Search Results (7)

Tannin-boron (TB) treatment is an effective method for enhancing the biological resistance of some types of wood, although knowledge regarding its efficacy as a preservative in a wider range of wood is limited. In this study, we investigated the effects of TB treatment on the mechanical and microscopic properties, and on biological resistance of six types of wood (Pinus massoniana Lamb., Cunninghamia lanceolata (Lamb.) Hook, Pseudotsuga menziesii (Mirb.) Franco, Intsia bijuga (Colebr.) Kuntze, Tectona grandis L. f., and Quercus mongolica Fisch. ex Ledeb.). The results showed that the six types of wood exhibited different boron retention after leaching, with the highest retention rate, 21.85%, observed in P. massoniana. The TB treatment did not significantly alter the original density and compressive strength of the wood, except in the case of I. bijuga, where the compressive strength significantly decreased after treatment. Scanning electron microscopy revealed that TB preservative is attached around the tracheids of softwood, or deposited within the vessels of hardwood. No-choice feeding tests showed that the TB-treated wood exhibited high resistance to Coptotermes formosanus with a maximum weight loss of 2.5%. TB treatment significantly improved the resistance of P. massoniana, C. lanceolata, P. menziesii, and T. grandis to Trametes hirsuta. These results demonstrate the potential usefulness of TB preservatives in different wood types. Full article

Teak (Tectona grandis L.f.) is a leading tropical plantation species valued for high-quality timber and carbon (C) storage. This study assessed stand growth across ages and sites, quantified biomass and C by tree component and stand, and developed DBH-based allometric equations for biomass and C estimation. Six stand ages (5, 6, 9, 11, 14, and 17 years) were assessed in three municipalities of Nayarit, Mexico. Dendrometric inventories in permanent plots and destructive sampling of 35 trees provided calibration data for leaves, branches, stem, and roots. C concentration was determined with an elemental analyzer, and nonlinear regression models were adjusted and validated. Stand biomass and C increased with age, peaking at ages 11–14 (>130 Mg ha⁻¹; >60 Mg C ha⁻¹), with lower values at age 17. San Blas and Rosamorada accumulated significantly more than Tuxpan, reflecting site quality. C concentration was stable across sites and ages, with stem and roots consistently ranging between 48% and 50%, and leaves and branches averaging 45%–46%. Allometric equations were most accurate for stem and total biomass/C (R² = 0.73–0.79), while foliage showed higher variability. On average, 60%–70% of biomass was allocated to the stem and 15%–20% to roots. Indicators were stable, with an aboveground-to-belowground ratio (A:B) ≈ 4.9 and a biomass expansion factor (BEF) ≈ 1.5. The current annual increment (CAI) presented two main peaks: ~20 Mg ha⁻¹ yr⁻¹ at ages 5–6 and ~11 Mg ha⁻¹ yr⁻¹ at ages 9–11, followed by a decline after age 14. Teak in western Mexico reaches peak productivity at ages 6–11, with belowground biomass essential for accurate C accounting. Full article

High-value-added biomolecules such as phenolic compounds and flavonoids from secondary metabolism and macromolecules such as sugars are the main constituents of several plants. Thus, this work aims to optimize the extraction of these biomolecules present in the pods of Cassia grandis L.f. Initially, the effect of choline-based ionic liquids—ILs (choline chloride [Ch]Cl, dihydrogen citrate [Ch][DHC], and bitartrate [Ch][BIT]) as extracting agents for phenolic compounds and flavonoids was evaluated based on their efficiency and selectivity. Then, a 2³ full factorial design with six central points was performed using the IL concentration, the solid–liquid ratio, and the temperature as independent variables. The extract obtained in the best condition was subjected to pervaporation, after which the concentrates and the crude extract were used to determine the physical properties (density, viscosity, and refractive index). The hydrophobic–hydrophilic balance of the extracting agent and the biomolecules are the extraction process’s driving force. The best extraction condition was formed by [Ch][DHC] at 15 wt%, with a solid–liquid ratio of 1:15, at 45 °C for 30 min, resulting in 153.71 ± 5.81 mg·g⁻¹ of reducing sugars; 483.51 ± 13.10 mg·g⁻¹ of total sugars; 11.79 ± 0.54 mg·g⁻¹ of flavonoids; and 38.10 ± 2.90 mg·g⁻¹ of total phenolic compounds. All the physical properties of the biomolecules are temperature-dependent; for density and refractive index, a linear correlation is observed, while for viscosity, the correlation is exponential. Increasing the temperature decreases all properties, and the extract concentration for 8× presents the highest values of density (1.283 g·cm⁻³), viscosity (9224 mPa·s), and refractive index (1.467). Full article

The potential to sequester carbon by tree species in tropical regions such as Bangladesh is promising in regard to carbon sequestration (CS) potentiality and reducing CO₂ emissions. This study focuses on perennial tree species within 488 hectares of Bangladesh Agricultural University (BAU) to assess the CS and to produce a C stock map for BAU. To compute the green and dry weight, weight of C and CO₂ sequestration in the tree, a simplified methodology from the National Computational Science Institute of the Shodor Education Foundation was applied. A total of 27,543 trees comprising 424 species were taken into consideration, dividing the whole study area into four segments. B. ceiba and L. acidissima received the maximum and minimum green, dry, and C weight values. The topmost five carbon stock accumulating trees are M. longifolium (264,768 kg yr⁻¹), S. mahagoni (257,290), A. lebbeck (118,310), M. indica (78,906), and T. grandis (51,744) whilst A. lebbeck is the major C stock accumulating tree within BAU. The top five CS potential are found for B. ceiba (181 kg), A. columnaris (139 kg), S. siamea (116 kg), F. elastica (113 kg), and F. religiosa (83 kg). To reveal the prospects of tree species in Bangladesh for emission reduction, the CS potential could be incorporated with the C trading scheme of the CDM (clean development mechanism) of the Kyoto Protocol. Full article

Limited agricultural land areas combined with increasing demands for food require breakthroughs in land use development using agroforestry systems. Intercropping root crops with trees could be an alternative for food production in forest areas. This study aimed to assess the feasibility of cocoyam (Xanthosoma sagittifolium (L.) Schott) farming on dry land within 12- and 42-year-old teak (Tectona grandis L.f.) forests to support local food security. The feasibility assessment took into account both productivity and socio-economic aspects. The agroforestry land productivity was measured using the land equivalent ratio (LER), and our analysis of the cocoyam farming within the teak stands was carried out using the revenue/cost ratio (R/C) at the demonstration plot scale. Furthermore, we also surveyed farmers’ perceptions of the production of cocoyam for food security. The results showed that the R/C values of cocoyam tuber production in agroforestry systems were lower than 1. However, the production rates of cocoyam tubers in the 12-year-old teak stand (48.3% light intensity) and the 42-year-old teak stand (62.5% light intensity) were 2.64 and 2.76 tons/ha, respectively. The overall yields from the teak and cocoyam agroforestry systems were more profitable than those of the monoculture system, as indicated by the LER values of 1.61 and 1.85. Cocoyam production was socially acceptable (77% of respondents) as a smallholder subsistence agroforestry practice to meet food demand. Increasing cocoyam productivity in teak forests requires the adoption of agroforestry silvicultural technology to achieve food security for rural communities. To increase their farming production and income, farmers could apply intensive silvicultural practices. Governmental support that could be provided includes encouraging product diversification and providing assistance for the processing and marketing of cocoyam products. Full article

The inter-annual variability in tree-ring cellulose δ¹³C (δ¹³C_TR, δ¹⁸O_TR), and tree-ring chronology in teak (TRW) (Tectona grandis L.f.) trees from Northwestern Thailand during 1901–2009 AD was performed. The δ¹³C_TR and δ¹⁸O_TR have a positive correlation, significant at r =0.400, p <0.0001, and both of the stable isotopes were not significantly related to the TRW. The TRW is related to rainfall in the first half of the rainy season and has a strong relationship with the relative humidity. The δ¹⁸O_TR captured moisture well throughout the rainy season, and the δ¹³C_TR had a strong correlation with rainfall in the second half of the rainy season and had a high correlation with cloud fraction and vapor pressure. The δ¹³C_TR and δ¹⁸O_TR were associated with the stomata conductance response, but had no effect on photosynthesis. The three indices of the teak annual ring respond well to the variability in the Asian monsoon, and give us a better understanding of both the hydrological cycle and the factors that contribute to the growing of tropical broadleaf trees under changing climates. Full article

Tropical reforestation initiatives are widely recognized as a key strategy for mitigating rising atmospheric CO₂ concentrations. Although rapid tree growth in young secondary forests and plantations sequesters large amounts of carbon (C) in biomass, the choice of tree species for reforestation projects is crucial, as species identity and diversity affect microbial activity and soil C cycling via plant litter inputs. The decay rate of litter is largely determined by its chemical and physical properties, and trait complementarity of diverse litter mixtures can produce non-additive effects, which facilitate or delay decomposition. Furthermore, microbial communities may preferentially decompose litter from native tree species (homefield advantage). Hence, information on how different tree species influence soil carbon dynamics could inform reforestation efforts to maximize soil C storage. We established a decomposition experiment in Panama, Central America, using mesocosms and litterbags in monoculture plantations of native species (Dalbergia retusa Hemsl. and Terminalia amazonia J.F.Gmel., Exell) or teak (Tectona grandis L.f.) to assess the influence of different litter types and litter mixtures on soil C dynamics. We used reciprocal litter transplant experiments to assess the homefield advantage and litter mixtures to determine facilitative or antagonistic effects on decomposition rates and soil respiration in all plantation types. Although litter properties explained some of the variation in decomposition, the microclimate and soil properties in the plantations also played an important role. Microbial biomass C and litter decomposition were lower in Tectona than in the native plantations. We observed non-additive effects of mixtures with Tectona and Dalbergia litter on both decomposition and soil respiration, but the effect depended on plantation type. Further, there was a homefield disadvantage for soil respiration in Tectona and Terminalia plantations. Our results suggest that tree species diversity plays an important role in the resilience of tropical soils and that plantations with native tree species could help maintain key processes involved in soil carbon sequestration. Full article