Search Results (63)

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

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

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

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

Rhyzopertha dominica and Tribolium castaneum are two significant insect pests that affect the quality, quantity, and commercial value of stored products. The aim of this study was to assess the chemical composition, repellency, and insecticidal activity of Pinus halepensis leaf EO on adults of Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). The EO of P. halepensis Mill. was extracted using hydrodistillation and analyzed for its chemical composition by GC-MS. The major components identified were 1-nonadecene (25.51%), 1-hexadecene (20.79%), pimaric acid (16.71%), and palmitic acid (12.47%). The repellency test was determined by the area-preference method. P. halepensis EO exhibited significant repellent activity against T. castaneum and R. dominica. It showed high class IV repulsion rates, reaching 63.60% against T. castaneum and 66.50% against R. dominica. The repellent effect was most potent at the highest concentration tested (16 µL/mL), achieving a 100% efficacy against T. castaneum after 4 h and after 3 h against R. dominica. The contact toxicity test was carried out by impregnating filter paper disks with increasing doses of the EO studied. P. halepensis EO was the most toxic against R. dominica (LC₅₀ = 17.11 µL/mL, LC₉₀ = 30.02 µL/mL) and T. castaneum (LC₅₀ = 20.92 µL/mL, LC₉₀ = 32.18 µL/mL) after 96 h of exposure. The ability of P. halepensis EO to repel and eliminate insects suggests that it could be used as a new treatment to prevent insect infestations of R. dominica and T. castaneum. Full article

The assessment of fire effects in Aleppo pine forests is crucial for guiding the recovery of burnt areas. This study presents a methodology using UAV-LiDAR data to quantify malleability and elasticity in four burnt areas (1970, 1995, 2008 and 2015) through the statistical analysis of different metrics related to height structure and diversity (Height mean, 99th percentile and Coefficient of Variation), coverage, relative shape and distribution strata (Canopy Cover, Canopy Relief Ratio and Strata Percent Coverage), and canopy complexity (Profile Area and Profile Area Change). In general terms, malleability decreases over time in forest ecosystems that have been affected by wildfires, whereas elasticity is higher than what has been determined in previous studies. However, a particular specificity has been detected from the 1995 fire, so we can assume that there are other situational factors that may be affecting ecosystem resilience. LiDAR metrics and uni-temporal sampling between burnt sectors and control aids are used to understand community resilience and to identify the different recovery stages in P. halepensis forests. Full article

Pinus species are notable in Mediterranean regions due to their ecological and economic importance. Various parts of these species are widely used in traditional medicine, especially pinecones, which are a significant source of bioactive compounds. The current study aimed to evaluate the phytochemical composition and biological properties of the aqueous extracts obtained by maceration from three Pinus petal fractions, from P. halepensis Mill., P. brutia Ten., and P. pinea L. (APW, BPW, and PPW respectively), and the core fractions of the same species (ACW, BCW, and PCW respectively). The results showed that APW demonstrated superior performance compared to other species and fractions (p ≤ 0.05), with the highest total polyphenol content (203.51 mg GAE/g DW) and the highest antioxidant potential (IC₅₀ = 13.51 µg/mL) against DPPH free radical. All extracts showed high anticancer activity against HeLa and HepG2 cancer cell lines, and low inhibition against HEK-293, a normal cell line (<15%), indicating that none of extracts have any toxicity effect. Furthermore, only APW exhibits a significant inhibition against α-glucosidase with 77.20% at 50 µg/mL. HPLC-DAD analysis was conducted to identify 14 compounds. GC-MS analysis was conducted to identify 28 compounds, of which 11 were detected for the first time in this species. This study offers valuable insights into phytochemistry and potential therapeutic applications of pinecones. Full article

Retsina, Greece’s most renowned traditional wine, has been produced for millennia, with archaeological and historical evidence supporting its legacy. It is legally defined as wine made exclusively in Greece using grape must infused with Aleppo pine resin (Pinus halepensis). This study examines the effects of varying resin concentrations (0.5 g/L and 1 g/L), two commercial yeast strains, and medium-toast oak (Nadalié Cooperage, Ludon-Médoc, France) American and French, on Retsina’s chemical and sensory properties to optimise its production. Wine samples from the Savatiano grape variety were analysed for classical wine parameters, oxidation stability, volatile compounds, organic acids, phenolic profiles, and sensory attributes. Principal Component Analysis (PCA) revealed that yeast strain selection significantly influences chemical composition, with Zymaflore X5 associated with higher organic acid levels. Oak addition altered phenolic profiles, with American oak increasing ellagic acid, while non-oaked wines showed higher syringic and p-coumaric acids. Resin addition elevated alpha-pinene, a key marker of resin aroma, but reduced esters linked to fruity and floral notes. These findings highlight the complex interactions between resin, yeast, and oak, offering insights for enhancing Retsina’s quality while preserving its traditional character. Full article

Background/Objectives: The emergence of antimicrobial resistance has urged researchers to explore new antimicrobial agents, such as essential oils (EOs). The aim of this study was to examine chemical composition and antimicrobial activity of the EOs from the needles and green cones of four Pinus species (Pinus mugo Turra., P. nigra J.F., P. syilvestris L., and P. halepensis Miller) from Bosnia and Herzegovina. Methods: Chemical profiles of EOs were assessed by gas chromatography, while microdilution method was used to test their antimicrobial activity. A synergistic action of EOs and gentamicin was investigated by the checkerboard assay. Results: The chemical composition of the tested EOs showed a high percentage of α-pinene, (E)-caryophyllene, limonene, germacrene D, myrcene, and δ-3-carene. EO from green cones of P. sylvestris showed high efficiency against S. aureus and E. faecalis. The MIC of P. nigra cones’ EO was 100 μg/mL against E. coli. The EO of P. halepensis green cones demonstrated the strongest activity against E. faecalis. EOs of P. halepensis needles and green cones exhibited the highest activity against C. albicans. Further, synergistic interaction was detected in combination of the selected EOs/gentamicin toward S. aureus and K. pneumoniae. Conclusions: Among the tested EOs, oils of P. sylvestris cones and P. halepensis cones and needles showed the greatest antimicrobial activity. The same EOs and EO from P. nigra cones displayed synergistic potential in combination with gentamicin, supporting their utilization as antimicrobial agents alone or in combination with antibiotics, which is in line with their ethnopharmacological usage and circular bioeconomy principles. Full article

Climate change influences carbon sequestration by forests, either positively or negatively. In the Mediterranean region, this effect is predominantly negative, although it seems to be compensated by the elevation. This study aims to analyse the impact of climate change on carbon sequestration in five pine species—Pinus halepensis, P. nigra, P. pinaster, P. pinea, and P. sylvestris—growing across an altitudinal gradient from 573 to 1743 m a.s.l. in central Spain. Data from 300 forest inventory plots in ten forests were used to first calculate carbon sequestration in 2024. To estimate future carbon sequestration, the expected values of precipitation and temperature for 2100 were determined, based on regionalised climate scenarios for RCP4.5 and RCP8.5. Values from 13 meteorological stations located around the forests, at different elevations, were analysed, conducting a statistical analysis to determine whether variations were significant. A statistically significant variation was detected for temperature and precipitation changes only under the RCP8.5 scenario. Using temperature and precipitation data for 2024 and 2100, net potential productivity in both years was established, considering its variation ratio equivalent as equivalent to that of growth and carbon sequestration. An inflection point was detected in 2100 at 1646 m a.s.l., with a decrease in productivity below and an increase above that elevation. Results reflect a decline in carbon sequestration in all the species, ranging from 6% in P. sylvestris to 28% in P. halepensis, conditioned by the elevation. Regionally, the average decrease would be 16.4%. In temperate and boreal regions, forest growth is expected to increase due to climate change, but the Mediterranean region will experience a significant decrease, except in mountain areas. To maintain current levels of carbon sequestration, it would be necessary to increase the existing carbon sinks through new plantations and the restoration of degraded forests. Full article

Indented growth rings were found long ago to be experimentally induced in Pinus halepensis Miller by thin parallel axial scratching of the bark up to the vascular cambium with a sharp blade. Here, we show that when the bark and vascular cambium of P. halepensis are wounded by wide and long parallel axial wounds (“windows”) rather than by thin scratches, the induced indented growth rings become dramatically more indented. All ten trees that were wounded by long parallel “windows” responded with very strong growth (especially in the first two years) that resulted in the formation of very conspicuous, extremely indented growth rings in the wood formed in between the long and wide woundings. This is true for both the trunks that were wounded all around their circumference and those that were wounded only in part of their circumference. We also suggest further lines of research. Full article

Various parts of the Pinaceae species, a traditional plant, have potential health benefits and exhibit antibacterial, anti-cancer, and antioxidant activities. This study aims to investigate the biochemical properties of both petal (P) and core (C) fractions from pinecones of P. halepensis (PA), P. brutia (PB), and P. pinea (PP). Pinecones were manually separated into P and C, which were then milled to investigate maceration with solvents of increasing polarity: cyclohexane (1SV), ethyl acetate (2SV), and methanol (3SV) at 20 °C. Spectrophotometry was utilized to quantify the total phenolic content (TPC) and to assess bioactivities. Gas chromatography with mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) were employed to identify the chemical composition. 3SV extracts demonstrated the highest TPC and a significant anti–oxidant potential. PA-P-3SV exhibited the highest TPC (460.66 mg GAE/g DW) and PP-P-3SV displayed the best IC₅₀ (10.54 µg/mL) against DPPH. 1SV and 2SV extracts showed interesting anticancer activity against Hela and HepG2 cells. No significant toxic effect of P and C extracts from pinecones was observed on HEK-293 cells. GC-MS analysis unveiled 46 volatile compounds, of which 32 were detected for the first time in these species. HPLC analysis identified 38 compounds, of which 27 were not previously detected in these species. This study highlights the significant potential of pinecones as a rich source of bioactive compounds. Full article

The modification of fire regimes and their impact on vegetation recovery, soil properties, and fuel structure are current key research areas that attempt to identify the thresholds of vegetation’s susceptibility to wildfires. This study aimed to evaluate the vulnerability of Mediterranean pine forests (Pinus halepensis Mill. and Pinus pinaster Aiton) to wildfires, analyzing two major forest fires that occurred in Yeste (Spain) in 1994 and 2017, affecting over 14,000 and 3200 hectares, respectively. Four recovery regions were identified based on fire severity—calculated using the delta Normalized Burn Ratio (dNBR) index—and recurrence: areas with high severity in 2017 but not in 1994 (UB94-HS17), areas with high severity in 1994 but not in 2017 (HS94-UB17), areas with high severity in both fires (HS94-HS17), and areas unaffected by either fire (UB94-UB17). The analysis focused on examining the recovery patterns of three spectral indices—the Normalized Difference Vegetation Index (NDVI), Normalized Moisture Index (NDMI), and Normalized Burn Ratio (NBR)—using the Google Earth Engine platform from 1990 to 2023. Additionally, the Relative Recovery Indicator (RRI), the Ratio of Eighty Percent (R80P), and the Year-on-Year average (YrYr) metrics were computed to assess the spectral recovery rates by region. These three spectral indices showed similar dynamic responses to fire. However, the Mann–Kendall and unit root statistical tests revealed that the NDVI and NDMI exhibited distinct trends, particularly in areas with recurrence (HS94-HS17). The NDVI outperformed the NBR and NDMI in distinguishing variations among regions. These results suggest accelerated vegetation spectral regrowth in the short term. The Vegetation Recovery Capacity After Fire (VRAF) index showed values from low to moderate, while the Vulnerability to Fire (V2FIRE) index exhibited values from medium to high across all recovery regions. These findings enhance our understanding of how vegetation recovers from fire and how vulnerable it is to fire. Full article

Wildfires are a natural part of the dynamics of Mediterranean forest ecosystems. The fire patterns in the Mediterranean basin have been altered mainly due to changes in land use and climate change. In 2017, a wildfire in Yeste (Spain) burned 3200 hectares of two Mediterranean pine forests. We investigated the effects of burn severity and postfire salvage logging practices on vegetation and soil properties in four experimental areas distributed within the wildfire perimeter. These areas included unburned, low, high, and high burn severity with salvage logging, all located under Pinus halepensis Mill and Pinus pinaster Aiton stands. Salvage logging was applied 18 months after the fire. We established 72 circular plots (nine per treatment and pine species). We collected soil samples to analyze physicochemical and biological soil properties, including pH, electrical conductivity (EC), soil organic matter (SOM) content, carbon from microbial biomass (CBM), basal soil respiration (BSR), metabolic quotient (qCO₂), and two enzymatic activities: β-glucosidase (GLU) and phosphatase (PHP). To understand how vegetation changed after fire, we implemented three linear transects per plot to calculate α-diversity indices (richness, Shannon, and Simpson), vegetation coverage (COBV), fraction of bare soil (BSOIL), the number of postfire seedlings (NSeed) and their average height (Hm), and we grouped vegetation into different postfire adaptive strategies: facultative seeder (R+S+), obligate resprouter (R+S−), obligate seeder (R−S+), and non-fire-adapted (R−S−). We ran ANOVA and Tukey’s HSD post hoc tests to evaluate the differences between burn severity and salvage logging practices on the variables examined for each pine stand. We used PCA and correlation analysis to identify plant-soil interactions. Our results suggest that Pinus halepensis stands were more affected by the wildfire than Pinus pinaster stands due to the distinct characteristics of each species (morphology of the leaves, bark thickness, cone structure, etc.) and the significant differences observed in terms of pH, SOM, CBM, qCO₂, GLU, PHP, and Nseed. The proportion of obligate resprouter species was higher in Pinus halepensis stands, and the obligate seeder species were higher in Pinus pinaster stands. The study highlighted the importance of monitoring burn severity and postfire management practices to promote forest recovery and reduce wildfire risk. Limiting the negative impact of postfire salvage logging practices can enhance the resilience of vulnerable ecosystems. Full article