Quercus Frainetto Research Articles

A modeling approach for estimating seasonal dietary preferences of goats in a Mediterranean Quercus frainetto–Juniperus oxycedrus woodland

Goats are characterized as selective feeders due to their specific feeding behavior, thus the study of their seasonal preferences in a Mediterranean oak-juniper ecosystem is of great interest. The current research was conducted in an open oak forest in Megalo Dereio region, northeastern Greece which was grazed mainly by a flock of 650 local breed goats. Grazing behavior data as the number of bites per plant species were recorded using a direct observation method in late spring (May), middle of summer (July) and late autumn (November) of 2010 and 2011. Additionally, a modeling approach was followed in order to study the factors influencing the dietary preferences of goats. Inference – by adopting the Bayesian paradigm – was based on the best multinomial response logistic regression model, selected by the suitable model assessment criteria. According to the results, seasonal and yearly effects were both important in explaining the grazing behavior of goats, with season being the dominant factor. The model’s estimation accuracy was additionally assessed by the comparison of the calculated model-based dietary preferences with the corresponding observed values. The model could be a useful tool to estimate the seasonal changes of dietary preferences of grazing goats.

Behavioural and physiological plasticity of gypsy moth larvae to host plant switching

AbstractLarvae of the gypsy moth, Lymantria dispar L. (Lepidoptera: Lymantriidae), a generalist species, frequently encounter spatial and temporal variations in diet quality. Such variation favoured the evolution of high behavioural and physiological plasticity which, depending on forest stand composition, enables more or less successful exploitation of the environment. Even in mixed oak stands, a suitable habitat, interspecific and intraspecific host quality variation may provoke significant variation in gypsy moth performance and, consequently, defoliation severity. To elucidate the insufficiently explored relationship between gypsy moth and oaks (Fagaceae), we carried out reciprocal switches between Turkey oaks (Quercus cerris L.) and less nutritious Hungarian oaks (Quercus frainetto Ten.) (TH and HT groups), under controlled laboratory conditions, and compared larval performance between the switched larvae and larvae continuously fed on either Turkey oak (TT) or Hungarian oak (HH). We found that larval traits were most strongly affected by among‐tree variation in oak quality and identity of the host consumed during the fourth instar. Switching from Turkey to Hungarian oak (TH) led to a longer period of feeding, decrease of mass gain, growth, and consumption rate, lower efficiency of food use and nutrient conversion, and increase of protease and amylase activities. Larvae exposed to the reverse switch (HT) attained values of these traits characteristic for TT larvae. It appeared that the lower growth in the TH group than in the TT group was caused by both behavioural (consumption, pre‐ingestive) and metabolic (post‐digestive) effects from consuming oaks. Multivariate analyses of growth, consumption, and efficiency of food use revealed that early diet experience influenced the sensitivity of the most examined traits to less suitable Hungarian oaks, suggesting the development of behavioural and physiological adjustments. Our results indicate that lower risks of defoliation by gypsy moth might be expected in mixed stands with a higher proportion of Hungarian oak.

High Genetic Differentiation among European White Oak Species (<i>Quercus</i> spp.) at a Dehydrin Gene

Dehydryn genes are involved in plant response to environmental stress and may be useful to examine functional diversity in relation to adaptive variation. Recently, a dehydrin gene (DHN3) was isolated in Quercus petraea and showed little differentiation between populations of the same species in an altitudinal transect. In the present study, inter- and intraspecific differentiation patterns in closely related and interfertile oaks were investigated for the first time at the DHN3 locus. A four-oak-species stand (Quercus frainetto Ten., Q. petraea (Matt.) Liebl., Q. pubescens Willd., Q. robur L.) and two populations for each of five white oak species (Q. frainetto Ten., Q. petraea (Matt.) Liebl., Q. pubescens Willd., Q. robur L. and Q. pedunculiflora K. Koch) were analyzed. Three alleles shared by all five oak species were observed. However, only two alleles were present in each population, but with different frequencies according to the species. At population level, all interspecific pairs of populations showed significant differentiation, except for pure Q. robur and Q. pedunculiflora populations. In contrast, no significant differentiation (p > 0.05) was found among conspecific populations. The DHN3 locus proved to be very useful to differentiate Q. frainetto and Q. pubescens from Q. pedunculiflora (FST = 0.914 and 0.660, respectively) and Q. robur (FST = 0.858 and 0.633, respectively). As expected, the lowest level of differentiation was detected between the most closely related species, Q. robur and Q. pedunculiflora (FST = 0.020). Our results suggest that DHN3 can be an important genetic marker for differentiating among European white oak species.

High Genetic Differentiation among European White Oak Species (<i>Quercus</i> spp.) at a Dehydrin Gene

Dehydryn genes are involved in plant response to environmental stress and may be useful to examine functional diversity in relation to adaptive variation. Recently, a dehydrin gene (DHN3) was isolated in Quercus petraea and showed little differentiation between populations of the same species in an altitudinal transect. In the present study, inter- and intraspecific differentiation patterns in closely related and interfertile oaks were investigated for the first time at the DHN3 locus. A four-oak-species stand (Quercus frainetto Ten., Q. petraea (Matt.) Liebl., Q. pubescens Willd., Q. robur L.) and two populations for each of five white oak species (Q. frainetto Ten., Q. petraea (Matt.) Liebl., Q. pubescens Willd., Q. robur L. and Q. pedunculiflora K. Koch) were analyzed. Three alleles shared by all five oak species were observed. However, only two alleles were present in each population, but with different frequencies according to the species. At population level, all interspecific pairs of populations showed significant differentiation, except for pure Q. robur and Q. pedunculiflora populations. In contrast, no significant differentiation (p > 0.05) was found among conspecific populations. The DHN3 locus proved to be very useful to differentiate Q. frainetto and Q. pubescens from Q. pedunculiflora (FST = 0.914 and 0.660, respectively) and Q. robur (FST = 0.858 and 0.633, respectively). As expected, the lowest level of differentiation was detected between the most closely related species, Q. robur and Q. pedunculiflora (FST = 0.020). Our results suggest that DHN3 can be an important genetic marker for differentiating among European white oak species.

Genetic structure of a natural oak community in central Italy: Evidence of gene flow between three sympatric white oak species (Quercus, Fagaceae)

Incomplete reproductive barriers between species, especially in sympatric areas where several species coexist, may result in hybridization and an increase in genetic diversity. Here we assessed the amount of genetic diversity in a community of three interfertile and sympatric European oaks (Quercus frainetto Ten., Q. petraea Liebl. Matt. and Q. pubescens Willd.) situated in central Italy. We used 11 microsatellite markers derived from Expressed Sequence Tag (EST-SSRs) and we implemented a Bayesian clustering analysis to assign individuals to species or hybrids. All genotyped loci were polymorphic for all the species and three genetic clusters corresponding to each species were detected. Significant differences and a higher level of gene flow were observed between the three oak species. Occurrence of hybrids varied markedly within the studied area: hybrids between Q. petraea and Q, pubescens were the most frequent, while hybrids between Q. petraea and Q. frainetto were particularly rare. Q. pubescens and Q. petraea showed the highest number of alleles compared to Q. frainetto,which was characterized by a low number of private, but highly frequent, alleles. However, Q. frainetto showed a lower genetic diversity and a stronger reproductive isolation from the other two oak species.

UV protection effects of phenolic extracts from chestnut fruit and forest industries residues

Extracts from different lignocellulosic sources were applied in the wood veneer dyeing process with the aim of preventing colour changes caused by ultraviolet (UV) degradation. Chestnut (Castanea sativa) fruit shell and bur, and barks from Pinus pinaster, Eucalyptus globulus and Quercus frainetto extracted using water or aqueous solutions of sodium sulphite and/or sodium hydroxide were used. Wood veneers from ash (Fraxinus excelsior), koto (Pterygota bequaertii) and lime (Tilia cordata) were dyed, treated with extracts and subjected to accelerated exposure to UV light for variable lengths of time. The colour degradation was measured and the results were studied using cluster analysis. Pinus pinaster bark extracts were the best protectors for dyed veneers. Chemical changes due to UV exposure were analyzed by X-ray photoelectron spectroscopy. The degraded untreated wood increased its functional groups rich in oxygen, that is, photo-oxidation occurred. Nevertheless chemical bonding of wood treated with extracts hardly underwent changes.

Antioxidant activity of phenolic extracts from chestnut fruit and forest industries residues

In this work, extracts from various lignocellulosic wastes were analyzed with the aim of applying them to prevent colour ultraviolet degradation of dyed veneers used for board coating. Chestnut fruit (Castanea sativa) shell and bur, barks from Pinus pinaster, Eucalyptus globulus, Quercus frainetto and Quercus robur and wood from Tilia cordata were extracted using water or aqueous solutions of sodium sulphite and/or sodium hydroxide. The extracts were analyzed for their antioxidant activity (using the ferric reducing antioxidant power, the free radical DPPH and the free radical ABTS essays), totals phenols content, molecular weight distribution and phenolic composition. Except for chestnut bur and steam peeled chestnut shell whose water extract was the best, the best antioxidant properties were obtained for the 2 % sodium sulphite extracts. Extracts from pine bark and steam peeled chestnut shell, with the highest total phenols content and antioxidant activity, not only showed the best properties as bioprotectors but also high extraction yields. These extracts also presented the higher average molecular weights. Extract antioxidant properties were related to the presence of various phenolic compounds identified by reverse phase high-performance liquid chromatography electrospray ionization time-of-flight mass spectrometry: flavan-3-ols, flavonols, flavonol glycosides, dihydroflavonols and phenolic acids.

Fine-scale spatial genetic structure in a multi-oak-species (Quercus spp.) forest

Abstract: 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.

Cryphonectria parasitica, the chestnut blight fungus, causes cankers on Quercus frainetto in Greece

In 2011, cankers were observed on Hungarian oak trees (Quercus frainetto) in three localities in Greece. The pathogen was identified as Cryphonectria parasitica on the basis of morphology and sequence analysis of the internal transcribed region (ITS), part of the elongation factor 1a (EF-1a) and part of the beta-tubulin region (βT). A pathogenicity test was performed and Koch’s postulates were confirmed by re-isolation of the fungus C. parasitica from artificially inoculated detached twigs. This is the first report of C. parasitica as the cause of cankers on Hungarian oak trees in Greece.

Feature extraction from geoeye-1 stereo pairs data for forested area

Abstract. Remote sensing facilitates the extraction of information for earth’s surface through its capability of acquiring images covering large areas and the availability of commercial software for their processing. The aim of this study is the feature extraction from three Geoeye-1 stereo pairs for forested area. The study area is located in central mountainous forested peninsula of Chalkidiki, in northern Greece. Dominant forest tree species of the site are oak (Quercus conferta), beech (Fagus moesiaca), black pine (Pinus nigra) and calabrian pine (Pinus brutia). Very High Resolution (VHR) Geoeye-1 stereo pair satellite images were utilized in panchromatic and multispectral mode. The panchromatic mode was employed for Digital Surface Model (DSM) generation and its evaluation. In this study the High Pass Filter (HPF) data fusion technique was applied between panchromatic and multispectral mode for acquiring a new image with the benefits of both contracting images. Because of the fact that the feature extraction was attempted in a forested region, NDVI index and Tasseled Cap transformation were applied in the fused images’ evaluation procedure. Optical assessment was also applied. The accuracy of the generated DSM and the evaluation results of the fused images were remarkable.

Site quality assessment of degraded Quercus frainetto stands in central Greece

The potential yield of a site is measured by site index, which is defined as the dominant height of a stand at a base age. A site index model for site quality assessment of Quercus frainetto (Hungarian oak) stands in central Greece was developed using a base age of 50 years. Data were collected from 39 temporary sample plots of 10 x 10 m. Linear regression models widely used in site index studies were fitted to height-age data. The adjusted coefficient of determination (R2adj), root mean square error (RMSE), bias, coefficient of determination for the prediction (R2pr) and residual plots were used for the choice of the best-fitting model. The best model was H = -0.231+0.251A-0.001A2, where H is the predicted height at age A. The guide curve method was adopted in constructing the sites curves, with the chosen model as the guide curve. Based on this curve, the study area was divided into three site quality classes (I to III), with class I representing the best and class III the poorest. Also, the presence of a Simpson’s paradox in these analyses is discussed. The results showed that a 50-year-old stand in the study area attained an average dominant height of about 11, 8 and 6 m on site quality classes I, II and III, respectively. The Hungarian oak stands of the present study can be considered very low productivity stands.

A new species of the genus Prozercon Sellnick, 1943 (Acari: Mesostigmata: Zerconidae) from Turkey

A new species of zerconid mites, Prozercon sultani sp. n., is described from İstanbul province, Turkey. This species was found in moss, litter and soil under Pinus halepensis, P. brutia and Quercus frainetto. The description of the species is based on adults of both sexes. Illustrations of female and male are provided.http://www.zoobank.org/urn:lsid:zoobank.org:pub:F01D6627-54E3-4FE7-A90E-835F786831DA

Effects of thinning on soil respiration and microbial respiration of forest floor and soil in an oak (Quercus frainetto) forest

The effects of tree thinning on soil respiration and microbial respiration in a Hungarian oak (Quercus frainetto Ten.) forest were examined over a 2-year period (2010–12). Tree density was reduced to 50% of the basal area. The research focus was on the main factors influencing the soil respiration (RS) and microbial respiration in the forest floor (RFFM) and in the soil (RSM): soil temperature, moisture, carbon (C), nitrogen (N), and pH; groundcover biomass (GC); forest floor mass, carbon and nitrogen; and fine root biomass. RS was measured twice monthly with the soda-lime method, and the incubation method was used to measure RSM and RFFM separately. The results were evaluated annually and over the 2-year research period. Correlation and stepwise regression analyses were used for statistical evaluation. Annual mean RS was significantly higher in thinned plots (1.92 g C m–2 day–1) than in the control plots (1.79 g C m–2 day–1). Over the 2-year research period, RS was higher in the thinned plots, and had linear correlations with GC, soil temperature and fine root biomass. GC was found to be the main factor that determined RS. The control plots had significantly higher RSM in first year, whereas the thinned plots had significantly higher RSM in second year; no significant difference was found over the 2-year research period. RFFM was significantly higher in the control plots than in the thinned plots, by 84% in the second year and by 34% over the 2-year study period. RSM had a linear correlation with soil N content and soil pH, whereas RFFM had linear correlations with C concentration and the C : N ratio of the forest floor in the thinned plots.

Future of the Main Important Forest Tree Species in Serbia from the Climate Change Perspective

Materials and Methods: Our study integrates climate change scenarios for the region of Serbia together with the current distribution of forest tree species. Evaluation was performed using forest aridity index which takes into account mean temperatures and sums of precipitation of the critical months during the growing season. Distribution data of the nine most abundant tree species in Serbia (European beech, Turkey oak, Sessile oak, Hungarian oak, Pedunculate oak, Norway spruce, Silver fir, Black and Scots pine) were taken from the National Forest Inventory. Results: Significant change of bioclimatic niches is expected for the majority of the studied tree species. The most endangered will be Pedunculate oak due to the extreme change of its habitats, while drought prone species (like pines and Hungarian oak) will be less endangered. Sessile oak, Turkey oak, Silver fir, Norway spruce and European beech will be out of their 20 th century bioclimatic niches before the end of 21 st century according to A2 scenario. Conclusion: Our results suggest that some of the most important tree species in Serbia (Sessile oak, Turkey oak, Silver fir, Norway spruce and European beech) will be endangered by the end of 21 st century. General adaption options and specific measurements for forestry sector have to be made for the region of southeast Europe due to the expected extreme change in climate.

Understory Development in an Oak Forest in Northern -Hungary: the Subcanopy Layer

Abstract Structural changes in the shrub layer were analysed in a Hungarian oak forest after the oak decline pandemics. This paper focuses on the following questions: (1) which of the woody species tolerated better the forest conditions after oak decline? (2) What are the ecological factors that explain the successful response of woody species to changes in light and thermal conditions? In the monitoring plot, the structural condition of specimens only above 8.0 m was observed. After the appearance of oak decline some Acer campestre, Cornus mas and Acer tataricum specimens appeared that reached between 8.0-13.0 m in height. Significant differences were revealed between top canopy density and foliage cover of the subcanopy and between top canopy density and mean cover of field maple. The findings of the study indicate that the forest responded to oak decline with significant structural rearrangement in the shrub layer and that three woody species compensated for the remarkable foliage loss in the top canopy. These species formed a second crown layer directly below the canopy formed by oaks.

Preference and performance of the larvae of Lymantria dispar (Lepidoptera: Lymantriidae) on three species of European oaks

The gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), causes enormous damage to broadleaved forests in the northern hemisphere where it frequently defoliates large areas of forest. Since outbreaks begin in oak forests, its most suitable habitat, we determined the preference and performance of gypsy moth larvae when reared on three species of native oaks: sessile oak, Quercus petraea (Matt.) Liebl.; Turkey oak, Q. cerris L.; and Hungarian oak, Q. frainetto (Ten.). Leaf expansion and selected physical and chemical characteristics of the oak leaves were also measured. The shortest development time and highest relative consumption (RCR), growth rate (RGR), assimilation efficiency (AD), efficiency of conversion of ingested food (ECI) and digested food into larval biomass (ECD) values were recorded when larvae were fed on Turkey oak. Two-choice tests revealed that Turkey oak is the preferred host plant. It had the highest total soluble protein and leaf nitrogen content, lowest C/N ratio and its phenology was well synchronized with the hatching of the larvae. The worst performance and lowest preference index were recorded when fed on Hungarian oak, the leaves of which had the lowest protein and nitrogen content, while in terms of the values for preference and performance the larvae fed on sessile oak were intermediate. Our results indicate that forests with Turkey oak are highly likely to be defoliated by gypsy moth larvae and therefore should be regularly monitored.

Biomass of the xerothermic oak ecosystem on a site of community importance, BG0001040 “Zapadna stara planina i predbalkan”, Bulgaria

The belowground and aboveground biomass was estimated for the tree story, sprouts and seedling regeneration in a representative Quercus frainetto – Quercus cerris ecosystem on “Zapadna Stara planina i Predbalkan”, a Site of Community Importance (SCI). The biomass was measured by destructive sampling (on sample or “model trees” representing three calculated density classes for each species and cut at the stump) of leaves, annual and perennial branches, wood, bark and root components. The belowground (root) biomass was also calculated from a subsample. The data obtained were compared to the results of previous studies and the values on the Bazilevich and Rodin [1971] scale. The ecological status of the forest ecosystem studied and its functional efficiency are discussed based on the study results and specific climate data.

Differentiation and hybridization of Quercus frainetto, Q. petraea, and Q. pubescens (Fagaceae): insights from macro-morphological leaf traits and molecular data

Macro-morphological leaf traits and genetic assignments were combined to study the differentiation and hybridization of three sympatric and inter-fertile white oak species (Quercus frainetto, Q. petraea, and Q. pubescens). The sampling was performed in a single forest stand of central Italy (Mount Vairano) in which the cover percentages of each of these three oak species were almost equal. The individuals classified as pure species and the hybrid individuals were divided into two subsets (A and B) which were subsequently statistically analysed. The results regarding the subset of pure individuals showed a clear separation between the three species on the basis of differences observed in the following leaf traits: basal leaf shape, petiole ratio, petiole length, number of intercalary veins, pubescence of the petiole, leaf area, number of lobes, lamina length, and percentage of venation. Regarding the subset of hybrid individuals, as expected, a wider pattern of leaf traits compared to that exhibited by the pure individuals was observed. The leaf traits of the pure species that had provided the greater genetic contribution in the hybridization process were easily identifiable. Quercus pubescens and its hybrids exhibited a higher degree of leaf traits variability when compared with those observed for Q. petraea and Q. frainetto.

Feeding preferences of native terrestrial isopod species (Oniscoidea, Isopoda) for native and introduced leaf litter

Due to current predictions for Central Europe that forecast higher frequencies of hot and dry summers, Mediterranean drought-tolerant oak species are being evaluated as future forest trees for German forest sites that are becoming increasingly damaged by water deficit. As a result of planting foreign tree species, the leaf litter composition and thus the food resources of native saprophagous macroarthropods will change, possibly altering primary decomposition processes. Therefore, experiments concerning the acceptance and palatability of introduced versus native litter for native isopods were undertaken. Consumption rates of four native isopod species (Porcellio scaber, Oniscus asellus, Trachelipus rathkii, Trachelipus ratzeburgii) were investigated in laboratory choice tests with introduced (Quercus pubescens, Quercus frainetto, Quercus ilex) and comparable native (Fagus sylvatica, Quercus robur) leaf litter. Litter was characterized by measurement of C/N-ratios and lignin content. Although species-specific preferences of isopods could be observed in the experiments, Mediterranean oak litter was consumed by all investigated species. Furthermore, two isopod species even preferred the leaf litter of the introduced Q. ilex. Compared to native beech or oak litter, litter from these introduced tree species thus apparently do not negatively influence the consumption rates of terrestrial isopods. Possible reasons for the determined preferences are discussed.

The oak forest Quercetum f rainetto-cerris on the foothills of the mountain range Galičica (Macedonia)

The xerothermic oak forests with <em>Quercus frainetto</em> and <em>Q. cerris</em> on the estern slope of Mt. Galičica in Macedonia were investigated in connection with the Yugoslavian contribution to the International Programme "MAB". Twenty field records were interpreted from the phytosociological and the phytogeographical points of view. -the forests under discussion represent the regional association <em>Quercetum frainetto-cerris</em> macedonicum Oberd. 1948 emend. Horvat 1959. which belongs to the <em>Quercion frainetto-cerris alliance</em>. The considerable share of Balkan and Submediterranean species in their composition is particularly significant.