Abstract Eucalyptus plays a key role in Brazil’s forest sector, yet studies in northeastern Brazil remain scarce, particularly on stand volume estimation. This study evaluated different integration levels between unmanned aerial vehicle (UAV) data and traditional forest inventory (TFI) in a 10-year-old Eucalyptus spp. stand in Palmeira do Piauí, Brazil. Twelve plots were sampled, and UAV-RGB imagery was used to generate an orthomosaic and canopy height model. Diameter-height models were fitted using ordinary least squares and linear mixed-effects (LME). UAV-derived tree heights matched TFI measurements, with a difference of 0.9 m. Automated tree detection underestimated tree density, indicating that improvements in detection algorithms are required under the evaluated canopy conditions. Combining LME-based diameter model with visually interpreted tree counts, UAV-derived stand volume estimates (63.5-75.6 m³ ha⁻¹) were statistically equivalent to TFI (79.3 m³ ha⁻¹). These findings support use of low-cost UAV-RGB data with LME modeling for reliable stand volume estimation.
Abstract We evaluated the composition and vertical distribution of epiphytic orchids in floodplain forests under intensive management for açaí production at the mouth of the Tocantins River, in the Brazilian Amazon. All host trees with a diameter at breast height ≥ 10 cm were sampled within a one-hectare area. We recorded 316 individuals of epiphytic orchids, belonging to 13 species and 12 genera. The most abundant species were Lockhartia imbricata (88 individuals) and Dimerandra emarginata (74). Seventeen trees from five families, eight genera, and eight species served as structural support for orchids. Hevea brasiliensis was the main host tree, with eight individuals supporting an average of 16 individual orchids each. The crown had the greatest number and abundance of orchid species, and 54% of the species occurred exclusively in this stratum. Our results are important for understanding the ecology of orchids inhabiting floodplain forests at river mouths impacted by anthropogenic activities.
Abstract Available species-specific allometric aboveground biomass (AGB) models for tree ferns occurring in the Atlantic forest are based on small calibration datasets, potentially leading to increased uncertainty in model parameter estimates. This study constructed common AGB models for Cyathea delgadii Sternb. and Dicksonia sellowiana Hook. using data from 75 individuals destructively sampled in the subtropical Atlantic forest. Three power-law models linking AGB to a single compound variable were calibrated. Incorporating a species effect into the scaling parameter through a dummy variable substantially improved prediction accuracy. Nonetheless, incorporating a species effect into the allometric - exponent resulted in weak parameter identifiability, suggesting that the two species can share a common allometric exponent. The selected AGB model achieved prediction accuracy comparable to available species-specific models, albeit with smaller uncertainty in model parameter estimates. Pooling data from species with similar allometric relationships was shown to be an efficient strategy for improving AGB models.
Abstract The proper use of agro-industrial waste is a sustainability strategy and can be applied in the forestry chain to replace polypropylene tubes. This study evaluated the performance of three different biodegradable containers (110 cm3), made from malt bagasse, poultry litter, and coconut coir fiber, respectively, in the production of Libidibia ferrea seedlings, and compared them with the control container (polypropylene) under nursery conditions. Morphological parameters and the Dickson Quality Index (DQI) were evaluated. Seedlings grown in malt bagasse showed superior growth in all morphological parameters (p < 0.01) and the highest DQI (0.23), significantly surpassing the other treatments. Malt bagasse provided total biomass gains (TBM) up to 6 times higher than polypropylene. Poultry litter and coconut coir fiber containers showed comparable performance to polypropylene. It is concluded that malt bagasse is a highly efficient technical and sustainable alternative container for producing L. ferrea seedlings.
Abstract This study explores ionothermal liquefaction (ITL) of mangrove cellulose into levulinic acid (LA) using deep eutectic solvents (DES) under ambient pressure. Choline chloride-lactic acid (ChCl:Lac) and its FeCl₃-modified variant (DES-FeCl3) were tested for cellulose breakdown and LA production. The highest yields (158.8 and 153.0 g/kg of delignified wood) were achieved with 1:7 DES at 180°C and 1:10 DES at 200°C. GC-MS and NMR confirmed LA as a major bio-oil component. Molecular dynamics simulations showed DES promotes cellulose depolymerization through hydrogen bonding, facilitating dehydration to LA. This approach offers an effective, low-impact alternative to acid hydrolysis, requiring no high-pressure systems or hazardous reagents. It demonstrates the potential for sustainable biofuel production in decentralized settings, reducing energy needs, minimizing environmental risks, and enhancing scalability, making it a promising pathway for eco-friendly biofuel technologies.
Abstract Reducing the consumption of single-use plastics is becoming reality in today’s society. More than 300 million tons of plastic waste are generated annually globally, with a significant portion coming from disposable food packaging. The development of sustainable paper-based packaging coated with biopolymers has gained prominence in the packaging sector due to its biodegradability, non-toxicity and biocompatibility properties. These materials offer additional advantages, such as resistance to moisture and oxidation, which increases the durability of packaged food products. Improving the knowledge and their applications are essential to ensure the sustainability of production processes and meet growing environmental and economic demands. However, ongoing research is needed to overcome challenges such as production scalability and the high cost of some biopolymers in order to ensure their viability on a large scale. Additionally, it has the potential to stimulate innovation in the packaging industry, offering solutions that align sustainability and competitiveness in the market.
Abstract Soils, together with forest biomass, are essential carbon reservoirs that play a key role in mitigating climate change. This study estimated soil organic carbon stock in a Regosol under a relict Pseudotsuga menziesii forest in Ejido Chinatú, Guadalupe y Calvo, Chihuahua, Mexico. Samples were collected at five depths (0-5, 5-15, 15-30, 30-60, and 60-80 cm), and organic carbon was determined using the modified Walkley and Black method. Carbon concentration decreased with depth, from 60.2 g kg⁻¹ at 0-5 cm to 24.9 g kg⁻¹ at 15-30 cm, while bulk density increased to 0.51 Mg m⁻³ at 60-80 cm. The total organic carbon stock (0-80 cm) was 100.48 Mg ha⁻¹, with the 30-60 cm layer contributing 34.21 Mg ha⁻¹. These findings highlight the importance of considering the entire soil profile when developing conservation and sustainable management strategies for temperate forests.
Declining forest productivity and increasing food demand are major concerns in Java. Intercropping, which combines clonal teak with turmeric as shade-tolerant, is one approach to addressing these problems. This study specifically examined intercropping of medium-aged clonal teak with turmeric at various densities. The objective of this research was to examine the impact of stand density on the productivity and profitability of 10-year-old clonal teak and turmeric. The research was conducted from 2019 to 2021 in Ngawi. Two treatments were applied, namely stand density (1111, 833, 416, 312, and 250 trees/ha) and intercropping patterns. The results showed that a lower stand density significantly enhanced the standing stock. Intercropping resulted in a larger productivity than monocultures. Furthermore, the highest turmeric productivity at 18-month-old (+/- 3.96 tons/ha) was observed at the second lowest density, while the highest curcumin (7.17%) was at a density of 416 trees/ha. Intercropping yielded a maximum NPV of USD 14,726.
Abstract The object of this research was to determine the sensitivity and bioindicator potential of the plant species Peltophorum dubium to glyphosate drift contamination by monitoring the effects of this herbicide in forests adjoining agricultural areas where it was applied. Sub dose glyphosate concentrations of 2%, 4%, 8%, 16%, and 32% of the recommended commercial dose of 1440 g ha-1 in simulated drift exposure tests revealed P. dubium intoxication to be very low (<4%) at doses lower than 115.2 g ha-1 and reached 40% when exposed to 460.8 g ha-1. In plants exposed to a dose of 460.8 g ha-1 there was a reduction in photosynthetic rate, transpiration, and stomatal conductance of 22.7%, 18.1%, and 33%, respectively, contrasted to the control dose. The morphophysiological responses of P. dubium indicate low sensitivity to glyphosate drift at lower exposure doses as well as the species’ survival capacity in areas contaminated by this herbicide.
Abstract Ants are among the most abundant soil invertebrates and provide important ecosystem services. We evaluated the relationship between ant assemblages and soil attributes in a Brazilian savanna area within the Amazon biome (Roraima State). Ground ants were sampled using baits and pitfall traps across five pedoenvironments: Latossolo Amarelo, Latossolo Vermelho, Argissolo Vermelho-Amarelo, Argissolo Amarelo, and Gleissolo Háplico. In total, 48 species, 22 genera, and seven subfamilies were recorded, with Pheidole (Myrmicinae) exhibiting the highest richness. The ant assemblage in Gleissolo Háplico showed high dissimilarity compared to the other pedoenvironments, characterized by lower richness and abundance of key groups like Dolichoderinae, Dorymyrmex, Nylanderia, and Tapinoma. This pattern was mainly attributed to the high levels of soil moisture, organic matter, and extractable acidity, resulting from Gleissolo’s location at the lowest point of the toposequence. These findings can help identify bioindicators for environmental quality and support conservation measures in this savanna threatened by agricultural expansion.
Abstract Given the strategic importance of commercial forest plantations of native species, this study aimed to select a tapering model to estimate the multiple products of Schizolobium parahyba var. amazonicum planting in integrated livestock-forestry systems in the Amazon and to identify the management regime with the highest production. The research was conducted in the state of Pará, comparing production as a function of variations in spacing and planting age. The Hradetzky, Schöepfer, and Max & Burkhart tapering models were evaluated, considering goodness-of-fit statistics and scatter plots. The Schöepfer model provided the most accurate estimate of tree cross-sectional volume. The management regime with 3.5 × 3.5 m spacing and 60 months promoted the highest assortment production (164 m3) and the lowest amount of residue (60 m3), indicating the largest spacing with the highest plant utilization.
Abstract Schizolobium parahyba, a fast-growing tree species from South America, was introduced to Indonesia as a potential timber source. This study aimed to evaluate the effects of heat-treatment at 150-200 ºC (4h) on the physical and mechanical properties of S. parahyba wood. The results show that weight loss (WL) increased from 2.62 ± 0.29% at 150 ºC to 9.22 ± 0.86% at 190 ºC, while anti-swelling efficiency (ASE) increased from 3.44 ± 0.78% at 150 ºC to 29.84 ± 5.40 % at 180 ºC. Compressive strength parallel to grain (CP) increased from 37.99 ± 6.49 MPa (control) to 46.50 ± 5.52 MPa at 170 ºC but declined at higher temperatures. Meanwhile, static bending strength and compressive strength perpendicular to grain (CT) decreased at ≥180 ºC. Overall, moderate heat-treatment at 170 and 180 ºC enhanced dimensional stability and improved CP, whereas higher temperatures (≥180 ºC) caused substantial weight and strength losses.
We analyzed the composition and abundance of the vascular epiphytic flora in non-flooded and flooded (v & aacute;rzea) forest in the Parque Estadual do Utinga Camillo Vianna (PEUT) in the Eastern Amazon. We sampled epiphytes from 10 canopy trees with DBH = 25-35 cm in each type of vegetation. We recorded 743 individuals from 10 families, 26 genera, and 41 species, with greater specific richness and abundance in non-flooded forest (443 individuals from 33 species and 22 genera) than in flooded forest (300 individuals from 26 species and 18 genera). Eighteen species were common to both types of vegetation. Araceae stood out with the highest species richness and Bromeliaceae with the greatest abundance. We recorded Pleopeltis and five Angiosperm species, including the aroid Heteropsis spruceana (endemic to the Brazilian Amazon), for the first time in PEUT. We also recorded Heteropsis flexuosa, a threatened with extinction species in Brazil.
Abstract The study evaluated the use of the nucleation method to plant native species on the Cagarras Islands (RJ), affected by invasive grasses such as crabgrass. Four native species (two pioneers and two late-successional species) were tested together with Muellera virgilioides (Vogel) M.J.Silva & A.M.G.Azevedo, which had been previously planted. After 18 months of monitoring, Schinus terebinthifolia Raddi was the most resistant species, with the highest survival and growth rates. Monteverdia obtusifolia Mart. (Biral) and Allopyllus puberullus (Cambess.) Radlk., on the other hand, showed poor performance. The study concludes that the method is viable, but in demanding environments it is better to use species with more vigorous growth to ensure restoration success.
Abstract This study aimed to evaluate the physiological changes in pindo palm (Butia capitata) seeds, a native fruit species of the Brazilian Cerrado, over time under different storage conditions. Pyrenes (endocarp+seed) were stored on the sand under shade and refrigeration conditions. The physiological quality of seeds and embryos (via in vitro culture) was evaluated over time. Moisture content decreased during storage until stabilization, while germination, germination speed index (GSI), and operculum resistance remained stable up to 90 days, with a significant decline at 120 and 150 days. Conversely, lipid peroxidation, measured by malondialdehyde (MDA) content, and electrical conductivity (EC) increased over time, especially after 90 days. Refrigeration promoted greater embryo elongation, but sheath and root emergence were reduced. Storage reduces seed dormancy in B. capitata but also decreases viability and vigor.
Abstract The use of biosolids as a sustainable alternative in the management of planted Pinus taeda forests affects availability of nutrients and beneficial elements. Calcium (Ca) and Silicon (Si) play important roles in plant regulatory and protective systems; therefore, our objective was to use scanning electron microscopy combined with energy-dispersive spectroscopy (SEM-EDS) to analyze the accumulation of elements in P. taeda needles grown in soil that received 0 to 60 Mg ha-1 applications of cellulosic waste. Microanalyses of needle sections were performed using a SEM with elemental detection by EDS. Mapping mode allowed for detection and analysis of Ca, Si, and C distributions in needle sections. Calcium and Si precipitation occurred in needles, with Ca accumulating in the phloem and Si in the epidermal cells. Application of 60 Mg ha-1 changed the availability and accumulation of elements, which resulted in more Ca crystals and fewer Si crystals.
Abstract Wood has long been one of the most widely utilized natural building materials. This study investigated the effect of thermal modification on the durability of Daniellia oliveri wood through laboratory and field decay tests. Five mature trees were selected and felled for the experiment. Wood samples were prepared and subjected to thermal treatment at 160, 180, and 200°C for three hours. The heartwood recorded a mass loss of 25.58% for the untreated wood, while the sapwood showed a slightly higher mass loss of 26.23%. Specimens treated at 200°C had the highest resistance to mass loss, with 7.08% for the heartwood and 8.73% for the sapwood. Similar trends were observed in the mass loss measured after exposure in the field, where mass loss decreased as the temperature increased. Thermal modification enhanced the resistance of D. oliveri wood, thereby increasing its durability and broadening its applications.
Abstract We evaluated the pontential architectural analysis of Cecropia pachystachya to estimate tree age and reconstruct growth history in the Brazilian Cerrado. By examining internode length, branch, and inflorescence scars, we employed a retrospective method developed for Amazonian species to date growth cycles in this seasonal environment. Variations in internode length facilitated annual delimitation, with individuals producing an average of 31.4 ± 4.8 nodes per year. Most trees were approximately six years old, aligning with farmer-reported land-use history. Growth analyses indicated a biannual pattern in internode production and flowering, likely influenced by solar insolation rather than rainfall. Branching exhibited weaker, supra-annual periodicity. Despite considerable inter-individual variability in C. pachystachya, internode length remained a reliable indicator of annual growth. These findings endorse architectural analysis as a cost-effective tool for ecological monitoring and estimating pioneer species age in landscapes impacted by swidden cultivation.
Abstract We present the first study on the reproductive phenology and above-ground and below-ground trait relationships of Andira humilis, an endemic underground tree from Brazil. We studied an A. humilis population in caatinga remnants. The phenology seasonality was assessed using circular statistics (monthly frequency) based on herbarium vouchers. We used PCA on functional traits and climate to examine their relationships, and linear regression to assess the effects of mean rainfall and temperature on phenophases. A. humilis exhibits seasonality, flowering in the dry season and fruiting in the rainy season. Functional traits (low-wood density and high-water storage) enable flowering during water stress. Temperature drives fruiting, while flowering is independent of rainfall or temperature. Fruiting is less seasonal than flowering, likely due to extended maturation periods. This study highlights the role of A. humilis functional traits in adapting to extreme water stress in dry forests.
Croton cajucara Benth. and C. sacaquinha Croizat are known as "sacaca" and "sacaquinha", respectively in the Amazon region. Both species are used in Amazon folk medicine for their pharmacological potential, associated mainly with rich phytochemical properties of leaves and essential oil. Aiming to identify and determine the number of secretory structures related to essential oil yield, leaves were harvested in the medicinal plant garden of Embrapa Amazonia Oriental, Belem, Par & aacute;, Brazil, and were submitted to microscopy techniques and essential oil extraction. The species presented differences in trichome types and frequency, as well as essential oil yield. Furthermore, a positive relationship between frequency of secretory trichomes and essential oil yield was observed. The results obtained highlight the potential of Croton species to provide oils and could represent a viable alternative for sustainable exploration and a source of income for Amazonian communities.
