Search Results (466)

Monitoring the height of secondary forest regrowth is essential for assessing ecosystem recovery, but current methods rely on field surveys, airborne or UAV LiDAR, and 3D reconstruction from high-resolution UAV imagery, which are often costly or limited by logistical constraints. Here, we address the challenge of scaling up canopy height monitoring by evaluating a recent deep learning model, trained on data from the Amazon and Atlantic Forests, developed to extract canopy height from RGB-NIR Planet NICFI imagery. The research questions are as follows: (i) How are canopy height estimates from the model affected by slope and orientation in natural forests, based on a large and well-balanced experimental design? (ii) How effectively does the model capture the growth trajectories of Pinus and Eucalyptus plantations over an eight-year period following planting? We find that the model closely tracks Pinus growth at the parcel scale, with predictions generally within one standard deviation of UAV-derived heights. For Eucalyptus, while growth is detected, the model consistently underestimates height, by more than 10 m in some cases, until late in the cycle when the canopy becomes less dense. In stable natural forests, the model reveals seasonal artifacts driven by topographic variables (slope × aspect × day of year), for which we propose strategies to reduce their influence. These results highlight the model’s potential as a cost-effective and scalable alternative to field-based and LiDAR methods, enabling broad-scale monitoring of forest regrowth and contributing to innovation in remote sensing for forest dynamics assessment. Full article

Studies on plant extracts as growth promoters and immunostimulants have shown promising results. However, their effects on fish health and growth remain unclear. This study evaluated the in vitro and in vivo effects of Eucalyptus globulus pyroligneous extract (PE) on Nile tilapia. In vitro, minimal inhibitory and bactericidal concentration (MIC and MBC) and antibiogram analyses showed that PE could eliminate key bacterial strains affecting fish and human health, but only if its volatile components were preserved. In vivo, Oreochromis niloticus juveniles were fed diets containing 0.5% and 1% PE. We assessed fish hematology, phagocytosis, survival against Streptococcus agalactiae, and growth parameters. Fish fed 1% PE had lower erythrocyte and lymphocyte counts but higher neutrophil levels than controls. Their phagocytic capacity was significantly enhanced compared to both the control and 0.5% groups. However, the 0.5% PE group had a higher phagocytic index than both the control and 1% groups. No protection against S. agalactiae or significant effects on growth were observed. In conclusion, distilled E. globulus PE shows potential as an immunostimulant for fish. However, further studies are needed to preserve its volatile compounds and optimize its use in aquaculture. Full article

Sugary phloem exudates are produced by many plant species and play key roles in carbon storage, defense, and ecological interactions. Among eucalypts, one such exudate, manna, is an important carbohydrate source for birds, mammals, and insects. Despite its ecological relevance, little is known about the composition and intra-specific variability of manna. Here, we investigated patterns of manna production in Eucalyptus viminalis, a widespread foundation tree species in southeastern Australia. We developed a repeatable ex situ method to extract and analyze manna, allowing us to characterize its sugar composition and examine variation within and between trees. Across years, manna contained six sugars, with sucrose and raffinose dominant. We found substantial variation in both the quality (sucrose/raffinose ratio) and quantity (mg) of manna produced. Both declined with increasing tree size (DBH), while quality increased with branch circumference. Seasonal and annual variation in manna was also evident, with quality increasing under drier conditions (positive correlation with aridity). Our findings demonstrate substantial intra-specific variation in phloem exudates (manna), shaped by temporal and tree-level factors. These patterns offer a foundation for future research into the ecological and physiological drivers of exudate variation and resource availability in foundation species like E. viminalis. Full article

This study investigates the potential of Eucalyptus benthamii wood from planted forests in southern Brazil for the production of cross-laminated timber (CLT) panels. The performance of E. benthamii CLT panels is compared to that of Pinus spp. panels and European commercial panels (KLH^®), using the finite element method applied to a two-story building model. Class 2 of the Brazilian standard ABNT NBR 7190-2 was adopted as the reference for the physical and mechanical properties of Pinus spp., while the European commercial specifications from KLH^® were used to represent European reference panels. The results indicate that E. benthamii wood exhibits superior mechanical properties, enabling reductions of 12.5% to 27.3% in panel thickness and a 20.7% decrease in wood volume when compared to Pinus spp., without compromising structural safety. Relative to the KLH^® and ETA 06/0138 standards, E. benthamii wood demonstrates higher stiffness (modulus of elasticity of 15,325 MPa vs. 12,000 MPa) and greater flexural strength (109.11 MPa vs. 24 MPa), allowing for the use of thinner panels. Stress and displacement analyses confirm that E. benthamii CLT slabs can withstand critical loads (wind and vertical) within normative limits, with maximum displacements of 18.5 mm. The reduction in material volume (22.8 m³ versus 28.7 m³ for Pinus spp.) suggests potential benefits in terms of environmental impact and logistical efficiency. It can be concluded that E. benthamii represents a sustainable and efficient alternative for CLT panels, combining high structural performance with resource optimization and contributing to the decarbonization of the construction industry. Full article

What is the potential impact on carbon storage of the native and introduced tree species commonly associated with coffee in the central Peruvian Amazon? Coffee is a pivotal crop within the Peruvian economy. Nevertheless, the establishment of new plantations—driven by the subsistence needs of smallholder farmers—has led to expansion into forested areas. Given the significance of this crop and the demonstrated ecosystem benefits of agroforestry systems (AFSs), the aim of this study was to evaluate the influence of native and introduced shade tree species on carbon storage in coffee plantations. This study was observational and exhibited characteristics of an unbalanced incomplete block design. Agroforestry systems (AFSs) with shade tree species such as Inga, Retrophyllum rospigliosii, Eucalyptus and Pinus, and three unshaded coffee plantations, were included in this study. The total carbon stored in each AFS was higher than in unshaded coffee plantations. Soil contributed between 47% and 91% to total carbon storage, shade trees (24–46%), coffee (2–7%), leaf litter (0.6–1.9%) and shrubs and herbaceous plants (0.02–0.3%). The AFS with R. rospigliosii achieved the highest carbon storage with 190.38 Mg ha⁻¹, highlighting the compatibility of this species with coffee plantations, as well as its positive effect on climate change mitigation in deforested areas. Full article

Eucalyptus scab disease (Elsinoë) is a harmful plant fungus that can disrupt various ecological and economic services provided by commercial forests. To effectively control and monitor the occurrence of forest pathogens, it is important to understand their spatial distribution within the infected area. Consistent monitoring, together with high-resolution imagery obtained from unmanned aerial vehicles (UAVs), has become important in forest management. Therefore, this study focuses on detecting and mapping the spatial distribution of E. masingae within commercial forests using image texture and vegetation indices (VIs) computed from a UAV sensor with machine learning (ML) and deep learning (DL) models. The fast large margin (FLM), random forest (RF), and deep learning (DL) models were used to determine which model effectively mapped the spatial distribution of the disease. The results indicated that image texture significantly increased the model accuracies (FLM = 94.8%; RF = 98.9%; DL = 98.9%) as opposed to the results without the use of image texture (FLM = 84.4%; RF = 76.1%; DL = 81.7%). Since the DL model obtained the fastest model run time and was proven to be the most significant model, it selected the mean, homogeneity, second moment, and correlation texture parameters which were predominantly determined from the red and blue bands of the UAV sensor containing visible bands. Additionally, the 3 × 3 moving window size was ideal for detecting E. masingae since the estimation of texture parameters was reduced efficiently. Overall, this study showcases the ability of UAVs to effectively map forest disease. Together with that, it has proven that the DL model outperformed the conventional ML models. Full article

Water use strategies reflect the ability of plants to adapt to drought caused by climate change. However, how these strategies change with stand development and seasonal drought is not fully understood. This study used stable isotope techniques (δD, δ¹⁸O, and δ¹³C) combined with the MixSIAR model to quantify the seasonal changes in water use sources and water use efficiency (WUE) of Eucalyptus urophylla S.T.Blake × E. grandis (E. urophylla × E. grandis) at four stand ages (2-, 4-, 9- and 14-year-old) and to identify their influencing factors. Our results showed that the young (2-year-old) and middle-aged (4-year-old) stands primarily relied on shallow soil water throughout the growing season due to the limitations of a shallow root system. In contrast, the mature (9-year-old) and overmature (14-year-old) stands, influenced by the synergistic effects of larger and deeper root systems and relative extractable water (REW), exhibited more flexibility in water use, mainly relying on shallow soil water in wet months, but shifting to using middle and deep soil layer water in dry months, and quickly returning to mainly using shallow soil water in the episodic wet month of the dry season. The WUE of E. urophylla × E. grandis was affected by the combined effect of air temperature (T), vapor pressure deficit (VPD), and REW. WUE was consistent across the stand ages in the wet season but decreased significantly with stand age in the dry season. This suggests that mature and overmature stands depend more on shifting their water source, while young and middle-aged stands rely more on enhanced WUE to cope with seasonal drought stress, resulting in young and middle-aged stands being more vulnerable to drought stress. These findings offer valuable insights for managing water resources in eucalyptus plantations, particularly as drought frequency and intensity continue to rise. Full article

Essential oils (EOs), which are complex mixtures of plant-derived volatile compounds, have been utilized for centuries in the medical, food, and pharmaceutical industries because of their diverse biological properties. In recent years, there has been growing interest in elucidating the bioactivities of essential oils and their underlying mechanisms of action. This study aimed to investigate the antioxidant, antimicrobial, and cytotoxic characteristics of Laurus nobilis, Eucalyptus camaldulensis, Rosmarinus officinalis, and Mentha suaveolens oils and relate them to their volatile compound content. The volatile compounds of the essential oils were characterized and quantified by gas chromatography, the antioxidant activity was quantified using the ABTS assay, the antibacterial activity was quantified using broth microdilution and agar diffusion techniques, and the MTT assay was used to establish the cytotoxic potential. This study revealed a significant antioxidant capacity, which correlated with the proportion of terpenes known for their antioxidant properties. The antioxidant potency was ranked in descending order: R. officinalis, M. suaveolens, E. camaldulensis, and L. nobilis. Antimicrobial testing demonstrated that all the examined essential oils were effective against the evaluated microbial species, including both Gram-positive (Listeria innocua) and Gram-negative (Escherichia coli) bacteria. Additionally, all the tested essential oils triggered cell death in the human epithelioid cervical carcinoma (HeLa) cell line. Collectively, this article highlights the promising therapeutic and alimentary potential of essential oils and underscores the need for further research to fully harness their benefits in industrial settings. Full article

Elevated temperatures and extended drought periods are driving significant changes in the structure and function of forest ecosystems. High-elevation alpine ash forests (Eucalyptus delegatensis R.T. Baker) in Australia are an example of forests that are already impacted by climate change. These obligate seeder forests can shift to non-forest ecosystems following extreme drought and altered fire regimes, raising concern about their adaptation to a rapidly changing environment and long-term forest persistence. Plant functional traits play a major role in determining adaptive mechanisms to environmental conditions. While alpine ash forests are vulnerable to climate change, it is unclear if different provenances have adapted to the climatic conditions in which they grow. We therefore studied the variation in expression of functional traits related to drought tolerance in 21 provenances of alpine ash distributed across an environmental gradient. We investigated if functional traits varied between the provenances and were related to climate of origin in order to identify provenances that may be better adapted to drought. We measured the following traits in a common garden experiment under well-watered conditions: stomatal density, specific leaf area, minimum stomatal conductance and osmotic potential at full turgor. There was very little variation in trait expression between the 21 provenances for all functional traits related to drought tolerance. All provenances had medium-range stomatal density (170–300 stomata mm²) and specific leaf area (SLA, 50–70 cm² g⁻¹), a very low minimum stomatal conductance (2–4 mmol m² s⁻¹) and a high osmotic potential at full turgor (−0.6–0.7 MPa). There was no statistically significant correlation of trait expression with the climate of origin. Thus, there is very little evidence for genetically controlled differences in trait expression of drought tolerance traits in this species. It is likely that the high elevation and high rainfall environment of the species’ ecological niche has not been subjected to frequent and extensive drought periods that would elicit an evolutionary pressure selecting for drought-tolerant traits. We could not identify provenances that would have different drought-tolerant functional trait responses than others, potentially conferring an adaptive advantage under climate change. This has implications for using climate-adjusted provenancing to improve resilience in alpine ash forests predicted to experience more frequent and severe droughts in the future. Full article

Eucalypts are a diverse group of Myrtaceae native to Australia and adapted to a wide range of edaphoclimatic conditions, including variation in phosphorus (P) soil availability. While Corymbia and Eucalyptus species have evolved in P-poor soils, they still respond to P additions. Nutrient ratios have been used to study nutritional imbalances in plants, as they relate to nutrient homeostasis within cells and ultimately productivity. This study investigated the effects of providing adequate (normal) and high doses of phosphorus (P) on nutrient ratios in leaves and stems of Eucalyptus and Corymbia species. High soil P may happen due to high natural soil concentration and over-fertilization. These species were pre-selected from a 22-eucalypt species screening, based on their responses—either positive, negative, or neutral—to increased dry mass at high soil P compared to normal P. Two species, Corymbia citriodora and C. maculata, which showed increased dry mass under high P levels, exhibited enhanced shoot growth and improvements in parameters related to photosystem efficiency. Except for Zn, which has an antagonistic relationship with P, the concentrations of other nutrients known to exhibit either antagonism or synergism with P were not significantly altered in the leaves and stems. As a result, there were no notable changes in the ratios with high P data compared to those with normal P data. Ratios calculated among K, Ca, Mg, Fe, and Mn data also remained unchanged. However, a principal component analysis, which was performed with all nutrient ratios, effectively separated the normal P and high P treatments and distinguished between species belonging to the genera Corymbia and Eucalyptus. The validity of such nutrient ratios is discussed, and it is suggested that they may not be applicable in studies involving high nutrient doses, which may also be true for other nutrients. Additionally, using ratios under unbalanced field fertilization may lead to an incorrect nutritional interpretation. Full article

Genomic selection in Eucalyptus enables the identification of superior genotypes, thereby reducing breeding cycles and increasing selection intensity. However, its efficiency may be compromised due to the complex structures of breeding populations, which arise from the use of multiple parents from different species. In this context, partial inbred lines have emerged as a viable alternative to enhance efficiency and generate productive clones. This study aimed to apply genomic selection to a self-fertilized population of different Eucalyptus spp. Our objective was to predict the genomic breeding values (GEBVs) of individuals lacking phenotypic information, with a particular focus on inbred line development. The studied population comprised 662 individuals, of which 600 were phenotyped for diameter at breast height (DBH) at 36 months in a field experiment. The remaining 62 individuals were located in a hybridization orchard and lacked phenotypic data. All individuals, including progeny and parents, were genotyped using 10,132 SNP markers. Genomic prediction was conducted using four frequentist models—GBLUP, GBLUP dominant additive, HBLUP, and ABLUP—and five Bayesian models—BRR, BayesA, BayesB, BayesC, and Bayes LASSO—using k-fold cross-validation. Among the GS models, GBLUP exhibited the best overall performance, with a predictive ability of 0.48 and an R² of 0.21. For mean squared error, the Bayes LASSO presented the lowest error (3.72), and for the other models, the MSE ranged from 3.72 to 15.50. However, GBLUP stood out as it presented better precision in predicting individual performance and balanced performance in the studied parameter. These results highlight the potential of genomic selection for use in the genetic improvement of Eucalyptus through inbred lines. In addition, our model facilitates the identification of promising individuals and the acceleration of breeding cycles, one of the major challenges in Eucalyptus breeding programs. Consequently, it can reduce breeding program production costs, as it eliminates the need to implement experiments in large planted areas while also enhancing the reliability in selection of genotypes. Full article

The current study researched the biostimulant impacts of a natural-based solution (NBS) that contained eucalyptus and rosemary essential oils on cucumber crops. The effects of NBS (one time-NBS1; two times-NBS2) application on plant development and physiological attributes (chlorophylls, stomatal conductance), total phenolics, non-enzymatic and enzymatic antioxidant activities, leaf minerals content, cucumber quality attributes at harvest and after one-week storage were assessed through experiments. NBS1 spraying was less effective than NBS2 application because it resulted in a decrease in mineral accumulation (like reduced nitrogen) and other physiological characteristics (like chlorophylls). The plants’ enhanced oxidative stress and activation of several enzymatic antioxidant systems were reflected in the use of a commercial solution (CS) based on amino acids and biostimulants, which also boosted stomatal conductance, reduced nitrogen, calcium, and magnesium accumulation, and antioxidant capacity. No differences were found in plant height, number of leaves, plant biomass, chlorophyll fluorescence, total phenols, and various fruit quality attributes, including firmness, fresh weight, respiration rates, total soluble solids, ascorbic acid, decay, and marketability among the treatments. In fact, the effects of both CS and NBS treatment on cucumber plants and fruits were less pronounced, suggesting that more than two applications should be explored in the future. Full article

Background: The gut–brain axis (GBA) is a complex bidirectional communication system that links the gastrointestinal tract and the central nervous system. Essential oils (EOs) have emerged as promising natural compounds capable of modulating this axis. Methods: A comprehensive analysis of the recent literature was conducted, focusing on studies investigating the effects of EOs on the GBA. Particular attention was given to the endocannabinoid system, the role of cannabis-derived EOs, and other plant-based EOs with potential neuroprotective and gut microbiota-modulating effects. Results: Among the EOs analyzed, cannabis essential oil (CEO) gained attention for its interaction with cannabinoid receptors (CBR1 and CBR2), modulating gut motility, immune responses, and neurotransmission. While acute administration of the CEO reduces inflammation and gut permeability, chronic use has been associated with alterations in gut microbiota composition, potentially impairing cognitive function. Other EOs, such as those from rosemary, lavender, eucalyptus, and oregano, demonstrated effects on neurotransmitter modulation, gut microbiota balance, and neuroinflammation, supporting their potential therapeutic applications in GBA-related disorders. Conclusions: EOs demonstrate promising potential in modulating the GBA through mechanisms including neurotransmitter regulation, gut microbiota modulation, and anti-inflammatory activity. At the same time, phytocannabinoids offer therapeutic value; their long-term use warrants caution due to potential impacts on microbiota. Future research should aim to identify EO-based interventions that can synergistically restore GBA homeostasis and mitigate neurodegenerative and gastrointestinal disorders. Full article

The establishment of forest stands after harvest requires an understanding of biomass and nutrient dynamics to support management decisions and ensure system productivity and sustainability. This study evaluated biomass and nutrient accumulation in Eucalyptus urophylla aged 2 to 5 years under planting and coppicing systems. A total of 1152 trees were assessed across eight treatments, combining four ages and two management systems. Aboveground biomass was estimated using 10 trees per treatment, while root biomass was assessed in 8 trees at ages 3 and 5. Nutrient concentrations were determined using three intermediate-diameter class trees per treatment. Biomass data were analyzed using Tukey’s test (5%), and biomass expansion factors (BEF) and the root-to-shoot ratio (R) were used to estimate root carbon. Total biomass was higher in the coppicing system (153 Mg ha⁻¹) compared to the planting system (119 Mg ha⁻¹), with greater root accumulation and carbon sequestration (≈17.2 t C ha⁻¹). The biological use coefficient (BUC) increased with age, except for Mn. Planted stands showed higher BUC for N and P, while coppiced stands were more efficient in Mg use. These results reinforce the need for distinct fertilization strategies for each system, aiming at productivity, nutrient efficiency, and carbon stock enhancement. Full article

This study presents a methodology for assessing the technical and economic potential of electricity generation from biomass residues, using thermochemical conversion technologies. Applied in the state of Minas Gerais, Brazil, the analysis focuses on residues from corn, soybean, coffee, eucalyptus, and sugarcane. A multi-criteria decision-making (MCDM) approach, integrated with GIS, was used to identify the most viable biomass sources and most suitable conversion technologies, namely the Rankine cycle, organic Rankine cycle, and gasification with internal combustion engines, based on Technological Readiness Levels (TRLs). Eucalyptus emerged as the most suitable residue due to its high energy density, while sugarcane residues were the most abundant. The economic feasibility analysis indicates levelized costs ranging from USD 0.10 to USD 0.24 per kWh, with the conventional Rankine cycle emerging as the most cost-effective option for plants with a capacity exceeding 5 MWe. The proposed methodology supports strategic bioenergy planning by integrating geospatial, technological, and economic factors. Full article