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We describe the spider communities collected by pitfall traps from forestry plantations at 16 areas across the UK, primarily planted with conifers, as part of the Biodiversity in Britain's Planted Forests research programme. The large collection of 13,863 identifiable individuals contained 191 species, mainly ones known to be associated with woodlands. The biggest source of variation in the data was a geographical gradient from the southeast to the northwest of the British Isles, presumably reflecting climatic conditions. The far northwestern sites held a relatively homogeneous assemblage typified by Micrargus apertus, while the southeastern sites held a more diverse mix of species. There was some evidence for tree species affecting the assemblage, with differences between the spiders of Sitka spruce and Norway spruce, also between Corsican pine and Scots pine. The age of forest was also influential, with highest diversity in the youngest stands. Overall, we suggest that these artificial plantations contribute to a surprising degree to our forest invertebrate biodiversity and merit further studies to elucidate the factors driving species assemblages within plantations of different tree species and of different ages. [ABSTRACT FROM AUTHOR]

Climate change has significant natural and economic implications, but its extent is particularly challenging to assess in forest management, a field which combines both of the previous aspects and requires the evaluation of the impact of climate change on tree species over a 100-year timeframe. Oaks are among the tree species of significant natural and economic value in Europe. Therefore, the aim of this study was to analyze all oak stands in Poland and verify the hypothesis regarding differences between Quercus robur and Quercus petraea stands in terms of soil type, annual total precipitation, average annual air temperature, and the length of the growing season. Additionally, this study aimed to analyze the impact of these differences on the growth rates of both oak species and test whether climate change may affect oak stands. A database containing 195,241 tree stands, including different oak species with varying shares in the stand (from 10% to 100%), was analyzed. A particular emphasis was placed on Q. robur and Q. petraea. The results show that, although both oak species have a wide common range of occurrence, there are clear differences in their habitat preferences. Based on the ordinal regression analysis of selected oak stands, it was concluded that an increase in air temperature of 1 °C could impair the growth of Q. robur and slightly improve the growth of Q. petraea. This may indicate the possibility of expanding the geographic range of sessile oaks towards the east and northeast under warming climatic conditions, provided that appropriate moisture conditions are maintained. [ABSTRACT FROM AUTHOR]

Most oak savannas in the Midwestern United States have been lost to agriculture and habitat degradation. Because of their rarity and high plant and animal diversity, savannas are often a target for restoration, which frequently relies on the direct planting of oak seedlings to establish the necessary canopy. Returning fire to the system is critical to the herbaceous component, but with planted seedlings, managers risk damaging or killing trees if burning is introduced too soon. We studied the growth and physiological responses of three oak species (Quercus alba, Quercus macrocarpa, and Quercus velutina) to prescribed fire to determine impacts on planted trees. This study utilized two restored oak savanna units that were planted in 1995 and 1998, each with burned and unburned areas. We tracked trees ranging from 0.9 to 29.8 cm in diameter at breast height (DBH) to determine the size threshold above which top kill is unlikely and documented differences in leaf structure and extension growth between the burned and unburned areas. There was no mortality observed. Moreover, no trees larger than 4 cm DBH were top killed by the fire. Fire responses in leaf mass per unit area and chlorophyll content were small and inconsistent across species. However, all oak species grew more in burned areas than trees in adjacent unburned areas. Therefore, the addition of low‐intensity prescribed fire to an oak savanna planting may increase the growth rate of planted trees with minimal risk of mortality once trees have reached sufficient size. [ABSTRACT FROM AUTHOR]

In bottomland forests, managing oak regeneration is challenging due to competition with other species. Low understory light levels in mature stands favor more shade-tolerant tree species, whereas harvest often results in release of fast-growing competitors. In the late 1990s, a study was initiated in northeastern Missouri to evaluate the effects of overstory harvests on stand development of bottomland forests, with particular interest in oak regeneration. Canopy removal resulted in rapid growth of undesired soft-mast species without increasing the abundance of oak reproduction. In 2017, bare-rooted pin oak (Quercus palustris Muenchh.) and swamp white oak (Quercus bicolor Willd.) seedlings were planted, to increase the oak component through enrichment planting in the stands that had previously been harvested and underplanting in the stands that had received no regeneration harvest. For all planted seedlings, three levels of midstory release treatments were applied after planting in 2017, including a control (no release), and light release, and a heavy release. This study tested the effects of the original overstory harvests and the subsequent midstory release on survival and development of planted oak advance reproduction over 5 years. Our results suggest that establishing oak advance reproduction prior to overstory harvest is more efficient than enrichment planting after overstory harvest. A prior midstory release is important to develop competitive oak advance reproduction before a later overstory harvest to ensure successful oak regeneration. [ABSTRACT FROM AUTHOR]

Aim: We examined range‐wide genetic variation in a widespread white oak species in western North America to determine phylogeographic patterns (including possible latitudinal gradients) and investigate their underlying causes. Location: Western North America. Taxon: Quercus garryana (Fagaceae). Methods: We sampled Q. garryana at 117 locations throughout its range and related species of white oaks in 8 additional populations. We sequenced DNA from four variable intergenic plastid spacers and the ribosomal nuclear ITS region. We constructed haplotype networks and phylogenetic trees, mapped the geographical distributions of plastid haplotypes, and analysed genetic diversity patterns. Results: We identified 25 plastid haplotypes that clustered in two major groups, each showing pronounced genetic variation with latitude. In contrast, ITS showed little or no geographical or phylogenetic variation. Quercus garryana shared several plastid haplotypes with related white oaks and was not differentiated from these species by ITS. Plastid haplotype diversity in Q. garryana was highest in the central part of its range and sharply reduced to the north. Two haplotypes (one from each haplotype group) occurred in the northern third of the range, with only one at the northern range limit. Populations at the southern range limit were characterised by distinct haplotypes. Main Conclusions: Genetic patterns of Q. garryana have been shaped both by post‐Pleistocene climate change, interacting with features of the landscape, and by hybridisation with other white oaks. The species contains substantial genetic variation with strong spatial structuring of plastid haplotypes, indicating (1) early divergence of southern (Sierra Nevada) and northern populations, and (2) northward dispersal during the Holocene resulting in greatly reduced genetic diversity in its northern range. Species that can adjust their ranges with changing climates may remain susceptible to loss of genetic variation, potentially affecting their ability to persist in novel conditions at northern range margins. [ABSTRACT FROM AUTHOR]

When compared to natural graphite, artificial graphite has advantages such a longer cycle life, faster charging rates, and better performance. However, the process of producing it, which frequently uses coal, raises questions about the impact on the environment and the depletion of resources. Eco-friendly, wood-based graphite must be developed in order to solve these problems. This study assessed and investigated the characteristics of charcoals derived from bamboo and oak which were utilized to produce graphite. After heating to 1500 °C at 10 K/min, 86.87 wt% of oak charcoal and 88.33 wt% of bamboo charcoal remained, indicating a yield of more than 85% when charcoal was graphitized. Depending on the species of wood, different-sized pores showed different shapes as the graphitization process advanced, as revealed by SEM surface analyses. The carbon atoms seen in the XRD crystal development changed into graphite crystals when heated to 2400 °C, and the isotropic peaks vanished. Bamboo charcoal has a higher degree of crystallinity than other wood-based charcoals, such as oak charcoal, which is made up of turbostratic graphite, according to Raman spectroscopic research. Lithium-ion batteries employ bamboo charcoal as their anode material. At this point, the values for soft carbon were determined to be 196 mAh/g and for hard carbon to be 168 mAh/g at a current density of 0.02 A/g. [ABSTRACT FROM AUTHOR]

Quercus, commonly known as oak, has great potential as one of the most widely cultivated plant species. However, the lack of superior varieties is a bottleneck for its usage and application in Southwest China. Here, this study aims to explore the growth and photosynthetic traits of 18 oak varieties with the goal of identifying the adaptable superior varieties for the region, focusing on nutrient growth, leaf morphology, chlorophyll content, and photosynthetic parameters over a 32-week growth period. The results showed that a significant diversity was observed among the varieties. Growth rhythm and fitted curves divided the 18 oak varieties into three patterns. Additionally, for the leaf morphological parameters, Q. denta boasted the maximum leaf area (167.24 cm2), leaf width (13.62 cm), and leaf aspect ratio (156.6); Q. mongo showed the greatest leaf length (20.37 cm); while Q. acutis had the largest leaf form factor (3.44) and leaf gap (0.39). Chlorophyll content was based on three-time-points investigation, with higher levels observed in Q. mongo, Q. robur 4, Q. wutai, Q. denta, Q. acutis, and Q. robur 1. The transpiration rate (E) (5.03 mmol m−2), stomatal conductance (gsw) (0.22 mol m−2 s−1), and total water vapor conductance (gtw) (0.19 mol m−2 s−1) were dominantly obtained in Q. robur 1, while Q. denta exhibited the highest intercellular CO2 concentration (Ci) (564.67 µmol mol−1). Conversely, Q. wutai displayed a significantly higher leaf chamber CO2 concentration (Ca) (502.11 µmol mol−1). Furthermore, growth traits showed a correlation with leaf morphological and photosynthetic traits. PCA analysis grouped the oak varieties into five clusters, with Q. acutis, Q. robur 1, Q. palus 3, Q. denta, Q. nutta, Q. mongo, and Q. wutai identified as superior varieties. These findings not only offer promising oak candidate varieties for Southwest China, but also provide insights for establishing efficient breeding program for other woody plants. [ABSTRACT FROM AUTHOR]

Veteran and ancient trees are key structures sustaining biodiversity in wooded landscapes. Their value depends on tree‐related microhabitats (TreMs) such as hollows, cracks and other structures related to wounds and wood decay. Decline and loss of veteran trees results in the loss of TreMs thus threatening the biodiversity associated with them. Veteranisation, that is, interventions aimed at creating or accelerating formation of rare TreMs in live trees, are thus increasingly applied to bridge gaps in habitat continuity and sustain the biodiversity associated with veteran trees. Several studies investigated the use of artificially created TreMs by various organisms. No study has, however, investigated saproxylic beetles attracted to freshly veteranised trees, and how different veteranisation techniques affect attractivity of veteranised trees to saproxylic beetles. We veteranised 48 sessile oaks using two types of deep and two types of shallow cuts and trapped saproxylic beetles on the veteranised and control trees in the first season after the intervention. The sampling yielded 280 species (6171 individuals) of saproxylic beetles, including 64 that are threatened. Veteranised trees attracted more abundant and diverse communities than control trees. Community composition differed between shallow and deep cuts and between the two types of deep cuts. Freshly veteranised trees thus attract diverse and abundant communities of saproxylic beetles consisting mainly of species potentially exploiting the wounds. The high proportion of threatened species, often associated with old oaks, suggests that veteranised trees benefit even some threatened saproxylic biodiversity already during the first year after the veteranisation. [ABSTRACT FROM AUTHOR]

Effects of thermoplastic polyurethane (TPU) types (Recycled (R) and Virgin (V)) composites with 15 wt% and 30 wt% oakwood flour addition were studied. Selected physical, mechanical, morphological, and thermal properties of resulting polymer composites were analyzed. Test samples were manufactured using injection molding, except that abrasion resistance specimens were manufactured using a compression molding process. The findings indicated that the types of TPU and filler contents played a significant role in the density and mechanical properties of the TPU test samples. The increased oak wood flour contents in both TPU types showed improvement in density, tensile modulus, hardness, flexural strength flexural modulus, dynamic impact strength, and yield strength of the composite while decreasing the elongation at break values. In addition, both TPU types and filler contents significantly affected the densities of VTPU and R-TPU. The TPUs type, filler content, and cycle-rpm affected Taber's abrasion resistance values. Weight loss, which increased with the number of cycles for the control samples, decreased with increasing wood flour content. This study aimed to provide an overview of the effect of the wood flour content in the manufacturing of thermoplastic-reinforced composites and to provide a basis for further research and development efforts. [ABSTRACT FROM AUTHOR]

Eurasian Jays (Garrulus glandarius) typically store seeds on the ground in shallow caches, promoting tree recruitment. However, speculation exists that Eurasian Jays occasionally store a portion of seeds in microhabitats unsuitable for proper germination. Here, we report that unexpected caching sites in Eurasian Jays can be much more widespread than previously considered and despite their accidental character it seems to be a durable aspect of Eurasian Jay's hoarding behavior. Out of 259 removed acorns of Pedunculate Oak (Quercus robur), we localized 31 consumed and 222 stored acorns. Six experimental acorns (3% of stored acorns) were found stored by jays in unexpected caching sites: (i) above the ground on individuals of Scots Pine (Pinus sylvestris), (ii) inside the woody stems of Reynoutria sp. individuals, (iii) in a rotten trunk, and (iv) among ruin debris. Our findings suggest the need to revise our understanding of so-called unexpected caching in Eurasian Jays. This highlights a previously overlooked aspect of oak-jay interactions, offering a valuable piece to the puzzle. [ABSTRACT FROM AUTHOR]

This study characterizes oak (sessile and pedunculate oak) and alternative wood (black locust, Myrobalan plum, wild cherry, and mulberry) species as important sources of volatile compounds of aged spirits. Nowadays, their fragments are used to hasten the brandies' aging process. The ATR-FTIR spectra of analyzed wood samples are similar, only the mulberry FTIR spectrum contains unique peaks primarily due to its highest lignin content (40.93%). Using the untargeted GC-MS approach, a total of forty-one volatile compounds were identified in the wood extracts in a model spirit solution. The volatile profiles of alternative wood extracts in a model spirit solution were significantly different, both quantitatively and qualitatively, compared to those of oak. Coniferyl (23.14 µg/g--26.6 µg/g) and sinapyl (23.56 µg/g--25.82 µg/g) alcohols were the most abundant volatile compounds in investigated oak extracts. Resorcinol and coniferyl alcohol were the most abundant volatile compounds in black locust, sakuranin in wild cherry, while resorcinol and ß-resorcinaldehyde in mulberry wood. To the best of our knowledge, sakuranin has not been detected in wild cherry wood until now. Besides wood chemical characteristics, the technology used during the aging process strongly influences on volatile profiles of aged brandies, thus, these compounds are potential chemical markers for discrimination between wood species as well as aging technologies. [ABSTRACT FROM AUTHOR]

This research was carried out in Idlib Governorate, located in northwestern Syria, during the years 2021, 2022, and 2023. The self-environment of the Crataegus genus was also studied in the study areas, by conducting botanical surveys there, according to the Braun-Blanquet method. The results showed that Crataegus has environmental flexibility as it spreads in multiple bioclimatic environments. Specie Crataegus monogyna belonging to the order Quercetaliapubescentis, which follows the Querceteapubescentis order, whose components are part of the plant alliance Quercioninfectoriae. Which includes deciduous oak forests within the Supra-Mediterranean structure. As for the species C. azarolus, it belongs to the order Quercetaliailicis, which belongs to the class Querceteailicis, and whose components are considered within the botanical alliance QuercionCalliprini within the Eu-Mediterranean structure. In general, the hawthorn did not constitute a characteristic type of species, but was always accompanying species, and did not rise to the level of characteristic types of species included in the designation of plant communities specialized in it. [ABSTRACT FROM AUTHOR]

Wildfires are considered a major disturbance to forest ecosystems in the Mediterranean countries of Southern Europe. Although ground-dwelling macroinvertebrates are crucial to many soil functions, there is a fundamental lack of understanding of how wildfires impact this community in the immediate term and of the role of stones in their survival. Hence, in the present study we assessed the immediate effects of wildfires in the ground-dwelling macroinvertebrate community found under stones by comparing communities in burnt and non-burnt Mediterranean oak forests. Our results revealed that stones allowed the survival of many taxa in the burnt area. However, abundance, richness, diversity, and equitability per stone were significantly lower at the burnt than unburnt sites. Furthermore, the results also showed that richness and abundance increased significantly with increasing stone depth and area, both at the burnt and unburnt sites. Significant changes at the trophic level were observed in the burnt area comparing to the unburnt, particularly a decline in predators. No significant differences were identified concerning habitat associations among taxa. Overall, this study stressed the role of stones as microhabitats and refuge for the ground-dwelling macroinvertebrate community during wildfires. [ABSTRACT FROM AUTHOR]

Soil efflux of CO2 ( F CO 2 ) is known to be dependent on natural drying and rewetting of the soil. Although the central Indian Himalayan region is predominantly occupied with two ecosystems, i. e. Pine (Pinus roxburghii) and Oak (Quercus leucotrichophora), differences in their F CO 2 dynamics and responses of F CO 2 to varying wet and dry spells were hardly known. To address this knowledge gap, this study provides a comparative assessment of F CO 2 variability from Pine and Oak ecosystems of central Himalaya as a response to rainfall induced wet and dry spells of monsoon and winter seasons. The F CO 2 data presented in this study are collected for 242 days of 2021–22 that include monsoon and winter seasons from a Pine and an Oak sites. The mean F CO 2 s of Pine and Oak sites are found to be 3.95(± 0.02) and 3.61(± 0.01) μmol.m−2.s−1, respectively. We find that the winter reduction in the F CO 2 in comparison to monsoon at the Pine site (78%) is more substantial than at Oak site (64.6%). The cross wavelet spectra of F CO 2 and monsoon rainfall amount at the Oak site, unlike the Pine site, indicate a negative relationship. The rainfall spell duration and amount of monsoon wet spells are noted to have an inverse relationship with F CO 2 at both sites, although, increasing rainfall spell duration in winter is noted to increase F CO 2 at Pine and Oak sites. Similarly, increasing F CO 2 is observed with increasing dry spells of monsoon at both sites. Results of this study indicate that in comparison to Oak, F CO 2 variability at Pine ecosystem is primarily driven by abiotic factors wherein wet spell is a major determinant. [ABSTRACT FROM AUTHOR]

In the last 20 years, several techniques have been developed for quantifying DNA methylation, the most studied epigenetic marks in eukaryotes, including the gold standard method, whole-genome bisulfite sequencing (WGBS). WGBS quantifies genome-wide DNA methylation but has several inconveniences rendering it less suitable for population-scale epigenetic studies. The high cost of deep sequencing and the large amounts of data generated prompted us to seek an alternative approach. Restricting studies to parts of the genome would be a satisfactory alternative had there not been a major limitation: the need to select upstream targets corresponding to differentially methylated regions as targets. Given the need to study large numbers of samples, we propose a strategy for investigating DNA methylation variation in natural populations, taking into account the structural complexity of genomes, their size, and their content in unique coding regions versus repeated regions as transposable elements. We first identified regions of highly variable DNA methylation in a subset of genotypes representative of the biological diversity in the population by WGBS. We then analysed the variations of DNA methylation in these targeted regions at the population level by sequencing capture bisulfite (SeqCapBis). The entire strategy was then validated by applying it to another species. Our strategy was developed as a proof of concept on natural populations of two forest species: Populus nigra and Quercus petraea. [ABSTRACT FROM AUTHOR]

Increasing tree species diversity in Mediterranean forests could reduce drought‐induced hydraulic impairments through improved microclimate and reduced competition for water. However, it remains unclear if and how species diversity modulates tree hydraulic functions and how impacts may shift during the growing season. Using unmanaged Mediterranean forest stands composed of one (i.e., monospecific) or four (i.e., multispecific) tree species, we examined the seasonal dynamics of in‐situ hydraulic traits (predawn and midday leaf water potential – Ψpd and Ψmd, xylem‐ and leaf‐specific hydraulic conductivity – KS and KL, percentage loss of conductivity – PLC, specific leaf area – SLA, and Huber value – HV) in four co‐existing Pinus and Quercus species over two years. We mainly observed adverse impacts of species diversity with lower Ψpd, Ψmd, KS, KL, and higher PLC in multispecific compared to monospecific stands, especially for the two pines. These impacts were observed all along the growing season but were stronger during the driest periods of the summer. Beneficial impacts of diversity were rare and only occured for oaks (Q. faginea) after prolonged and intense water stress. Our findings reveal that mixing oaks and pines could mainly enhance hydraulic impairments for all species during the dry season, suggesting a potential decline in mixed Mediterranean forests under future climate. [ABSTRACT FROM AUTHOR]

Current wood identification struggles to differentiate white and red oak (Quercus alba and Quercus rubra) due to highly similar microstructures, as demonstrated by morphological microscope analysis. The present research explores lignin composition as a potential discriminating factor. Here, a rapid and sustainable method for extracting high‐quality lignin from oak samples using acidic γ‐valerolactone (GVL) under mild conditions is described. As‐extracted lignin is thoroughly characterized using various analytical methods, and results reveal a distinct structural difference between the lignin from the two species. White oak lignin possesses a unique “Hibbert ketone” unit detectable by nuclear magnetic resonance spectroscopy (NMR), which is absent in red oak lignin. In addition, infrared spectroscopy differentiates the species based on specific carbonyl groups present in their lignin. These findings suggest that identifying the presence of the Hibbert ketone unit in lignin may offer a highly efficient and reliable method for differentiating white and red oak, opening new avenues for wood identification. [ABSTRACT FROM AUTHOR]

The use of sustainable energy sources is an alternative for fossil fuels, which can represent a positive factor to alleviate many current environmental issues. In that sense, not only sustainable industrial development is important, but also sustainable practices at the local level, including households. Specifically, heating and cooking are one of the most important activities that require energy in households, where the role of biomass could be of interest, as it can provide an energy source with lower environmental impact. However, there is room for improvement in biomass stoves, whose adaptability to specific wastes, as well as their improvement in efficiency, should be accomplished. The aim of this work was to assess the improvement of combustion performance of a domestic stove by the implementation of a programmable logic converter for a better adaptation to different biomass samples (holm oak, pear tree, poplar, and sugarcane bagasse pellets). This work provides further information about the current working protocol, being an alternative for better approaches that could be implemented in future works. Thus, the working regime of the stove was controlled, especially concerning the screw conveyor (to regulate pellet feeding) and flue gas fan (to change oxygen supply). As a result, better combustion performances were obtained, with heat capacities from 5.66 to 8.67 kW for the selected samples. Also, thermal capacities of the stove (1.43, 1.60, 2.22, and 1.83 kW for holm oak, pear tree, poplar, and sugarcane bagasse, respectively) were obtained, with a better combustion performance compared to previous studies (1600 and 120 ppm peak emissions for CO and NOx, respectively, and 15% as the lowest O2 concentration). On the other hand, different improvements of the combustion stove to avoid blockages, for instance, are proposed as further steps. [ABSTRACT FROM AUTHOR]

Introduction: Forest assisted migration has been proposed as a means to align tree populations with shifting climate habitats under climate change. Here we report on the growth and survival of oak species and seed sources at five assisted migration trials in southern Ontario -- an important transition zone between boreal and temperate ecosystems. Methods: Each trial featured one or more oak species -- including red oak (Quercus rubra), white oak (Q. alba), burr oak (Q. macrocarpa), and swamp white oak (Q. bicolor) -- and seed sources from Ontario, Pennsylvania, and/or Tennessee. The trials were measured for survival and height at between 7 and 13 years after planting. Results: For several trials and species, southern seed sources performed nearly as well as local sources. However, southern seed sources of burr oak performed significantly worse than local sources at 2 trials in eastern Ontario. These outcomes may have been influenced by reduced quality of southern seed source planting stock at these trials. Discussion: Our findings generally support previous work that suggests northward movements of seed sources of several hundred kilometers may be safe for assisted migration efforts involving broadleaf tree species. Notably, the trial sites were located at the northern range limits of two oak species in this study (Q. alba and Q. bicolor), suggesting the potential for modest range expansions in this boreal-temperate transition zone. These findings help forest managers to better understand potential assisted migration outcomes under climate change. [ABSTRACT FROM AUTHOR]

Adaptive introgression, which can provide genetic diversity resulting in the expansion to novel habitats and the creation of different ecotypes, has been proposed in oaks (genus Quercus). In northern Japan, Quercus mongolica var. crispula (Qc) is common in inland habitats, and Quercus dentata (Qd) occurs in coastal habitats. At the northern distributional limit of Qd, Quercus × angustilepidota (Qa), a hybrid taxon between Qc and Qd, occurs in coastal habitats. These taxa, Qc, Qa, and Qd, were transplanted to inland and coastal common gardens (sites). Genotypes at 27 495 loci, phenotypes of eight leaf and shoot traits, and the size of 30‐year‐old trees were measured for 224 individuals in both sites. Genotypic variation revealed a hybrid zone between Qc and Qd, including both northern‐edge Qd admixed with Qc and coastal Qa backcrossed to Qc. Phenotypes of Qa trees were intermediate between those of Qc and Qd trees. The size of Qa and Qd trees was smaller than that of Qc trees in the inland site but was larger in the coastal site, suggesting adaptation of Qa and Qd to coastal environment. Local ancestry was estimated from phased genotypes of admixed trees using reference genotypes of 47 Qc and 25 Qd trees, indicating heterogeneous ancestry along chromosomes. Admixture mapping of local ancestry detected loci significantly associated with a leaf trait, which were located in an introgressed genomic region with genes related to stress response. Further studies are necessary to elucidate the genetic basis of adaptive introgression resulting in Qd‐like phenotypes of Qa. [ABSTRACT FROM AUTHOR]

Grammoptera ustulata (Schaller, 1783) was described from Halle environs (Germany) but its area is extending to Euro-Anatolian species of oak forests. Grammoptera ustulata var. geniculata Kraatz, 1886 from Andalusia (Spain) was known as a variation. Based on the morphological differences, the status of Grammoptera geniculata, Kraatz, 1886 should be reinstated to the species level. The present paper provides additional morphological features of this taxon. [ABSTRACT FROM AUTHOR]

The ability of plants to retain nitrogen (N) for a long period of time is critical to their N use efficiency, growth, and fitness, particularly in infertile environments. The mean residence time of leaf N (MRTL) and its two determinants, leaf lifespan and N resorption efficiency (rN, the fraction of the total leaf N pool that is resorbed during leaf senescence), have been hypothesized to increase plastically with decreasing soil N fertility but this remains to be fully tested. To avoid confusion by random changes in these characteristics in a relatively narrow N fertility range, MRTL, leaf lifespan, and N resorption efficiency were measured in Quercus glauca over a broad N fertility range. In the high to moderate N fertility range, leaf lifespan and rN increased with decreasing N addition rate, and thus the MRTL increased. However, in the moderate to low N fertility range, leaf lifespan increased but rN decreased significantly, so MRTL decreased. The decrease in rN occurred because the senesced leaf N concentration was almost constant at the lower limit while the green leaf N concentration decreased in this range. The hump‐shaped quadratic responses of MRTL and rN along the N fertility gradient suggest that incorrect conclusions about the response of these traits to N fertility variation may be drawn from experiments that include only a few fertility levels, and N recycling within leaf canopy alone cannot achieve efficient N use in infertile environments. [ABSTRACT FROM AUTHOR]

Quercus subsect. Campylolepides contains three species: Q. acutissima, Q. variabilis and Q. chenii, which is the East Asian clade of Quercus section Cerris. Species formation and phylogeography of whole subsection or species within the subsection have been studied in detail. It has been also found that section Cerris had an ancient gene introgression with section Ilex, which led to the plastid capture. However, the specific evolutionary history of plastids in subsect. Campylolepides and section Ilex remains unclear. Our study performed low-coverage whole genome sequencing on 15 samples from section Ilex and integrated previously published data from subsect. Campylolepides and its relatives, resulting in a total of 325 resequencing data, of which 276 individuals were from three subsect. Campylolepides species and 19 populations. We assembled 325 plastids to perform phylogeographic analysis. The results were as follows: (1) There were shared haplotypes among three species of subsect. Campylolepides, but the plastid haplotypes of the entire subsect. Campylolepides form a monophyletic branch nested within section Ilex species which are distributed from central China to Liangshan, Sichuan. (2) A relictual haplotype of subsect. Campylolepides from the Liaodong Peninsula clustered with Q. pseudosetulosa, a specie of the section Ilex. (3) Both plastid capture events occurred in the middle Miocene, after which no plastid capture occurred between subsect. Campylolepides and section Ilex. It is hypothesized that subsect. Campylolepides and section Ilex have formed almost complete reproductive isolation. The study demonstrates that section Ilex and subsect. Campylolepides have undergone ancient plastid capture events in their evolution history, ultimately lead to the gradual formation of relatively independent evolutionary paths. [ABSTRACT FROM AUTHOR]

Cycle‐cup oaks (Quercus section Cyclobalanopsis) are one of the principal components of forests in the tropical and subtropical climates of East and Southeast Asia. They have experienced relatively recent increases in the diversification rate, driven by changing climates and the Himalayan orogeny. However, the evolutionary history and adaptive mechanisms at the chloroplast genome level in cycle‐cup oaks remain largely unknown. Therefore, we studied this problem by conducting chloroplast genomics on 50 of the ca. 90 species. Comparative genomics and other analyses showed that Quercus section Cyclobalanopsis had a highly conserved chloroplast genome structure. Highly divergent regions, such as the ndhF and ycf1 gene regions and the petN—psbM and rpoB—trnC‐GCA intergenic spacer regions, provided potential molecular markers for subsequent analysis. The chloroplast phylogenomic tree indicated that Quercus section Cyclobalanopsis was not monophyletic, which mixed with the other two sections of subgenus Cerris. The reconstruction of ancestral aera inferred that Palaeotropics was the most likely ancestral range of Quercus section Cyclobalanopsis, and then dispersed to Sino‐Japan and Sino‐Himalaya. Positive selection analysis showed that the photosystem genes had the lowest ω values among the seven functional gene groups. And nine protein‐coding genes containing sites for positive selection: ndhA, ndhD, ndhF, ndhH, rbcL, rpl32, accD, ycf1, and ycf2. This series of analyses together revealed the phylogeny, evolutionary history, and ecological adaptation mechanism of the chloroplast genome of Quercus section Cyclobalanopsis in the long river of earth history. These chloroplast genome data provide valuable information for deep insights into phylogenetic relationships and intraspecific diversity in Quercus. [ABSTRACT FROM AUTHOR]

This work studies the influence of the thickness of oak alternatives on the composition and quality of red wines. A red wine was aged in control conditions and also in contact with oak chips, and with thin and thick oak staves for 12 months. As expected, all the wines aged in contact with all the oak alternatives were enriched in total polyphenols and had a higher colour intensity. In addition, the contact with all the oak alternatives enriched the wine in furfural and total furans, vanilla and total aldehydes and ketones, eugenol and total volatile phenols, and in β-methyl-γ-octalactones. However, the thickness of the oak alternative seems to play an important role in the composition and quality of the wine. Specifically, the wines aged in contact with the two types of staves had a more intense colour than the wine aged with oak chips, as well as a higher total phenolic index and higher eugenol concentration. Moreover, the β-methyl-γ-octalactones concentration was higher in the wine supplemented with thick staves. Finally, the wines supplemented with the two types of staves had a higher intensity of the spicy attribute than the wine aged with oak chips. The wine supplemented with thick staves had a higher intensity of candy/pastry, toasted, smoked, complexity, aromatic intensity, sweetness, structure, and persistence. Finally, the panel preferred the wine aged with thick staves followed by, in descending order, the wines aged with thin staves, oak chips, and the control. [ABSTRACT FROM AUTHOR]

To study the changes in structural characteristics of oak forests due to tree mortality, the Shalam forested area in the western Iran was selected. For this, 20 stands with different topographical conditions were selected to determine whether the stand or tree characteristics changed following tree mortality as well as were essential factors in the variation of tree mortality. In each stand, three plots of 1000 m² were established randomly and systematically, and variables of tree diameter (diameter at breast height), maximum and minimum crown diameter, origin and form of trees and shrubs of all species, crown dieback percent, and number of dead trees were measured and recorded. Results showed that the tree mortality rate in the study area averaged 35.33 trees/ha, and 97.65% of it was related to Persian oak. The amount of stand density, basal area, and canopy cover decreased by 15.7%, 14.23%, and 4.19%, respectively, due to tree mortality. The abundance of most species has decreased, and the rate of species frequency reduction was more remarkable in Persian oak and Acer monspessulanum. Of the trees, 20.37% were healthy, and 79.63% were affected by crown dieback. The highest density of tree mortality was in the diameter classes of 10–30 cm, and the highest rate of tree mortality was in the diameter classes of 5, 60, and 75 cm. Based on the dead tree density, the pattern of tree mortality was L-shaped, while based on the dead tree percentage, the pattern was U-shaped. Tree mortality correlated significantly with diameter at breast height. Multiple regression analysis also showed that tree mortality has a significant relationship with stand basal area, diameter at breast height, and stand canopy cover; so these variables played a significant role in variation of forest structure under effect of tree decline. [ABSTRACT FROM AUTHOR]

Effects of thermoplastic polyurethane (TPU) types (Recycled (R) and Virgin (V)) composites with 15 wt% and 30 wt% oakwood flour addition were studied. Selected physical, mechanical, morphological, and thermal properties of resulting polymer composites were analyzed. Test samples were manufactured using injection molding, except that abrasion resistance specimens were manufactured using a compression molding process. The findings indicated that the types of TPU and filler contents played a significant role in the density and mechanical properties of the TPU test samples. The increased oak wood flour contents in both TPU types showed improvement in density, tensile modulus, hardness, flexural strength flexural modulus, dynamic impact strength, and yield strength of the composite while decreasing the elongation at break values. In addition, both TPU types and filler contents significantly affected the densities of V-TPU and R-TPU. The TPUs type, filler content, and cycle-rpm affected Taber’s abrasion resistance values. Weight loss, which increased with the number of cycles for the control samples, decreased with increasing wood flour content. This study aimed to provide an overview of the effect of the wood flour content in the manufacturing of thermoplastic-reinforced composites and to provide a basis for further research and development efforts.

Abstract This study aimed to investigate the performance and factors affecting the species classification of convolutional neural network (CNN) architecture using whole-part and earlywood-part cross-sectional datasets of six Korean Quercus species. The accuracy of species classification for each condition was analyzed using the datasets, data augmentation, and optimizers—stochastic gradient descent (SGD), adaptive moment estimation (Adam), and root mean square propagation (RMSProp)—based on a CNN architecture with three to four convolutional layers. The model trained with the augmented dataset yielded significantly superior results in terms of classification accuracy compared to the model trained with the non-augmented dataset. The augmented dataset was the only factor affecting classification accuracy in the final five epochs. In contrast, four factors in the entire epoch, such as the Adam and SGD optimizers and the earlywood-part and whole-part datasets, affected species classification. The arrangement of earlywood vessels, broad rays, and axial parenchyma was identified as a major influential factor in the CNN species classification using gradient-weighted class activation mapping (Grad-CAM) analysis. The augmented whole-part dataset with the Adam optimizer achieved the highest classification accuracy of 85.7% during the final five epochs of the test phase.

Establishment of oak seedlings, which is an important factor in forest restoration, is affected by drought that hampers the survival, growth, and development of seedlings. Therefore, it is necessary to understand how seedlings respond to and recover from water-shortage stress. We subjected seedlings of two oak species, Quercus acutissima and Quercus palustris, to drought stress for one month and then rewatered them for six days to observe physiological and genetic expression changes. Phenotypically, the growth of Q. acutissima was reduced and severe wilting and recovery failure were observed in Q. palustris after an increase in plant temperature. The two species differed in several physiological parameters during drought stress and recovery. Although the photosynthesis-related indicators did not change in Q. acutissima, they were decreased in Q. palustris. Moreover, during drought, content of soluble sugars was significantly increased in both species, but it recovered to original levels only in Q. acutissima. Malondialdehyde content increased in both the species during drought, but it did not recover in Q. palustris after rewatering. Among the antioxidant enzymes, only superoxide dismutase activity increased in Q. acutissima during drought, whereas activities of ascorbate peroxidase, catalase, and glutathione reductase increased in Q. palustris. Abscisic acid levels were increased and then maintained in Q. acutissima, but recovered to previous levels after rewatering in Q. palustris. RNA samples from the control, drought, recovery day 1, and recovery day 6 treatment groups were compared using transcriptome analysis. Q. acutissima exhibited 832 and 1076 differentially expressed genes (DEGs) related to drought response and recovery, respectively, whereas Q. palustris exhibited 3947 and 1587 DEGs, respectively under these conditions. Gene ontology enrichment of DEGs revealed "response to water," "apoplast," and "Protein self-association" to be common to both the species. However, in the heatmap analysis of genes related to sucrose and starch synthesis, glycolysis, antioxidants, and hormones, the two species exhibited very different transcriptome responses. Nevertheless, the levels of most DEGs returned to their pre-drought levels after rewatering. These results provide a basic foundation for understanding the physiological and genetic expression responses of oak seedlings to drought stress and recovery. [ABSTRACT FROM AUTHOR]

Key Message: Leaves of seedlings from five oak species (Quercus robur L.; Q. pubescens L.; Q. suber L.; Q. afares Pomel; Q. ilex L.) displayed large, mainly inter-specific, differences in leaf mass-to-area ratio (LMA) and lignin content, as well as in the 13C composition of bulk leaf biomass. The variation in leaf lignin content and LMA did not impact the offset between the 13C composition measured in bulk leaf material versus soluble sugars. This observation, as well as the similar correlations between intrinsic leaf water use efficiency and the 13C compositions of bulk material or soluble sugars extracted from leaves, confirms their reliable use as a proxy for the former even when there is a large variation in LMA or lignin among samples. Context: Carbon isotope composition (δ13C) of bulk leaf biomass is frequently used as a proxy for intrinsic water use efficiency (iWUE) in large-scale intra- and inter-specific comparisons. However, post-photosynthetic 13C discrimination during the synthesis of lignin combined with differences in leaf mass-to-area ratio (LMA) may bias the relationship between δ13C of bulk leaf matter and iWUE and thus its use as a proxy of iWUE. Aims: To quantify the impact of differences in lignin content and LMA on the relationship between δ13C of bulk leaf biomass and iWUE over a large gradient of lignin contents across five oak species (deciduous: Quercus robur, Q. pubescens, Q. afares and evergreen: Q. ilex and Q. suber). Methods: We measured lignin content, LMA, and δ13C of bulk leaf biomass and of soluble sugars extracted from the leaves, as well as intrinsic water use efficiency (derived from leaf gas exchange) in seedlings of the five oak species grown under common conditions in a greenhouse and measured in a climate chamber. Results: There was a large range (mainly across species) in lignin content (4 to 33%) and LMA (60–180 g m−2). δ13C of bulk leaf biomass and soluble sugars were tightly correlated, showing a significant mean offset of − 0.4‰. This offset was stable across species and not correlated to the lignin content of the leaves. A very loose correlation was found between the offset and LMA, mainly due to one species. Conclusion: Our results are a demonstration that potential variations in leaf lignin content or LMA have no or only a little effect on the δ13C of bulk leaf biomass. They are unlikely to cause a bias when using bulk leaf δ13C as a proxy for variations in intrinsic water use efficiency among Mediterranean and temperate broad-leaf forest tree species. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the performance and factors affecting the species classification of convolutional neural network (CNN) architecture using whole-part and earlywood-part cross-sectional datasets of six Korean Quercus species. The accuracy of species classification for each condition was analyzed using the datasets, data augmentation, and optimizers—stochastic gradient descent (SGD), adaptive moment estimation (Adam), and root mean square propagation (RMSProp)—based on a CNN architecture with three to four convolutional layers. The model trained with the augmented dataset yielded significantly superior results in terms of classification accuracy compared to the model trained with the non-augmented dataset. The augmented dataset was the only factor affecting classification accuracy in the final five epochs. In contrast, four factors in the entire epoch, such as the Adam and SGD optimizers and the earlywood-part and whole-part datasets, affected species classification. The arrangement of earlywood vessels, broad rays, and axial parenchyma was identified as a major influential factor in the CNN species classification using gradient-weighted class activation mapping (Grad-CAM) analysis. The augmented whole-part dataset with the Adam optimizer achieved the highest classification accuracy of 85.7% during the final five epochs of the test phase. [ABSTRACT FROM AUTHOR]

The tussock moth, Orgyia trigotephras Boisduval (Lepidoptera: Erebidae), is one of the main emerging pests of kermes oak, Quercus coccifera L. (Fagaceae), in the Mediterranean area, where it can cause the defoliation of several hectares of forests during its population outbreaks. Despite this, no specific sampling procedures to properly estimate the population density of this pest have been developed yet. The aims of this research were to develop and compare enumerative and binomial sequential sampling plans to estimate the population density of O. trigotephras in forest environments. Data were collected in four forest stands dominated by Q. coccifera in Tunisia for 7 years (from 2013 to 2019) to take into consideration the potential spatio‐temporal variability in pest density. Plant community composition was determined at the beginning of the experimental trials, and enumerative and binomial sampling plans were developed at precision levels of 0.15 and 0.25. Over the entire sampling period, the average O. trigotephras egg batch density differed significantly among sites. Sample sizes of enumerative sampling plans were approximately 39 and 109 trees to estimate an average density of 0.50 O. trigotephras egg batches per tree at the precision levels of 0.25 and 0.15, respectively. Instead, binomial sequential sampling plans required smaller sampling sizes than the enumerative sampling plan. Our findings represent the baseline to develop a program for monitoring O. trigotephras at a large spatial scale. [ABSTRACT FROM AUTHOR]

Oak gall wasps have evolved strategies to manipulate the developmental pathways of their host to induce gall formation. This provides shelter and nutrients for the developing larva. Galls are entirely host tissue; however, the initiation, development, and physical appearance are controlled by the inducer. The underlying molecular mechanisms of gall formation, by which one or a small number of cells are reprogrammed and commit to a novel developmental path, are poorly understood. In this study, we sought a deeper insight into the molecular underpinnings of this process.Oak gall wasps have two generations each year, one sexual, and one asexual. Galls formed by these two generations exhibit a markedly different appearance. We sequenced transcriptomes of both the asexual and sexual generations of Neuroterus quercusbaccarum and Neuroterus numismalis. We then deployed Nanopore sequencing to generate long‐read sequences to test the hypothesis that gall wasps introduce DNA insertions to determine gall development.We detected potential genome rearrangements but did not uncover any non‐host DNA insertions. Transcriptome analysis revealed that transcriptomes of the sexual generations of distinct species of wasp are more similar than inter‐generational comparisons from the same species of wasp.Our results highlight the intricate interplay between the host leaves and gall development, suggesting that season and requirements of the gall structure play a larger role than species in controlling gall development and structure. [ABSTRACT FROM AUTHOR]

Urban trees possess different capacities to mitigate ozone (O3) pollution through stomatal uptake. Stomatal closure protects trees from oxidative damage but limits their growth. To date, it is unclear how plant hydraulic function affect stomatal behaviour and determine O3 resistance. We assessed gas exchange and hydraulic traits in three subtropical urban tree species, Celtis sinensis, Quercus acutissima, and Q. nuttallii, under nonfiltered ambient air (NF) and elevated O3 (NF60). NF60 decreased photosynthetic rate (An) and stomatal conductance (gs) only in Q. acutissima and Q. nuttallii. Maintained An in C. sinensis suggested high O3 resistance and was attributed to higher leaf capacitance at the full turgor. However, this species exhibited a reduced stomatal sensitivity to vapour pressure deficit and an increased minimal gs under NF60. Such stomatal dysfunction did not decrease intrinsic water use efficiency (WUE) due to a tight coupling of An and gs. Conversely, Q. acutissima and Q. nuttallii showed maintained stomatal sensitivity and increased WUE, primarily correlated with gs and leaf water relations, including relative water content and osmotic potential at turgor loss point. Our findings highlight a trade‐off between O3 resistance and stomatal functionality, with efficient stomatal control reducing the risk of hydraulic failure under combined stresses. Summary statement: A trades‐off between O3 resistance and stomatal functionality existed in subtropical urban greening trees, where species with high O3 resistance exhibited stomatal dysfunction. Tight stomatal control in O3‐stressed trees increased water use efficiency under the regulation of leaf water relations. [ABSTRACT FROM AUTHOR]

Resolving evolutionary relationships among closely related species with interspecific gene flow is challenging. Genome‐scale data provide opportunities to clarify complex evolutionary relationships in closely related species and to observe variations in species relationships across the genomes of such species. The Himalayan–Hengduan subalpine oaks have a nearly completely sympatric distribution in southwest China and probably constitute a syngameon. In this study, we mapped resequencing data from different species in this group to the Quercus aquifolioides reference genome to obtain a high‐quality filtered single nucleotide polymorphism (SNP) dataset. We also assembled their plastomes. We reconstructed their phylogenetic relationships, explored the level and pattern of introgression among these species and investigated gene tree variation in the genomes of these species using sliding windows. The same or closely related plastomes were found to be shared extensively among different species within a specific geographical area. Phylogenomic analyses of genome‐wide SNP data found that most oaks in the Himalayan–Hengduan subalpine clade showed genetic coherence, but several species were found to be connected by introgression. The gene trees obtained using sliding windows showed that the phylogenetic relationships in the genomes of oaks are highly heterogeneous and therefore highly obscured. Our study found that all the oaks of the Himalayan–Hengduan subalpine clade from southwest China form a syngameon. The obscured phylogenetic relationships observed empirically across the genome are best explained by interspecific gene flow in conjunction with incomplete lineage sorting. [ABSTRACT FROM AUTHOR]

The effect of invertebrates like termites and beetle larvae on dead wood could be time-dependent due to changes in wood traits and invertebrate species composition over time. This study assessed changes in the impact of termites and beetle larvae on dead wood decomposition in two tree species, Pinus densiflora and Quercus acutissima, in South Korea over a 6-year period (2016–2022). Wood samples were prepared, with half of them encased in a stainless-steel mesh to prevent access by invertebrates larger than 0.26 mm. These samples were placed in three regions representative of different environments in South Korea (southern, eastern, and western). Significant variations in the mass loss of dead wood were observed based on the tree species, region, and time (p < 0.05). The mean standardized invertebrate effect, assessed with Hedges' d and a 95% confidence interval, was 0.83 ± 2.19 for P. densiflora and 1.08 ± 2.26 for Q. acutissima. Termites were found in the southern and western regions, with the highest invertebrate effect after two years. Our results indicate that the influence of invertebrates, especially termites, on dead wood decomposition could be most significant during the initial decomposition stages, as noted in the southern region of this research. [ABSTRACT FROM AUTHOR]

The inter- and intra-specific structure of genetic variability was studied using 18 microsatellite loci (nSSRs) in closely related roburoid white oaks in the Crimean-Caucasian region. The seven most widespread Quercus taxa in the region were studied in 29 morphologically pure populations from different parts of the North Caucasus, Transcaucasia, Crimea and northeastern Europe. Most taxa were studied using nSSR markers for the first time. Among the 492 trees studied, Bayesian clustering method implemented in STRUCTURE identified clusters corresponding to the pedunculate oak Quercus robur, the Hartwiss oak Q. hartwissiana, the Caucasian oak Q. macranthera, the downy oak Q. pubescens and three subspecies of sessile oak: Q. petraea ssp. petraea, Q. petraea ssp. iberica, Q. petraea ssp. medwediewii. Geographic structure was identified within Q. robur, Q. pubescens and Q. p. ssp. petraea. The 18 nSSR loci used are efficient in the taxonomic assignment of individuals, and identifying hybrids. The close relationship between the "long-peduncle" roburoid oaks (Q. robur and Q. hartwissiana) is shown, with a greater difference from other species. For one of the subspecies of sessile oak, widespread in the North Caucasus and Crimea Q. petraea ssp. medwediewii (syn. Q. calcarea), or limestone oak, significant differences from other taxa were found, reaching the inter-species level. The assumption of a possible hybrid origin of this taxon as a result of hybridization of Q. petraea and Q. pubescens is not confirmed by genetic analysis. The other two subspecies of Q. petraea (Q. p. ssp. petraea and Georgian durmast oak Q. p. ssp. iberica) are differentiated to a lesser extent and are related to each other, which confirms the legitimacy of distinguishing two geographically isolated taxa at the rank of subspecies. The highest variability was observed in Q. pubescens (He = 0.777). In Q. p. ssp. medwediewii variability was lower than in other widespread taxa (He = 0.652), and was approximately at the level of variability of Q. hartwissiana (He = 0.633) and Q. macranthera (He = 0.659). Clear differentiation of taxa by nuclear markers shows the limited introgression in closely related oak species in the Caucasus and Crimea. The identified genetic clusters can be used as reference groups for further population genetic studies of oaks in the Crimean-Caucasian region. [ABSTRACT FROM AUTHOR]

Heatwaves and soil droughts are increasing in frequency and intensity, leading many tree species to exceed their thermal thresholds, and driving wide‐scale forest mortality. Therefore, investigating heat tolerance and canopy temperature regulation mechanisms is essential to understanding and predicting tree vulnerability to hot droughts. We measured the diurnal and seasonal variation in leaf water potential (Ψ), gas exchange (photosynthesis Anet and stomatal conductance gs), canopy temperature (Tcan), and heat tolerance (leaf critical temperature Tcrit and thermal safety margins TSM, i.e., the difference between maximum Tcan and Tcrit) in three oak species in forests along a latitudinal gradient (Quercus petraea in Switzerland, Quercus ilex in France, and Quercus coccifera in Spain) throughout the growing season. Gas exchange and Ψ of all species were strongly reduced by increased air temperature (Tair) and soil drying, resulting in stomatal closure and inhibition of photosynthesis in Q. ilex and Q. coccifera when Tair surpassed 30°C and soil moisture dropped below 14%. Across all seasons, Tcan was mainly above Tair but increased strongly (up to 10°C > Tair) when Anet was null or negative. Although trees endured extreme Tair (up to 42°C), positive TSM were maintained during the growing season due to high Tcrit in all species (average Tcrit of 54.7°C) and possibly stomatal decoupling (i.e., Anet ≤0 while gs >0). Indeed, Q. ilex and Q. coccifera trees maintained low but positive gs (despite null Anet), decreasing Ψ passed embolism thresholds. This may have prevented Tcan from rising above Tcrit during extreme heat. Overall, our work highlighted that the mechanisms behind heat tolerance and leaf temperature regulation in oak trees include a combination of high evaporative cooling, large heat tolerance limits, and stomatal decoupling. These processes must be considered to accurately predict plant damages, survival, and mortality during extreme heatwaves. [ABSTRACT FROM AUTHOR]

Quercus griffithii is an ecologically and economically important tree species utilized for firewood, fodder, compost, and building-making. It is also a good source of food for wildlife. The genetic diversity of Q. griffithii is poorly understood; therefore, in the present study, 16 polymorphic SSR markers were used to assess the extent and pattern of genetic diversity in Q. griffithii samples collected from the northeastern region of India. The SSR markers revealed significant discriminating power (PIC range, 0.15˗0.81) and resulted in the amplification of 119 alleles. At the species level, it showed moderate levels of genetic diversity (Ho = 0.47; He = 0.52) with low genetic differentiation (FST = 0.06) and high gene flow (Nm = 3.91). Two genetic clusters, with high admixture populations were estimated in the Bayesian analysis of STRUCTURE, which was in accordance with clusters of UPGMA and PCoA. This is the first study to assess genetic diversity using SSR markers in Q. griffithii. The genetic information generated in this study will be helpful in the future conservation and restoration of Q. griffithii in the northeastern region of India. [ABSTRACT FROM AUTHOR]

This paper presents the results of static and dynamic crushing of sandwich tubes with carbon or glass skins and different wood cores. Wood cores were made with poplar, birch, or oak veneer. The core thicknesses of the tubes were equal even if the thicknesses of the species veneers were different for availability reasons. For a tube with a birch core and carbon skins, the Specific Energy Absorption was 50.4 J/g in quasi-static tests and 66.6 J/g in dynamic, and the energy absorbed was 5427 J in quasi-static and 7025 J in dynamic. The birch layers were shown to make a very significant contribution although they were 40 times less expensive than carbon layers. Results from the research work described here show that these materials are appropriate candidates for energy absorption at low carbon emission and with renewable materials. [ABSTRACT FROM AUTHOR]

Quercus rehderiana Hand.-Mazz. belongs to Quercus sect. Heteroallenes' of the Fagaceae family. It is widely distributed in forests with rocky and non-rocky desertification in Guizhou Province of Southwest China. However, our knowledge of the adaptation strategies of Quercus in forests with rocky desertification is surprisingly lacking. In this study, 16 leaf traits (morphological, anatomical, and chemical) of Quercus rehderiana were investigated in 15 individuals in five 20 × 20 m quadrants of forests with rocky and non-rocky desertification. The aim was to analyze their strategies of adaptation to arid and poor-soil environments in forests with rocky desertification. The results showed that Quercus rehderiana leaves in forests with rocky desertification had a greater leaf thickness, specific leaf area, abaxial epidermis thickness, and sponge mesophyll thickness but a lower leaf area than in forests with non-rocky desertification. Quercus rehderiana leaves in forests with rocky desertification had higher calcium and magnesium concentrations and a higher N:P ratio but lower potassium and phosphorus concentrations than in forests with non-rocky desertification. The results of principal component analysis showed that forests with rocky desertification tended to show resource-conserving strategies with thicker leaf tissue and a lower nutrient concentration, while forests with non-rocky desertification tended to show resource acquisition strategies with a greater leaf area and potassium concentration. In resource-poor environments, species that adopt conservative resource strategies are more likely to survive; therefore, we forecasted that more conservative, slow-growing Quercus rehderiana will be more stable over time. [ABSTRACT FROM AUTHOR]

Oak is one of the most economically important hardwood tree species in Europe, and its prevalence will increase due to progressing global climate change, according to predictive models. With the increasing demand for timber and with the need for a balance between carbon emissions and sequestration, it is essential to address the afforestation of agricultural land. Therefore, this research aimed to investigate the physico-mechanical properties and anatomical structure of pendulate oak (Quercus robur L.) wood—specifically focusing on the trunk's cross-section—in post-agricultural areas compared with the forest land in the western part of Poland. Wood density, bending strength, modulus of elasticity, and other parameters were analyzed from 1626 wood samples. The analysis of physico-mechanical properties reveals that, historically, agricultural land use has an almost negligible impact on wood quality. Despite significant differences in small vessel diameter and fiber length favoring trees from post-agricultural land, the physico-mechanical properties remain consistent. Large vessel measurements show comparable diameter and length in both land types. These findings suggest that post-agricultural land can serve as an effective alternative for high-quality pendulate oak wood production for industrial purposes. However, wood from post-agricultural land may exhibit a decrease in modulus of rupture by over 30% and potentially lower density above the trunk's halfway point. This observation hints at the fact that oak trees in post-agricultural areas could be cultivated in shorter rotation periods compared to forest land. [ABSTRACT FROM AUTHOR]

Plantations are increasing in frequency and extent across the landscape, especially in China, and forest thinning can accelerate the development of late-successional attributes, thereby enhancing plantation stand structural heterogeneity. To quantify the effect of forest restoration thinning on the spatial heterogeneity and the structure of Quercus variabilis plantations, a restoration thinning experiment in a 40-year-old Quercus variabilis plantation by removing trees from the upper canopy level was conducted; two one-hectare sample plots with thinning and a control (i.e., unlogged) were sampled; and geostatistics methods were used to analyze the spatial distribution pattern of the DBH, height, and density of the stand. We found that restoration forest thinning in the Quercus variabilis plantation had a significant impact on the average DBH and tree height of the stand. Meanwhile, the coefficient of variation and structure ratio of the DBH, tree height, and stand density in the thinning plot were larger than those in the control plot. The range and spatial autocorrelation distance of the DBH and stand density in the thinning plot were smaller than those in the control plot, but the fractal dimension showed the opposite trend. The range and spatial autocorrelation distance of tree height in the thinning plot were higher than those in the control plot. These findings suggested that, compared with the control plot, the stereoscopic distribution of the DBH and stand density in the thinning plot fluctuated less and changed gentler, and its spatial continuity was not high but its variation was significant; meanwhile, the stereoscopic distribution of the tree height in the thinning plot was highly fluctuating and changed more significantly, with a strong spatial dependence and strip gradient distribution. Hence, forest restoration thinning could improve the distribution of the DBH and stand density and adjust the spatial heterogeneity of the DBH, tree height, and stand density of Quercus variabilis plantations. [ABSTRACT FROM AUTHOR]

Background: The extent of past Indigenous cultural burning in the eastern US remains contested. Historical documents (e.g. early histories, journals, and reports) contain descriptions of burning. Scholars have summarised descriptions, but few have compiled them into databases. Aims: This paper presents efforts to compile descriptions of past Indigenous burning in the eastern US and early results from mapped descriptions. Methods: Utilising previously cited descriptions and those discovered from digitised historical texts, the current dataset mapped >250 descriptions of burning in the northeastern US. Most were historical summaries from 19th century authors, and fewer were firsthand observations. Descriptions are currently shared as a GIS data layer, a tabular file, and an interactive web map. Key results: Descriptions correspond with fire-adapted vegetation, and clusters of descriptions suggest burning over large extents (e.g. southern New England, western New York). Estimated dates of burning or initial Euro-American settlement show an east–west succession in Indigenous fire exclusion and replacement with early Euro-American burning. Conclusions: Historical descriptions suggest regional-extent influence of Indigenous burning upon past forested ecosystems, but the veracity of descriptions should be carefully evaluated. Implications: This study provides a dataset for further examination of Indigenous burning and comparison with other methodologies for historical cultural fire reconstruction. This study creates a dataset of historical descriptions of Indigenous wildland burning from digitised historical texts in the eastern US. The current version of the dataset contains >250 descriptions in the northeastern US, mainly from 19th century historians. Descriptions correspond with geographic patterns in past fire-adapted vegetation. [ABSTRACT FROM AUTHOR]

Herbivory is a fundamental ecological force in the evolution of plant physiological, morphological, and chemical attributes. In this study, we explored how browsing pressure by local deer populations affected leaf form and function in two California native tree species, Quercus agrifolia (coast live oak) and Umbellularia californica (California bay laurel). Specifically, we investigated how leaf and stem vascular attributes differed between browsed and non-browsed zones of each species. Browsing significantly altered traits such as leaf to phloem ratios and leaf area, but we observed few meaningful differences in leaf and stem anatomy between browsed and non-browsed material. We discuss these results in the context of leaf and stem adaptations to herbivory and water use efficiency and explore future research considerations for investigating leaf and stem vascular trait development with herbivore presence. [ABSTRACT FROM AUTHOR]

This study aimed to investigate and compare the non-anatomical characteristics of six Korean oak wood species (Quercus variabilis, Q. serrata, Q. mongolica, Q. dentata, Q. aliena and Q. acutissima) to provide identification keys and quality indices for the effective utilization of these species. Non-anatomical characteristics, including heartwood fluorescence, fluorescence and color of water and ethanol extracts, froth test, chrome azurol S test and burning splinter test, were evaluated according to the International Association of Wood Anatomists (IAWA) lists. None of the six Korean oak species displayed heartwood fluorescence or fluorescence in the ethanol extract. Only Q. serrata exhibited bright blue fluorescence in the aqueous extract. Each species showed distinct colors in both water and ethanol extracts, and the water extract of all species was darker than that of the ethanol extract. A weak positive reaction in the froth test was observed only for Q. serrata. Furthermore, Q. variabilis and Q. acutissima showed positive reactions to both heartwood and sapwood in the chrome azurol S test. The burning splinter test revealed that only Q. acutissima was transformed into charcoal. Thus, water extract fluorescence and color, ethanol extract color, froth test, chrome azurol S test, and burning splinter test can be used to identify the six Korean oak species. [ABSTRACT FROM AUTHOR]

Background: Organisms frequently experience environmental stresses that occur in predictable patterns and combinations. For wild Saccharomyces cerevisiae yeast growing in natural environments, cells may experience high osmotic stress when they first enter broken fruit, followed by high ethanol levels during fermentation, and then finally high levels of oxidative stress resulting from respiration of ethanol. Yeast have adapted to these patterns by evolving sophisticated "cross protection" mechanisms, where mild 'primary' doses of one stress can enhance tolerance to severe doses of a different 'secondary' stress. For example, in many yeast strains, mild osmotic or mild ethanol stresses cross protect against severe oxidative stress, which likely reflects an anticipatory response important for high fitness in nature. Results: During the course of genetic mapping studies aimed at understanding the mechanisms underlying natural variation in ethanol-induced cross protection against H2O2, we found that a key H2O2 scavenging enzyme, cytosolic catalase T (Ctt1p), was absolutely essential for cross protection in a wild oak strain. This suggested the absence of other compensatory mechanisms for acquiring H2O2 resistance in that strain background under those conditions. In this study, we found surprising heterogeneity across diverse yeast strains in whether CTT1 function was fully necessary for acquired H2O2 resistance. Some strains exhibited partial dispensability of CTT1 when ethanol and/or salt were used as mild stressors, suggesting that compensatory peroxidases may play a role in acquired stress resistance in certain genetic backgrounds. We leveraged global transcriptional responses to ethanol and salt stresses in strains with different levels of CTT1 dispensability, allowing us to identify possible regulators of these alternative peroxidases and acquired stress resistance in general. Conclusions: Ultimately, this study highlights how superficially similar traits can have different underlying molecular foundations and provides a framework for understanding the diversity and regulation of stress defense mechanisms. [ABSTRACT FROM AUTHOR]