Search Results (20)

Melina (Gmelina arborea Roxb.) is a tree native to Asia, whose timber is not utilized in that region for a variety of reasons. However, the tree’s fast growth and extensive range of applications have increased its acceptance in other world’regions. G. arborea was introduced to Mexico in 1971, and it is currently the fifth most utilized forest species in commercial forest plantations (CFPs). However, its genetic diversity has not been evaluated in Mexico. The objective of this research was to investigate the genetic variability of Melina in Mexico using molecular markers. This investigation was undertaken to acquire valuable insights for the implementation of effective improvement strategies. A total of 85 Melina samples were collected from various locations in southeastern Mexico between 2017 and 2022. Genetic fingerprints were obtained using ten simple primer amplification reactions (SPARs): five Directed Amplification of Minisatellite DNA regions (DAMD), and five Inter-Simple Sequence Repeats (ISSRs). The polymorphic information content (PIC) was 0.940 and 0.950 for the DAMD and ISSR, respectively, and the similarity coefficients ranged from 0.12 to 0.88, indicating a high degree of polymorphism in the species under investigation. This is the first attempt to ascertain the genetic variability of Gmelina arborea in Mexico. Full article

Effective forest management strategies to adapt to climate change are essential. Water use efficiency (WUE), which integrates biomass production and water consumption, is a key indicator of forest adaptation. This study evaluated the WUE of Gmelina arborea plantations in the tropical dry forest and identified the main influencing factors, with implications for silviculture and management. Data on total biomass (TB) and total volume (V) were obtained from permanent sample plots in the upper and lower Magdalena River basin in Colombia. WUE was calculated as m³ of V (WUE_V) or kg of TB (WUE_TB) per m³ of evapotranspired water. Significant regional differences were found, with higher WUE in the Caribbean plains (WUE_TB = 1 kg m⁻³ and WUE_V = 0.0018 m³ m⁻³) compared to the inter-Andean valleys (WUE_TB = 0.77 kg m⁻³ and WUE_V = 0.013 m³ m⁻³). Stand variables had the greatest influence on WUE, showing positive associations with site productivity and stand density measures. Soil variables such as texture, available water, and calcium content, along with a drier climate, were crucial for achieving higher WUE. The study underscores the importance of comprehensive site selection and effective silvicultural practices to maximize WUE and productivity, especially in the context of climate change. Full article

Costa Rica produces a considerable, important quantity of wood residues. This waste can be pyrolyzed to produce charcoals as main products that can be effectively used as an energy source or to immobilize carbon for soil treatment. However, there is a lack of information about the pyrogenic carbonaceous materials (PCMs), such as charcoal or biochar, obtained at different pyrolysis temperatures. Hence, this study aimed to evaluate the quality of PCMs (physical, mechanical, ultimate analysis, and FTIR analysis) and charcoal characteristics (energetic properties and thermogravimetric analysis—TGA) and biochar characteristics (conductivity, pH, initial contact angle, and wetting rates) for four tropical wood residues produced in five temperatures (300 °C, 350 °C, 400 °C, 450 °C, and 500 °C). In general, pyrolysis temperature between 450 °C and 500 °C produced charcoals with lower values of density, moisture content, compression strength, volatiles, H and O content, and higher values of C and ash contents, conductivity, pH, initial contact angle, and wetting rates. FTIR and TGA analyses show that celluloses and lignin are pyrolyzed at these temperatures, so these temperatures are recommended. The range of 300–350 °C is not recommended, as these parameters were inverse. Multivariate analysis shows that (i) PCMs obtained at lower temperatures (300–350 °C) from Dipteryx panamensis, Hieronyma alchorneoides, and Tectona grandis belong to a cluster with poorer properties, indicating that these temperatures are not adequate for pyrolysis of these species; (ii) all the PCMs obtained from Gmelina arborea were grouped into one cluster, suggesting different PCM quality; and (iii) the PCMs produced from D. panamensis, H. alchorneoides, and T. grandis at 400–500 °C were grouped into another cluster with better properties, suggesting this pyrolysis temperature range as the best for these species. Full article

Livestock supplementation with forage trees is becoming a sustainable alternative to traditional grazing on the open pastures during the dry season in Benin. However, little is known about the feeding preferences of sheep and the digestibility of such native tree/shrub fodder. Such knowledge could improve their use on smallholder farms. Multiple-choice feeding preference tests were conducted on six tree fodders (Annona senegalensis, Blighia sapida, Cassia sieberiana, Gmelina arborea, Khaya senegalensis, and Mangifera indica) to determine the best choice to feed the local rams and ewe Djallonke sheep. The cafeteria test involved four rams and four ewes. In addition, an in vivo trial using metabolic cages was conducted to evaluate the voluntary intake of dried woody leaves and the dry matter digestibility of diets containing these dried leaves. Preferences varied significantly (p ≤ 0.05) according to the woody species. Based on relative intake values, sheep preferred, in decreasing order, the leaves of M. indica, B. sapida, K. senegalensis, G. arborea, A. senegalensis, and C. sieberiana. The apparent digestibility of dry matter was highest (p ≤ 0.01) in the G. arborea diet (86.8%); all diets presented a value higher than 70%. This study provided helpful information about better resource utilization to improve animal productivity. Further study could evaluate the growth performance of sheep supplemented with tree fodder. Full article

This study focused on the thermal modification of Gmelina arborea Roxb. wood following processes using the open reactor and low-pressure closed reactor systems. The aim is to determine the optimum treatment conditions suitable for gmelina wood due to its poor drying characteristics using the low-pressure closed reactor thermal modification. Subsequent to thermal modification under both processes, the dimensional stability and mechanical properties of gmelina wood were investigated. Effects of the thermal modifications under the open and low-pressure closed reactor systems on mechanical properties were additionally reported. The outcome of this investigation revealed that mass loss increased with increasing treatment temperatures, but minimal mass losses were observed for samples modified in the low-pressure closed reactor system. Due to the low-pressure regime used in the closed reactor system, a lesser improvement was found in volumetric shrinkage, fibre saturation point and tangential-to-radial swelling compared to the improvement in these properties in the open reactor system. Results further revealed that the mechanical properties of gmelina wood deteriorated more rapidly after modification in the open reactor system. Since the properties of modified gmelina wood are comparable at 180 °C under both systems, the closed reactor system will be investigated further to arrive at a suitable treatment condition under higher pressure variations. The thermal modification of gmelina wood with the closed reactor system is more promising in delivering a better quality of modified gmelina wood. Full article

At present, there is a high demand for carbon (C) sequestration alternatives; thus, understanding tree growth and the efficacy of remote sensing techniques to capture forest plantation ecophysiology is crucial. This study evaluated the effect of contrasting stockings of Gmelina arborea on its initial growth and aboveground Carbon stock, and the efficacy of aerial images obtained using drones to capture the crown cover at different stockings. The results indicated that denser stockings showed greater tree heights and stem diameter increments, contrary to traditional measurements. The C storage capacity of Gmelina arborea was promising, with an aboveground estimated C stock of about 13 Mg ha⁻¹ in 9 months, making it a valuable and promising species for CO₂ sequestration under the context of climate change. The use of simple Red-Green-Blue (RGB) cameras and drones to detect and estimate crown areas in young plantations was mainly viable within the commercial range of stockings (500–2000 trees ha⁻¹), and can be used as a powerful tool to better understand tree initial growth. The results showed effective discrimination without weeds independently of the stocking level; however, when weeds were present, the effectiveness decreased. This research provides valuable insights into forest management and improves the understanding of the silviculture behavior of a potential native species for reforestation in the tropics. Full article

Uncertainties continue to prevail in the potential of natural forests and plantations in carbon stock assessment. The present study was carried out to assess the carbon stock in natural and plantation forests of Manipur using geo-informatics in Imphal East and West districts. The integrated approach of geospatial technology, along with field inventory based data, was used in spatial modeling of biomass carbon of selected natural and plantation forests. The stand density was similar for both LNG and TRS forests (680 individuals ha⁻¹) and lowest for KHP forest (640 individuals ha⁻¹). Paulownia fortunei (770 individuals ha⁻¹) showed highest density among tree species while Tectona grandis (54.07 m² ha⁻¹) followed by Gmelina arborea (42.18 m² ha⁻¹) had higher basal area compared to other tree species. The soil moisture content (%) in the natural forest ranged from 19.13 ± 0.47 to 26.9 ± 0.26%. The soil moisture content in the plantation forest ranged from 19.16 ± 0.98 to 25.83 ± 0.06%. The bulk density of natural forests ranged from 1.27 g cm⁻³ to 1.37 g cm⁻³ while for plantation forests it ranged from 1.18 g cm⁻³ to 1.34 g cm⁻³. Among the studied sites of natural forest, TRS forest had both the highest AGBC value of 132.74 t ha⁻¹ as well as the BGBC value of 38.49 t ha⁻¹. Similarly, among the plantations, T. grandis plantation showed the highest AGBC (193 t ha⁻¹) and BGBC (55.97 t ha⁻¹). On the other hand, Tharosibi forest and T. grandis plantation had the highest total carbon stock for natural and plantation forest with values of 274.824 t ha⁻¹ and 390.88 t ha⁻¹, respectively. The total above-ground carbon stock estimated for the natural forest of KHP, LNG and TRS were 109.60 t ha⁻¹, 79.49 t ha⁻¹ and 132.74 t ha⁻¹, respectively. On the other hand, the estimated total above-ground carbon stock in plantation of GA, PD, PF and TG were 62.93 t ha⁻¹ 62.81 t ha⁻¹, 45.85 t ha⁻¹ and 193.82 t ha⁻¹. In the present study, the relationship with the biomass was observed to be better in SAVI compared to NDVI and TVI. The linear regression analysis performed to determine the relationship between the estimated and predicted biomass resulted in a correlation coefficient of R² = 0.85 for the present study area, which is an indication of a good relationship between the estimated and predicted biomass. Full article

Climate change, land degradation, and desertification lead to the loss of carbon present in the soil and plants. The carbon dioxide (CO₂) concentration in the atmosphere has reached 412 ppm. This is a rise of 47% since the start of the industrial period, when the concentration was close to 280 ppm. Therefore, the sequestration of carbon from the atmosphere to earth is the need of the hour. Many scientists have suggested agroforestry as a potent instrument for climate change mitigation as well as to fetch lucrative benefits. The Indian government is also promulgating tree-based systems for increasing tree cover up to 33% of the total geographical area to mitigate climate change. Therefore, the expansion of the commercial agroforestry system of fast-growing tree species producing higher biomass could be a sustainable and ecologically benign technique to sequester carbon, increase green cover, and improve the financial status of farmers. This review highlights the commercial agroforestry systems, biomass and carbon sequestration potential, and case studies of poplar and eucalyptus. The species such as poplar (Populus deltoides), nilgiri (Eucalyptus spp.), subabul (Leucaena leucocephala), tree of heaven (Ailanthus excelsa), willow (Salix spp.), malabar neem (Melia dubia), cadamba (Neolamarckia cadamba), and white teak (Gmelina arborea) are the suitable tree species for carbon sequestration under agroforestry. Among these species, poplar and eucalyptus are major agroforestry tree species that have been adopted by millions of farmers in India since the 1990s. Indo-Gangetic plains are considered the birthplace of commercial or industrial agroforestry, as poplar and eucalyptus are widely planted. This review reports that poplar and eucalyptus have the potential to sequester carbon stock of 212.7 Mg C ha⁻¹ and 237.2 Mg C ha⁻¹, respectively. Further, the net carbon sequestration rate in poplar and eucalyptus was 10.3 and 12.7 Mg C ha⁻¹ yr⁻¹, respectively. In conclusion, the commercial agroforestry system was very successful in the Indo-Gangetic regions of the country but needs further expansion with suitable compatible crops in different parts of the country. Full article

The success of any wood treatment process and the measure of protection conferred on treated wood are determined by the uptake and penetration of the treatment chemicals, in addition to the efficacy of the chemicals used for the treatment. Hence, the level of treatability of wood species should be pre-determined prior to the wood treatment to ensure the overall protection of the treated wood. Gmelina arborea wood, due to its low durability, requires impregnation with chemicals for preservation or chemical modification to enhance its durability. However, more details are required to establish the influence of its anatomy on impregnation to recommend appropriate treatment methods. Therefore, gmelina wood samples were treated under pressure to determine the solution uptake and penetration, while anatomical studies were carried out with light microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) measurements. Variations in stem heights, stem diameters, and samples from other tree stands were considered. The outcome of the study showed that the liquid uptake was generally low for gmelina wood among the selected stands (16%–23%) and there was no significant difference in stem diameters; meanwhile, penetration was less than 4 mm in the axial direction, and very low in the lateral (radial and tangential) direction. Vessels of gmelina wood have abundant tyloses, while crystalline structures with needlelike shapes are present in a large proportion of the ray parenchyma cells, and are confirmed with SEM-EDX to be made up of calcium oxalate. The low liquid uptake and penetration in gmelina wood suggest that the impregnation of chemicals into its microstructure is next to impossible. Hence, alternative treatment methods other than those involving impregnation with chemicals should be sought to enhance its durability. Full article

Forest and tree cover loss decreases the ecosystem services that they may provide such as food and livelihood, protection from calamities, oxygen to breathe, and storing of carbon. This study assessed the diversity, species composition, and carbon stock potential of trees located in Aurora, Philippines. Two areas were surveyed to represent preserved and developed ecosystems. The preserved ecosystem was represented by the ultramafic forest in Baler, Aurora, whereas the developed ecosystem was represented by the urbanizing portion of Dipaculao, Aurora. The sampling site in Baler included 27,400 m² plots and the site surveyed in Dipaculao had a total of 72.72 hectares of developed area. Results showed a higher tree diversity in Baler (H′ = 4.096) than in Dipaculao (H′ = 3.278). Species composition assessment also revealed a higher number of ecologically important species in Baler. Ecologically important species in Baler included 100% natives, 34.5% endemics, and 20.86% threatened. Dominant species in Baler were the native, endemic, and threatened Xanthostemon philippinensis Merr. and the native Teijsmanniodendron ahernianum (Merr.) Bakh. On the other hand, the developed ecosystem had 54.4% native, 4.41% endemic, and 11.76% threatened species. Dipaculao was dominated by introduced and invasive species such as Swietenia macrophylla King and Gmelina arborea Roxb. ex Sm. For the tree carbon stock assessment, a tremendous difference was found wherein the preserved ecosystem had 272.28 tons/ha carbon whereas the developed ecosystem had 16.28 tons/ha carbon. This study revealed ideal forest ecosystem characteristics in preserved forests with high diversity, the presence of many important species, and a large amount of carbon stock. This calls for immediate action from the government to continuously protect the natural forests and prioritize proper land use planning and the right choice of species to be integrated with developed areas to improve the ecosystem’s capacity to provide vital ecological services. Full article

Cocoa-based agroforests play an important role in farmer livelihood and the global environment; however, despite these facts, their low yields and tree aging put at risk their fate. This project investigated the carbon storage potential, productivity, and economics of different agroforestry arrangements of cocoa (Theobroma cacao) with Melina (Gmelina arborea) trees, in the southwest of Colombia. We established the experiment under a Randomized Complete Blocks design with seven treatments and three repetitions. Different allometric models were tested. Allometric models were made for G. arborea trees with dbh, ranging between 30.24 and 50.11 cm. The total carbon accumulation fluctuated between 49.2 (Treatment 4) and 88.5 t ha⁻¹ (Treatment 2), soil organic matter (SOM) ranged between 9 and 17%, bulk density decreased from 0.83 to 0.77 g cm⁻³. Cocoa yield ranged between 311 kg ha⁻¹ year⁻¹ (Treatment 7, traditional farm) and 922 kg ha⁻¹ year⁻¹ (Treatment 6). Treatment 6 showed the best performance with a net present value (NPV) of COP 1,446,467 (US $337.6), an internal rate of return (IRR) of 42%, and a cost-benefit ratio (B/C) of 1.67%. The benefits of AFS were also evidenced in some of the physical and chemical soil properties. Despite local marginality, these cocoa agroforest arrangements are a viable alternative to improve the traditional (local) cocoa systems because cacao agroforest arrangements increased cacao yield and carbon storage becoming a suitable alternative to improve traditional systems. Full article

Community forest management for timber production requires short- and long-rotation companion species to fulfill the demands of the timber industry, improve farmer welfare and maintain environmental sustainability. Four species (Falcataria moluccana, Neolamarckia cadamba, Acacia mangium and Gmelina arborea) were tested as short-rotation timber crop companion species for teak (Tectona grandis) on dry-rocky soil in the Gunungkidul community forest. The selection of short-rotation timber species was based on growth performance and survival rate at the teak site. Two years after planting, the viability of G. arborea (87.3%) and A. mangium (78.2%) was significantly (p < 0.05) higher than that of N. cadamba (40.6%) and F. moluccana (18.0%). G. arborea and N. cadamba achieved the best growth in terms of height, diameter, basal area, and volume, with the growth of A. mangium and F. moluccana being significantly inferior. Gmelina arborea has the ability to adapt to teak sites, grow well, and accompany teak. Neolamarckia cadamba demonstrated good growth with potential as a teak companion, and it demonstrated limited drought tolerance on the dry-rocky soils of the study sites. Acacia mangium had a high survival but produced slow growth, indicating that it required an advance evaluation in future years. Falcataria moluccana has different growing site requirements to teak so the performance was relatively poor at the study site. This mixed pattern provides benefits to farmers through commercial thinning of short rotations species, 5–8 years post establishment. Thinning operations will also increase the productivity of residual teak stands. The diversification of timber species in community forests can provide earlier returns, enabling the adoption of silviculture management by smallholders and communities. Full article

When restoring degraded landscapes, approaches capable of striking a balance between improving environmental services and enhancing human wellbeing need to be considered. Agroforestry is an important option for restoring degraded land and associated ecosystem functions. Using survey, key informant interview and rapid carbon stock appraisal (RaCSA) methods, this study was conducted in five districts in West Java province to examine potential carbon stock in agroforestry systems practiced by smallholder farmers on degraded landscapes. Six agroforestry systems with differing carbon stocks were identified: gmelina (Gmelina arborea Roxb.) + cardamom (Amomum compactum); manglid (Magnolia champaca (L.) Baill. ex Pierre) + cardamom; caddam (Neolamarckiacadamba (Roxb.) Bosser) + cardamom; caddam + elephant grass (Pennisetum purpureum Schumach.); mixed-tree + fishpond; and mixed-tree lots. Compared to other systems, mixed-tree lots had the highest carbon stock at 108.9 Mg ha⁻¹. Carbon stock variations related to species density and diversity. Farmers from research sites said these systems also prevent soil erosion and help to restore degraded land. Farmers’ adoption of agroforestry can be enhanced by the implementation of supportive policies and measures, backed by scientific research. Full article

In the modern era, Gmelina arborea plantations are a hotspot of future research because of their high carbon sequestration potential. The present work was conducted during 2018 to 2020 on a young unmanaged Gmelina farm to understand the ecosystem’s carbon and its dynamics. The study area was categorized into three age classes: ≤5, 5–10, and 10–15 years. In a plantation, Gmelina trees (10%) were randomly selected while other trees (90%) were also taken into the consideration for ecosystem carbon. A stratified random nested quadrate sampling method was adopted for analyzing other vegetation forms under study. Overall, 51 individual species in the studied Gmelina farm were found which includes 23 tree species, 7 shrub species, 16 herbs, 2 climbers, and 3 species of ferns. The estimated quantitative vegetation parameters and diversity indices indicate that the plant assemblages were heterogeneous with native diverse species evenly distributed with fairly higher densities, frequencies, and abundance. Herbs were the most important species followed by shrubs and trees. Consequently, with the increasing age of plantation, the richness of plant species increased. Soil properties were significantly influenced by the age of the plantation but exhibited no discreet trend. Total biomass density and total carbon density increased with increasing plantation age while no drastic variation was found in available soil organic carbon (SOC) because of insignificant variability in litter production. Total carbon, available SOC (up to 60 cm depth) and ecosystem carbon in the three age class plantations fell in the ranges of 54.51–59.91, 48.18–55.73, and 104.81–110.77 Mg ha⁻¹, respectively. The carbon sequestration potential of Gmelina arborea is higher compared to other reported species and highly supportive of converting unutilized agricultural landscapes to reduce the atmospheric carbon dioxide in future. Full article

Mortality, diameter at 30 cm over ground level, height, biomass production, and carbon capture (CC) for different tree components (trunk, bark, branches, and leaves) in two locations in Costa Rica, during their first three years and with three plantation spacings (1.0 × 0.5 m, 1.0 × 1.0 m, and 1.0 × 2.0 m) were obtained for Gmelina arborea Roxb. trees growing in short rotation coppice systems (SRC). In addition, regression models were developed to predict biomass production and CC using location, age, spacing, and their interactions. Biomass production was measured by weight of trees without considering dendrometric variables. Results showed that mortality was lower than 15% for one location, with probable high fertility, and almost 85% for the other location. Diameter and height of trees increased with plantation age in both locations. The highest biomass production and CC were observed in the spacings of 1.0 × 0.5 m² and 1.0 × 1.0 m², with 20 Mg/ha/year and 8 Mg/ha/year, respectively. The models to predict biomass production in trunk with bark, branches, leaves, total biomass without leaves, and CC in trunk, branch, and total biomass were developed using this equation: Y = β₁ + β₂ (location × age) + β₃ (age) + β₄ (spacing). The R² values varied from 0.66 to 0.84, with error from 0.88 to 10.75 and indicators of goodness of fit from 60 to 83%. Full article