Search Results (21)

Urbanization often negatively impacts pollinator abundance and richness; however, its effects on different pollination components and plant reproductive success are highly variable. Previous research efforts have also shown geographic and taxonomical bias, with non-insect-pollinated plant species in tropical cities underrepresented in the literature. Although bats represent the most persistent mammal group in urban ecosystems, studies addressing the effect of urbanization on chiropterophilous plants are scarce. Here, we addressed the impacts of urbanization on flowering phenology, pollination, and reproductive success in the chiropterophilous tree Ceiba pentandra (L.) Gaertn. (Malvaceae) in two major tropical cities of the Yucatan Peninsula. We found that urbanization has led to an earlier flowering phenology; however, no effect of urbanization was detected in the two pollination components evaluated: pollinator visitation rate and pollen deposition. Finally, the effects of urbanization on the reproductive success of C. pentandra were mixed. While marginally negative effects of urbanization were found in fruit set, positive effects were found in seed germination. These findings suggest that urban pollinators can provide similar levels of pollination services and thus lead to comparable reproductive success for C. pentandra in forests and cities. Full article

This study examines the physicochemical and biological changes in meads produced from five honey types sourced from the Mekong region: Tree Marigold (Tithonia diversifolia, Myanmar), Coffee (Coffea canephora, Vietnam), Kapok (Ceiba pentandra, Cambodia), Rubber (Hevea brasiliensis, China), and Mixed Floral (Thailand). Honey musts were fermented with Saccharomyces cerevisiae at 25 °C for two weeks. After fermentation, meads exhibited lighter coloration, a stable pH (3.5–4.5), and varying bioactivities. All meads showed antimicrobial activity against Escherichia coli, while activity against Staphylococcus aureus and Klebsiella pneumoniae varied by honey source and depended on fermentation. Antioxidant activity ranged from 19.25 to 68.11% inhibition, and peaked in Tree Marigold honey after fermentation. Total phenolic and flavonoid contents fluctuated, with Mixed Floral mead showing the highest post-fermentation phenolic levels. The results of a sensory analysis ranked Tree Marigold mead the highest across taste, mouthfeel, aftertaste, and overall preference. These findings underscore the influence of honey origin and fermentation on the physicochemical, antimicrobial, and sensory properties of mead. Full article

Reliable values for carbon content in trees are essential for quantifying forest carbon stocks and estimating carbon dioxide emissions. This study analyzed the carbon content in the boles of commercial tree species in the Brazilian state of Acre, in the southwestern Amazon. Composite samples were prepared from wood wedges obtained along each individual’s commercial bole (the trunk from the point of cut to the first significant branch). Fifty-seven trees were analyzed, spanning nine families, seventeen genera, and nineteen species in the Amazon forest. The results revealed a variation in carbon content ranging from 49.08% (±3.36) to 51.81% (±0.6), with an overall mean of 50.48% (±0.42). Handroanthus serratifolius, Astronium lecointei, and Dipteryx odorata exhibited the highest carbon contents. The statistical analysis included the calculation of 95% confidence intervals for each species, indicating the precision of the carbon content estimates. ANOVA analysis showed a large effect (η² = 0.83), indicating that 83% of carbon variability is due to species differences, highlighting the distinct carbon profiles across species. One species (Ceiba pentandra) showed a significant increase in carbon with height along the bole, while the others showed varying but non-significant trends with height. Mean carbon content differed significantly (Tukey’s post hoc test) among the 19 species studied, with the greatest difference between H. serratifolius and Ceiba pentandra. Although differences between species may seem small, in some cases, they can lead to considerable underestimations or overestimations of carbon stocks and emissions when extrapolated to large areas such as the Amazon. The mean carbon content measured in this study (50.48%) exceeds the 0.47 IPCC default value generally used in national reports to the Climate Convention and in various estimates of deforestation emissions and Amazon carbon stocks. This suggests that both emissions and stocks may have been underestimated. Full article

Tropical dry forests (TDFs) are among the ecosystems most threatened by agricultural use and climate warming. However, the long-term growth responses to climate variability of woody plants in TDFs are understudied because not all TDF species form conspicuous annual rings. To address this issue, we sampled trees (26 species) and lianas (2 species) in TDFs subjected to contrasting climate conditions and located in Colombia, Ecuador, and Bolivia. First, we examined the potential to form conspicuous tree-ring boundaries in 22 tree species (Amyris pinnata, Aspidosperma tomentosum, Beilschmiedia sp., Bursera graveolens, Caesalpinia pluviosa, Ceiba pentandra, Centrolobium microchaete, Citharexylum kunthianum, Cordia alliodora, Croton gossypiifolius, Cupania cinerea, Eugenia sp., Genipa americana, Guarea guidonia, Hymenaea courbaril, Machaerium capote, Pithecellobium dulce, Rapanea guianensis, Sapindus saponaria, Senna spectabilis, Zanthoxylum monophyllum, Zanthoxylum rhoifolium, and Zanthoxylum verrucosum) and two liana species (Bignoniaceae and Combretaceae families). Second, we built mean series of ring-width indices in selected tree (A. tomentosum, B. graveolens, C. alliodora, C. cinerea, C. microchaete, P. dulce, S. spectabilis, and Z. verrucosum) and liana species and related them to climate variables. Wet conditions during the current and prior growing seasons enhanced growth in tree and liana species in different TDFs. Coexisting species showed individualistic responses to climate variability. Full article

The search for efficient oil spill remediation techniques leads to the use of physical, chemical, and biological methods, featuring both natural and modified lipophilic materials. Kapok fibers (Ceiba pentandra (L.) Gaerth) have been studied as a result of their unusual natural oil sorption capacity, which can be improved even further through physical or chemical treatments that augment their rugosity and alter their functional properties. Furthermore, the exact role of fiber morphology is not completely clear regarding the sorption process. Hence, this study investigated the efficacy of kapok fibers using different treatments, based on chemical and physical approaches, and characterized using advanced techniques (FTIR, SEM, AFM), aiming to improve the understanding of application possibilities in oil contamination scenarios. The results indicate that treatments using a low thermal intensity and low concentration do not lead to variation in sorption properties nor in surface structural features. Fiber rugosity varied from 4.40 to 12.35 nm, whereas an excessive increase in roughness was observed when the material was subject to more extreme conditions, such as a temperature of 120 °C and high concentrations (2.0 M) of both acid or alkali, accompanied by a loss in functionality and affecting the material sorption capacity. Thus, the study provides conditions to suggest that these treatments are not necessary for this type of material when inserted into sorption processes. Full article

Alpha-cellulose, a unique, natural, and essential polymer for the fiber industry, was isolated in an ecofriendly manner using eleven novel systems comprising recycling, defibrillation, and delignification of prosenchyma cells (vessels and fibers) of ten lignocellulosic resources. Seven hardwood species were selected, namely Conocorpus erectus, Leucaena leucocephala, Simmondsia chinensis, Azadirachta indica, Moringa perigrina, Calotropis procera, and Ceiba pentandra. Moreover, three recycled cellulosic wastes were chosen due to their high levels of accumulation annually in the fibrous wastes of Saudi Arabia, namely recycled writing papers (RWPs), recycled newspapers (RNPs), and recycled cardboard (RC). Each of the parent samples and the resultant alpha-cellulose was characterized physically, chemically, and anatomically. The properties examined differed significantly among the ten resources studied, and their mean values lies within the cited ranges. Among the seven tree species, L. leucocephala was the best cellulosic precursor due to its higher fiber yield (55.46%) and holocellulose content (70.82%) with the lowest content of Klasson lignin (18.86%). Moreover, RWP was the best α-cellulose precursor, exhibiting the highest holocellulose (87%) and the lowest lignin (2%) content. Despite the high content of ash and other additives accompanied with the three lignocellulosic wastes that were added upon fabrication to enhance their quality (10%, 11%, and 14.52% for RWP, RNP, and RC, respectively), they can be considered as an inexhaustible treasure source for cellulose production due to the ease and efficiency of discarding their ash minerals using the novel CaCO₃-elimination process along with the other innovative techniques. Besides its main role for adjusting the pH of the delignification process, citric acid serves as an effective and environmentally friendly additive enhancing lignin breakdown while preserving cellulose integrity. Comparing the thermal behavior of the ten cellulosic resources, C. procera and C. pentandra exhibited the highest moisture content and void volume as well as having the lowest specific gravity, crystallinity index, and holocellulose content and were found to yield the highest mass loss during their thermal degradation based on thermogravimetric and differential thermal analysis in an inert atmosphere. However, the other resources used were found to yield lower mass losses. The obtained results indicate that using the innovative procedures of recycling, defibrillation, and delignification did not alter or distort either the yield or structure of the isolated α-cellulose. This is a clear indicator of their high efficiency for isolating cellulose from lignocellulosic precursors. Full article

Wood basic density (WD) plays a crucial role in estimating forest biomass; moreover, improving wood-density estimates is needed to reduce uncertainties in the estimates of tropical forest biomass and carbon stocks. Understanding variations in this density along the tree trunk and its impact on biomass estimates is underexplored in the literature. In this study, the vertical variability of WD was assessed along the stems of large trees that had a diameter at breast height (DBH) ≥ 50 cm from a dense ombrophilous forest on terra firme (unflooded uplands) in Acre, Brazil. A total of 224 trees were sampled, including 20 species, classified by wood type. The average WD along the stem was determined by the ratio of oven-dry mass to saturated volume. Five models were tested, including linear and nonlinear ones, to fit equations for WD, selecting the best model. The variation among species was notable, ranging from 0.288 g cm⁻³ (Ceiba pentandra, L., Gaertn) to 0.825 g cm⁻³ (Handroanthus serratifolius, Vahl., S. Grose), with an average of 0.560 g cm⁻³ (±0.164, standard deviation). Significant variation was observed among individuals, such as in Schizolobium parahyba var. amazonicum (H. ex D.), which ranged from 0.305 to 0.655 g cm⁻³. WD was classified as low (≤0.40 g cm⁻³), medium (0.41–0.60 g cm⁻³), and high (≥0.61 g cm⁻³). The variability in WD along the stem differs by wood type. In trees with low-density wood, density shows irregular variation but tends to increase along the stem, whereas it decreases in species with medium- and high-density wood. The variation in WD along the stem can lead to underestimations or overestimations, not only in individual trees and species but also in total stocks when estimating forest biomass. Not considering this systematic bias results in significant errors, especially in extrapolations to vast areas, such as the Amazon. Full article

The ferry from Havana to Regla, Cuba, transports visitors from today’s cruise ship docks across a brief stretch of water in about 20 min. Despite its brevity, this watery passage symbolically foregrounds the Marian devotion on the southern rim of the grand harbor. In this way, water conjoins African diasporic histories of enslavement, labor, survival, resistance, daily life, and religiosity within Havana Bay, into which two urban geographies project. Regla historically served as a municipality for dockworkers and shipwrights and became an enclave for identity creation, civil association, and religious worship for people of African descent. The church and sanctuary of Nuestra Señora de Regla (“Our Lady of Regla”) has nurtured this connection as it houses effigies of the venerated Virgin, adorned in blue. The Virgin of Regla represents one of two, along with El Cobre, of the most important Marian devotions on the island of Cuba and is the focus of insular and diasporic pilgrimage. In Regla, the Virgin’s nautical iconography decorates the sanctuary and historically connects her to the working populations who sustained this devotion as they serviced Havana Harbor with their labor. Adjacent to the church is a waterfront park that looks out on the water and the city of Havana beyond. Bordered on one side by a low wall, the park incorporates a large ceiba tree, ceiba pentandra, also known as the silk cotton or kapok tree, a tropical species with a large trunk and spreading tree canopy native to Mexico and Central America, the Caribbean, northern South America, and West Africa (with a similar variety found in South and Southeast Asia). This article considers landscape as a methodology for examining the interplay of this tree and the adjacent church as interwoven and mutually reinforcing sites of devotion for the worship of the Virgin Mary and the oricha Yemayá in Regla, Cuba, with a view toward a broader set of local and global spaces. Full article

The increasing degradation of fossil fuels has motivated the globe to turn to green energy solutions such as biofuel in order to minimize the entire reliance on fossil fuels. Green renewable resources have grown in popularity in recent years as a result of the advancement of environmental technology solutions. Kapok fiber is a sort of cellulosic fiber derived from kapok tree seeds (Ceiba pentandra). Kapok Fiber, as a bio-template, offers the best alternatives to provide clean and renewable energy sources. The unique structure, good conductivity, and excellent physical properties exhibited by kapok fiber nominate it as a highly favored cocatalyst for deriving solar energy processes. This review will explore the role and recent developments of KF in energy production, including hydrogen and CO₂ reduction. Moreover, this work summarized the potential of kapok fiber in environmental applications, including adsorption and degradation. The future contribution and concerns are highlighted in order to provide perspective on the future advancement of kapok fiber. Full article

The bonding quality is a key property for wood-based composites. Determination of the bonding quality of sandwich panels with veneer faces and <50 mm thick cork core is not covered either by the EN 314-1, which refers to plywood, nor by its Annex B, which refers to insulating cores with a thickness of at least 50 mm. This technical note assesses the possibility of using the prescriptions of Annex B of EN 314-1 to test the bonding quality (shear strength) of the concerned panels. For this purpose, sandwich panels were realized by bonding fromager (Ceiba pentandra) veneers to a 5 mm thick core, and their bonding quality was tested. Two types of panels were realized, based on the adhesive used (glue spread 340 g/m² for double glue lines): urea–formaldehyde (UF) and urea–melamine–formaldehyde (UMF); the panels were pressed at 103 °C for 8 min at a nominal pressure of 0.4 MPa. Pre-treatments were dry-conditioned at 20 °C/65% relative humidity until attainment of the equilibrium moisture content, and immersed in water: cold water for UF panels (5.1.1 of EN 314-2) and boiling water for UMF panels (5.1.2 of EN 314-2). The effect of pre-treatment was statistically significant, with shear resistance reductions of 56% and 43% in UF and UMF panels, respectively. Based on this first investigation (2 panels × 10 specimens per panel = 40 specimens), the test method can be considered suitable for providing reliable results. This study constitutes a useful reference to test the bonding quality of sandwich panels with veneer faces and thin cork cores. Full article

Large old trees (LOTs) are emblematic elements of the cultural landscape and can live for hundreds of years. They represent an intermediate aspect of cultural heritage, linking spirits and humans. They can also provide a range of ecosystem services. In spite of their importance, declining numbers have been reported. This study examined the diversity of LOTs and the impact of anthropogenic threats on their preservation in three districts of southern Benin: Ketou and Abomey, which represent historical districts with royal courts, and Lokossa, which does not have a tradition as a dynastic seat. Semi-structured interviews focused on ethnobotanical aspects and storytelling were conducted with a total of 150 community leaders and traditional practitioners; these were coupled with an inventory of LOTs to demonstrate their importance in maintaining the heritage and providing ecosystem services in cultural landscapes. Diversity, cultural importance, and ethnobotanical indices were calculated to compare positive and negative attitudes towards LOTs by the local people of the study areas. A total of 270 LOT individuals belonging to 14 species were recorded. The most common species was Adansonia digitata (70 individuals), followed by Milicia excelsa (47 individuals), Ceiba pentandra (37 individuals), and Blighia sapida (25 individuals). Sacred forests and the royal palaces (ten for Abomey and three for Kétou), which are protected by a traditional veto, had the highest number of LOTs (145 individuals) belonging to nine species. Details of 79 specific uses were documented for each plant part of LOTs. The most frequently reported were related to medicinal (80.64%), cultic (16.65%), and craft uses (2.6%). Based on a standard area of 100 km², mean Shannon diversity (H’) and evenness (J) were lower in the cultural landscape of Ketou (H′ = 0.26 ± 0.42; J = 0.23 ± 0.37) compared to Lokossa (H′ = 0.27 ± 0.32; J = 0.21 ± 0.24) and Abomey (H′ = 0.42 ± 0.37; J = 0.35 ± 0.31). The threat patterns suggest that, irrespective of the species involved, certain determining factors (urbanization (35%), the timber trade (18%), and decisions made during the Marxist–Leninist revolution in Benin in 1972 (11%)) have affected and continue to affect LOT abundance and diversity. For better management of LOTs, there is a need to promote decision-making strategies that better align human cultural values and ecological objectives. Full article

Kapok fiber (Ceiba pentandra) belongs to a group of natural fibers that are mainly composed of cellulose, lignin, pectin, and small traces of inorganic compounds. These fibers are lightweight with hollow tubular structure that is easy to process and abundant in nature. Currently, kapok fibers are used in industry as filling material for beddings, upholstery, soft toys, and nonwoven materials. However, kapok fiber has also a potential application in the adsorptive removal of heavy metal ions and dyes from aqueous systems. This study aims to provide a comprehensive review about the recent developments on kapok fiber composites including its chemical properties, wettability, and surface morphology. Effective and innovative kapok fiber composites are analyzed with the help of characterization tools such as scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and Brunauer-Emmett-Teller analysis. Different pre-treatment methods such as alkali and acid pre-treatment, oxidation pre-treatment, and Fenton reaction are discussed. These techniques are applied to enhance the hydrophilicity and to generate rougher fiber surfaces. Moreover, surface modification and synthesis of kapok fiber-based composites and its environmental applications are examined. There are various methods in the fabrication of kapok fiber composites that include chemical modification and polymerization. These procedures allow the kapok fiber composites to have higher adsorption capacities for selective heavy metal and dye removal. Full article

The embedded immobilized enzymes (Rhizopus-oryzae) on the magnetic nanoparticles (Fe₃O₄-NPs) is a new application for the sustainable production of high-quality biodiesel. In this study, biodiesel is derived from Kapok oil via ultrasonication (US)-assisted catalytic transesterification method. A novel attempt is made to prepare magnetic nanoparticles embedded by an immobilized enzyme to solve the problem of enzyme denaturation. This innovative method resulted in optimum biodiesel conversion of 89 ± 1.17% under reactant molar ratio (methanol: oil) of 6:1, catalyst loading 10 wt% with a reaction time of 4 h at 60 °C. The kinetic and thermal study reveals that conversion of Kapok oil to biodiesel follows a pseudo first-order reaction kinetic with a lower ΔE of 30.79 kJ mol⁻¹. The ΔH was found to be 28.06 kJ mol⁻¹ with a corresponding ΔS of −237.12 J mol⁻¹ K⁻¹ for Fatty Acid Methyl Ester formation. The ΔG was calculated to be from 102.28 to 109.40 kJ mol⁻¹ for temperature from 313 K to 343 K. The positive value of ΔH and ΔG is an indication of endothermic and non-spontaneous reaction. A negative ΔS indicates the reactant in the transition state possesses a higher degree of ordered geometry than in its ground state. The immobilized catalysts provided great advantages towards product separation and efficient biodiesel production. Highlights: 1. Effective catalytic transesterification assisted by the ultrasonication method was used for bi-odiesel production. 2. Magnetite nanoparticles synthesized by the co-precipitation method were used as heteroge-neous catalysts. 3. An immobilized enzyme (Rhizopus-oryzae) was embedded in the heterogeneous catalyst, as it is reusable and cost-effective. 4. The maximum biodiesel yield obtained from Kapok oil was 93 ± 1.04% by catalytic trans-esterification reactions. Full article

The species of the genus Ceiba produces fruits with fibers with a high content of cellulose. The fiber is used for textiles, cushion filling and for industrial purposes and its characteristics have been studied in some species including Ceiba pentandra (kapok), C. speciosa and C. aesculifolia. The use of the trunk and seeds of Ceiba has also been described for different species. This article presents a review on the biological diversity of the genus Ceiba (Malvaceae). The genus Ceiba has 18 recognized species that are distributed naturally in America and Africa. However, some Ceiba trees have been introduced to various countries, especially in Asia, due to their ornamental interest and potential uses for their fiber. Ecophysiological studies of different Ceiba species have shown that resistance to adverse environmental conditions varies from species to species. Therefore, Ceiba species are considered potentially useful in restoring ecosystems impacted by human activity. The information related to the classification, morphological characteristics, phenology, ecophysiology and distribution of the different species will be extremely relevant for the sustainable production of kapok fiber. Finally, the recent genomic and transcriptomic studies also provide a valuable resource for further genetic improvement and effective use of Ceiba trees. Full article

An existing diesel engine was fitted with a common rail direct injection (CRDi) facility to inject fuel at higher pressure in CRDi mode. In the current work, rotating blades were incorporated in the piston cavity to enhance turbulence. Pilot fuels used are diesel and biodiesel of Ceiba pentandra oil (BCPO) with hydrogen supply during the suction stroke. Performance evaluation and emission tests for CRDi mode were carried out under different loading conditions. In the first part of the work, maximum possible hydrogen substitution without knocking was reported at an injection timing of 15° before top dead center (bTDC). In the second part of the work, fuel injection pressure (IP) was varied with maximum hydrogen fuel substitution. Then, in the third part of the work, exhaust gas recirculation (EGR), was varied to study the nitrogen oxides (NOx) generated. At 900 bar, HC emissions in the CRDi engine were reduced by 18.5% and CO emissions were reduced by 17% relative to the CI mode. NOx emissions from the CRDi engine were decreased by 28% relative to the CI engine mode. At 20%, EGR lowered the BTE by 14.2% and reduced hydrocarbons, nitrogen oxide and carbon monoxide by 6.3%, 30.5% and 9%, respectively, compared to the CI mode of operation. Full article