Search Results (151)

Rising temperatures and droughts are triggering forest die-off in climate warming hotspots such as the Mediterranean Basin. UAVs equipped with LiDAR and multispectral sensors offer a powerful tool for surveys of tree vigor at landscape level. We used UAV-acquired LiDAR data and multispectral camera imagery to segment individual tree crowns, classify species, and assess the health status in two drought-affected forests in northeastern Spain: a mixed Pinus pinaster–Quercus ilex forest and a Pinus halepensis forest. Individual trees were segmented and classified using object-based image analysis with the Random Forest algorithm incorporating spectral, structural, and topographic variables. Greenness indices (NDVI and EVI) were analyzed in relation to crown height, topography (slope and elevation) and solar radiation, and their interactions. Analyses showed satisfactory crown segmentation (F-Score = 0.85–0.86) and species classification (Overall accuracy = 0.86–0.99), though distinguishing spectrally similar classes remained challenging. Taller P. pinaster trees exhibited higher NDVI, while taller P. halepensis displayed higher NDVI values in dense neighborhoods and on gentle slopes. These findings highlight the potential of high-resolution UAV-based remote sensing for effective near-real-time detection and attribution of forest die-off. Future research should aim to improve algorithm accuracy and better integrate field-based validation across different forest types. Full article

Sequestration of atmospheric CO₂ in the Yatir Mediterranean semi-arid Aleppo Pine Forest (Pinus halepensis) close to the border of the semi-arid timberline was characterized and quantified under field conditions. Measurements of organic and inorganic CO₂ sequestration with gas exchange, stock counting approach, and remote sensing were made in both rainfed control (~12% average annual Soil Moisture) and long-term experiment of irrigation (~10 years with ~24% annual average SM) plots, providing the opportunity to separate the effects of atmospheric water demand from soil water stress on the atmospheric CO₂ sequestration responses. Measurements yield an organic carbon sequestration (OCS) rate of ~550 g CO₂ m⁻² yr⁻¹, 60% in soil and 40% in biomass (standing and removed). In addition, measurements yield an inorganic carbon sequestration (ICS) rate of ~65 g CO₂ m⁻² yr⁻¹ (for half meter soil depth) via calcite (CaCO₃) precipitation in the soil due to root exhalation of CO₂ (25%) and microbial activity (75%). The drip-irrigated plot showed approximately 3 times higher organic CO₂ sequestration than the control plot, divided equally between the soil and the biomass. For the irrigated plot, the inorganic CO₂ sequestration rate was ~1.8 times higher than that of the control plot. These measured values demonstrate the relatively high potential for carbon sequestration in Mediterranean drylands forests under irrigated and non-irrigated conditions. Full article

This article describes a field- and laboratory-based framework that can be used to monitor the C balance in Mediterranean pine forest ecosystems under different management practices that determine their structure and function. By jointly monitoring stand structure, gas exchange, litter, and decomposition dynamics, this protocol enables the assessment of how management-driven changes regulate carbon uptake, turnover, and losses, thereby affecting carbon sequestration potential. As an example, we suggest the implementation of the protocol at ten (10) permanent monitoring plots across three study areas located in Greece. The first group of plots represents a post-fire chronosequence in pine stands with no management interventions. The second group includes pine stands that exhibit variation in overstory and understory density driven by differences in microclimate and management history. The third group consists of peri-urban pine stands subjected to thinning of varying intensity. The monitoring protocol is implemented across all plots and the collected data can be classified into three analytical domains: (a) demography, encompassing measurements of tree growth and mortality; (b) litter and decomposition dynamics, involving the quantification of litterfall and its seasonality and the estimation of its decomposition rates; and (c) gas exchange, focusing on measurements of leaf photosynthesis and respiration (including relevant leaf functional traits) and monitoring of soil respiration. These three data domains can be used to comparatively consider the effect of forest management on key ecosystem processes and to constrain local-scale vegetation dynamics models. Full article

Pine needles are traditional herbal remedies used for centuries to treat various ailments, including rheumatism, bronchitis, burns, inflammation, and infections. This study aimed to evaluate the antioxidant, analgesic (peripheral and central), and wound-healing activities of Pinus pinaster (PPN) and Pinus halepensis (PAN) needles while identifying the bioactive compounds responsible for these effects. Phytochemical analysis revealed several phenolic compounds, including p-coumaroylquinic acid, quercetin, narcissin, and myricetin-3-O-glucoside. Both extracts showed strong antioxidant activity, with high total phenolic content (TPC: 384.84 ± 0.84 and 524.46 mg GAE/g DM for PPN and PAN, respectively) and flavonoid content (TFC: 109.44 ± 0.62 and 111.64 ± 0.62 mg QE/g DM, respectively). Peripheral analgesic activity, assessed using the acetic acid-induced writhing test, revealed that PAN (300 mg/kg) significantly reduced pain by 72.3%, while central analgesic effects, evaluated by the tail immersion test, were comparable to the reference drug for both extracts. In vivo wound-healing tests showed accelerated wound contraction and complete closure by day 21, indicating strong regenerative potential. Overall, this study demonstrates that PPN and PAN needle extracts possess significant antioxidant, analgesic, and wound-healing activities, supporting their traditional use and highlighting their potential as natural therapeutic agents for managing oxidative stress, pain, and skin injuries. Full article

This study aimed to investigate the chemical composition and biological potential of needle extracts from five pine species, including antimicrobial, antioxidant, and cytotoxic activity, as well as their influence on cell cycle progression. Needle extracts were prepared using three extraction methods: conventional maceration (CM), ultrasound-assisted extraction (UAE), and digestion (D). The chemical profile was determined with an emphasis on phenolic acids, flavonoids, and related phenolic compounds. The highest total phenolic content was observed in Pinus sylvestris (3.438 mg/g GAE), followed by Pinus heldreichii (2.732 mg/g GAE). Rutin, ferulic acid, and quercitrin were identified as the predominant phenolic compounds. The highest total flavonoid content was found in Pinus pinea extracts obtained by digestion (1.213 mg/g QE), followed by P. heldreichii (1.074 mg/g QE) and Pinus halepensis (1.074 mg/g QE), both obtained by UAE. Among all examined species, Pinus pinea exhibited the highest TTC values, regardless of the extraction method (7.31–8.21 mg/g GAE). Antibacterial testing showed that P. pinea had an MIC of 19 mg/mL against Enterococcus faecium, while P. sylvestris had the same MIC against Bacillus spizizenii. All extracts exhibited cytotoxic effects using MTT assay against HeLa cells at concentrations of 8%, 16%, and 32%, while LS 174T cells were the least sensitive. Pine needle extracts from Montenegro are a valuable source of phenolic and flavonoid compounds, and they demonstrate antimicrobial and cytotoxic activities. The results support the need for further in vivo studies and elucidation of mechanisms of action in order to assess their potential application as novel bioactive agents. Full article

The sustainability of apiculture within Mediterranean forest ecosystems is contingent upon the extent and health of melliferous tree habitats. This study outlines a five-year initiative (2020–2024) aimed at mapping and monitoring four principal honey-producing tree species—pine (Pinus halepensis and Pinus nigra), Greek fir (Abies cephalonica), oak (Quercus ithaburensis subsp. macrolepis), and chestnut (Castanea sativa)—across Evia, Greece. This is achieved through the utilization of high-resolution Sentinel-2 satellite imagery in conjunction with a hierarchical deep learning framework. Distinct from prior vegetation mapping endeavors, this research introduces an innovative application of a hierarchical framework for species-level semantic segmentation of apicultural flora, employing a U-Net convolutional neural network to capture fine-scale spatial and temporal dynamics. The proposed framework first stratifies forests into broadleaf and coniferous types using Copernicus DLT data, and subsequently applies two specialized U-Net models trained on Sentinel-2 NDVI time series and DEM-derived topographic variables to (i) discriminate pine from fir within coniferous forests and (ii) distinguish oak from chestnut within broadleaf stands. This hierarchical decomposition reduces spectral confusion among structurally similar species and enables fine-scale semantic segmentation of apicultural flora. Our hierarchical framework achieves 92.1% overall accuracy, significantly outperforming traditional multiclass approaches (89.5%) and classical ML methods (76.9%). The results demonstrate the framework’s efficacy in accurately delineating species distributions, quantifying the ecological and economic impacts of the catastrophic 2021 forest fires, and projecting long-term habitat recovery trajectories. The integration of a novel hierarchical approach with Deep Learning-driven monitoring of climate- and disturbance-driven changes in honey-producing habitats marks a significant step towards more effective assessment and management of four major beekeeping tree species. These findings highlight the significance of such methodologies in guiding conservation, restoration, and adaptive management strategies, ultimately supporting resilient apiculture and safeguarding ecosystem services in fire-prone Mediterranean landscapes. Full article

The pine nut, the seed of the stone pine, is highly valued in local cuisine and dietetics for its nutritional qualities. These nuts still come from forest stands, which results in their limited and irregular presence on the market. Domesticating the species through orchard management practices could increase its production. In this context, two irrigation schedules were tested in a grafted stone pine orchard that was planted in 2009 and has been under drip irrigation since 2011. Water needs were calculated weekly using the water balance method (ETc-P). The treatments considered were as follows: T₁, irrigation from April to the end of summer; T₂, irrigation from April to the end of June; and T₀, rainfed as the control. Monitoring of the pines, considering vegetative and reproductive responses, was carried out from 2015 (7th leaf) to 2023. T₁ and T₂ increased primary and secondary growth and resulted in higher strobili production compared to T₀. The tree’s ability to sustain the reproductive load was enhanced under irrigation versus rainfed treatment. The longest irrigation schedule increased productivity. However, when the environmental cost of supplying twice as much water in the Mediterranean region—an annual average of 900 m³ ha⁻¹ (T₂) versus 1900 m³ ha⁻¹ (T₁)—is considered, the overall assessment changes. The irregularity of stone pine mating was not prevented by a regular water supply, but it was mitigated, promoting sustainable production. Full article

The aim of this study was to assess the long-term adaptation and growth performance of 50 species introduced in 1991 on the island of Porto Santo, Madeira Archipelago, in order to guide afforestation and soil restoration under the island’s arid conditions, especially in biosphere reserves. The experiment was conducted in Alentejo, Pico Juliana and Matinho, three sites with different types of elevation, soil and exposure. A total of 502 experimental units (five plants each) were established with a completely randomized design in the three sites in 1991 to test the adaptation of 50 species from Mediterranean, African, Australian and American dry climates. Plants were grown in local nursery conditions and planted in rows with 1 × 4 m spacing. Soil properties were analyzed, and survival and growth (height and stem diameter) were monitored in 1991, 1992 and 2025. An analysis of variance was performed for the whole experiment, with the three sites showing significant differences in survival and height among species and sites thirty-four years after the planting. Some species showed high survival and growth, such as Pinus halepensis, Eucalyptus sideroxylon and Casuarina cunninghamiana. Others, like Schinus terebinthifolius and Thevetia neriifolia, showed good adaptation, and invasive behavior at the best sites, but their performance was strongly dependent on site conditions, with Alentejo being the most limiting site. This study demonstrates the long-term value of forest experiments and of long-term monitoring, providing rare data on species adaptation under semi-arid insular conditions. The findings support future afforestation strategies focusing on ecological suitability and invasiveness risk. Full article

Post-fire soil and vegetation changes can intensify erosion and sediment yield by altering the factors controlling the runoff–infiltration balance. Erosion barriers (EBs) are widely used in hydrological and forest restoration to mitigate erosion, reduce sediment transport, and promote vegetation recovery. However, precise spatial assessments of their effectiveness remain scarce, requiring validation through operational methodologies. This study evaluates the impact of EB on post-fire vegetation recovery at two temporal and spatial scales: (1) Remotely Piloted Aircraft System (RPAS) imagery, acquired at high spatial resolution but limited to a single acquisition date coinciding with the field flight. These data were captured using a MicaSense RedEdge-MX multispectral camera and an RGB optical sensor (SODA), from which NDVI and vegetation height were derived through aerial photogrammetry and digital surface models (DSMs). (2) Sentinel-2 satellite imagery, offering coarser spatial resolution but enabling multi-temporal analysis, through NDVI time series spanning four consecutive years. The study was conducted in the area of the Luna Fire (northern Spain), which burned in July 2015. A paired sampling design compared upstream and downstream areas of burned wood stacks and control sites using NDVI values and vegetation height. Results showed slightly higher NDVI values (0.45) upstream of the EB (p < 0.05), while vegetation height was, on average, ~8 cm lower than in control sites (p > 0.05). Sentinel-2 analysis revealed significant differences in NDVI distributions between treatments (p < 0.05), although mean values were similar (~0.32), both showing positive trends over four years. This study offers indirect insight into the functioning and effectiveness of EB in post-fire recovery. The findings highlight the need for continued monitoring of treated areas to better understand environmental responses over time and to inform more effective land management strategies. Full article

Retsina is a wine deeply rooted in Greek tradition, often misunderstood, and exclusively produced in Greece by adding pine resin to the must. Typically, it is bottled in flint glass bottles, although it is known that light can damage wine aroma compounds. However, the effect of light exposure in Retsina wines has never been studied. It remains unknown whether the enrichment with resin-derived compounds can protect Retsina from photodegradation. The main aim of this work was to study the behavior of Retsina’s volatile components when stored in flint glass bottles, and so 12 Retsina wines, prepared with three levels of resin addition, were stored for four weeks under light exposure in flint (clear) glass bottles or protected by light in a box, and then they were analyzed by a GC-MS/MS method. Some compounds were influenced by resin addition, others by light exposure and a few by both conditions. Several terpenes increased with resin addition but decreased due to light exposure, while norisoprenoids decreased under light exposure. Some esters were reduced due to resin addition, and 2-aminoacetophenone was increased by light exposure. The study demonstrated that flint glass bottles should be avoided, as resin does not provide sufficient protection against photodegradation. Full article

Wildfires are a major ecological disturbance in Mediterranean forests, whose frequency and intensity are increasingly driven by climate change and land-use dynamics. This study investigated post-fire natural regeneration and soil properties in Aleppo pine stands seven years after a high-severity crown fire in southern Italy. Two stand types—pure pine and mixed pine—were compared, differing in fire severity and structural composition. We evaluated seedling density and dendrometric parameters (height and collar diameter), as well as soil parameters (pH, organic matter, and bulk density) to assess their role in post-fire recovery. Regeneration was abundant and composed exclusively of Aleppo pine, with significantly higher seedling density in the pure pine stand, where fire severity was greatest. In mixed pine stand, moderate fire severity combined with interspecific competition limited regeneration density. Deadwood presence enhanced microclimatic conditions favorable to seedling establishment, supporting a post-fire recovery dynamic consistent with self-succession, whereby pre-fire dominant species are favored. Soil analyses revealed higher organic matter content and lower bulk density in the pure stand, which likely facilitated regeneration. Overall, these findings underscore the ecological value of deadwood retention and passive management strategies in fostering spontaneous forest recovery. A better understanding of post-fire regeneration patterns and soil conditions can inform adaptive management approaches to strengthen forest resilience in Mediterranean forests under increasing climate pressure. Full article

Background/Objectives: This study aimed to investigate the traditionally claimed anti-inflammatory effect of essential oil (EO) derived from pine green cones per se and after encapsulation into liposomes, which is expected to enhance its bioactivity and stability. Methods: The chemical profiling of EO was conducted using GC/GC-MS. The physico-chemical characterization of the liposomal formulation (LEO) included encapsulation efficiency, FTIR spectroscopy, and AFM imaging. Additionally, parameters such as mean particle diameter, polydispersity index, zeta potential, pH, and electrical conductivity were evaluated and reassessed after 30 days and 1 year to determine formulation stability. The in vivo anti-inflammatory effect of the EO and LEO was examined using a carrageenan-induced rat paw edema model. Results: The Pinus halepensis EO contained 14 components, mainly, α-pinene, myrcene, and (E)-caryophyllene. Encapsulation efficiency was 97.35%. AFM analyses confirmed the nanoscale dimensions and spherical shape of liposomes, while FTIR indicated successful encapsulation through overlapping functional groups. The droplet size of blank liposomes (L) ranged from 197.4 to 217 nm, while adding the EO decreased the droplet size and electrical conductivity. The polydispersity index (PDI) remained below 0.2. The zeta potential of the liposomes was between −35.61 and −49.43 mV, while the pH value was in the range of 4.35 to 5.01. These results indicate satisfactory stability across repeated measurements. Administration of LEO significantly inhibited paw edema relative to the controls, with a percentage inhibition of approximately 69%, which does not significantly differ from the effect of hydrocortisone, which was used as a positive control. Conclusions: This is the first study to report liposomal encapsulation and in vivo anti-inflammatory activity of an EO derived specifically from green cones of P. halepensis. Our findings demonstrate that EO-loaded liposomes exhibited favorable physico-chemical properties and notable anti-inflammatory activity, comparable to that of hydrocortisone. These results support their potential application in the development of effective topical anti-inflammatory formulations. Full article

In the Mediterranean basin, wildfires burn an average of 600,000 ha per year, causing severe ecological, economic, and social impacts. Fire behavior modeling is essential for wildfire prevention and control. Three-dimensional physics-based fire behavior models, such as Fire Dynamics Simulator (FDS), can represent heterogeneous fuels and simulate fire behavior processes with greater detail than conventional models. However, they require accurate information about species composition and 3D distribution of fuel mass and bulk density at the voxel level. Working in a Mediterranean ecosystem study area we developed a methodology based on the use of geometric and spectral features from UAS-based digital aerial photogrammetric point clouds for (i) species segmentation and classification using machine learning algorithms, (ii) generation of biomass prediction models at individual plant level, and (iii) creation of 3D fuel scenarios and modeling wildfire behavior. Field measurements were conducted on 22 circular plots with a radius of 5 m. Data from the field measurements, combined with species-specific allometric equations, were used for the evaluation of classification and prediction models. Fire behavior variables such as rate of spread, heat release rate, and mass loss rate were monitored and assessed as outputs from 20 different scenarios using FDS. The overall species classification accuracy was 80.3%, and the biomass regression R² values obtained by cross-validation were 0.77 for Pinus halepensis and 0.83 for Anthyllis cytisoides. These results are encouraging further improvement based on the integration of sensors onboard UAS, and the characterization of fuels for fire behavior modeling. These high-resolution fuel representations can be coupled with standard risk assessment tools, enabling fire managers to prioritize treatment areas and plan for resource deployment. Full article

The aim of this study was to evaluate the suitability of eight softwood species most commonly used by Greek timber industries, including furniture manufacturers and companies producing roundwood, sawn timber, and plywood. The analysis was based on integrated Multi-Criteria Decision Analysis (MCDA), using a combined approach of the PROMETHEE method and the Analytical Hierarchy Process (AHP), taking into consideration some important criteria that affect timber quality. According to the PROMETHEE complete ranking, Aleppo pine (Pinus halepensis Mill.) achieved the best performance under the selected criteria among the examined softwood species, underlying the importance of Aleppo pine to the Greek timber industry. Our findings could be highly beneficial to the wood industry, promoting the recovery and advancement of the forest sector in general, taking into account that sustainable wood supply is lower than the total biomass available in Europe. Policymakers should prioritize the selection of conifer tree species that can strengthen Greece’s forestry sector, promote sustainable management practices, and increase the economic value derived from the country’s diverse forest resources. Full article

Forests and scrubland comprise a large proportion of terrestrial ecosystems and, due to the long lifespan of trees and shrubs, their capacity to grow and store carbon as lasting woody tissues is particularly sensitive to warming-enhanced drought occurrence. Climate change may trigger a transition from forests to scrubland in many drylands during the coming decades due to the higher resilience of shrubs. However, we lack standardized frameworks to compare the response to drought of woody plants. We present a framework and develop an index to estimate the drought-induced vulnerability (DrVi) of trees and shrubs based on the radial growth trajectory and the response of growth variability to a drought index. We used tree-ring width series of three tree (Pinus halepensis Mill., Juniperus thurifera L., and Acer monspessulanum L.) and three shrub (Juniperus oxycedrus L., Pistacia lentiscus L., and Ephedra nebrodensis Tineo ex Guss.) species from semi-arid areas to test this framework. We compared the DrVi values between species and populations and explored their temporal changes. Across species, the strongest DrVi values were found in declining P. halepensis stands and J. oxycedrus from the same site, while the lowest DrVi values were found in A. monspessulanum, P. lentiscus, and E. nebrodensis. Across populations, J. oxycedrus presented higher vulnerability in one of the dry sites. The P. halepensis declining stand showed a steady increase in DrVi value after the 1980s as the climate shifted toward warmer and drier conditions. We conclude that the DrVi allows comparing species and populations using a standardized general framework. Full article