbon, by tree-ring analysis. The results showed that the lianas caused a change in tree-ring anatomy of host trees in last 10 years, mainly. We observed that trees occupied by lianas had a decrease the radial growth and carbon in the two species, an increase of the vessels size in teak and a decrease of the IADF frequency in Caribbean pine. In teak, the climate-tree relationship indicated that trees with lianas had lower response to rainfall and higher response to temperature in the summer (rainy and hottest period); in Caribbean pine, we observed that trees with lianas had a 2-month delay in the radial growth response to rainfall in the dry season. In the teak group, we observed that host trees had higher wood density values than liana-free tree in the outer rings, and the opposite was showed for pine. These findings show that tree-ring growth of host trees are a strong bioindicator of forest disturbance caused by aggressive colonization of lianas. We believe that these methods are applicable to future studies relating to the effects of habitat fragmentation and forest degradation on biodiversity and ecosystem services, particularly in the context of global climate change. (Resume d'auteur)

RESUMO O presente estudo teve como objetivos estimar a produção, a taxa de decomposição, o tempo médio de renovação e decomposição da serapilheira em povoamentos da espécie Tectona grandis Linn. F. (Teca). O estudo foi realizado em três povoamentos de teca localizados no município de Nossa Senhora do Livramento - MT. Para as coletas da serapilheira foi delimitada uma área de 1 (um) ha em cada talhão com idades de cinco, seis e sete anos, na qual foram distribuídos, aleatoriamente, 20 coletores de madeira suspensos e vazados, com área de 0, 64 m2. O material vegetal depositado nos coletores foi recolhido a cada 30 dias, durante 12 meses, levado ao laboratório separando-se folhas, ramos (menores que um centímetro de diâmetro) e miscelânea, e depois de secos foram pesados. A serapilheira produzida nos talhões com sete, seis e cinco anos de idade foi, respectivamente, 7.280,25; 6.739,42 e 6.419,61 kg ha-1. As folhas representaram 86% do total de serapilheira depositada, os ramos, 4%, e as miscelâneas, 10%. As constantes de decomposição da serapilheira (K) nas árvores com cinco, seis e sete anos de idade foram, respectivamente, de 0,54; 0,60 e 0,58. O tempo médio de renovação, em anos, foi de 1,84 (671 dias) aos cinco anos, 1,67 (609 dias) aos seis anos e 1,71 (624 dias) aos sete anos. Para que ocorresse a decomposição de 50% da serapilheira, o tempo médio estimado foi de 1,28 anos (467 dias), 1,15 anos (419 dias) e 1,19 anos (434 dias) para as árvores com cinco, seis e sete anos, respectivamente. Para a decomposição de 95% da serapilheira, o tempo médio estimado foi de 5,53 anos (2.018 dias), 5,00 anos (1.825 dias) e 5,14 anos (1.876 dias) para a mesma sequência das idades. ABSTRACT The objective of this study was to estimate the litter production and decomposition rate, litter renewal and decomposition period in Tectona grandis Linn. F. (Teca) populations. The research was carried out in three different populations located in the city of Nossa Senhora do Livramento - MT state. Litter fall was collected from a limited forest area of 1 (one) ha containing plots with five, six and seven years old, from 20 wood collectors suspended and cast, covering an area of 0,64 m². The accumulated material was collected every 30 days, for 12 months, sent to the laboratory and segregated into leaves, branches (less than one centimeter in diameter) and mixed material, then dried and weighed. The litter fall collected from plots with seven, six and five years old had, respectively, 7,280.25; 6,739.42 and 6,419.61 kg ha-1. The leaves corresponded to 86% of the deposited litter, branches, 4%, and mixed material, 10%. The decomposition rate constant (K) of the plots with five, six and seven years old were, respectively, 0.54; 0.60 and 0.58. The average time of material renewal per plot, in years, was of 1.84 (671 days) for those with five, 1.67 (609 days) for those with six and 1.71 (624 days) for those with seven years old. The estimated time to decompose 50% of the litter material in the plots consisted in 1.28 years (467 days), 1.15 years (419 days) and 1.19 years (434 days) to the plots with five, six and seven years old, respectively. The estimated time to decompose 95% of the litter fall collected from plots with of five, six and seven years old consisted in 5.53 years (2018 days), 5.00 years (1825 days) and 5.14 years (1876 days), respectively.

The present study aimed to evaluate the biological resistance of teak (Tectona grandis) heartwood and sapwood to the action of Trametes versicolor and Gloeophyllum trabeum fungi in laboratory accelerated decay assays. The mass loss evaluation of the samples was performed periodically. The heartwood presented a higher percentage of extractives and the sapwood of holocelluloses. The sapwood and heartwood subjected to the fungus Gloephyllum trabeum remained stable. For the Trametes versicolor fungus, there was an increasing loss of mass over time for both regions, presenting a mass loss of 40% for the sapwood and of 20% for the heartwood at the conclusion of the assay. Teak wood was classified as highly resistant to the fungus Gloeophyllum trabeum, and moderately resistant to Trametes versicolor.

The relationship between nutrients and plant growth requires in-depth studies and the application of statistical analysis capable of explaining these interactions. An experiment was prepared with N, P2O5 and K2O doses. Effects on the correlations between growth and nutrients in Tectona grandis seedlings were based on the canonical correlation analysis. Seedlings were submitted to doses of N = 0, 2.5, 5.0, 7.5 kg m–3 with urea, P2O5 = 0, 3.0, 6.0, 12.0 kg m–3 with common superphosphate, and K2O = 0, 3.0, 6.0, 12.0 kg m–3 with potassium chloride, in a completely randomized design. Canonical correlations showed that biomass was the most salient morphological characteristic in relation to the growth of T. grandis seedlings. Height and diameter were also underscored by interactions between macro- and micronutrients in the substrate, after fertilization. Results show that N, Mn and Cu were the most important nutrients for the increment of these characteristics. RESUMO Determinar a relação existente entre os nutrientes e o crescimento das plantas implica em estudos e a aplicação de análise estatística capaz de explicar essas interações. Diante disso, estabeleceu-se experimento com doses de N, P2O5 e K2O e seus efeitos nas correlações entre crescimento e os nutrientes em mudas de Tectona grandis, a partir da correlação canônica. As mudas foram submetidas às doses de N = 0, 2,5, 5,0 e 7,5 kg m–3 com ureia, P2O5 = 0, 3,0, 6,0 e 12,0 kg m–3 com superfosfato simples e K2O = 0, 3,0, 6,0 e 12,0 kg m–3 com cloreto de potássio, em delineamento inteiramente casualizado. As correlações canônicas demonstraram que a biomassa foi a característica morfológica que mais se destacou em relação ao crescimento das mudas de T. grandis. Essa característica, assim como altura e diâmetro, foi favorecida pelas interações entre os macro e micronutrientes, que ocorreram no substrato após a adubação. N, Mn e Cu foram os nutrientes mais importantes para o incremento dessas características.

The objective of this work was to evaluate the development and quality of clonal seedlings of teak (Tectona grandis) grown in substrate with two types of biochar. The assay was carried out in a randomized complete block design, with ten treatments and four replicates: CS, commercial substrate, composed of pine bark and vermiculite at a ratio of 4:1; NS, nursery substrate composed of carbonized rice husk and coconut fiber at 1:1; and the remaining treatments were composed of the inclusions of biochar (BC) or activated biochar (BCA) in the CS, at the proportions of 25, 50, 75, and 100%. The development and quality parameters of seedlings were evaluated 90 days after striking the minicuttings in the substrates. BCA substrate additions at 25, 50, and 100% allowed for a development of height and stem diameter comparable to that of the NS. Biochar without the activation procedure does not improve quality parameters of seedlings, in comparison with the commercial substrate. The use of 25% activated biochar added to the commercial substrate is enough to improve seedling growth performance to the same level as that provided by the already validated NS. Resumo O objetivo deste trabalho foi avaliar o desenvolvimento e a qualidade de mudas clonais de teca (Tectona grandis) cultivadas em substrato com dois tipos de biochar. O ensaio foi realizado em delineamento de blocos ao acaso, com dez tratamentos e quatro repetições: SC, substrato comercial, composto de casca de pinus e vermiculita à proporção de 4:1; SV, substrato do viveiro, composto de casca de arroz carbonizada e fibra de coco a 1:1; e o restante dos tratamentos foi composto de inclusões de biochar (B) e biochar ativado (BA), nas proporções de 25, 50, 75 e 100% do SC. Os parâmetros de desenvolvimento e qualidade das mudas foram avaliados 90 dias após o plantio das estacas nos substratos. A adição de 25, 50 e 100% de BA possibilitou o desenvolvimento em altura e diâmetro do coleto comparável ao proporcionado pelo SV. O biochar sem o procedimento de ativação não melhora os parâmetros de qualidade das mudas, em comparação ao substrato comercial. A adição de biochar ativado na proporção de 25% já é suficiente para melhorar o crescimento das mudas para o mesmo nível proporcionado pelo já validado SV.

Some common, general biomass allometric equations were developed and tested for estimating the stem and aboveground biomass (AGB) of Tectona grandis and Eucalyptus camaldulensis plantations. In total, 84 datasets for T. grandis and 94 datasets for E. camaldulensis were gathered from published papers. The general allometric equations were then developed and the slopes and elevations were tested using ANCOVA. Spacing of 2 m × 4 m, 2 m × 8 m, 3 m × 3 m and 4 m × 4 m for T. grandis and 2 m × 3 m, 2 m × 4 m, 2 m × 8 m and 3 m × 3 m for E. camaldulensis were used as control factors. The results confirmed that diameter at breast height (D) and total height (H) were the best parameters for biomass estimation, of which the simple combination D 2 H produced the best estimation. The general allometric equations which gave the best fit ( p T. grandis was AGB = 0.045(D 2 H) 0.921 and for E. camaldulensis was AGB = 0.033(D 2 H) 0.959 . Comparison of the measured and estimated datasets showed no statistically significant differences ( p > 0.05). The range of D and H was 4.4–41.2 cm and 5.5–31.0 m, respectively, for T. grandis and 0.5–19.8 cm and 1.7–26.0 m, respectively, for E. camaldulensis .

International audience; Background and aims For a given genotype, the observed variability of tree forms results from the stochasticity of meristem functioning and from changing and heterogeneous environmental factors affecting biomass formation and allocation. In response to climate change, trees adapt their architecture by adjusting growth processes such as pre- and neoformation, as well as polycyclic growth. This is the case for the teak tree. The aim of this work was to adapt the plant model, GreenLab, in order to take into consideration both these processes using existing data on this tree species. Methods This work adopted GreenLab formalism based on source-sink relationships at organ level that drive biomass production and partitioning within the whole plant over time. The stochastic aspect of phytomer production can be modelled by a Bernoulli process. The teak model was designed, parameterized and analysed using the architectural data from 2- to 5-year-old teak trees in open field stands. Key results Growth and development parameters were identified, fitting the observed compound organic series with the theoretical series, using generalized least squares methods. Phytomer distributions of growth units and branching pattern varied depending on their axis category, i.e. their physiological age. These emerging properties were in accordance with the observed growth patterns and biomass allocation dynamics during a growing season marked by a short dry season. Conclusions Annual growth patterns observed on teak, including shoot pre- and neoformation and polycyclism, were reproduced by the new version of the GreenLab model. However, further updating is discussed in order to ensure better consideration of radial variation in basic specific gravity of wood. Such upgrading of the model will enable teak ideotypes to be defined for improving wood production in terms of both volume and quality.

International audience; Key message Teak (Tectona grandis L.f.) is one of the most important tropical hardwood tree species, which is widely planted in Indonesia. Wood properties are strongly influenced by forest management conditioning further utilization of wood.Context In Indonesia, teak wood has been supplied from the state forests (Perhutani) for long rotation teak and from community teak plantations for short rotation teak. Short rotation teak has been harvested at 7-10 years and long rotation teak at 40-60 years.Aims This paper discusses the characterization of technical properties of short and long rotation teak wood based on the chemical, anatomical, physical, and mechanical properties.Methods The properties of short rotation and long rotation teak woods were characterized by measuring their density, extractive contents, chemical composition, swelling, wettability, water sorption isotherm, decay resistance, anatomical properties, bending strength (modulus of rupture (MOR), modulus of elasticity (MOE)), and hardness.Results The results indicate that short rotation teak was not particularly different in swelling, MOE and MOR, and Brinell hardness compared to long rotation teak, although it was less dense and less durable due to lower heartwood and extractive contents. Therefore, careful attention should be given to the use of short rotation teak in some wood-processing technologies.Conclusion Lower wood density and durability of the short rotation compared to the long rotation teak will restrict its utilization to some extent for both indoor and outdoor applications. Fast-growing teak from community cannot be used as usual heartwood teak from Perhutani because of the very low proportion of useful heartwood in the stem.

This study investigated the effect of the heat treatment on the wettability of the surface of juvenile teak (Tectona grandis) wood assessed by drop shape analyzer. Heartwood and sapwood samples were heat-treated at 180 and 200ºC. Contact angle measurements were done every 5 s for 120 s using a KRÜSS DSA100. Heartwood had lower wettability than sapwood. Heat-treatment decreased the surface wettability of both heartwood and sapwood, especially in the wood treated at 200ºC. Heartwood had lower wettability than sapwood, even after heat treatment.

Há pouca informação disponível sobre a relação entre folhas e raízes de teca, cultivada no Brasil. O objetivo deste trabalho foi avaliar se a biomassa dos componentes da parte aérea e a área foliar são bons estimadores da biomassa e da superfície de raízes, em povoamentos de teca (Tectona grandis). Na amostragem, realizada em árvores de teca, com 17 e 90 meses de idade, em parcelas estabelecidas em talhões comerciais em Tangará da Serra, MT, foram individualizados os componentes raízes, folhas, galhos e tronco, determinando-se, posteriormente, suas biomassas secas, AFE (área foliar específica) e ARE (área radicular específica). A superfície da folha de uma árvore jovem é quatro vezes maior que a superfície de uma folha de árvore adulta de teca. A superfície de raízes finas (< 2 mm) das árvores adultas é quatro vezes maior que a superfície de raízes médias (2 a 5 mm). A AFE foi de 13,14 m² kg-1 e a ARE de 13,86 m² kg-1, indicando eficiência semelhante quanto à utilização do C na produção de superfícies para aquisição de radiação solar, água e nutrientes e, ainda, que há sincronia na alocação de C entre folhas e raízes finas para formação de novos tecidos foliares e radiculares. O IAF (Índice de Área Foliar) médio foi 1,2 m2 m-2, nas árvores jovens, e de 8,3 m2 m-2, nas árvores adultas. As relações entre áreas foliares e biomassas das partes aéreas com as áreas superficiais e biomassas de raízes finas e médias refletem os padrões de alocação de carbono nas árvores, até a idade em que foram avaliadas. A área foliar é um bom estimador da área superficial de raízes de teca. Made available in DSpace on 2019-02-13T23:42:40Z (GMT). No. of bitstreams: 1 2018cpamtmaurelbehlingrelacaoaerearaizespovoamentoteca.pdf: 823655 bytes, checksum: a706bffb4004acadd4af8a79612c34f0 (MD5) Previous issue date: 2019-02-13

The limited availability of fossil fuels has encouraged the need of replacement fuels of renewable nature. Among the renewable fuels, biodiesel that produced from oil seeds and food wastes has been favored by the majority of researchers. In this study, Tectona Grandis seed oil has been investigated as a non edible feedstock for biodiesel. The oil content of seed is 43% which makes it suitable for commercial production of biodiesel. The production of biodiesel from Tectona Grandis oil was done with transesterification reaction giving high percentage yield of biodiesel which reached to 89%. The Tectona Grandis biodiesel was subjected to determine various physicochemical parameters by standard testing methods and found in agreement with the ASTM D 6751 and EN 14214 standards. The fatty acid methyl ester composition for the biodiesel is composed of 42.71% oleic acid, 13.1% palmitic acid and 31.51 % linoleic acid.. The biodiesel showed low oxidation stability which is attributed to high percentage of unsaturation. To address this issue, synthetic antioxidants were added to increase its resistance towards oxidation. By considering all the parameters, present study reveals that the Tectona Grandis seed oil is reliable for the production of biodiesel with encouraging probability in future.

Background and Purpose: Nigeria is greatly endowed with numerous tree species of which majority of them are native while few are exotic. Report shows that high percentage of man-made forests in the country is dominated with exotic species. This culminated from the assumption that exotic trees are fast growing. However, this study investigated the growth of indigenous trees in tandem with that of exotic species with a purpose to clarify the assumption about the growth and conservation of indigenous species in natural forests. Materials and Methods: The study was conducted at the nursery unit of the Department of Forest Resources Management, University of Ibadan, Nigeria. Five (5) different one year old tree species seedlings were used for the study. Two of the species (Tectona grandis and Gmelina arborea) are exotic while the other three species (Khaya senegalensis, Khaya grandifolia and Afzelia africana) are native to Nigeria. They were planted on the field in a completely random design and then replicated eight times. Data were collected every month on their height growth, collar diameter and leaf number. Data obtained were subsequently analyzed with ANOVA. Results and Conclusions: Results show that K. grandifolia (45.39 cm) grew significantly better (p

No-choice feeding tests using ethanol, chloroform, and acetone extractives of teak (Tectona grandis) heartwood clearly showed feeding deterrent activity and toxicity to the subterranean termite Reticulitermes speratus. The amount of 2-methylanthraquinone (MAQ) in teak wood extractives was not related to the feeding deterrents or toxicity, as shown by the no-choice feeding tests conducted using crude extractives containing various amounts of MAQ, MAQ alone, and fractions of crude extractives. As a native pest, the subterranean termite Coptotermes formosanus was more tolerant to the fractions of crude extractives than Reticulitermes speratus, and the mortality observed in C. formosanus was not due to the presence of MAQ.

Teak has become one of the most widely planted species in tropical regions of the world, given its high price for its timber in international markets. This has motivated the development of tree improvement programs in the Latin American region and in the tropical world in general. The latest advances have achieved clonal forestry at an operational scale. Recently, important efforts are being made to advance towards the next breeding generation, since knowledge about floral biology and pollen management have become important issues. A breeding program is being developed through the Tree Improvement Cooperative GENFORES&mdash, a vinculation model between the academy and forestry companies that was initiated in Costa Rica and now involves six Latin American countries. In order to advance into the next breeding generations, building capacities in topics such as pollen banks requires pollen quality, thus enabling the exchange of pollen among cooperative members. Pollen fertility studies are of considerable value in breeding programs, in order to determine pollen viability and germination in collections of genotypes, before going into mating operational activities. In this study, we optimized pollen quality analysis protocols in terms of the viability and germination of fresh teak pollen. Results of this research show that 90% viability and 28% germination can be achieved in fresh pollen grains, both inside and outside the anther, previously dehydrated in silica gel for 2 to 4 h (40% and 33% humidity, respectively). Brewbacker and Kwack (BK) medium at 10% of its salts + 10% sucrose and at a pH of 7 must be used as the germination medium. It is possible to evaluate teak pollen quality using the parameters defined in this study, which will in turn allow pollen management and purification, providing an opportunity for carrying out controlled crosses at an operational scale as part of teak breeding programs.

Leaf-cutting ants of the genus Atta are an important insect pest in forest plantations in many countries of South America. The objective of this work was to evaluate the potential for using Landsat-8 images, with medium spatial resolution and distributed free of charge, to detect leaf-cutting ant nests in Tectona grandis plantations in Brazil, using partial least squares discriminant analysis (PLS-DA). The regression model adjusted by PLS-DA selected three principal components with a cross-validation error of 0.275 to map and predict the presence of leaf-cutting ant nests in these plantations. The most important bands and vegetation indices were selected using the main variables in the projection (VIP) and predicted pixels with the presence or absence of leaf-cutting ant nests with an accuracy of 72.3% on an independent validation data set. The study indicates that Landsat-8 OLI images have the potential to detect and map leaf-cutting ant nests in T. grandis plantations.

Tocos de árvores desbastadas de Tectona grandis apresentam rebrota intensa que compete com as árvores remanescentes. O objetivo deste trabalho foi avaliar a eficácia da aplicação isolada ou combinada de diferentes concentrações dos herbicidas picloram e triclopyr, associados ou não à aplicação de danos físicos, no controle dessas brotações. Em um povoamento com quatro anos de idade, os tocos foram tratados imediatamente após o desbaste. Em outro povoamento com seis anos, foram tratadas as brotações presentes nos tocos desbastados no ano anterior. Foi registrada a porcentagem de tocos mortos, o número de brotações por toco e as respectivas alturas. No primeiro ensaio, a aplicação combinada de picloram a 0,48% com triclopyr a 0,96%, associada a 20 rachas com machado matou todos os tocos. No segundo ensaio, a maior eficácia, 21,7%, foi registrada com roçada prévia das brotações e a aplicação de picloram a 0,96%. Após o desbaste, a aplicação isolada de picloram ou combinada com triclopyr associada ou não aos danos físicos é eficiente para controlar os brotos de teca. A aplicação nas rebrotas de tocos desbastados no ano anterior apresenta alguma eficiência, mas com menor percentual de tocos mortos em relação à aplicação após o desbaste. The stumps of thinning trees of Tectona grandis L.f. present intense sprouts that compete with the remaining trees. The efficacy of the control of sprouts with the herbicides picloram and triclopyr, associated or no it applications of physical damages, were evaluated. Immediately after thinning, in plantation with four years old, the stumps were treated, and in other plantation, with age of six, the sprouts of stumps thinned in the previous year, were treated. The percentage of died stumps, the number of sprouts by stump and the respective heights were registered. In the first trial, the combined application of picloram at 0.48% with triclopyr at 0.96%, associated a 20 cracks with axe killed all stumps. In the second trial, the best efficacy, 21.7%, was obtained with the previous mowing of sprouts and application of picloram at 0.96%. After thinning, the isolated application of picloram or combined with triclopyr, associates or not a physical damage is efficient to control sprouts of teak. The application in the sprouts of stumps thinned in the last year present any efficiency, with least percentage of dead stumps in relation to application after thinning.

A new naphthoquinone derivative was isolated from the heartwood of the teak stem. The chemical structure of this new compound, 40,50-dihydroxy-epiisocatalponol, was determined using 1-D and 2-D nuclear magnetic resonance experiments, vibrational circular dichroism, HRMS, and optical rotation. We showed that this new naphthoquinone derivative plays a key role in the variability of decay resistance in teak wood. A high negative correlation was found between its concentration and the mass losses of the wood samples after exposure to the brown rot Antrodia sp., the fungus that is the most virulent against teak (R ¼ _0.9; r < 0.0001). In-vitro bioassays allowed us to demonstrate that 40,50-dihydroxyepiisocatalponol acted as a fungicide against Trametes versicolor (white rot) at 58 mg ml-1 (0.22 mM). Overall, our results demonstrated that the concentration of 40,50-dihydroxy-epiisocatalponol could be used as a new tool to evaluate teak wood durability.

A phytochemical study on the most bioactive extract from Tectona grandis led to the isolation of two new norlignans, tectonoelin A and tectonoelin B, together with ten known compounds. The structures of the compounds were determined by a combination of 1D and 2D NMR techniques. This is the first time that this type of compound (C8–C8′ linkage norlignans) has been isolated from a dicotyledon. The general bioactivities of the isolated compounds have been studied using etiolated wheat coleoptiles. The activities showed that the isolated lignans and norlignans should be part of the defence mechanisms of this plant.

Se modelaron cinco funciones no segmentadas de conicidad para Tectona grandis, especie forestal que ha incrementado notoriamente su área plantada en la zona costera ecuatoriana y donde se desconocen formulaciones de este tipo. Se realizó un proceso de regresión no lineal por el método de máxima verosimilitud a una muestra de 125 árboles y se evaluó su ajuste. Posteriormente, se hizo un proceso de validación independiente, se aplicaron pruebas no paramétricas y un análisis por altura relativa, para identificar fortalezas y debilidades en cada parte del fuste. La función polinomial de quinto grado presentó el mejor ajuste (Sesgo Absoluto = 1.009, Índice de Ajuste = 0.962), por ello se calculó la forma integrada de esta ecuación. Se espera que estos modelos desarrollados y sus bondades de aplicación puedan ser de utilidad para la comunidad forestal ecuatoriana.

A 27 year old clonal seed orchard of teak (Tectona grandis L.f ) in Padangan, East Java comprising 24 clones, was evaluated for fertility, offspring diversity, and genetic drift. Flower and fruit productions were used to assess clone fertility in the orchard. Fertility variation measured as ‘sibling coefficient’ was found to be 1,62, having high genetic diversity (0,97) and low coancestry (0,03). The clones varied in fertility in which, 25 % of the most fertile clones in the orchard contributed to 47,5 % of flower and fruit yields. Effective population size in the orchard was 15, indicating that 15 of the clones contributed effectively to seed yield. Separating on the amounts of seeds that can be collected, individual collection, and proportional mixing of seed per clone might be useful in restricting over representation of highly reproductive clones thereby increasing genetic diversity in the seed crop. Another way to improve seed yield in the orchard is by increasing the effective population size. Thinning or prunning on highly reproductive clones might be useful in increasing effective population size.

International audience; 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 micro- satellite 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 conser- vation of teak forest diversity is discussed

Este estudo foi realizado com os objetivos de ajustar e avaliar modelos de crescimento e produção para plantio de teca (Tectona grandis), localizados na região de Tangará da Serra, MT, com idades inferiores a 6 anos. Para isso, foram utilizados dados provenientes de 50 parcelas permanentes com pelo menos cinco medições sucessivas. Após as análises, verificou-se que o modelo alternativo se apresentou mais preciso do que o de Clutter (1963). The objective of this study was to adjust and evaluate growth and yield models for young stands of Tectona grandis (aged less than 6 years), located in Tangará da Serra, Mato Grosso, Brazil. Thus, 50 permanent plots with at least five successive measurements were used. After the analysis, it was verified that the alternative model is more precise than the Clutter´s model.

Tectona grandis is an important wood in the commercial market due to its excellent workability, durability and aesthetic characteristics. Therefore, it is important to improve the conditions of reproduction and development in commercial plantations using clone reproduction, in order to produce trees with better wood quality. In this study we analyzed the general properties, physical properties and color of 20 adult teak clones (fifteen-year-old) from the area of Guanacaste, Costa Rica. It was found that at 15 years, the clones have a diameter which varies from 19.82 cm to 30.13 cm, the percentage of heartwood ranges from 49.76 to 60.02%, and that these values are similar to those found in the literature. In regards to the physical properties, it was found that the specific gravity ranges from 0.45 to 0.60 g.cm-3, the green moisture content varies from 70% to 110.6%. In the color properties, it was found that L* values ranged from 48 to 59, a* 7 to 9.5 and b * from 20.5 to 26.3. Likewise it was determined that the color change (ΔE*) compared to commercial wood color, is commonly categorized as perceptible in all clones. However, three of the clones studied have a darker color and reddish wood which indicates a color more desirable to the end user. RESUMO A madeira de Tectona grandis é importante no mercado devido às suas excelentes características de trabalhabilidade, durabilidade e estética. Por isso é importante melhorar as condições de reprodução e do desenvolvimento das plantações comerciais utilizando clones com o objetivo de produzir árvores produtoras de madeira de boa qualidade. No presente estudo foram estudadas as propriedades gerais, físicas e a coloração da madeira de 20 clones de teca (20 anos de idade) da região de Guanacaste, Costa Rica. Os resultados indicaram que clones no 15º ano atingem um diâmetro do tronco variando de 19,82 a 30,13 cm e a porcentagem de cerne de 49,76 a 60,02 %, ambas em valores similares aos reportados na literatura. Em relação às propriedades físicas da madeira, verificou-se que a massa especifica varia de 0,45 a 0,60 g.cm-3, o teor de umidade na condição verde de 70 a 110,6%. Em relação à cor da madeira, os valores de L* variaram de 48 a 59, a* de 7 a 9,5 e b* de 20,5 a 26,3. Determinou-se que a coloração da madeira (ΔE*) em relação à da madeira comercial é comumente categorizada como perceptível para todos os clones. Entretanto, três dos clones estudados apresentaram madeira mais escura e tonalidade avermelhada que indica ser a coloração mais apreciada do usuário final.

Tree mono-plantations are susceptible to soil nutrient impoverishment and mixed species plantations have been proposed as a way of maintaining soil fertility while enhancing biodiversity. In the Solomon Islands, mixed species plantations where teak (Tectona grandis) is inter-planted with a local tree species (Flueggea flexuosa) have been used as an alternative to teak mono-plantations and are expected to increase soil microbial diversity and modify microbial biogeochemical processes. In this study, we quantified the abundance of microbial functional genes involved in the nitrogen (N) cycle from soil samples collected in teak, flueggea, and mixed species plantations. Furthermore, we measured soil properties such as pH, total carbon (C) and total N, stable N isotope composition (δ(15)N), and inorganic N pools. Soil pH and δ(15)N were higher under teak than under flueggea, which indicates that intercropping teak with flueggea may decrease bacterial activities and potential N losses. Higher C:N ratios were found under mixed species plantations than those under teak, suggesting an enhancement of N immobilization that would help preventing fast N losses. However, inorganic N pools remained unaffected by plant cover. Inter-planting teak with flueggea in mixed species plantations generally increased the relative abundance of denitrification genes and promoted the enrichment of nosZ-harboring denitrifiers. However, it reduced the abundance of bacterial amoA (ammonia monooxygenase) genes compared to teak mono-plantations. The abundance of most denitrification genes correlated with soil total N and C:N ratio, while bacterial and archeal nitrification genes correlated positively with soil NH4 (+) concentrations. Altogether, these results show that the abundance of bacterial N-cycling functional guilds vary under teak and under mixed species plantations, and that inter-planting teak with flueggea may potentially alleviate N losses associated with nitrification and denitrification and favor N retention. Mixed plantations could also allow an increase in soil C and N stocks without losing the source of income that teak trees represent for local communities.

O presente trabalho, conduzido no Município de Sinop, Estado de Mato Grosso, teve por objetivo avaliar a circunferência, a altura total e a produção de biomassa de plantas de Tectona grandis, em diferentes densidades populacionais, obtidas com diferentes espaçamentos e arranjos de plantio. Foram avaliados os espaçamentos de 3x2 m, 3x3 m, 4x3 m, 4x4 m, 5x3 m, 5x4 m e 5x5 m, com densidades populacionais que variaram de 400 a 1.666 plantas por hectare. Selecionaram-se três árvores por tratamento, constituindo a individualização dos componentes folhas, galhos e tronco. O experimento teve duração de 76 meses. O aumento da densidade populacional promoveu diminuição na circunferência das plantas de teca, enquanto a altura permaneceu constante. No espaçamento mais denso, a produção de biomassa total da parte aérea teve aumento nas plantas de tectona grandis, concentrando-se principalmente no tronco da árvore. This work was carried out in the municipality of Sinop, State of Mato Grosso with the objective of evaluating the circumference, total height and biomass production of Tectona grandis plants, in different population densities, obtained with different spacings and planting arrangements. The spacings 3x2 m, 3x3 m, 4x3 m, 4x4 m, 5x3 m, 5x4 m and 5x5 m, were evaluated with the population density varying from 400 to 1.666 plants / hectare. Three trees were selected per treatment, with the individualization consisted of leaves, branches and trunk components. The experiment lasted for 76 months. The increase in population density caused a decrease in teak tree circumference, whereas the height was constant. There was increase in total biomass production of the aerial part of the Tectona grandis plants in the denser spacings, concentrated mainly in the tree trunk.

Os objetivos deste estudo foram desenvolver e avaliar quantitativamente um modelo de distribuição diamétrica para manejo de povoamentos desbastados de teca (Tectona grandis L. f.). A construção do modelo envolveu dados provenientes de uma rede de parcelas permanentes instaladas em povoamentos de teca, no Estado do Mato Grosso, de propriedade da empresa Floresteca Agroflorestal Ltda. Foram empregadas 239 parcelas permanentes, com área útil de 490,8 m2. O primeiro desbaste foi realizado aos 58 meses (idade média) e consistiu na redução sistemática de 36% do número de árvores, em média. A recuperação da distribuição diamétrica foi feita a partir de equações que compreendem relações lineares e não-lineares entre os parâmetros da função Weibull em uma idade futura (b2 e g2) e os parâmetros em uma idade atual (b1 e g1) e com características do povoamento em uma idade atual e futura. Foram avaliados três sistemas de equações. Para verificar a consistência dos sistemas, foram realizadas análises de compatibilidade de cada sistema e de identidade entre eles. O sistema selecionado garantiu a propriedade de que, quando a idade futura (I2) é igual à idade atual (I1), a distribuição diamétrica na idade futura é igual à distribuição diamétrica na idade atual. Pôde-se concluir que o modelo é compatível e indicado para manejo de povoamentos de Tectona grandis submetidos a desbaste. Concluiu-se também que a predição dos parâmetros da função Weibull, em uma idade futura, em função dos parâmetros observados em uma idade atual, é lógica e gera estimativas consistentes e precisas. The objective of this study was to develop and quantitatively evaluate a diametric distribution model for the management of thinned teak (Tectona grandis L. f.) stands. Model construction involved data from a net of permanent plots established in teak stands, in Mato Grosso State, Brazil, owned by Floresteca Agroflorestal Ltda. A total of 239 permanent plots with a mean area of approximately 490.8 m2 were used. The first thinning was carried out at 58 months (mean value) and consisted in the systematically reduction in approximately 36% of the tree number . The recovery of the diametric distribution was taken from equations comprising linear and non-linear relations between the Weibull function parameters at a future age (b2 and g2) and the parameters at a present age (b1 and g1), and stand characteristics in a present and a future age. Three equations systems were analyzed. Compatibility analyses of each system and identity among them were performed oo verify the consistence of the systems. The selected system guaranteed the property in which if the future age (I2) is equal to the present age (I1), the diametric distribution in the future age is equal to the diametric distribution in the present age. It was concluded that the model is compatible and recommended for thinned stands of Tectona grandis. It was also concluded that the prediction of the Weibull function parameters at a future age in function of the parameters observed at a present age is logical and generates consistent and accurate estimates.

Background Well known as teak, Tectona grandis is widely used in African folk medicine for its pharmacological relevance. In Cameroon, this species is a reputed laxative in the Northern Region while in the Western Region, it is used in the treatment of skin diseases and diarrhoea. Materials and methods Separation and isolation of compounds were performed using different chromatographic methods while their structures were elucidated by spectroscopic techniques including MS and NMR, and by comparison of data with those reported in the literature. Isolated compounds as well as crude ethanol extract were tested for their antibacterial activities using broth micro-dilution method against four Gram negative bacteria strains Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (PA 01), Klebsiella pneumonia (ATCC 11296) and Escherichia aerogenes (ATCC 13048). Results Three known compounds were isolated, including two quinones and one triterpene. They were identified as tectograndone (1), 6-methyl-1,4-dihydroxyanthraquinone (2), and 2β-hydroxyursolic acid (3) respectively. Crude ethanol extract showed good activity against the bacteria strains tested with MIC of 64–256 μg/mL. Among the isolated metabolites, 6-methyl-1,4-dihydroxyanthraquinone exhibited a strong activity against Escherichia aerogenes with MIC of 16 μg/mL, while tectograndone showed a moderate activity against Escherichia coli with MIC of 32 μg/mL. The antibacterial screening of the fruits of this plant as well as that of compounds 1 and 2 is reported herein for the first time. Conclusion The research work presented here shows that Tectona grandis fruits possess compounds which could be developed in the treatment of bacterial diseases.

O conhecimento das características do sistema radicular auxilia na definição de práticas de preparo de solo e fertilização. O objetivo deste trabalho foi estimar a biomassa, o conteúdo de nutrientes em raízes, o comprimento e a área de raízes finas e médias e a eficiência de utilização de macronutrientes da teca (Tectona grandis) para formação de área radicular em diferentes profundidades do solo. A separação das raízes do solo foi feita estratificando-as em grossas (>5 mm), médias (2 a 5 mm) e finas (< 2 mm), para determinação de N, P, K, Ca, Mg e S. As raízes médias e finas (± 0,5 g) foram digitalizadas e quantificadas por intermédio do programa QuantRoot®, obtendo-se o diâmetro, a área e o comprimento. A biomassa total de raízes finas e médias foi de 1.335 e 1.258 kg ha-1 respectivamente, e 56,2% das raízes finas e 44,4% das raízes médias concentram-se nos primeiros 20 cm do solo. O comprimento total de raízes finas foi de 8.237 km ha-1, com 57,4% nos primeiros 20 cm de profundidade. A superfície total de raízes finas foi de 18.441 m² ha-1, com 57% dessa superfície nos primeiros 20 cm do solo. A quantidade total de nutrientes nas raízes, na camada de solo estudada (0-60 cm), em ordem decrescente, foi K > Ca > N > Mg > P > S. O fósforo e o enxofre são os nutrientes com maior eficiência de utilização para formação de área radicular em plantios de teca. Knowing root system characteristics aids in the definition of practices of soil preparation and fertilization. The objective of this work was to estimate the biomass, root nutrient content, fine and medium roots length and area and the macronutrient use efficiency for the teak (Tectona grandis) regarding the formation of roots area in different soil depths. The separation of roots from the soil was made stratifying them in thick (> 5 mm), medium (2 to 5 mm) and fine roots (< 2 mm), for N, P, K, Ca, Mg and S determination. Medium and fine roots (± 0.5 g) were scanned and quantified by the QuantRoot® program, generating the diameter, area and length. The total fine and medium roots biomass was of 1.335 and 1.258 kg ha-1, respectively, with 56.2% of the fine roots and 44.4% of the medium roots concentrated in the 0-20 cm layer. The total fine roots length was 8.237 km ha-1 with 57.4% in the first 20 cm depth. The total fine roots surface was 18.441 m2 ha-1, with 57% of this surface in the first 20 cm of soil. The total amount of nutrients in the roots, in the studied soil layer (0-60 cm), in decreasing order, was K > Ca > N > Mg > P > S. Phosphorus and sulfur are the nutrients with higher use efficiency for roots area formation in teak stands.