Quercus Frainetto Research Articles

Selection of tree species for forests under climate change: is PSI functioning a better predictor for net photosynthesis and growth than PSII?

A chlorophyll fluorescence (ChlF) assessment was carried out on oak seedlings (Quercus ilex L., Quercus pubescens Willd., Quercus frainetto Ten.) of Italian and Greek provenance, during the years 2017 and 2018, in a common garden in central Italy planted in 2017. This trial aimed to test the relative performances of the oak species in the perspective of assisted migration as part of the actions for the adaptation of forests to climate change. The assessment of the photosynthetic performance of the tree species included the analysis of the prompt chlorophyll fluorescence (PF) transient and the modulated reflection (MR) at 820nm, leaf chlorophyll content, leaf gas exchange (net photosynthesis, stomatal conductance), plant growth (i.e., height) and mortality rate after 2 years from the beginning of the experiment. The assessment of the performance of the three oak species was carried out 'in vivo'. Plants were generated from seeds and exposed to several environmental factors, including changing seasonal temperature, water availability, and soil biological and physical functionality. The results of PF indicate a stable functionality of the photosynthetic system PSII (expressed as FV/FM) across species and provenances and a decline in photochemistry functionality at the I-P phase (ΔVIP) in Q. frainetto, thus indicating a decline of the content of PSI in this species. This result was confirmed by the findings of MR analysis, with the speed of reduction and subsequent oxidation of PSI (VRED and VOX) strongly correlated to the amplitude of ΔVIP. The photosynthetic rates (net photosynthesis, PN) and growth were correlated with the parameters associated with PSI content and function, rather than those related to PSII. The low performance of Q. frainetto in the common garden seems to be related to early foliar senescence with the depletion of nitrogen, due to suboptimal climatic and edaphic conditions. Chlorophyll fluorescence allowed discrimination of populations of oak species and individuation of the less (or/and best) suitable species for future forest ecology and management purposes.

Shifts in Growth Responses to Climate and Exceeded Drought-Vulnerability Thresholds Characterize Dieback in Two Mediterranean Deciduous Oaks

Drought stress has induced dieback episodes affecting many forest types and tree species worldwide. However, there is scarce information regarding drought-triggered growth decline and canopy dieback in Mediterranean deciduous oaks. These species face summer drought but have to form new foliage every spring which can make them vulnerable to hotter and drier conditions during that season. Here, we investigated two stands dominated by Quercus frainetto Ten. and Quercus canariensis Willd. and situated in southern Italy and Spain, respectively, showing drought-induced dieback since the 2000s. We analyzed how radial growth and its responses to climate differed between non-declining (ND) and declining (D) trees, showing different crown defoliation and coexisting in each stand by: (i) characterizing growth variability and its responsiveness to climate and drought through time, and (ii) simulating growth responses to soil moisture and temperature thresholds using the Vaganov–Shashkin VS-lite model. Our results show how growth responsiveness to climate and drought was higher in D trees for both oak species. Growth has become increasingly limited by warmer-drier climate and decreasing soil moisture availability since the 1990s. These conditions preceded growth drops in D trees indicating they were more vulnerable to warming and aridification trends. Extremely warm and dry conditions during the early growing season trigger dieback. Changes in the seasonal timing of water limitations caused contrasting effects on long-term growth trends of D trees after the 1980s in Q. frainetto and during the 1990s in Q. canariensis. Using growth models allows identifying early-warning signals of vulnerability, which can be compared with shifts in the growth responses to warmer and drier conditions. Our approach facilitates establishing drought-vulnerability thresholds by combining growth models with field records of dieback.

Variation in the access to deep soil water pools explains tree-to-tree differences in drought-triggered dieback of Mediterranean oaks

Individual differences in the access to deep soil water pools may explain the differential damage among coexisting, conspecific trees as a consequence of drought-induced dieback. We addressed this issue by comparing the responses to a severe drought of three Mediterranean oak species with different drought tolerance, Quercus pubescens L. and Quercus frainetto Ten., mainly thriving at xeric and mesic sites, respectively, and Quercus cerris L., which dominates at intermediate sites. For each species, we compared coexisting declining (D) and non-declining (ND) trees. The stable isotope composition (δ2H, δ18O) of xylem and soil water was used to infer a differential use of soil water sources. We also measured tree size and radial growth to quantify the long-term divergence of wood production between D and ND trees and non-structural carbohydrates (NSCs) in sapwood to evaluate if D trees presented lower NSC values. The ND trees had access to deeper soil water than D trees except in Q. frainetto, as indicated by significantly more depleted xylem water values. However, a strong δ2H offset between soil and xylem water isotopes observed in peak summer could suggest that both tree types were not physiologically active under extreme drought conditions. Alternative processes causing deuterium fractionation, however, could not be ruled out. Tree height and recent (last 15-25years) growth rates in all species studied were lower in D than in ND trees by 22 and 44%, respectively. Lastly, there was not a consistent pattern of NSC sapwood concentration; in Q. pubescens, it was higher in ND trees while in Q. frainetto, the D trees were the ones exhibiting the higher NSC concentration. We conclude that the vulnerability to drought among conspecific Mediterranean oaks depends on the differential access to deep soil water pools, which may be related to differences in rooting depth, tree size and growth rate.

Testing Hungarian oak (Quercus frainetto Ten.) provenances in Romania

Abstract: In this study ten Hungarian oak provenances from Southern Romania were tested in two comparative trials 10 years after planting. The diameter at breast height (dbh) and tree height (Th) were measured in family progenies and the survival rate was determined. In both trials, the local provenances (Bals and Seaca 2) revealed superior fitness in terms of growth and adaptability traits, confirming the recommendation of using local provenances with priority in afforestation activities. Based on the measured traits, families which ranked in the first ten positions at age 3 and age 10 years were identified in both trials. The analysis of variance revealed statistically significant differences in growth traits between provenances and families in both comparative trials. Duncan’s test for 5% transgression probability revealed different results for dbh and Th in terms of provenance homogeneity in the two test sites, with a superior homogeneity in the Aramadia trial for dbh and in the Bals trial for Th. Growth performances of the Hungarian oak provenances were significantly influenced by the experimental location and by the interactions between provenance, family and locality, suggesting that maximum precaution must be taken in the choice of forest reproductive materials to be planted in different environmental conditions. The family mean heritability (h2f) was significantly lower than the individual heritability (h2i), suggesting the possible adoption of an individual selection strategy in the next stage of the current breeding programme. The juvenile-adult correlations will be made at the age of 40 years and will take advantage of the results of this study to shorten the testing period for the selection of genetically improved material in Hungarian oak.

Varijabilnost morfometrijskih svojstava žira sladuna (Quercus frainetto Ten.)

The results of morphometric analysis of Hungarian oak seeds originating from Lipovica Forest Management Unit are presented in this paper. The seeds have been collected from 50 trees evenly distributed on the forest management unit area. The length, width and mass of acorns are measured on the sample consisting of 50 acorns per tree. The volume and shape index of acorns are calculated based on the measured values of their length and width. The mean values of morphometric characteristics obtained in research indicate there is a high variability among the studied genotypes. The latter has also been confirmed by means of an analysis of variance which determined statistically significant differences between the sampled mother trees for all the observed morphometric characteristics. The results obtained represent a good starting point for future research on breeding of the species and can be utilised for improvement of the mass production of high quality Hungarian oak planting material in Serbia.

The effects of leaf litter chemistry and anatomical traits on the litter decomposition rate of Quercus frainetto Ten. and Quercus cerris L. in situ

This paper presents the results of a one-year decomposition experiment on Quercus frainetto Ten. and Quercus cerris L. leaf litter in natural conditions. The decomposition rate constant was 0.831 yr?1 (Q. frainetto) and 0.458 yr?1 (Q. cerris). For the initial chemical composition of the oaks? litter, differences were not found in concentrations of lignin and fats, waxes and oil fractions, but were found for water-soluble matter, hemicellulose and cellulose. Later decomposition stages indicated that lignin and fats, waxes and oil fractions influenced differences in both oaks? litter decay rates. Anatomical analysis revealed differences between the oaks in leaf mesophyll and epidermis but not in the entire leaf and lower epidermis. Results after 12 months of the experiment revealed that 48.04% of the entire leaf, 53.30% of mesophyll, 32.93% of lignified upper and 47.67% of lower epidermis in Q. frainetto, and 28.70% of the entire leaf, 31.60% of mesophyll, 25.17% of lignified upper and 20.93% of lower epidermis in Q. cerris were decomposed. Reduction in leaf thickness mainly was caused by the reduction of mesophyll parenchyma, composed of easily degradable plant materials. Leaf tissues with the most recalcitrant plant materials were lignified upper epidermis, covered by a thick cuticle composed of fats and waxes, and xylem within the leaf veins.

Impact of regional climatic conditions on tree growth on mainland Greece

Abstract Forest growth is commonly used to explore tree vitality and ability to resist to environmental changes or climatic fluctuations. This paper illustrates and examines how regional climatic conditions can be related to the decline of tree growth, which were found to be more distinct in Quercus frainetto Ten. (Hungarian oak) and Fagus sylvatica L. (European beech) and less pronounced in Abies borissi-regis Matt f. (Bulgarian fir) on three long-term intensive monitoring plots (ICP Forests-Level II) in Greece during the period 1996–2009. Relative basal area increment and volume increment were calculated, expressing tree growth in terms of mean relative annual periodic increment. A decline in the growth of basal area and volume was observed after hot and dry periods, where annual temperatures and precipitation were far from the mean of the analyzed period. This observation was statistically confirmed in oak and beech plots regarding summer precipitation only and are in agreement with the findings of previous studies in Europe. The representativeness of the results at a national scale needs further investigation, although our results provide a good basis for further and more intensive monitoring programs to address various forest management scenarios against the background of potential climatic changes in the Mediterranean area.

Spread and potential host range of the invasive oak lace bug [Corythucha arcuata(Say, 1832) – Heteroptera: Tingidae] in Eurasia

AbstractThe North American oak lace bug feeds on leaves of ‘white oaks” in its native range. In Europe, it was first discovered in northern Italy in 2000. In recent years, it has subsequently spread rapidly and population outbreaks have been observed in several European countries. In the present study, we summarize the steps of its expansion.To predict its potential host range, we checked 48 oak species in 20 sentinel gardens in seven countries between 2013 and 2018.In total, 27 oak species were recorded as suitable hosts; 13 of them are globally new ones, 23 out of the 29 in sectionQuercus(∼ white oaks, an intrageneric taxonomic unit within genusQuercus), including Asian oaks, native to Japan, Korea and China, and four out of five in sectionCerris(another intrageneric unit of the same genus), were accepted as hosts. None of the species in sectionLobatae(red oaks) or in theIlexgroup was accepted.Host records were also collected in forest stands of 10 countries. We found 11 oak species that were infested. Outbreak populations were most commonly found onQuercus robur,Quercus frainetto,Quercus petraeaandQuercus cerris, comprising widespread and outstandingly important oaks species in Europe.Based on our findings, we conclude that suitable hosts for oak lace bug are present in most of Europe and Asia. This means that a lack of hosts will likely not restrict further range expansion.

Towards the Biological Control of Devastating Forest Pathogens from the Genus Armillaria

Research Highlights: A large scale effort to screen, characterize, and select Trichoderma strains with the potential to antagonize Armillaria species revealed promising candidates for field applications. Background and Objectives: Armillaria species are among the economically most relevant soilborne tree pathogens causing devastating root diseases worldwide. Biocontrol agents are environment-friendly alternatives to chemicals in restraining the spread of Armillaria in forest soils. Trichoderma species may efficiently employ diverse antagonistic mechanisms against fungal plant pathogens. The aim of this paper is to isolate indigenous Trichoderma strains from healthy and Armillaria-damaged forests, characterize them, screen their biocontrol properties, and test selected strains under field conditions. Materials and Methods: Armillaria and Trichoderma isolates were collected from soil samples of a damaged Hungarian oak and healthy Austrian spruce forests and identified to the species level. In vitro antagonism experiments were performed to determine the potential of the Trichoderma isolates to control Armillaria species. Selected biocontrol candidates were screened for extracellular enzyme production and plant growth-promoting traits. A field experiment was carried out by applying two selected Trichoderma strains on two-year-old European Turkey oak seedlings planted in a forest area heavily overtaken by the rhizomorphs of numerous Armillaria colonies. Results: Although A. cepistipes and A. ostoyae were found in the Austrian spruce forests, A. mellea and A. gallica clones dominated the Hungarian oak stand. A total of 64 Trichoderma isolates belonging to 14 species were recovered. Several Trichoderma strains exhibited in vitro antagonistic abilities towards Armillaria species and produced siderophores and indole-3-acetic acid. Oak seedlings treated with T. virens and T. atrobrunneum displayed better survival under harsh soil conditions than the untreated controls. Conclusions: Selected native Trichoderma strains, associated with Armillaria rhizomorphs, which may also have plant growth promoting properties, are potential antagonists of Armillaria spp., and such abilities can be exploited in the biological control of Armillaria root rot.

Seven years of arboreal pollen monitoring in the İğneada waterlogged forests (NW Turkey)

This study was carried out in the İğneada Waterlogged Forests (Kırklareli) located downhill of Istranca mountains at 20 km distance to Bulgaria border line and had a shore to Black Sea. These forests have different vegetation types such as waterlogged forest, peat, bog and sand dunes plant communities, sand zone and wetlands. The main arboreal species of these forests are Acer campestre, Acer trautvetteri, Alnus glutinosa, Carpinus betulus, Carpinus orientalis, Fraxinus angustifolia, Fraxinus ornus, Juglans regia, Quercus cerris, Quercus frainetto, Quercus petraea, Quercus robur, Ulmus leavis and Ulmus minor. Pollen monitoring results were obtained from six different sampling sites in the waterlogged forests around Mert and Saka Lake. The purpose of this study is to determine the modern pollen distribution of these forests and to create a basic calibration scheme for the fossil pollen studies. For this purpose, seven years of modern pollen distribution was monitored between September 2009 and 2016 using Tauber pollen traps which were placed at 6 different points in this study area. These traps were changed once a year in the field and transferred to the Palynology Laboratory of Istanbul University-Cerrahpaşa. The protocol of European Pollen Monitoring Programme (EPMP) was followed in the laboratory methodology. The majority of the pollen influx obtained from the Tauber pollen traps in the İğneada Waterlogged forests belongs to Fraxinus and Carpinus from 2009 to 2016. As a result of this study, the annual arboreal pollen influxes of Fraxinus, Carpinus, Quercus, Acer, Corylus, Ulmus, Hedera helix and Alnus was higher respectively in the years of 2009-2016. Seven-year pollen influx data of these pollen traps reflects the current vegetation.

Phytohormone effect on seedling quality in Hungarian oak

Aim of study: to find out the effects of four phytohormones, including Indole Butyric Acid (IBA), Indole Acetic Acid (IAA), and Gibberellic acids (GA3, GA4) on seedling growth of Hungarian oak which has a natural distribution in the northwestern of Turkey.Area of Study: Mature acorns of Hungarian oak were collected from a natural stand in Zonguldak-Ereğli at northwestern region of Turkey.Material and Methods: Collected acorns of the species were pretreated with 300 ppm of each phytohormone for 24 hours and sown in Yenihan State Forest Nursery of Bartin, Turkey. Two years old bare-root seedlings were used for the measurements of seedling height, root collar diameter, stem, root and seedling fresh weights, and stem, root and seedling dry weights of two bare-root seedlings for each phytohormone treatment.Main results: Best performance of all studied seedling traits with the exception of root collar diameter was revealed in seedlings with IBA. In contrast, treatment of seeds with GA3 reduced all seedling traits apart from seedling height and root collar diameter. According to Dickson quality index, IBA was displayed to be the most beneficial phytohormone application for generating Hungarian oak seedlings with better mechanical resistance during transplanting.Research Highlights: IBA should be adopted in planting the seedlings of Hungarian oak for plantation activities.Keywords: Field performance; Morphology; Phytohormone, Quality; Quercus frainetto.Abbreviations used: Dickson quality index (DQI), gibberellic acid (GA), indole acetic acid (IAA), indole butyric acid (IBA), root collar diameter (RCD), root dry weight (RDW), root fresh weigh (RFW), seedling dry weight (SEDW), seedling fresh weight (SEFW), seedling height (SH), Statistical Package for the Social Sciences (SPSS), stem dry weight (STDW), stem fresh weight (STFW).

Two aspects of honeydew honey authenticity: Application of advance analytical methods and chemometrics

Taking into account a growing market and small number of articles related to honeydew honey, a metabolomic approach associated with multivariate analysis and modelling was proposed to discriminate five varieties of honey. Advanced analytical techniques were used for determination of 20 elements, 14 carbohydrates and stable carbon isotope ratio. No chemical marker has been found within sugar compounds, but several elements (Ba, Ca, Mg, Sr, Mn, Al, Co, Ni, Se) were marked as characteristic of honey type and allow classification of three botanical origins (Abies alba, Quercus frainetto, Quercus ilex). Sugars turanose, trehalose, arabinose and raffinose, elements Ba, Sr, P, Cd and Se, and δ13C values of honey, have different concentrations in honeys of the same botanical origin but harvested in different season. In addition to a confirmation of authenticity in terms of production, the values of δ13C of protein could be a good indicator of botanical origin.

Growth characteristics of one-year-old seedlings of three autochthonous oak species in suboptimal growing conditions

The paper presents the growth characteristics of one-year-old seedlings of three autochthonous oak species (Fagaceae family): Turkey oak (Quercus cerris L.), Hungarian oak (Quercus frainetto Ten.) and downy oak (Quercus pubescens Willd.) in suboptimal growing conditions. The analyzed oak species are widely distributed in Serbia. One of the most important benefits of oak species is wood production (Hungarian and Turkey oak), and they have a promising role for the use in the future regarding the climate change as all species can be encountered on dry sites. Acorns were collected in the autumn of 2017 in natural stands and a sample of 400 acorns per each oak species was immediately sown in a nursery seedbed in the form of a random block system with four replicates. At the end of 2018, the available sample of seedlings was analyzed morphometrically. The seedlings were classified according to the number of shoot growth flushes into one-flush-growth and multi-flush growth seedlings. Turkey Oak had the highest number of seedlings which also recorded higher values in total height, root collar diameter and number of leaves. These results were obtained on alkaline soil with the presence of weeds and rodents and the absence of irrigating. The presence of multi-flush growth was recorded in all three oak species. Differences between analyzed three oak species exist in these suboptimal conditions. However, in full light conditions, a similar growth pattern was recorded, indicating to the similar adaptability of the species.

Growth characteristics of one-year-old Hungarian oak seedlings (Quercus frainetto Ten.) in full light conditions

U radu su prikazane značajke rasta jednogodišnjih biljaka sladuna u uvjetima potpunog svjetla u poljskom pokusu 2016. godine. U odnosu na višegodišnji prosjek (1981.–2010. godine) srednja temperatura zraka u vegetacijskom razdoblju 2016. godine bila je veća za 1.3<sup>°</sup>C, a količina oborina za 30.1 mm. Broj ožiljaka terminalnih pupova na jednogodišnjim biljkama sladuna (Slika 1), definira broj faza rasta u visinu na temelju kojega su izdvojeni tipovi rasta biljaka: biljke s jednofaznim, dvofaznim i trofaznim rastom. U analiziranom uzorku, 39,8% biljaka pripada jednofaznom tipu rasta, 58,2% dvofaznom, a svega 2,0% trofaznom tipu rasta (Slika 2). S obzirom na mali broj biljaka s trofaznim rastom u visinu, sve biljke su podijeljene u dvije skupine: biljke sa jednofaznim i biljke sa višestrukim rastom u visinu (Tablica 2). Postoje statistički značajne razlike u varijancama uzoraka kod svih značajki rasta između biljaka s jednofaznim i višestrukim rastom na razini p < 0,05, a na razini p < 0,01 između srednjih vrijednosti svih analiziranih elemenata rasta između biljaka s jednofaznim i višestrukim rastom. Primjetno je da raspodjela svih elemenata rasta varira između dvije definirane skupine biljaka. S obzirom na visinu primarnog rasta (H<sub>1</sub>), biljke s jednofaznim rastom su po apsolutnoj varijabilnosti nešto manje varijabilne, a po relativnoj duplo manje varijabilne od biljaka s višestrukim rastom, s blago pozitivnom asimetrijom. Što se tiče ukupne visine, biljke sa višestrukim rastom su znatno varijabilnije kako glede apsolutne varijabilnosti, tako i relativne varijabilnosti i s više izraženom desnom asimetrijom u odnosu na biljke s jednofaznim rastom. Kod biljaka s višestrukim rastom, apsolutna varijabilnost broja listova je dvostruko veća, a ukupne površine listova trostruko veća s izraženom desnom asimetrijom u usporedbi s biljkama s jednofaznim rastom. Postoje značajne razlike između raspodjela biljaka s jednofaznim i višestrukim rastom u visinu. Biljke s jednofaznim rastom imaju manju ukupnu visinu, manji promjer korjenovog vrata, manji broj i ukupnu površinu listova, ali se odlikuju većom srednjom visinom primarnog rasta u odnosu na biljke sa višestrukim rastom, što ukazuje na različite značajke rasta u početnoj fazi i tijekom vegetacijskog razdoblja između ovih tipova biljaka.

Immediate Changes in Organic Matter and Plant Available Nutrients of Haplic Luvisol Soils Following Different Experimental Burning Intensities in Damak Forest, Hungary

One of the major pedological changes produced by wildfires is the drastic modification of forest soil systems properties. To our knowledge, large research gaps are currently present concerning the effect of such fires on forest Haplic Luvisols soils in Central Europe. In this study, the effects of experimental fires on soil organic matter and chemical properties at different burning intensities in a Central European forest were examined. The study was conducted at Damak Forest, in Hungary, ecosystem dominated by deciduous broadleaf trees, including the rare Hungarian oak Quercus frainetto Ten. The experimental fires were carried out in nine different plots on Haplic Luvisol soils transferred from Damak Forest to the burning site. Three types of fuel load were collected from the forest: litter layer, understorey and overstorey. Groups of three plots were burned at low (litter layer), medium intensity (litter and understorey) and high intensity (litter, understorey and overstorey). Pre-fire and post-fire soil samples were taken from each plot, analysed in the laboratory and statistically compared. Key plant nutrients of organic matter, carbon, potassium, calcium, magnesium and phosphorus were analysed from each sample. No significant differences in soil organic matter and carbon between pre- and post-fire samples were observed, but high intensity fires did increase soil pH significantly. Calcium, magnesium and phosphorus availability increased significantly at all fire intensity levels. Soil potassium levels significantly decreased (ca. 50%) for all intensity treatments, in contrast to most literature. Potassium is a key nutrient for ion transport in plants, and any loss of this nutrient from the soil could have significant effects on local agricultural production. Overall, our findings provide evidence that support the maintaining of the current Hungarian fire prevention policy.

Nutrients in litterfall, forest floor and mineral soils in two adjacent forest ecosystems in Greece

The fluxes of masses and the nutrients Ca, Mg, K, N, P and S were determined in the litterfall of two adjacent forest ecosystems of Hungarian oak (Quercus frainetto L.) and European beech (Fagus sylvatica L.) in a mountainous area of northeastern Greece in 2010–2015. The foliar litterfall for both species reached about 70% of the total litterfall, and was significantly higher from the other two fractions (woody and rest litterfall). The fluxes of masses and nutrients were compared between ecosystems for each fraction separately. Only one significant statistical difference was found, that of K in the woody litterfall. In addition, the stocks of masses and nutrients were calculated in the forest floors and mineral soils of the two ecosystems. Likewise, the stocks of nutrients in the forest floors and mineral soils were compared between ecosystems. In the L horizon of the forest floors, statistical differences, as a result of species effect, were found for the stocks of Ca and N. In the FH horizons, the masses and all the nutrient stocks differed significantly, as the beech plot had much higher quantities of organic matter and nutrients. These higher quantities were probably due to low soil temperatures (microclimate) and high acidity in the beech plot (species effect) that slowed down decomposition. In the mineral soils, the propagation of random error derived from random errors of the individual soil layers was an important factor in the statistical comparisons. Because of the soil acidity in the beech plot, the stocks of exchangeable base cations were significantly higher in the oak plot, whereas the other nutrient stocks did not differ.

Effect of site and provenance on the length of transfusion parenchyma of Douglas-fir needles

Douglas-fir has been the most common introduced conifer species in European plantations since 1825. The analysis of the characteristics of the introduced tree species by conducting genetic tests may predict the success of transfer of Douglas-fir seed of different provenances. The projection of the model of provenance test aims at providing information on adaptation to habitat and climate conditions in new ecosystems in Serbia. The original seed of Douglas-fir from North America was used for setting the experiment of different provenances at two sites in Serbia. The first experiment was set in a beech forest (Fagetum moesiacae montanum Jov. 1976) on district cambisol in the area of Juhor mountain in central Serbia, while the second one was set in Tanda near the town of Bor in eastern Serbia on the habitat of Hungarian and Turkey oak (Quercetum frainetto-cerris Rud. 1949) on eutric cambisol. Through the analysis of the anatomical structure of Douglas-fir needles this paper tends to determine whether there are statistically significant differences in the length of transfusion parenchyma of provenances located in different habitats. The important function of parenchyma in needles is the physiological process of water, organic and mineral matter flow. The effects of the sites where the experiments were set on the transfusion parenchyma of needles were determined by statistical analysis.

Different Woods in Cooperage for Oenology: A Review

Contact of wine with wood during fermentation and ageing produces significant changes in its chemical composition and organoleptic properties, modifying its final quality. Wines acquire complex aromas from the wood, improve their colour stability, flavour, and clarification, and extend their storage period. New trends in the use of barrels, replaced after a few years of use, have led to an increased demand for oak wood in cooperage. In addition, the fact that the wine market is becoming increasingly saturated and more competitive means that oenologists are increasingly interested in tasting different types of wood to obtain wines that differ from those already on the market. This growing demand and the search for new opportunities to give wines a special personality has led to the use of woods within the Quercus genus that are different from those used traditionally (Quercus alba, Quercus petraea, and Quercus robur) and even woods of different genera. Thus, species of the genus Quercus, such as Quercus pyrenaica Willd., Quercus faginea Lam., Quercus humboldtti Bonpl., Quercus oocarpa Liebm., Quercus frainetto Ten, and other genera, such as Robinia pseudoacacia L. (false acacia), Castanea sativa Mill. (chestnut), Prunus avium L. and Prunus cereaus L. (cherry), Fraxinus excelsior L. (European ash), Fraxinus americana L. (American ash), Morus nigra L, and Morus alba L. have been the subject of several studies as possible sources of wood apt for cooperage. The chemical characterization of these woods is essential in order to be able to adapt the cooperage treatment and, thus, obtain wood with oenological qualities suitable for the treatment of wines. This review aims to summarize the different species that have been studied as possible new sources of wood for oenology, defining the extractable composition of each one and their use in wine.

Gallic acid as main product in the water extractives of Quercus frainetto ten

The autoclave extraction of Hungarian oak (Quercus frainetto Ten.) wood gave 5.3% extractives. The chloroform soluble fraction obtained from the extracts of Q. frainetto allows to identify sesamin. The insoluble fraction contains mainly ribose and mannose. Water extraction in autoclave of thermo-treated Q. frainetto wood gave a lower amount of extractives (3.31%). The main product of the insoluble fraction was, on the basis of its mass spectrum, the monoacetyl derivative of gallic acid.

Effect of heat treatment on wood chemical composition, extraction yield and quality of the extractives of some wood species by the use of molybdenum catalysts

The effect of heat treatment and the presence of some molybdenum catalysts on the amount of extractives in Populus nigra, Larix decidua, Paulownia tomentosa, Castanea sativa and Quercus frainetto wood were studied. There are an increase in the amount of lignin and extractives and a decrease in the amount of holocellulose following thermo-treatment, in the treatment temperature range. Autoclave treatment of wood with water in the presence of some molybdenum catalysts can increase the amount of extracts, but it reduces solubility. Soxhlet extraction of wood with ethanol/toluene mixture in the presence of H3PMo12O40 increases the amount of extractives and their solubility in chloroform, while in the presence of MoO3 only the solubility of extractives increases. GC–MS analysis of insoluble fraction showed the presence of myo-inositol and some simple carbohydrates, mainly ribose, xylose and glucose. GC–MS analysis of soluble fraction showed the presence of long-chain acids and fatty acid esters of 10–20 carbon atoms, mainly decanoic acid, hexadecanoic acid and octadecanoic acid, which can be a source of fatty acids for biodiesel production.