Search Results (109)

Leaf phenology is a crucial functional trait in temperate forest trees that integrates environmental signals and reflects species’ adaptive capacity to stress. This study examined how moderate drought and elevated phosphorus availability, alone and in combination, affect the spring and autumn phenology of juvenile Fagus sylvatica and Quercus petraea saplings from two climatically distinct Croatian provenances. In a common garden experiment, saplings were subjected to four treatments involving drought and phosphorus addition. Phenological stages were scored using standardized ordinal scales across two growing seasons. Results revealed that phosphorus consistently advanced autumn leaf senescence in both species, independent of drought, while drought effects were species- and provenance-specific. Spring phenology was more sensitive to drought: beech from the drier provenance advanced budburst, suggesting an escape strategy, whereas oak delayed leaf-out under the same conditions. Notably, combined drought and phosphorus treatments often neutralized individual effects, indicating physiological compensation. Provenance-level differences highlighted contrasting strategies—phenotypic plasticity versus stress tolerance—under multi-stressor conditions. These findings underscore the dominant role of phosphorus in regulating phenology and the complex, non-additive nature of drought–nutrient interactions, emphasizing the need for integrative approaches in predicting phenological responses under climate change. Full article

Quercus petraea subsp. pinnatiloba is a narrowly distributed oak taxon in southeastern Türkiye, and its taxonomic position has long remained uncertain. This study aims to clarify its distinctiveness by integrating morphological, molecular, and biogeographical evidence. Principal Component Analysis (PCA) and Stepwise Discriminant Analysis (SDA) of 14 leaf traits revealed that subsp. pinnatiloba constitutes a morphologically stable and distinctly differentiated group from other Q. petraea subspecies and closely related taxa, characterized by key diagnostic traits such as petiole length (PL), lamina length (LL), length of leaf blade at its broadest point (WP), and lobe width at the tip of the widest lobe (LW). Phylogenetic analyses based on nuclear ITS and plastid markers (rbcL, psbA-trnH) confirmed its placement within sect. Quercus, yet consistently distinguished it genetically from other subspecies for the first time. Molecular dating (BEAST) suggested divergence in the Miocene (11 Mya with 95% HPD 3.01, 20.95) while RASP biogeographical analysis indicated an origin in the Euro-Siberian region with later dispersal into the Mediterranean. These integrative results support its recognition at species rank as Quercus pinnatiloba, clarifying its phylogenetic placement and underscoring the conservation importance of this lineage. Full article

The increasing interest in fibre-enriched and functional bakery products has led to the exploration of novel plant-based ingredients with both technological functionality and consumer acceptance. This study evaluates the effects of incorporating flours derived from apple (Malus domestica cv. Oberländer Himbeerapfel), sweet chestnut (Castanea sativa), horse chestnut (Aesculus hippocastanum), and red, sessile, and pedunculate oak (Quercus rubra, Q. petraea, and Q. robur) into wheat bread at 5%, 10%, and 15% substitution levels. The impact on crumb structure, crust colour, textural parameters (hardness, adhesiveness, springiness), and sensory attributes was assessed. The inclusion of apple and sweet chestnut flours resulted in a softer crumb, lower adhesiveness, and higher sensory scores related to flavour, aroma, and crust appearance. In contrast, higher levels of oak- and horse-chestnut-derived flours increased crumb hardness and reduced overall acceptability due to bitterness or excessive density. Apple flour preserved crumb brightness and contributed to warm tones, while oak flours caused more intense crust darkening. These findings suggest that selected non-traditional flours, especially apple and sweet chestnut, can enhance the sensory and physical properties of wheat bread, supporting the development of fibre-rich, clean-label formulations aligned with consumer trends in sustainable and functional baking. Full article

Palaeoecological investigations connected with extensive pre-bog, stone walls, and field systems at Kilmore, Dingle peninsula, Ireland, are presented. The main pollen profile, KLM I, spans the last 4000 years. When the record opened, pine (Pinus sylvestris) was already a minor tree, oak (probably Quercus petraea) was the main tall-canopy tree, and birch and alder were dominant locally. Substantial farming is recorded between ca. 1530 and 600 BCE (Bronze Age) when the stone walls were likely constructed. From ca. 560 CE onwards, intensive farming was conducted for much of the time. A largely treeless landscape emerged in the late twelfth century CE. Fine-spatial reconstructions of landscape and vegetation dynamics, including the timing of blanket bog initiation, are made. Post-glacial change in the western Dingle peninsula, based on published Holocene lake profiles and drawing on the new information presented here, is discussed. Reported are (a) fossil spores of the filmy ferns Hymenophyllum tunbrigense, H. wilsonii, and Trichomanes speciosum; (b) the first fossil pollen record for Arbutus unedo (strawberry tree) in the Dingle peninsula (540 CE); and (c) the first published records for Fagopyrum fossil pollen in Ireland, indicating that buckwheat was grown at Kilmore in the late eighteenth/early nineteenth centuries. Full article

Oak wood color plays a critical role in veneer production, where visual consistency directly affects material value. However, production choices are still often based on experience rather than systematic scientific data. Although many studies have examined individual factors affecting wood color, such as species or drying conditions, few have brought together ecological and industrial perspectives. This review addresses that gap by examining how habitat, species characteristics, and processing parameters influence color variation in Quercus robur and Quercus petraea. A structured literature review was conducted using Web of Science, Scopus, and Google Scholar, complemented by industry observations. The results show that site-specific factors—such as soil type, forest type, and regional climate—can significantly affect oak wood color, in some cases more than genetic differences. Drying methods, wood age, and log storage also contribute to variations in color and homogeneity. These findings highlight the potential for better raw material selection and processing strategies, leading to improved quality, sustainability, and economic efficiency in veneer production. Remaining knowledge gaps—particularly in predictive modeling and veneer-specific studies—point to important areas for future research. Full article

In recent decades, the use of wood pieces has been promoted as a viable alternative to barrels to improve the quality of white wines. However, most available studies have focused on red wines. Given that white and red wines present significant oenological differences that affect their development and final characteristics, it is necessary to expand research specifically to the case of white wines. For this reason, this study evaluates the impact of using pieces of traditional oak wood (Quercus petraea (two origins: French and Romanian) and Quercus alba), other oaks (Quercus humboldtti and Quercus candicans) and other genera (Robinia pseudoacacia, Acacia dealbata, Prunus avium and Nothofagus pumilio) on the quality of white wine during the short period of contact with the wood. The results show that aging with the different woods has little effect on the oenological parameters of the wine; however, it does lead to a change in the phenolic composition and in the final chromatic characteristics of the white wines. From a sensory point of view, the wines showed different sensory profiles depending on the type of wood used. In general, the tasting panel preferred the white wine aged with French Quercus petraea wood pieces, followed by the wine aged with Quercus humboldtti wood pieces and the wine aged with Robinia speudoacacia wood pieces. This research improves our understanding of the potential impact of using pieces of different woods in white wines, describing the potential interest of some that have not been studied before, such as Quercus humboldtti. Full article

For forests to provide ecosystem services and function optimally, they need to be managed. Forest management measures can cause significant environmental changes, which sometimes appear extreme. The most notable disturbance caused by forest regeneration is the change in canopy cover. Alteration of the canopy cover is followed by the modifications of many microclimatic factors. These changes subsequently affect all the living organisms in the forest. The present study was conducted to determine how the changes caused by modifications of canopy closure by shelterwood regeneration affect the leaf-mining insect community on sessile oak (Quercus petraea (Matt.) Liebl.). We identified that the removal of the canopy significantly affects the microclimate, vegetation, and the leaf miner community. The insolation and temperature increased in the more open areas, while relative air humidity decreased. This affects the characteristics of the young oak plants, which grow taller and produce more leaves in the open-canopy areas. All these changes consequentially affect the leaf miner community. While the species richness and abundance per tree increased with the decrease in canopy closure, the species richness and abundance per leaf decreased. The opening of the canopy positively affected the leaf miners in the end by increasing the diversity and evenness of their community. Full article

National Forest Inventories (NFIs) offer a comprehensive and consistent dataset for forest analysis, enabling the refinement of growth and yield models by integrating regional environmental factors. This study investigates the influence of climate on the growth of three dominant tree species in Romania: Norway spruce (Picea abies L. Karst), European beech (Fagus sylvatica L.), and Sessile oak (Quercus petraea (Matt.) Liebl). Increment core analysis revealed a general increase in diameter growth since 1960, partially correlated with temperature trends. Repeated measures analysis confirmed significant variations in radial growth across ecoregions. The analysis further explored the impact of climatic variables on diameter at breast height (DBH) and basal area (BA) growth and yield. Among nine climatic attributes and their combinations, total precipitation and average growing season temperature significantly affected DBH and BA growth. However, yield was largely insensitive to precipitation, with only Sessile oak yield showing a temperature dependence. Beyond ecoregion and climate, the growth and yield of DBH and BA exhibited positive correlations with the calendar year, age, and previous growth/yield values. Notably, DBH and BA growth demonstrated a dependence on the preceding four to five years, whereas yield was significantly influenced only by the previous year. The observed influence of both the calendar year and previous years suggests a prolonged environmental memory in tree growth and yield responses. Full article

During drought, a major abiotic stressor for European forests, excessive reactive oxygen species (ROS) are produced, causing oxidative damage that affects structural and metabolic tree functions. This research examines the effects of drought, phosphorus (P) fertilization, and provenance on photosynthetic pigments, malondialdehyde (MDA) concentrations, and antioxidant enzyme activities in common beech (Fagus sylvatica L.) and sessile oak (Quercus petraea (Matt.) Liebl.) saplings from two provenances. In a common garden experiment, four treatments were applied: regular watering with (+PW) and without P fertilization (−PW), and drought with (+PD) and without (−PD) P fertilization. Results showed that drought increased both MDA concentrations and antioxidant enzyme activity, particularly superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), which are responsible for ROS scavenging. Additionally, chlorophyll a + b concentrations were lower in drought-exposed plants. Phosphorus fertilization minimally affected MDA levels but enhanced antioxidant responses, particularly APX and CAT activities in oak during drought. Provenance differences were notable, with oak and beech from the drier provenance showing better adaptation, reflected in lower MDA levels and higher enzyme activities. This study underscores the importance of antioxidant defenses in coping with drought stress, with phosphorus fertilization and provenance shaping the species’ adaptive capacity. Full article

The ageing of wine in oak barrels enhances its sensory properties, with the toasting level and grain size of the wood significantly influencing the volatile composition of the wine. This study evaluated the impact of three toasting levels (light toasting, medium toasting, and medium long toasting) and two grain sizes (standard grain and extra fine grain) on the volatile profile of Tempranillo red wines aged in Quercus petraea barrels over 12 and 18 months. Gas chromatography–mass spectrometry was employed to quantify wine volatile compounds. The results revealed that lighter toasting combined with standard grain barrels enhanced the wine volatile concentration during shorter maturation periods, while medium long toasting with extra fine grain barrels was more effective for longer ageing periods. Toasting level was found to have a stronger influence on the wine volatile composition than grain size. These findings underscore the importance of tailoring barrel specifications to the desired maturation durations and sensory outcomes. Future studies exploring other grape varieties, wood origins, and longer ageing periods could further refine these insights and enhance winemaking practices. Full article

Traditional forest management models could potentially be used to combat changes in environmental conditions by stimulating soil properties and supporting tree growth. In this study, we compare the effects of different oak (Quercus petraea /Matt./Liebl.) forest models [coppice, coppice-with-standard, stocked coppice (reference)] on seasonal variability in soil properties at upland igneous and sedimentary sites (280–418 m a.s.l.). Soils were sampled at 0–5 and 10–15 cm in 50 × 50 m model and reference plots in January, April, July and October between 2015 and 2019, and soil organic matter, soil respiration, enzyme activity, pH and water-holding capacity were determined. The effects of forest model and seasonality were then compared using time-series analysis, analysis of variance and discriminant analysis. Overall, the models differentiated subsurface soil horizons from the topsoil and their feedback varied between sites. While water-holding capacity increased at the igneous stands, acid phosphomonoesterase activity increased and nitrogen content decreased at the sedimentary site. While the most significant negative influence of the forest model on soil properties was observed at the sedimentary site, the greatest increase in soil organic matter and water holding capacity was registered at the igneous coppice-with-standards site. Consequently, using the appropriate forest management model on different subsoil types could be valuable for improving carbon sequestration and drought resistance. Full article

The rapid environmental changes associated with climate change increase the need for adaptation strategies in forest management based on profound knowledge about tree species, particularly in the context of assisted migration. For research purposes, selected native and non-native tree species were planted in Brandenburg, Germany more than 120 years ago. Today, these sites provide an opportunity to gather insights about their performance and growth-response throughout the past century. We analyzed the height growth increment of 18 tree species on 1765 long-term experimental plots, the earliest of which have been monitored since 1878. We additionally investigated the stand-level volume increments on 60 unmanaged plots for two of these species. Our results show increasing trends in forest stand growth for Scots pine (Pinus sylvestris L.) and Sessile oak (Quercus petraea (Matt.) Liebl.). However, long-term height increment showed positive, negative, and indifferent growth trends in reaction to changing environmental conditions. Remarkably, 16 out of 18 species showed a growth decline between the years 2000 and 2020, likely attributable to increasing frequencies of single and consecutive drought events. We found non-native species to perform comparably to native tree species. Forest management should reconsider the role of native and non-native species in climate-adapted forests. We recommend focusing on provenance and local site adaptability in assisted migration efforts and argue that maintenance of long-term experiments can provide us with valuable insights on species performance in the near future. Full article

The high leaf morphological variability of European white oaks is largely documented in the botanical literature, and several papers have been published in the last two decades focusing on inter- and intraspecific leaf phenotypic plasticity. Studies involving landmark-based geometric morphometrics proved to be useful in highlighting relationships between leaf size and shape variation and environmental factors, phylogenetic patterns, or hybridization events. In this paper, the leaf size and shape variations of 18 populations of Quercus petraea distributed throughout a wide geographical area were analyzed by means of geometric morphometric methods (GMMs). This study involved 10 European countries and investigated the intraspecific leaf variability of Q. petraea within a wide latitudinal and longitudinal gradient. Analyses of variance for shape and centroid size were performed through Procrustes ANOVA. Multivariate analysis procedures, partial least squares method, and regression analyses were used to highlight possible patterns of covariation between leaf shape and size and geographical/environmental variables. The results revealed that the Q. petraea populations analyzed mainly differed in their leaf size, where a decrease was observed according to a north to south geographical gradient. Both leaf size and shape were found to be significantly related to latitude, and, to a lesser extent, to mean annual temperature and the leaf isotopic signature of ¹⁵N. All the other variables considered did not provide significant results. Unexpected differences observed comparing the leaf traits of geographically strictly adjacent populations suggest the involvement of local hybridization/introgression events. However, with a few exceptions, Q. petraea turned out to be quite conservative in its leaf shape and size at both the local and continental scale. Full article

We know little about how parasitoids of herbivorous insects use herbivore-induced volatile organic compounds (VOCs) to locate potential hosts on saplings in forests, and how this depends on tree composition. Therefore, we performed an experiment in a forest in Poland where we placed pairs of oak saplings (Quercus robur or Q. petraea) in neighborhoods dominated by oak, beech, or pine trees. We treated one sapling in each pair with the phytohormone methyl jasmonate, which triggers induced responses in plants. We measured the VOC emissions of thirty-six saplings and placed Malaise traps with five of the pairs. We counted the parasitoids in the ten Malaise samples and identified them using DNA metabarcoding. We used parasitoids reared from oak-feeding caterpillars to estimate which species are associated with oaks. The two species of oak differed in both the proportions of VOCs and the specific VOCs that were elevated following the application of methyl jasmonate. We did not detect any overall effects of treatment on parasitoid abundance or community composition. However, some parasitoid species that were associated with oaks appeared to be attracted to elevated emissions of specific induced VOCs. The parasitoid communities differed significantly between sites and showed marginally significant differences between neighborhoods. Overall, our results suggest that parasitoids in the understory are affected by tree composition of the canopy, but the effects of VOC emissions are limited. Full article

This study aimed to synthesize palladium nanoparticles (PdNPs) using bioactive compounds from aqueous extracts of Quercus species (Quercus dalechampii, Quercus frainetto, and Quercus petraea) with potential biomedical applications. To optimize PdNPs biosynthesis, various parameters were explored, including the concentration of PdCl₂, the extract-to-PdCl₂ ratio, and the pH of the solution. The nanoparticles were characterized using ultraviolet/visible spectroscopy (UV/Vis), Fourier-transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS). Total polyphenol content was measured using the Folin–Ciocâlteu method, while antioxidant capacity was evaluated through radical neutralization assays, including ABTS and DPPH, and through iron and copper reduction tests. Antimicrobial activity was tested against Gram-positive and Gram-negative bacteria, as well as Candida species. Phenolic compounds and flavonoids from the extracts were essential for the reduction in palladium ions and the stabilization of the nanoparticles. UV/Vis spectroscopy showed a distinct surface plasmon resonance peak, indicating the successful formation of PdNPs. FTIR analysis confirmed the interaction between the bioactive compounds and PdNPs, revealing characteristic peaks of phenolic groups. DLS analysis indicated a hydrodynamic diameter of 63.9 nm for QD-PdNPs, 48 nm for QF-PdNPs, and 63.1 nm for QP-PdNPs, highlighting good dispersion and stability in solution. Although the PdNPs did not exhibit strong antioxidant properties, they demonstrated selective antimicrobial activity, especially against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). PdNPs also exhibited significant antifungal activity against Candida krusei, with a minimum inhibitory concentration (MIC) of 0.63 mg/mL, indicating their ability to compromise fungal cell integrity. This study contributes to developing eco-friendly biosynthesis methods for metallic nanoparticles and underscores the potential of PdNPs in various applications, including in the biomedical field. Full article