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Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines. In the present study, the aroma compounds were analyzed from the ‘Merlot’ dry red wines, which were fermented in two types of fermenters (stainless steel tank and rotated oak barrel) and aged in six types of oak barrels (three geographic origins × two toasting degrees) for different time (0, 3, 6 and 9 months, respectively). Results showed that 30 volatiles were associated with barrels and increased during oak aging. The fermenters could influence the intensities of the toast, leathery, smoky, fruity, floral and caramel aromas. The concentration of whisky lactone, eugenol, cis-isoeugenol, and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels. The concentrations of guaiacol, syringol, trans-isoeugenol, furfural alcohol, vanilla, cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones. The compounds originating from the barrels could be used to distinguish the types of different barrels, but the other general grape-derived and fermentation-derived volatiles could not. The fermenters, oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged ‘Merlot’ dry red wines, but the influence of the geographic origin was not obvious.

Quercus arkansana (Arkansas oak) is at risk of becoming endangered, as the total known population size is represented by a few isolated populations. The potential impact of climate change on this species in the near future is high, yet knowledge of its predicted effects is limited. Our study utilized the biomod2 R package to develop habitat suitability ensemble models based on bioclimatic and topographic environmental variables and the known locations of current distribution of Q. arkansana. We predicted suitable habitats across three climate change scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5) for 2050, 2070, and 2090. Our findings reveal that the current suitable habitat for Q. arkansana is approximately 127,881 km2 across seven states (Texas, Arkansas, Alabama, Louisiana, Mississippi, Georgia, and Florida); approximately 9.5% is encompassed within state and federally managed protected areas. Our models predict that all current suitable habitats will disappear by 2050 due to climate change, resulting in a northward shift into new regions such as Tennessee and Kentucky. The large extent of suitable habitat outside protected areas suggests that a species-specific action plan incorporating protected areas and other areas may be crucial for its conservation. Moreover, protection of Q. arkansana habitat against climate change may require locally and regionally focused conservation policies, adaptive management strategies, and educational outreach among local people. [ABSTRACT FROM AUTHOR]

Traditionally, due to its light ecology, oak is regenerated on clear cuts or areas where the crown coverage is heavily reduced. Thus, the regeneration phase is relatively short. Recently, selective long-term regeneration phases avoiding large gaps in the canopy but fostering mixed-species stands have been advocated as being more in keeping with close-to-nature forestry in Central European forests. However, examples of the successful regeneration of oak in mixtures following this type of regeneration are largely missing. Here, we report the results of long-term experiments located in three different forest types, where oak was long-term regenerated under different mixing and canopy cover situations. The observation periods reached from 26 to 36 years. We focused on the dynamics of stem number reduction, as well as the height and biomass development of oaks and their interaction with interspecific competition and canopy density. The probability of oaks occurring in the regeneration basically decreased over the duration of the regeneration period. Despite this, considerable regeneration biomass growth could be observed, especially in the case of the lower standing volume of the mature stand. The development of beech as the main competitor is scarcely slowed down by the canopy cover compared to oak. Increasing canopy cover noticeably impeded oak regeneration in the considered mixed stands. The model results suggest that a reduction in competition within the regeneration by lowering the proportion of beech below 30% enhanced the success of oak regeneration in the long run even in small patches. The productivity of the remaining stand was primarily driven by standing volume. However, a negative trend of its productivity emerged with high regeneration biomasses. The study results show that small-scale oak regeneration with prolonged regeneration duration is possible in principle. However, oak regeneration requires active and continuous silvicultural assistance, which has to be adjusted to the specific site conditions. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effects of water-deficit stress on the leaf anatomical traits, physiological traits, and stem starch content in Quercus acutissima Carruth and Quercus serrata Murray by subjecting their seedlings to well-watered (WW) and water-deficit stress (WS) treatments. The water stress-induced changes in trichome density, trichome-to-stomata ratio, mesophyll thickness, vein density, vein distance, vein loopiness, vessel diameter, transpiration (E), stomatal conductance (gs), water use efficiency (WUE), and starch content were analyzed between two time points. While trichome density did not vary between treatments in Q. acutissima, it dramatically increased in Q. serrata (62.63–98.96 trichomes mm−2) at the final week. The WS-treated seedlings had a thicker palisade mesophyll (162.85–169.56 µm) than the WW-treated samples (118.56–132.25 µm) in both species. The vein density and loopiness increased significantly in the WS-treated Q. serrata seedlings. Small-sized vessels (10–50 µm) were more frequent in the WS than the WW in Q. serrata. The E, gs, WUE, and starch content declined significantly in the WS-treated seedlings compared with WW-treated samples in both species. Further, principal component analysis revealed significant relationships between anatomical and physiological traits, particularly in the WS-treated seedlings of Q. serrata. The coordinated changes in leaf anatomical traits, physiological traits, and stem starch content indicate an important role in the survival of Q. acutissima and Q. serrata seedlings in water-deficit stress environments, although Q. serrata may show higher survivability under prolonged water stress than Q. acutissima. [ABSTRACT FROM AUTHOR]

Antheraea proylei Jolly (Lepidoptera: Saturniidae), a polyphagous insect feds on different species of Quercus. Nutritional parameters like consumption, assimilation, tissue growth, AD, ECD and ECI were observed forAntheraea proylei on two host plants Quercusfloribunda Lindl. (Fagales: Fagaceae) and Quercus glauca Thunb (Fagales: Fagaceae) during spring and autumn seasons under laboratory conditions. During spring season, total larval duration from 1st to 5th larvae was 33.0 and 42.8 days when fed on Q. floribunda and Q. glauca, respectively. The rate of nutrition for all the five larval instars was directly influenced by the quality of leaves provided in both the seasons. Consumption was higher during spring season as compared to autumn season. Larval tissue growth on two host plants was higher due to higher consumption in spring season as compare to autumn season. ECD and ECI were maximum for the 5th instar larva, while AD decreased gradually from first to fifth instar larvae on both food plants. [ABSTRACT FROM AUTHOR]

Quercus -dominated forests are among the most important broad-leaved evergreen forests of the Hindu Kush ranges and are currently prone to drastic anthropogenic and climatic changes. The aim of this study was to provide basic data for the development of a regional oak forest ecosystem framework for ecological restoration and management plan development to maintain local peoples' livelihoods. Hence, we analyzed distribution patterns and environmental factors that affect regional oak forests' species composition and diversity. Ward's Agglomerative clustering divided oak-dominated forest communities into three groups: i.e., Group I, dominated by Quercus baloot had an importance value index (IVI) of 89.87 ± 4.31, Group II, dominated by Quercus dilatata had an IVI of 32.16 ± 15.01, and Group III, dominated by Quercus oblongata had an IVI of 83.14 ± 4.67, respectively. The environmental factors which vary significantly within these communities were latitude, elevation, clay content and bulk density of the soil. Wilting point, saturation point, and electrical conductivity were also considered as ecosystem structural variables. Canonical correspondence analysis (CCA) indicated that community structure was affected by various environmental factors including precipitation, slope angle, elevation, clay content, and relative humidity. [ABSTRACT FROM AUTHOR]

Aims Understanding variation and coordination of leaf traits at multiscales along elevational gradients can help predict the likely responses of dominant species to climate change. We seek to determine the extent to which variation in leaf stomatal, anatomical and morphological traits is associated with environmental factors, and whether ecological strategies of Cyclobalanopsis species shift with elevations. Methods In a tropical forest landscape in Jianfengling, South China, we determined leaf traits related to stomata, anatomy and morphology of six evergreen oak species (Cyclobalanopsis bambusaefolia , C. hui , C. patelliformis , C. fleuryi , C. tiaoloshanica and C. phanera) along a long elevational gradient (400–1400 m above sea level). Important Findings We found that stomatal density and stomatal pore index increased, whereas spongy mesophyll thickness to leaf thickness ratios decreased, significantly with elevation. The leaf area and leaf dry matter content increased and decreased, respectively, with elevation. Variations in stomatal, anatomical and morphological traits were mainly correlated to the mean annual temperature, mean annual sum precipitation and soil pH. At low and high elevations, the oak species exhibited strong stress tolerance combined with competition strategy, while they shifted toward more clearly the competitive strategy at intermediate elevations. And the changes in soil phosphorus concentration and soil pH along the elevation may drive the shift of ecological strategy. The results showed that the dominant oak species in tropical forests respond to environmental change by modulating traits at multiple levels, from that of the individual cell, through tissue and up to the whole leaf scale. [ABSTRACT FROM AUTHOR]

Traditionally, due to its light ecology, oak is regenerated on clear cuts or areas where the crown coverage is heavily reduced. Thus, the regeneration phase is relatively short. Recently, selective long-term regeneration phases avoiding large gaps in the canopy but fostering mixed-species stands have been advocated as being more in keeping with close-to-nature forestry in Central European forests. However, examples of the successful regeneration of oak in mixtures following this type of regeneration are largely missing. Here, we report the results of long-term experiments located in three different forest types, where oak was long-term regenerated under different mixing and canopy cover situations. The observation periods reached from 26 to 36 years. We focused on the dynamics of stem number reduction, as well as the height and biomass development of oaks and their interaction with interspecific competition and canopy density. The probability of oaks occurring in the regeneration basically decreased over the duration of the regeneration period. Despite this, considerable regeneration biomass growth could be observed, especially in the case of the lower standing volume of the mature stand. The development of beech as the main competitor is scarcely slowed down by the canopy cover compared to oak. Increasing canopy cover noticeably impeded oak regeneration in the considered mixed stands. The model results suggest that a reduction in competition within the regeneration by lowering the proportion of beech below 30% enhanced the success of oak regeneration in the long run even in small patches. The productivity of the remaining stand was primarily driven by standing volume. However, a negative trend of its productivity emerged with high regeneration biomasses. The study results show that small-scale oak regeneration with prolonged regeneration duration is possible in principle. However, oak regeneration requires active and continuous silvicultural assistance, which has to be adjusted to the specific site conditions.

In this study, we investigated the effects of water-deficit stress on the leaf anatomical traits, physiological traits, and stem starch content in Quercus acutissima Carruth and Quercus serrata Murray by subjecting their seedlings to well-watered (WW) and water-deficit stress (WS) treatments. The water stress-induced changes in trichome density, trichome-to-stomata ratio, mesophyll thickness, vein density, vein distance, vein loopiness, vessel diameter, transpiration (E), stomatal conductance (gs), water use efficiency (WUE), and starch content were analyzed between two time points. While trichome density did not vary between treatments in Q. acutissima, it dramatically increased in Q. serrata (62.63–98.96 trichomes mm−2) at the final week. The WS-treated seedlings had a thicker palisade mesophyll (162.85–169.56 µm) than the WW-treated samples (118.56–132.25 µm) in both species. The vein density and loopiness increased significantly in the WS-treated Q. serrata seedlings. Small-sized vessels (10–50 µm) were more frequent in the WS than the WW in Q. serrata. The E, gs, WUE, and starch content declined significantly in the WS-treated seedlings compared with WW-treated samples in both species. Further, principal component analysis revealed significant relationships between anatomical and physiological traits, particularly in the WS-treated seedlings of Q. serrata. The coordinated changes in leaf anatomical traits, physiological traits, and stem starch content indicate an important role in the survival of Q. acutissima and Q. serrata seedlings in water-deficit stress environments, although Q. serrata may show higher survivability under prolonged water stress than Q. acutissima.

Aging cachaça in wooden barrels is essential to improve its quality. The level of maturation of distillates can be determined based on the contents of aging-marker phenolic compounds extracted from the lignin of the wooden barrel. This study aimed to characterize the aging process of cachaça by analyzing the mechanism of lignin degradation during its maturation in new barrels made from two oak species, European (Quercus petraea) and American (Quercus alba), for up to 60 months. Evaluation was based on the analyses of cinnamic aldehydes (sinapaldehyde and coniferaldehyde), benzoic aldehydes (syringaldehyde and vanillin), and benzoic acids (syringic and vanillic acids) using high-performance liquid chromatography. Oak species had a significant effect on all the studied phenolic compounds. Higher contents of all the identified phenolic compounds were found in cachaça aged in barrels made from American oak. The total contents of benzoic acids (vanillic and syringic acids) can be considered for predicting the level of maturation of cachaça aged in barrels made from both oak species. Based on the composition of maturation-related congeners, it is likely that for cachaça each year of aging in new oak barrels corresponds to approximately 5 years of aging for spirits in general commercialized worldwide.

Summary: Many perennial plants display masting, that is, fruiting with strong interannual variations, irregular and synchronized between trees within the population. Here, we tested the hypothesis that the early flower phenology in temperate oak species promotes stochasticity into their fruiting dynamics, which could play a major role in tree reproductive success.From a large field monitoring network, we compared the pollen phenology between temperate and Mediterranean oak species. Then, focusing on temperate oak species, we explored the influence of the weather around the time of budburst and flowering on seed production, and simulated with a mechanistic model the consequences that an evolutionary shifting of flower phenology would have on fruiting dynamics.Temperate oak species release pollen earlier in the season than do Mediterranean oak species. Such early flowering in temperate oak species results in pollen often being released during unfavorable weather conditions and frequently results in reproductive failure. If pollen release were delayed as a result of natural selection, fruiting dynamics would exhibit much reduced stochastic variation.We propose that early flower phenology might be adaptive by making mast‐seeding years rare and unpredictable, which would greatly help in controlling the dynamics of seed consumers. [ABSTRACT FROM AUTHOR]

A summary of achievements in the development of genomic and transcriptomic resources in forest species are presented in an international context. The first steps in the development of genomic resource in oak species of Romania are presented and national research priorities were discussed and determined. The application of Next Generation Sequencing (NGS) technologies may foster at the national level to identify valuable genotypes of tree forest species with increased productivity and adaptive capacity. In the framework of the Research Station of Simeria was implemented a fully equipped NGS laboratory for applications that are of interest to National Institute for Research and Development in Forestry "Marin Drăcea". At the national level there is an increased interest in development of genomic and transcriptomic resources for forest species that would allow to produce valuable new knowledge about molecular mechanisms involved in adaptation processes of tree species to biotic and abiotic stress factors. For the first time, at the national level have been developed genomic resources for oak species such as Quercus pedunculiflora, Q. pubescens, Q. robur, Q. petraea, Q. virgiliana, and Q. frainetto. Additionally, genomic resources have been developed for late bud flushing variety (var. tardifolia Czern.) found in Quercus pedunculiflora and Q. robur. The late bud flushing variety (var. tardifolia Czern.) in oak species is of great importance in forestry because of harder and more durable wood (Kleinschmit, 1993), as well as this variety is less affected by defoliators (Nețoiu et al., 2016). The employment of forest material from certified genetic resources can contribute towards successful restoration of degraded forest ecosystems and to foster resilience and stability of forests to global changes. [ABSTRACT FROM AUTHOR]

Abstract There is a lack of knowledge about the possibility that plants facing abiotic stressors, such as drought, have an altered perception of a pulse of O 3 and incur in alterations of their signalling network. This poses some concerns as to whether defensive strategy to cope episodic O 3 peaks in healthy plants may fail under stress. In this study, a set of saplings of two Mediterranean deciduous species, Quercus cerris and Q. pubescens , was subjected to water withholding (20% of daily evapotranspiration for 15 days) while another set was kept well-watered. Saplings were then subjected to a pulse of O 3 (200 nl l−1 for 5 h) or maintained in filtered air. Q. pubescens had a more severe decline of photosynthesis and leaf PDΨ w (about −65% and 5-fold lower than in well-watered ones) and events of cell death were observed under drought when compared to Q. cerris , which is supportive for a higher sensitivity to drought exhibited by this species. When O 3 was applied after drought, patterns of signalling compounds were altered in both species. Only in Q. pubescens , the typical O 3 -induced accumulation of apoplastic reactive oxygen species, which is the first necessary step for the activation of signalling cascade, was completely lost. In Q. cerris the most frequent changes encompassed the weakening of peaks of key signalling molecules (ethylene and salicylic acid), whereas in Q. pubescens both delayed (salicylic and jasmonic acid) or weakened (ethylene and salicylic acid) peaks were observed. This is translated to a higher ability of Q. cerris to maintain a prompt activation of defensive reaction to counteract oxidative damage due to the pollutant. Our results reveal the complexity of the signalling network in plants facing multiple stresses and highlight the need to further investigate possible alteration of defensive mechanism of tree species to predict their behavior. Graphical abstract Unlabelled Image Highlights • Possible alteration of O 3 -signalling wave by drought was investigated in oak species. • Two Mediterranean deciduous species with different water requirements were compared. • Gas exchange, chlorophyll a fluorescence and main signalling molecules were assessed. • Drought alters profoundly the typical O 3 -triggered reaction cascade. • Prediction of future plant behavior requires the deepening of signalling pattern. [ABSTRACT FROM AUTHOR]

We analyzed the structure of pollarded oak forest and biometric indices of pollarded oak species in relation to aspect in northern Zagros forests, western Iran. A number of 319 circular plots (0.1 ha) were established using a systematic random method over the study area. In each plot, for all trees (diameter at breast height ≥5 cm) diameter was measured and tree species was recorded. Total height, trunk height, and major and minor diameter axis of the crown of two trees in each plot (nearest tree to the center of the plot and the largest tree in term of diameter) were measured. As the dispersion of slope and altitude classes in the study area were identical, the effect of these factors was assumed to be constant. To evaluate the effect of aspect on biometric indices of oak trees a comparison was used for each oak species separately. The results indicated that the forest species composition differed statistically significant in main aspects except for easterly and westerly aspects (P < 0.01). The diameter of similar oak trees was significantly different except for Lebanon oak in northerly and southerly and Gall oak in easterly and westerly aspects (P < 0.01), but there was no significant difference between the total height and crown area of similar oak species in different aspects. Differences in diameter, height, and crown area distributions showed a significant difference in main aspects. The basal area and tree density in northerly and southerly aspects were significantly different (P < 0.05). [ABSTRACT FROM AUTHOR]

The accuracy of the description regarding tree architecture is crucial for data processing. LiDAR technology is an efficient solution for capturing the characteristics of individual trees. The aim of the present study was to analyze tree shape variability in a mixed oak forest consisting of four European white oak species: Quercus petraea, Q. frainetto, Q. pubescens, and Q. robur. Moreover, we tested for association between tree shape and individual heterozygosity and whether oak trees identified as pollen donors in a previous genetic study have a larger size in terms of crown and trunk characteristics than non-donors. The woody structure of a tree was defined by the quantitative structure model (QSM) providing information about topology (branching structure), geometry, and volume. For extracting the 3D point clouds a high-speed 3D scanner (FARO FocusS 70) was used. The crown variables were strongly correlated to each other, the branch volume being influenced by branch length, maximum branch order, and the number of branches but not influenced by diameter at breast height (DBH), trunk length, trunk volume, or tree height. There was no relationship between the individual heterozygosity based on nuclear microsatellite genetic markers and crown and trunk characteristics, respectively. Branch volume, total area, DBH, trunk volume, and the total volume of tree were significantly larger in pollen donors compared to non-donor Q. petraea trees. Thus, the mean branch volume was more than three times higher. Pollen donors had nearly two and half times larger total area in comparison to non-donor individuals. Our results suggest that a thorough characterization of tree phenotype using terrestrial laser scanning may contribute to a better understanding of mating system patterns in oak forests.

The aging of wines is a process used to preserve wine but also to enhance its properties. It is a process of great interest, mainly because of the additional properties it adds to wines and because of its economic implications. Historically, barrels have been employed for centuries for preserving and aging wine due to their resistance and relative impermeability. In general terms, the wine aging process can be divided into two phases: oxidative and reductive aging. Oxidative aging traditionally takes place in barrels while reductive phase occurs in the bottle. During both processes, oxygen plays a fundamental role as well as other factors, for instance: temperature, light, bottle position, microbial growth or storage time. Likewise, during the aging process, a series of chemical reactions take place influencing the composition and organoleptic profile of wine. At this point, oxidative aging in barrels is a fundamental step. Barrels are directly involved in the produced changes on wine’s composition due to the transference of oxygen and phenolic and aromatic compounds from wood to wine. This way, barrels act as an active vessel capable of releasing compounds that affect and improve wine’s characteristics. Regarding, the importance of barrels during aging process, some attention must be given to the species most used in cooperage. These species are conventionally oak species, either French or American. However, other non-conventional species are currently being studied as possible wood sources for the production of wines, such as chestnut robinia or other oak species. In the last decades, new approaches have been developed for barrel aging to find new alternatives more suitable, affordable and feasible to sanitize the process, such as other materials different from wood or the use of wood chips, which is regulated since 2006 by the EU. However, even though some of them have shown promising data, barrels are currently the most used technology for the oxidative stage of table wines aging.

Patterns of fine-scale spatial distribution of multilocus genotypes can provide valuable insights into the biology of forest tree species. Here we tested for the existence of spatial genetic structure (SGS) in a four-oak-species forest with contrasting species abundances and hybridization rates. A total of 483 adult trees were mapped over 8.6 ha and genotyped using 10 highly polymorphic genomic regions. A weak but significant SGS was observed in each of the four oak species, with Quercus frainetto, the species with the lowest density in the sampling plot, exhibiting the strongest SGS. The values of the Sp statistic were 0.0033, 0.0035, 0.0042, and 0.0098 for Q. petraea, Q. robur, Q. pubescens, and Q. frainetto, respectively. The spatial correlogram of the total population was significantly different when hybrids were removed from the analysis, which suggests that hybridization influenced the SGS. Interspecific SGSs were significantly correlated with the rates of hybridization. Implications of the obtained results for the conservation and management of forest genetic resources are discussed.

Oak wood has been highly praised since the Middle Ages for its strength and durability. This is one of the densest naturally occurring materials; it has good folding qualities despite its natural durability and has a high tannin content which makes it resistant to insects and pests. It is durable, impregnates easily, resists moisture absorption and thanks to its aesthetics and resistance, it is recommended as an excellent feedstock for the furniture industry and beyond, it is often used to manufacture floors, stairs, exterior and interior joinery, interior architectural elements, natural or stained plywood, boards, tiles, ornaments turners, profiles, barrels and it should be continuously promoted because it is a renewable and sustainable raw material. The oak stands have a significant position in the Romanian forests (18% of the country's total forest area) and in the European ones; they are perhaps more appreciated now than in the past, not only for the particular structural qualities of the wood, but also because they contribute to the biological wealth of the forest ecosystems and for how they participate to the conservation of biodiversity creating an environment that helps to fulfil the social demands. Due to the present-day high market demand, the recent wood industry development and the multiple available transport options, oak wood is imported and exported at a high rate. It would be desirable to promote only those oak raw materials which originate from certified forest areas which are sustainably managed, where forest ecosystem services as well as certified wood chains of custody are promoted. That is why we need to identify, study and monitor the areas which are suitable for obtaining valuable forest stands with Quercus robur (pedunculate oak), Quercus petraea (sessile oak) or Quercus frainetto (Italian oak), and to ensure their growth by applying a sustainable forest management. [ABSTRACT FROM AUTHOR]

Sprouting shoot biomass of five tree species in the oak forest was measured at the end of the first and second year with different stump diameter and height (cm), and site quality (unburnt and burnt). The influence of stump diameter and height, shoot diameter, number of survived shoots and total leaf area on shoot biomass production is significant (P < 0.001). The net primary productivity of sprouts of these tree species is in the following order: Lithocarpus dealbata (15.29 kg stump-1 yr-1) > L. fenestrata (7.05 kg stump–1 yr-1) > Castanopsis tribuloides (6.68 kg stump-1 yr-1) > Quercus griffithii (6.19 kg stump–1 yr-1) > Q. serrata (2.28 kg stump-1 yr-1). The treatment factor (site quality) also has significant effect on the sprouting shoot biomass production (P < 0.05). The value of Durbin–Watson statistics was found to be 1.75 (close to 2), so that the fitted adjusted regression is useful to predict the pattern of biomass in the present study. [ABSTRACT FROM AUTHOR]

Abstract: Acorn predation by insects and its effects on seedling establishment were investigated among three co-occurring oak species (Quercus variabilis, Q. serrata and Cyclobalanopsis glauca) in a subtropical evergreen broadleaved forest, Southwest China. All oak species had high tannin concentration (over 10%) but differed in acorn mass and germination schedule. We hypothesized that the defensive traits in acorns (e.g. seed mass, tannins and germination schedule) act together to reduce damage from insect seed predators. Q. variabilis had significantly lower predation (51.2%) than either Q. serrata (71.4%) or C. glauca (73.8%). Seedling establishment decreased with increasing injury for all oak species studied. As much as 43% of insect infested acorns germinated and established as viable seedlings despite extensive acorn mortality due to insect seed predators. The larger seed mass of Q. variabilis appears to tolerate insect infestation and retain enough stored reserves for seed germination and early growth of seedlings. Autumn germination also benefited Q. variabilis and Q. serrata, allowing escape from both direct and ancillary effects of insect feeding by fast reserve shifting to immediate germination of mature acorns. Our results indicate that large seed mass, tannin and autumn germination act together to ameliorate effects of insect seed predation, and the joint evolution of resistance and tolerance (as well as escape through autumn germination) in acorns may be the selective consequences driven in part by interactions with insect seed predators. [Copyright &y& Elsevier]

Fusarium eumartii is a fungus associated with declining Quercus robur, in which it is found in the vessels. The response of oak species to infection is known to vary: Q. robur is susceptible, but Quercus cerris and Quercus pubescens are resistant. An experiment was carried out in 1996 and repeated in 1997, to examine how F. eumartii colonization differed in oak species that were susceptible or resistant to the fungus by counting the number of vessels with mycelium at various distances from the inoculation site in infected seedlings and by determining the amount of viable fungus in infected tissue. Infected vessels with mycelium were counted on sections (10 μm thick) cut at 0, 2, 4, 6, 8 and 10 cm from the inoculation site on 1-year-old inoculated seedlings as well as on sections cut every 2 cm to the seedling tip. The amount of viable fungus was determined by counting the colony forming units (CFUs) in stem segments from the same seedlings. Quercus robur seedlings had the greatest number of infected vessels and the greatest number of CFUs. Forty days after inoculation, the extent of vertical fungal spread was 28.12 cm in Q. robur, 3.15 cm in Q. cerris and 3.00 cm in Q. pubescens. The greatest number of CFUs was found in Q. robur at day 5 after inoculation. Analysis of variance confirmed the results. [ABSTRACT FROM AUTHOR]

Decomposition of oak Quercus spp. logs (25--35 cm diameter, 3 m long) was compared among log substrates in Oregon, Minnesota, Kansas and North Carolina during the first five years on the ground. Decomposition of whole logs (weighted by substrate) averaged 0.069 yr-1 (~ 0.16 SD), but followed a 2-exponential model (k = 0.12 yr-1 year 1 and k = 0.06 yr- 1 years 2--5), reflecting qualitative differences among log substrates (outer and inner bark, sapwood and heartwood). Rapid loss from bark substrates contributed tothe initial rapid decay rate. Sapwood decay rate averaged 0.15 yr-1 and dominated the second log decay rate. Heartwood lost only 6%, mass during the first five years, for an overall decay rate of0.012 yr-1 that likely will represent a longer-term thirdexponential decay, rate. Carbon loss amounted to ca 5 kg yr-1 per 170 kg log. Nutrient concentrations generally declined during the first five years, but nitrogen, sulfur, and sodium accumulated in sapwood and heartwood during this period. Sulfur content increasedin all substrates and doubled in whole logs during this 5-yr period.Complex patterns of nutrient content suggest patterns of microbial colonization and nutrient utilization. Polynomial models were developed to describe rates of carbon and nutrient flux in log substrates. [ABSTRACT FROM AUTHOR]

The accuracy of the description regarding tree architecture is crucial for data processing. LiDAR technology is an efficient solution for capturing the characteristics of individual trees. The aim of the present study was to analyze tree shape variability in a mixed oak forest consisting of four European white oak species: Quercus petraea, Q. frainetto, Q. pubescens, and Q. robur. Moreover, we tested for association between tree shape and individual heterozygosity and whether oak trees identified as pollen donors in a previous genetic study have a larger size in terms of crown and trunk characteristics than non-donors. The woody structure of a tree was defined by the quantitative structure model (QSM) providing information about topology (branching structure), geometry, and volume. For extracting the 3D point clouds a high-speed 3D scanner (FARO FocusS 70) was used. The crown variables were strongly correlated to each other, the branch volume being influenced by branch length, maximum branch order, and the number of branches but not influenced by diameter at breast height (DBH), trunk length, trunk volume, or tree height. There was no relationship between the individual heterozygosity based on nuclear microsatellite genetic markers and crown and trunk characteristics, respectively. Branch volume, total area, DBH, trunk volume, and the total volume of tree were significantly larger in pollen donors compared to non-donor Q. petraea trees. Thus, the mean branch volume was more than three times higher. Pollen donors had nearly two and half times larger total area in comparison to non-donor individuals. Our results suggest that a thorough characterization of tree phenotype using terrestrial laser scanning may contribute to a better understanding of mating system patterns in oak forests. [ABSTRACT FROM AUTHOR]

The aging of wines is a process used to preserve wine but also to enhance its properties. It is a process of great interest, mainly because of the additional properties it adds to wines and because of its economic implications. Historically, barrels have been employed for centuries for preserving and aging wine due to their resistance and relative impermeability. In general terms, the wine aging process can be divided into two phases: oxidative and reductive aging. Oxidative aging traditionally takes place in barrels while reductive phase occurs in the bottle. During both processes, oxygen plays a fundamental role as well as other factors, for instance: temperature, light, bottle position, microbial growth or storage time. Likewise, during the aging process, a series of chemical reactions take place influencing the composition and organoleptic profile of wine. At this point, oxidative aging in barrels is a fundamental step. Barrels are directly involved in the produced changes on wine's composition due to the transference of oxygen and phenolic and aromatic compounds from wood to wine. This way, barrels act as an active vessel capable of releasing compounds that affect and improve wine's characteristics. Regarding, the importance of barrels during aging process, some attention must be given to the species most used in cooperage. These species are conventionally oak species, either French or American. However, other non-conventional species are currently being studied as possible wood sources for the production of wines, such as chestnut robinia or other oak species. In the last decades, new approaches have been developed for barrel aging to find new alternatives more suitable, affordable and feasible to sanitize the process, such as other materials different from wood or the use of wood chips, which is regulated since 2006 by the EU. However, even though some of them have shown promising data, barrels are currently the most used technology for the oxidative stage of table wines aging. [ABSTRACT FROM AUTHOR]

Aging cachaça in wooden barrels is essential to improve its quality. The level of maturation of distillates can be determined based on the contents of aging-marker phenolic compounds extracted from the lignin of the wooden barrel. This study aimed to characterize the aging process of cachaça by analyzing the mechanism of lignin degradation during its maturation in new barrels made from two oak species, European ( Quercus petraea ) and American ( Quercus alba ), for up to 60 months. Evaluation was based on the analyses of cinnamic aldehydes (sinapaldehyde and coniferaldehyde), benzoic aldehydes (syringaldehyde and vanillin), and benzoic acids (syringic and vanillic acids) using high-performance liquid chromatography. Oak species had a significant effect on all the studied phenolic compounds. Higher contents of all the identified phenolic compounds were found in cachaça aged in barrels made from American oak. The total contents of benzoic acids (vanillic and syringic acids) can be considered for predicting the level of maturation of cachaça aged in barrels made from both oak species. Based on the composition of maturation-related congeners, it is likely that for cachaça each year of aging in new oak barrels corresponds to approximately 5 years of aging for spirits in general commercialized worldwide., Competing Interests: The authors declare no conflict of interest., (© 2020 The Author(s).)

Il existe de nombreuses espèces de chênes dans le monde: quelques-unes d'entre elles sont présentes en France où deux ont une importance forestière considérable. Les propriétés du bois dépendent de l'espèce et des conditions de milieu dans lesquelles se développent les arbres. La sylviculture joue un rôle important sur la qualité du bois produit et donc sur ses utilisations. Certaines propriétés correspondent plus particulièrement à certains emplois, que ce soient des propriétés physiques, physicochimiques, chimiques, biologiques, anatomiques. L'ensemble de ces propriétés présente une variabilité souvent importante, comme c'est d'ailleurs le cas pour toutes les espèces ligneuses. Certaines de ces propriétés sont évoquées pour illustrer les questions liées à l'aptitude à l'emploi de certaines espèces de chênes, notamment en matière de tonnelerie. +++ Here is a lot of species of oaks in the world: some species are present in France, where two have a considerable forest importance. The wood properties of the oaks depend on the species and on the environ mental conditions in which the trees grow. The sylviculture plays an important part on the wood quality and then on the uses of the wood. Some properties suit more particularly to some uses: physical, chemical, biological, anatomical properties. All these properties often have an important variability: it is besides the case for all the species of trees. Some of these properties are called up in order to illustrate the questions related to the capacity of some oaks species to a given use, specially for the cooperage.