This study investigates the climate sensitivity and resilience of radial growth in eight coniferous and deciduous tree species in the Vienna Woods, Austria. Using dendrochronological methods, we analyzed tree-ring width data from 63 forest plots to assess growth responses to meteorological variability over the period 1933-2023. Historic climate records were used to develop a water balance model, from which we derived seasonal growth factors. Linear mixed effects models were applied to quantify species-specific relationships between tree-ring width and climatic conditions during the current and preceding two years. Tree-ring width responded not only to climatic conditions of the current growing season but also strongly to those of the previous year. Soil moisture and air temperature emerged as the principal drivers of radial growth, with soil moisture positively and temperature negatively affecting ring width. Climatic conditions during June-July of the current year exerted the strongest impact on ring formation. Using regional climate trends and projected air temperature and precipitation trajectories for Central Europe under RCP4.5 and RCP8.5, we forecast future growing conditions for the region. Both scenarios predict an extended growing season, increased transpiration demand, and heightened drought risk - more pronounced under RCP8.5. However, projected increases in precipitation partly offset the drought risk. By combining historical climate sensitivity of radial increment with future climate projections, we modelled expected tree-ring growth for eight tree species. Most species are predicted to experience notable declines in radial growth, with the strongest reductions in conifers, including European larch (Larix decidua), Norway spruce (Picea abies), Austrian pine (Pinus nigra) and Scots pine (Pinus sylvestris). Deciduous species - Sycamore maple (Acer pseudoplatanus), European beech (Fagus sylvatica), and sessile oak (Quercus petraea) - show moderate declines. In contrast, Turkey oak (Quercus cerris) is projected to increase radial growth under future climate scenarios. These findings suggest that forest management in the Vienna Woods and adjacent regions should prioritize the promotion of warm- and drought-tolerant tree species such as Quercus cerris to enhance forest resilience and sustainability in the face of climate change.

High acorn predation limits assisted regeneration in Mediterranean oak woodlands.

In this study, the effects of different canopy closures and slopes on aboveground, soil, and belowground biomass (B) and carbon (C) storage in pure black pine (Pinus nigra subsp. pallasiana), mixed black pine - Scots pine (Pinus sylvestris), and black pine-Turkey oak (Quercus cerris) natural stands were investigated. The study was conducted in 88 sample areas selected using a selective sampling method within the boundaries of Atakum (Ada) and the Boğaziçi Forest Management Directorate in Samsun Province. Samples were taken for the aboveground, soil, and belowground components of these areas. The mean tree method was used to estimate tree C storage, while multiple variance analyses were applied to evaluate differences in B and C stocks. According to the obtained findings, average aboveground tree B in pure black pine, mixed black pine - Scots pine, and black pine - Turkey oak stands were 63.61 t/ha, 67.41 t/ha, and 86.51 t/ha, respectively; total vegetative mass was 102.97 t/ha, 101.43 t/ha, and 127.84 t/ha, respectively; aboveground tree C was calculated as 28.93 t/ha, 30.45 t/ha, and 36.49 t/ha, respectively. Similarly, total plant C amounts were 46.07 t/ha, 47.85 t/ha, and 53.08 t/ha; soil organic carbon (SOC) values were 119.42 t/ha, 103.07 t/ha, and 100.88 t/ha. While land slope had no significant effect on B and C storage, B and C storage varied with canopy closure. Additionally, it was found that stand structure, rather than soil properties, was a key determinant of C storage.

Urban forests serve as representations of nature within city landscapes. Green Forest, spanning 5,198,412 square meters, has been incorporated into the Municipality of Timișoara's public domain and designated as a forest park. This fact increased green space per capita and enriched biodiversity within Timișoara's landscape architecture. This study explores the diversity of Green Forest trees and highlights their contribution to the urban landscape. Statistical methods, including comparative and linear relationships analyses, were employed to assess significant variations in the dendrometric parameters of the analyzed tree species: mean tree height, mean trunk diameter at breast height (DBH), tree age, and stand density. Principal Component Analysis (PCA) and cluster analysis were applied to uncover underlying patterns in the data. Using ArchiCAD and Lumion, high-quality 3D visual representations were developed for an ecological education area, an active recreation region, and a passive recreation area within Green Forest. Due to their morphological characteristics and phenotypic traits, the predominant tree species include Quercus robur, Quercus cerris, Quercus rubra, Fraxinus excelsior, Acer platanoides, Acer pseudoplatanus, Ulmus campestris, and Robinia pseudoacacia, which contribute to Timișoara's urban aesthetic. Moreover, the results of the dendrometric analysis provide a foundation for further research in urban ecology. A key practical application of this study is landscape design renderings, which provide detailed and realistic visualizations to effectively communicate the design and functionality of Green Forest's spaces. If implemented, these developments will encourage public engagement with nature, promoting mental and physical well-being within the community.

A new species, Pseudoneuroterus saltabundus Sottile & Cerasa sp. nov., associated with a section Cerris oak, Quercus cerris L., is described from Italy. Notably, its galls possess the ability to jump, a behaviour we explore in this study, offering hypotheses on the potential evolutionary advantages this trait may confer. Detailed descriptions, illustrations, and diagnoses of both adults and galls are provided, together with observations on biology, host associations, and distribution. Morphology and molecular data are combined in an integrative approach that provides clear evidence for the recognition and delimitation of this new species. The study also includes a revised key to Western Palaearctic Cynipini genera lacking the transscutal articulation, as well as an updated identification key to Pseudoneuroterus asexual generations, providing a more coherent framework for the placement of the new species. Furthermore, new video evidence confirms the gall jumping behaviour in the congeneric species Pseudoneuroterus saliens.

Urban environments host invasive species that threaten tree and shrub vegetation in green infrastructure. In recent years, non-native pests and pathogens have been identified in Bulgaria, causing significant damage to host plants and altering the species composition of urban green spaces. The current study aimed to evaluate the risk of invasion and spread of aggressive insect pests and fungal pathogens, leading to the degradation of tree and shrub vegetation in urban green areas of a pilot site—the largest city park, ‘St. George’, in Dobrich (northeastern Bulgaria). From 2024 to 2025, the health status of 46 tree and shrub species was assessed using specific indicators, including crown defoliation, the presence of dried or rotted trees that could pose a threat to human health, and the presence of pests and pathogens that could cause allergic reactions. A mobile-based system with ArcGIS Field Maps was used to collect data during the field assessment. This system included 20 indicators for evaluating tree health status and transferring the data to electronic records. The most important pests that caused severe damage were oak ( Corythucha arcuata ) and sycamore ( C. ciliata ) lace bugs, Cinara cedri cedri , found on Cedrus atlantica ; both the leaf miner ( Cameraria ohridella ) and the horse leaf blotch fungus Phyllosticta paviae caused leaf damage and premature defoliation of horse chestnut ( Aesculus hippocastanum ) leaves. Pine species were affected by the pathogens Dothistroma septosporum , D. pini and Diplodia sapinea . The fungal pathogen Botryosphaeria dothidea caused severe blight and dieback on Sequoiadendron giganteum trees. A xylariaceous ascomycete, Biscogniauxia mediterranea , a causal agent of charcoal canker disease, was detected on Quercus cerris and Q. rubra trees. The adverse effects of invasive pests and pathogens have worsened the health of tree species and reduced the ecosystem services provided by Dobrich’s largest city park. Water stress during recent growing seasons appears to have reduced trees’ resistance and increased their vulnerability to infection by invasive pests and pathogens. 

The production of particleboard is influenced by various technological and technical factors that affect both quality and economic performance. Among these, board density is particularly important-higher density enhances mechanical properties but increases production costs. Therefore, medium-density particleboards are typically manufactured from softwood species, whose low density provides favorable strength characteristics. In contrast, hardwood species often reduce mechanical performance, limiting their proportion in the mixture to 20–30%. However, in the Republic of Bulgaria, 32% of forested areas are covered with oak species, including 9% with turkey oak (Quercus cerris L.), making its exclusion from production impractical. This study explores the potential for greater use of turkey oak in three-layer particleboards made from aspen. Layers of turkey oak particles were added to the face layers at 10%, 20% and 30%. In two additional panels, turkey oak was included in the core layer at 10% and 20%, resulting in a total content of 40% and 50%. The panels were manufactured under laboratory conditions at 180°C, 2.3 MPa and 330 seconds, with a target density of 640 kg·m⁻³. The results showed consistently high values of modulus of rupture and modulus of elasticity at all levels of turkey oak inclusion.

Forest restoration programs are increasingly adopted to mitigate climate change-driven ecosystem degradation, yet the plant functional strategies underpinning successful tree establishment are not fully understood. We investigated the effect of vapour pressure deficit and soil conditions on the interplay between leaf gas exchange and carbon metabolism in three-year-old saplings of different species characterised by distinct functional strategies, as well as non-structural carbohydrate (NSC) partitioning at plant desiccation. We performed two complementary experiments to evaluate interspecific functional differences between Fraxinus ornus L., Quercus cerris L., and Quercus pubescens Willd. in a Mediterranean restored woodland and to compare them with fully irrigated nursery conspecifics. Stomatal sensitivity to closure was similar between species, whereas higher leaf gas exchange and reduced leaf shedding increased twig sugars, as in the case of F. ornus, likely contributing to its better establishment. Irrigation augmented gas exchange rates in potted saplings under moderate evaporative demand but overall did not increase NSCs compared with outplanted conspecifics, possibly because of different carbon demand. Desiccated saplings maintained substantial NSCs, but their reduced pools, especially starch, suggested that they were consumed as a response to drought. Overall, findings indicate that NSC allocation can help define proxies of plant performance in restoration programs.

Early post-germination physiological responses determine oak seedling establishment success under changing environmental conditions. This study investigated four oak species (Quercus cerris, Q. frainetto, Q. petraea, and Q. pubescens) through direct seeding experiments across four locations in Serbia representing varying habitat conditions. Physiological parameters (quantum yield of photosystem II, total stomatal conductance, and leaf vapor pressure deficit) were measured intensively during the first growing season, along with morphological traits and survival rates. Results revealed that microclimatic and soil conditions exerted stronger effects on seedling physiology than species identity, with air humidity, temperature, and soil moisture being primary drivers of photosynthetic performance. Surviving seedlings exhibited 18% higher PhiPSII and 128% higher stomatal conductance compared to non-survivors, demonstrating that physiological performance is a reliable predictor of establishment success. Species-specific differences were evident. Q. cerris and Q. frainetto maintained the highest photosynthetic activity across sites, Q. pubescens showed intermediate resilience, and Q. petraea displayed greater sensitivity to environmental stress. These findings highlight the dominant role of microsite conditions in shaping early seedling physiology and survival. Physiological measurements, particularly PhiPSII and gtw, provide useful early indicators of establishment success during the first growing season following direct seeding.

Two new records for the Turkish oak gall wasp fauna (Cynipidae: Cynipini) were recorded during a field study conducted in Burdur province, located in southwestern Türkiye. Andricus cryptobius Wachtl, 1880, and Dryocosmus destefanii Cerasa & Melika, 2018, were found for the first time on Quercus trojana Webb, a native oak species that is prevalent in this region. These new records expand the known diversity of cynipid species in Türkiye, enhancing knowledge of the oak gall wasp fauna and extending the known global distribution of these species. Data regarding the occurrence of the recorded species in Türkiye, their global distribution, and host plants are provided

The paper investigated the variability of the morphological-anatomical traits of one-year-old oak seedlings (Quercus cerris L. and Quercus rubra L.) produced in three different container types (Hiko, Plantagrah, biodegradable). A two-factorial ANOVA showed for the morphological characteristics (root collar diameter and height) statistically significant difference between the species and between the containers, too. The interaction between the variability factors (container type and species) also affects height and root collar diameter. As for the obtained results of two-factorial ANOVA for anatomical parameters (wood, bark, pith proportion, and vessel width), statistically significant differences were obtained for all of them between species, as well as between container types. On the other hand, the interaction of container type and species does not affect vessel width and bark content unlike wood and pith proportion. Comparing the species, it can be concluded that the average values of all traits, apart from vessel width, are higher in Q.rubra L. The largest dimensions of all elements regardless of the species were obtained for Hiko, then Plantagrah, and the smallest for biodegradable container.

This study investigates the color variations of Turkey oak (Quercus cerris L.) wood originating from different regions in Hungary and different growing site types. Samples were collected from pure and mixed stands under both good and poor growing conditions across several regions. Color parameters were monitored and presented using the CIE L*a*b* color measurement system. Significant differences were detected between sapwood and heartwood, with sapwood being lighter and more yellowish. Growing site type had a marked effect on color parameters, especially on lightness (L*), confirming the influence of site quality and stand composition. Within-tree color homogeneity was generally high, although mixed stands under poor conditions exhibited greater variation, up to 17.6%. Pure stands produced more uniform color, indicating their higher suitability for industrial uses requiring visual consistency. These results contribute to our understanding of Turkey oak’s esthetic and material properties, and support its broader utilization in furniture and interior applications.

On the spring of 2025 in the north-western part of Romania, to Dealurile Tășnadului, in two neighbouring localities, both edges of mixed forests dominated by Quercus cerris L., three specimens of Pammene querceti (Gozmány, 1957) were attracted to artificial light. This is the first record of the species from Romania. It was found to be sympatric and synchronic with Dioszeghyana schmidtii (Diószeghy, 1935) (Noctuidae), which was collected in larger number and also in another locality, and is new record to Satu Mare County.

Globally, forests are increasingly at risk from more frequent droughts, threatening their composition, structure, and functioning. However, growth responses to drought are still unclear for many tree species making predictions of future forest dynamics highly uncertain. In this study, we compare three growth response variables to drought, namely resistance, resilience, and recovery for Abies alba , Alnus glutinosa , Acer pseudoplatanus , Fagus sylvatica, Fraxinus excelsior , Larix decidua , Picea abies , Pinus nigra , Pinus sylvestris , Prunus avium , Pseudotsuga menziesii , Quercus cerris , Quercus petraea and Quercus rubra in the Vienna Woods, Austria, a temperate forest landscape in Central Europe. We quantified species-specific drought tolerance by comparing radial growth during the 1983, 2000, 2003, and 2015 droughts to growth during pre- and post-drought periods. Species were ranked by drought tolerance to identify the most drought-tolerant species using linear mixed models. Our results show that conifer species (excluding P. menziesii ) are generally more drought-tolerant than broadleaved species. Species such as L. decidua , Pinus sylvestris and P. avium were the most drought tolerant, while A. pseudoplatanus , Fraxinus excelsior , and P. menziesii were the most susceptible. Fagus sylvatica , the dominant tree species in this ecosystem, ranked only eleventh in drought tolerance among the 14 analyzed species, and exhibited a weaker recovery from the last analyzed drought event compared to all other species except P. menziesii . These results provide critical insights into species-specific drought responses, informing forest management strategies under changing climate conditions. • Drought tolerance of 14 tree species was assessed in Eastern Austria. • Conifers, except Pseudotsuga menziesii , showed higher drought tolerance than broadleaves. • Larix decidua and Pinus sylvestris were the most drought-tolerant species. • Pseudotsuga menziesii and Fraxinus excelsior were the least drought-tolerant species. • Findings support adaptive forest management under changing climate conditions.

All four butterfly species of the genus Phengaris are protected under Annex II and Annex IV of the Habitats Directive 92/43/EEC and are also listed in the annexes of the Romanian Government Emergency Ordinance (GEO) 57/2007. These legal frameworks require the designation of Sites of Community Importance (SCI), or protected areas to ensure their long-term survival. However, in Romania significant gaps still exist regarding the precise distribution of these species. The present study aims to address some of these gaps by combining data from the literature with field observations carried out by the authors in recent years in northwestern Romania. The study area covers Bihor, Satu Mare, Maramureș, and Sălaj counties. The investigations led both to the reconfirmation of historical records and to the discovery of new populations, as follows: Phengaris teleius – 16 localities (including new records), P. alcon – 4 localities, P. arion – 12 localities, while P. nausithous showed no recent confirmed occurrences. Within the Tășnad Hills, suitable habitats were identified for three of these species (P. teleius, P. alcon, P. arion), which makes this area eligible for designation as a Natura 2000 site. Key habitats are represented by traditionally managed wet meadows, extensive Quercus cerris forests, and semisteppe hills, ecosystems that retain a semi-natural character due to limited human impact. Nevertheless, the recent degradation and disappearance of these meadows represent a major threat to the species that depend on them. The results highlight the urgent need to integrate these habitats into conservation programs, in accordance with European and national legislation, to prevent further declines of Phengaris populations. At the same time, the proximity to the Tășnad Tourist Resort offers opportunities for developing ecotourism trails, generating benefits for both biodiversity conservation and local rural communities.

ABSTRACT Urbanization can have a substantial impact on rhizosphere activity by generating a hostile environment that hinders plant resource uptake. To study the effects of urbanization on plant-microbe interactions, Quercus cerris L. seedlings were cultivated in rhizoboxes with soil collected from non-urban, peri-urban, and urban forest sites in Campobasso, Italy. Urban and peri-urban soils showed higher enzyme activity, attributable to their nutrient content, that also caused root structural changes, modeling microbial communities. In particular, an increase in root diameter was found in urban and peri-urban soils while plants developed a root system ideal for exploring and/or exploiting the non-urban soil. Microbial community analysis revealed a higher number of phyla associated with cellular processes in non-urban soils while peri-urban and urban soils were dominated by phyla involved in metabolic pathways. This approach provides a framework for studying plant-microbe interactions, offering valuable insights to enhance urban area health and resilience.

In order to document the gall wasp fauna (Hymenoptera: Cynipidae) of Aydn province, extensive field studies were conducted between 2023 and 2025. As a result of these surveys, a total of 51 species were determined. Gall samples were collected from 150 different localities within the study area from Quercus frainetto Ten., Quercus infectoria Olivier, and Quercus pubescens Willd. host plant species in section Quercus, as well as from Quercus cerris L. and Quercus ithaburensis Decne. in section Cerris, and from section Ilex, comprising Quercus coccifera L. and Quercus ilex L. Of the species previously known from the Cynipidae fauna of Trkiye, 36 were recorded from Aydn province for the first time through this study resulting in a total of 54 species now known for the province. For each species, data on distributions within the study area, and their host plants and/or host galls is provided.

ABSTRACT Osmoderma italicum Sparacio (2000) is a rare and localized saproxylic beetle (sometimes considered a subspecies of the widespread western European Osmoderma eremita Scopoli, 1783), currently known from a limited number of sites in southern Italy. Classified as Endangered according to The International Union for Conservation of Nature (IUCN) criteria B2ab(i,ii,iii); D, and listed under Annexes II and IV of the EU Habitats Directive, it is primarily associated with mature and old-growth forests that provide essential microhabitats such as hollow trees and decaying wood. This study presents an updated assessment of the O. italicum geographical distribution, ecological preferences, and altitudinal range in southern Italy, with a particular focus on the region of Calabria. The results indicate a broad but fragmented altitudinal distribution and highlight key habitat associations with tree species such as Fagus sylvatica, Quercus cerris, Q. petraea subsp. austrotyrrhenica, Q. pubescens, Castanea sativa, Alnus cordata, and Pinus heldreichii subsp. leucodermis. Citizen science data, combined with field surveys and Natura 2000 records, have contributed significantly to refining the known range of this taxon. Despite recent advances in data availability, critical knowledge gaps remain, particularly regarding population dynamics and habitat connectivity. We discuss current threats to the taxon and propose a set of conservation actions, including the protection of old-growth forest remnants, the promotion of deadwood retention in managed forests, and the integration of citizen science into long-term monitoring frameworks.

Accurate species identification, the first crucial step for effective root studies, is a time-demanding, experience-based and error-prone process. Molecular methods are therefore needed to ensure this process, especially in urban settings where root sampling is challenging. Here, we developed a novel molecular method for root identification in complex environments. Specifically, we focused on detecting Quercus cerris—a species common in European cities and non-urban areas and used in afforestation—from bulk root samples, including those collected non-invasively. To achieve this, we conducted the first comprehensive analysis of candidate DNA regions to discriminate among Quercus species. Among the candidate sequences tested, ITS and ITS2 showed the highest discriminatory power compared to commonly used barcodes such as matK, psbA-trnH, rbcL, rpoC1, trnL-trnF. Based on this results, we designed specific primers to target ITS and ITS2 and we developed a PCR-based protocol capable of reliability and specificity detecting Q. cerris within mixed Quercus root samples. This method was then successfully applied to root bulk samples collected via excavation and non-invasive soil coring in the urban area of Campobasso (central Italy), with results validated through traditional identification techniques. The outcome is a novel, rapid, low-cost, and non-invasive molecular approach for monitoring Q. cerris roots. More broadly, this tool enable in situ root identification and mapping which support the study of root functioning and dynamics in ecosystems and is particularly valuable in challenging urban environments.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-18162-z.

The Ilex Hairstreak (Satyrium ilicis) is listed as “critically endangered” in the German federal state of Baden-Württemberg. We investigated the small-scale distribution and habitat preferences of this species in one of its last areas of occurrence in Baden-Württemberg, the district of Heidenheim, in winter 2023/24. We surveyed a total of 1.986 young oak trees at 26 different study sites for S. ilicis eggs and confirmed the presence of the species at ten sites, grouped into four different clusters with distances > 1.2 km between clusters. We compared habitat patches and individual young oak trees where S. ilicis eggs were found with habitat patches and young oak trees without S. ilicis eggs. Our data show that the average height of oak trees in the habitat patches determines the selection of oviposition sites at the habitat patch level. Satyrium ilicis was most likely to occur in habitat patches with an average oak tree height of 2-3 m. At the level of individual host plants, S. ilicis preferred oaks in sheltered situations and oaks with small distances between the ground and the first branch. In addition to native oak species, we also observed eggs on planted Turkey oaks (Quercus cerris). From our results we derive characteristics of suitable larval habitats and provide recommendations for the conservation of S. ilicis in the study area. The recommended management measures aim to improve the spatio-temporal availability and connectivity of early successional habitats with young oak trees. In order to stabilise the critically endangered S. ilicis population, we recommend an early start of habitat management in the vicinity of currently occupied habitat patches.