Quercus Cerris Research Articles

Identifying substitute host tree species for epiphytes: The relative importance of tree size and species, bark and site characteristics

AbstractQuestionsCan bark characteristics be used to determine the suitability of trees to host epiphytic bryophytes and lichens or are other tree and site characteristics more important? Identification of substitute hosts is required in the face of epidemic tree deaths due to diseases that are a threat to affiliated epiphytic communities. We assess the suitability of seven phorophytes to host the epiphytes associated with the UK native oak species, Quercus petraea and Quercus robur, which are currently threatened by a range of pests and pathogens.LocationSix botanic gardens and arboreta across the UK.MethodWe recorded the site, habitat, tree (height, diameter at breast height [1.3 m; DBH], percentage canopy cover) and bark characteristics (pH, conductivity, density, water‐holding capacity, hardness, topography) and epiphytic community composition on Acer pseudoplatanus, Castanea sativa, Fagus sylvatica, Fraxinus excelsior, Quercus cerris, Quercus petraea, Quercus robur, Quercus rubra and Tilia × europaea. In total 230 trees were surveyed across the six sites.ResultsComparisons between all trees showed significant correlations between similarities in community composition and bark characteristics. However, “tree characteristics” (species, height, DBH and canopy over) explained more of the variation in epiphytic community composition than bark and site characteristics. Phorophytes with similar epiphytic community richness or composition to native oaks did not necessarily have similar bark characteristics. Non‐native oaks and the non‐native hybrid Tilia × europaea supported similar epiphyte communities to the native oaks and are suggested as substitute phorophytes.ConclusionUsing bark traits is not a reliable method to assess the suitability of substitute phorophytes to conserve epiphytic communities. Instead, the epiphytes hosted by a wider range of phorophytes should be recorded to allow an assessment of their suitability as substitute hosts and hence aid management decisions on replacement phorophytes following tree loss.

Rediscovery of Cerroneuroterus apenninus (Trotter, 1923) (Hymenoptera: Cynipidae: Cynipini) a valid species from Italy with description and neotype designation.

Neuroterus apenninus Trotter, 1923 associated with a Cerris section oak, Quercus cerris L., was rediscovered in Italy in 2017. Alessandro Trotter (1903) described a leaf gall collected on Q. cerris from the Italian Apennines; he did not obtain the gall inductor and ascribed the galls to the genus Neuroterus, based on morphological similarity with other Neuroterus galls. We have found the same gall and obtained the gall inducer. Detailed study of morphological characters of adults revealed that the species belongs to the genus Cerroneuroterus Melika Pujade-Villar, 2010. The asexual generation of Cerroneuroterus apenninus comb. n. is described for the first time, a neotype is designated, and a diagnosis, host associations and biological notes are given; an identification key to the Western Palaearctic Cerroneuroterus species is provided.

Patterns and drivers of deadwood quantity and variation in mid-latitude deciduous forests

Deadwood is a fundamental forest habitat component and highly important for biodiversity conservation. Its availability, composition, size, categories and distribution depend on various structural and environmental factors (e.g., forest age, management, tree mortality, climate, decomposition). We analysed deadwood patterns along altitudinal gradients of managed (three) and unmanaged (one) deciduous forests in Western Romania. A total of 153 plots (119 managed, 34 unmanaged) of four pre-classified forest types dominated by Fagus sylvatica, Quercus petraea, Quercus frainetto with Quercus cerris, and Tilia tomentosa were evaluated, the former two both in managed and unmanaged stands.The managed forest types displayed an average deadwood volume of 47 m3 ha−1 with lying deadwood accounting for over 70%. About 40% of deadwood objects occurred in the early to intermediate decomposition stage. Deadwood volumes in unmanaged forest types exceeded those of managed forests two- to threefold although the deadwood amounts observed in managed forests were similar to low-intervention or recently abandoned forests, lying within critical threshold values considered important for the long-term preservation of biodiversity. Linear-mixed-effects models confirmed the positive impact of non-management and the negative effect of annual mean temperature on deadwood volume. Prediction models suggested that management and annual mean temperature showed additive effects, indicating that a combination of environmental and structural parameters determines the amount of deadwood in the studied forest types. As climatic variables strongly influence tree species composition and thus forest type, management involving deadwood retention or accumulation should consider forest-type specific characteristics and thresholds.

Incubation of a foreign object by a Common Nighthawk (Chordeiles minor) in Florida

Ground-nesting birds typically maintain a nest free of foreign materials but occasionally are known to incubate a foreign object, often in the presence of other eggs. In May 2012, we discovered a Common Nighthawk (Chordeiles minor) incubating a turkey oak (Quercus cerris) acorn along with 2 eggs within a mesic flatwoods forest in Clay County, Florida, USA. Herein, we report this observation and include 3 possible hypotheses for this behavior.

Quality of Oil- and Wax-Based Surface Finishes on Thermally Modified Oak Wood

In this study, natural linseed oil, hard wax oil, and hard wax, commonly used as finishes for wooden furniture and parquet, were used for surface finishes on Turkey oak wood (Quercus cerris L.), thermally modified at temperatures of 175 °C and 195 °C for 4 h. Several resistance surface properties were investigated. The mechanical resistance properties of all surface finishes were very much allied to interactions between the finish and the type of substrate. The adhesion strength and impact resistance decreased if higher temperature was used for thermal modification of the substrate. The surface hardness and the resistance to abrasion were high and increased slightly with increasing temperature during thermal modification of wood. It was also found that surface adhesion, hardness and resistance to impact were very much related to interactions between the coating film and the substrate. The resistance properties of finishes, such as resistance to cold liquids and mold, were mainly influenced by the type of the surface finish. The resistance to cold liquids increased in the order: surface finish with hard wax < linseed oil < finish system of linseed oil + hard wax oil. The lowest resistance to cold liquids showed up in condensed milk and sanitizer. Resistance to Aspergillus niger and Penicillium purpurogenum was relatively weak, however apparently improved during the first 7 days of the fungal test; the surfaces were covered with a lower distribution density of fungal mycelium after 21 days of the fungal test. Individual surface performances of oil and wax-based surface finishes on native wood were different from thermally modified wood.

Low-temperature pyrolysis products of waste cork and lignocellulosic biomass: product characterization

In recent years, there has been growing interest in the pyrolysis of biomass due to economic and environmental reasons. Low-temperature pyrolysis is one of the most straightforward and low-cost pyrolysis processes that may be used to produce added-value biochars as well as liquid and gas products from waste biomass. Lignocellulosic biomass obtained from the fractionation of Quercus cerris bark including cork-rich and phloem-rich granules were subjected to low-temperature pyrolysis (250–325 °C) and the resulting pyrolysis products were examined. The results showed that 59–90% biochar, 8–24% bio-oil, and 2–16% gas products could be obtained from the waste cork, while phloem results in 53–89% biochar, 8–21% bio-oil, and 3–30% gas. The produced chars are rich sources of calcium, magnesium, and potassium and these elements are concentrated in the char as the pyrolysis temperature increases. The pyrolysis condensates contain high amounts of lignin-derived phenolic compounds with 2-methoxy phenol being the most abundant compound.

Estimation of fresh sprout biomass based on tree variables of pollarding Turkey oak (Quercus cerris L.).

Pollarding of oak trees for livestock and animal feeding is a traditional application, and it has been used for centuries from generation to generation in southern and southeastern Turkey. Estimation of the fresh sprout biomass (FSB) potential of pollarded oak forests in high accuracy is important for sustainable forest management. In the present study, 40 trees were sampled from Turkey oak (Quercus cerris L.) stands that have been irregularly pollarded for animal husbandry in Adıyaman, southeastern Turkey. In order to estimate FSB, a multiple logarithmic linear model was developed with explanatory variables such as tree diameter at breast height (DBH), total tree height (H), mean sprout length (SL), and mean sprout age (SA), which are in a significant relationship with FSB. Stepwise multiple regression analysis was used to fit this multiple logarithmic linear model and to determine the best independent variable set. As a result of stepwise regression analysis, three models were obtained in which SL, DBH, and SA are independent variables. Model 1 estimates the FSB by taking only SL, Model 2 uses SL and DBH, and Model 3 uses SL, DBH, and SA as independent variables. All models were significant at p = 0.001 level. Model 1 explained the variation in FSB by 65%, Model 2 by 81%, and Model 3 by 86%. Inclusion of DBH in the model (Model 2) decreased the mean absolute error (MAE) of FSB by 26% and the inclusion of SA (Model 3) decreased MAE by 43%.

Mešovita mezofilna brdska bukova šuma (Fagetum submontanum serbicum) na planini Vidlič

On the Vidlič mountain, mixed mesophilic mountain beech forests (Fagetum submontanum serbicum) have been recorded at altitudes of 700 - 1000 m, at the following localities: Crni vrh, Vazganica, Kranjci, Planinarski dom, and Visočka Ržana. Phytocenological research was performed on the mentioned localities by the Braun-Blanquet method (Braun-Blanquet, 1964). It was taken 11 phytocenological plots. Beech (Fagus moesiaca) and turkey oak cer (Quercus cerris) were the main edificators and have the highest degree of presence in the examined phytocenoses on the tree floor. In the floor of shrubs, the following species: Viburnum lantana, Crataegus monogyna, Rosa canina, Daphne mezereum, Clematis vitalba, and Ligustrum vulgare have been noticed with the highest degree of presence. Acer campestre has been dominated with the highest degree from the shoots of trees. In the floor of herbaceous plants, the species: Viola alba, Cruciata glabra, Brachypodium sylvaticum, Euphorbia amygdaloides, Helleborus odorus, Fragaria vesca were with the highest degree of presence.

Wood identification of charcoal with Confocal Laser Scanning Microscopy

Wood identification of barbecue charcoal from commercial packages of three retailers (B1, B2, B3) in Slovenia and Croatia was performed with help of Confocal Laser Scanning Microscopy (CLSM). CLSM enabled us to image key identification features of charcoal wood that were compared with light micrographs of wood from the reference collection. Product B1 contained charcoal made exclusively of beech wood (Fagus sylvatica) and the declaration indicated the address of the producer, in Serbia which allowed traceability of the wood. The selection of wood species in product B2, consisted of red oak (Quercus cerris or Q. rubra), black locust (Robinia pseudoacacia), and cherry (Prunus avium), which could originate from Serbia, and it did not contain tropical wood as stated on the package. Product B3 contained wood from at least four (sub)topical species which could not be exactly identified to species/genus level. The declaration on the product did not allow traceability of wood. As the risks of illegal logging are high for wood of (sub)tropical origin, our results support the initiative that the monitoring of the charcoal trade should be covered by the EUTR - European Timber Regulations.

Two new species of oak gall wasps from Turkey (Hymenoptera: Cynipidae, Cynipini).

Two new species of oak gall wasps, Cynips izzetbaysali sp. nov. and Callirhytis afion sp. nov. (Hymenoptera: Cynipidae: Cynipini) are described from Turkey. The new Cynips species is known only from asexual females and induces detachable leaf galls on Quercus infectoria. The sexual generation of the new Callirhytis species is known to induce acorn galls on Quercus cerris. Data on the diagnosis, distribution, and biology of the two new species are given.

Saçlı meşe (Quercus cerris L.)’nin fidan kalitesi üzerinde tüp boyutu ve kökçük kırmanın etkisi

This aim of this study was to assess the effect of container size and radicle pruning at the time sowing on seedling quality in Turkey oak (Quercus cerris L.), which are among the preferred species in afforestation studies in arid and semi-arid regions in our country. In the study, some morphological (root collar diameter, height, shoot and root dry weight, shoot:root ratio, number of main roots, number of lateral roots, sturdiness ratio etc.) and physiological (shoot and root total carbohydrate content, root growing potential) characteristics were determined in 1+0 year old seedling grown in four different polybag sizes (11x22 cm, 12x25 cm, 14x35 cm and 18x30 cm) with or without radicle pruning. According to the results, the container size had significant effect on the seedling quality, except for the number of main roots and stem total carbohydrate content. The radicle pruning did not affect the shoot: root ratio, the number of lateral roots greater than 1 mm in diameter, the sturdiness quotient (seedling height:diameter ratio), the stem total carbohydrate content and the root growing potential. The root collar diameter, height, shoot dry weight, main, lateral and total root dry weight increased with increasing polybags size with radicle pruning. Radicle pruning increased number of main roots, but the root percentage and root total carbohydrate content were decreased. Seedling grown in the largest polybags had greater diameter, taller, heavier, higher the number of lateral branches and the number of lateral roots.

Functional and ecosystem service differences between tree species: implications for tree species replacement

Tree species differ in their functioning at the scale of an individual tree which will result in differences in ecosystem service provision. Replacement trees for diseased trees should take account of functional differences. Globally tree species composition is changing due to species loss from pests and pathogens. The impact of this change on ecological functioning is rarely tested. Using six sites across the UK, with multiple tree species at each site, we test for functional differences between three species threatened by disease in the UK: Quercus petraea, Q. robur and Fraxinus excelsior and six other species: Acer pseudoplatanus, Castanea sativa, Fagus sylvatica, Quercus cerris, Quercus rubra, and Tilia x europaea, which have previously been suggested as ecological replacements. Differences between species were detected for all the variables measured: nitrogen mineralization, decomposition rate, total soil carbon and nitrogen, soil pH, soil temperature, and bark water holding capacity. Non-native Quercus species were only suitable replacements for native Quercus for some of the functions measured but replicating native Quercus functioning using a mixture of other species may be possible. The functioning of F. excelsior was different from most other tree species, suggesting that replicating its functioning with replacement tree species is difficult. The work highlighted that which species replaces diseased trees, even at the scale of single trees, will impact on the functions and ecosystem services provided.

Vitality and Growth of the Threatened Lichen Lobaria pulmonaria (L.) Hoffm. in Response to Logging and Implications for Its Conservation in Mediterranean Oak Forests

Forest logging can be detrimental for non-vascular epiphytes, determining the loss of key components for ecosystem functioning. Legal logging in a Mediterranean mixed oak forest (Tuscany, Central Italy) in 2016 heavily impacted sensitive non-vascular epiphytes, including a large population of the threatened forest lichen Lobaria pulmonaria (L.) Hoffm. This event offered the background for this experiment, where the potential effects of logging in oak forests are simulated by means of L. pulmonaria micro-transplants (thallus fragments <1 cm). Our working hypothesis is that forest logging could negatively influence the growth of the thalli exposed in logged stands compared to those exposed in unlogged stands. One hundred meristematic lobes and 100 non-meristematic fragments are exposed for one year on 20 Turkey oak trees (Quercus cerris), half in a logged and half in an unlogged stand. Chlorophyll (Chl) a fluorescence emission and total chlorophyll content are used as a proxy for the overall vitality of the transplants, while their growth is considered an indicator of long-term effects. Generally, vitality and growth of the transplants in the logged stand are lower than in the unlogged stand. Both vitality and growth vary between the meristematic and non-meristematic fragments, the former performing much better. Hence, irrespective of forest management, meristematic fragments show higher growth rates (0.16–0.18 cm2 year−1) than non-meristematic ones (0.02–0.06 cm2 year−1). Considering that a conservation-oriented management for this species should be tailored at the habitat-level and, especially, at the tree-level, our results suggest that for appropriate conservation strategies, it is necessary to consider the life cycle of the lichen, since the probability of survival of the species may vary, with meristematic fragments having more chance to survive after logging.

Chemical characterization, bioactive and fuel properties of waste cork and phloem fractions from Quercus cerris L. bark

Waste biomass composed of cork-rich and phloem-rich granules obtained from the fractioning of Quercus cerris L. bark were characterized for bulk density, chemical composition, bio-active components, ash composition, and higher heating value.Bulk density of the fractions relate to their cork content and deceases with smaller particle size due to a cork enrichment in the finer particles. The bulk density may therefore be used as an indicator of suberin content of waste cork and phloem fractions. Waste cork fractions are rich sources of lipophilic and polar extracts while waste phloem fractions contain high amount of polar extracts. The polar extracts of both biomass fractions showed very high antioxidant capacities with IC50 values between 2.5 and 7.3 μg extract mL-1 for cork fractions and 5.8 and 11.7 μg extract mL-1 for phloem fractions.Higher heating values in waste cork fractions increase with decreasing particle size and ranged between 20 and 22 MJ kg-1. A biorefinery scheme was developed for the valorization of the waste cork and phloem fractions based on their physical, chemical, bioactive, and higher heating values.

Low-temperature biochars from cork-rich and phloem-rich wastes: fuel, leaching, and methylene blue adsorption properties

Waste cork and phloem fractions from the bark of Turkey oak (Quercus cerris) were subject to low-temperature pyrolysis between 250 and 325 °C and residence times of 30 or 60 min. The fuel, leaching, and methylene blue adsorption properties of the produced biochars were evaluated for the first time. The results indicate that cork and phloem containing bark fractions have a promising potential for the production of biochars. The pyrolysis process reduces the bark wastes and contributes to their efficient use. The cork and phloem biochars produced above 300 °C showed promising H/C and O/C atomic ratios that were comparable with lignite. Methylene blue adsorption on cork and phloem biochars was inversely affected by pyrolysis temperature and residence time. Activated carbons for soil amendment applications may be produced from the biochars via a steam activation method with optimum temperature and residence time of approximately 300 °C and 30 min in order to harness the nutrient release while avoiding the potential of toxicity from phenolic leaching.

Spatial variability of nutrients in soils and plants of forest ecosystems located near the highway.

The variability of selected biogenic elements in soils and leaves of three dominant plant species was studied in segments of Querci-Fageta typica and Fagi-Querceta typica forest ecosystems located near R1 Pribina highway in SW Slovakia. The amounts of nutrients (Mg, K, Na and Zn) in soils distant 30m from the highway were mostly low and increased significantly with a depth of soil. On the other hand, the highest Ca concentrations were found in the surface humus horizons and decreased significantly with soil depth. The Mg, K and Zn contents found in soil mineral horizons 8000m from the highway were more balanced than those found at 30m from the highway. The nutrient content of plant leaves was mostly significantly higher at a distance of 30m from the highway than 8000m from the highway, for Ca (Prunus spinosa, Melica uniflora), Mg (P. spinosa), Na (Quercus cerris, P. spinosa) and Zn (Q. cerris, M. uniflora). The tightness of the relationships between nutrient contents in leaves and the distance from the highway was the highest for Ca (P. spinosa, M. uniflora), Mg, Na, Zn (Q. cerris, P. spinosa) and K (M. uniflora). The K/(Mg + Ca) ratios in Q. cerris and P. spinosa leaves distant 8000m from the highway were more balanced than those found at 30m from the highway. This markedly points to favourable biological activity and better stability of the more distant control ecosystem with lower level of pollutants.

Wood Modification for Under-Utilised Hardwood Species

The different wood modification processes give the opportunity to improve the applicability of such wood materials, which due to their lower biological resistance and/or weather resistance and/or dimension stability have a limited application field. Beside several plantation grown species (e.g. poplars or black locust), there are some species that are not plantation grown but available in considerable quantities, but with low added value during their utilization. These species are mainly used for energy recovery, but they have also the potential for the utilization with higher added value (e.g. furniture, claddings, etc.). These hardwood species are Turkey oak (Quercus cerris L.), hornbeam (Carpinus betulus L.) and tree-of-heaven (Ailanthus altissima Mill.). They have in general high density, strength values and surface hardness. By improving of the properties their application could be widened by substituting more valuable wood species. Different modification techniques were used for the improvement of the properties of these wood species, namely heat treatment and oil heat treatment. In this paper selected wood properties were investigated which are important by the specification of the application fields of the treated material.

Biomass estimation of aboveground tree components for Turkey oak (Quercus cerris L.) in south-eastern Turkey.

Biomass equations were developed for different components of oak trees (Quercus cerris L.), which have been managed in coppices at different development stages-small-diameter forest (SDF) and medium-diameter forest (MDF). In this context, four biomass regression models-two based on diameter at breast height (DBH) alone and two based on DBH and total tree height (H)-were developed for each of the crown, stem, and total aboveground biomass components. Akaike's information criterion (AIC), root mean square error percentage (RMSE (%)), mean absolute error percentage (MAE (%)), adjusted coefficient of determination (Adj.R2), and bias values were used to evaluate and compare the suitability of a total of 12 regression models developed for biomass components. As a result, in the estimation of crown biomass, only DBH-based models provided higher estimation accuracy than DBH-H-based models. For the most suitable model, estimated values were Adj.R2 = 0.60, bias = - 0.009, RMSE = 66%, and MAE = 41%. In models developed to estimate stem biomass, the estimation accuracy of DBH-H-based models was higher. In the goodness-of-fit statistics calculated for the most suitable model, Adj.R2, bias, RMSE, and MAE were 0.89, 0.010, 38%, and 23%, respectively. The models developed to estimate the total aboveground biomass were all close in terms of estimation accuracy. The biomass components (crown andstem) in the total aboveground biomass were proportionally as follows: crown at 38% and stem at 62% in the SDF stage, and crown at 35% and stem at 65% in the MDF stage, indicating lower crown and higher stem partitioning as the development stage increased.

A multi-proxy approach reveals common and species-specific features associated with tree defoliation in broadleaved species

Tree crown defoliation is the most widespread indicator of forest health and vitality in Europe. It is part of the ICP Forests Pan-European survey and it is adopted for reporting under Forest Europe. It is readily understandable and can count on fairly harmonized, long-term, large-scale data series across Europe. On the other hand, it is unspecific with respect to possible causes of damage, and its relation with tree functioning remains unclear. This study focused on European beech (Fagus sylvatica L.), Turkey oak (Quercus cerris L.), and holm oak (Quercus ilex L.), three important broadleaved forest species in southern Europe. We investigated whether and to what extent morpho-physiological (functional) leaf traits and other indicators of foliar, branch and stem health condition are associated with tree defoliation. We tested the relationship between defoliation and leaf-, branch- and stem attributes, and whether indicators of damage and functional leaf traits significantly differ (Mann-Whitney U Test) between defoliated (defoliation > 25%) and undefoliated trees (defoliation ≤ 25%). For each species, we considered one site (three to five plots each) and n = 11–19 randomly selected trees. For each tree, the following indicators were measured: crown condition (defoliation; leaf-, branch- and stem damage, in terms of extent and intensity of damage), leaf morphology (leaf thickness, leaf area, lamina length, fluctuating asymmetry, specific leaf area, damaged leaf surface), leaf physiology and chemistry (chlorophyll a fluorescence, chlorophyll content, carbon and nitrogen stable isotopes composition δ13C, δ15N, carbon/nitrogen ratio). Results show that, for the selected trees of all the three species, defoliation was positively related to the extent of damage on branches. While increasing defoliation in European beech was also accompanied by several significant differences at leaf level (i.e., leaf damage, leaf volume, dry weight, carbon/nitrogen ratio and photosynthetic efficiency), for Turkey oak and holm oak the significant differences between defoliated and undefoliated trees were limited to damage on branches (both species).

Low-Molecular-Weight Phenols Recovery by Eco-Friendly Extraction from Quercus Spp. Wastes: An Analytical and Biomass-Sustainability Evaluation

In this work, chemical–physical protocols aimed at the implementation of eco-friendly and biomass-sustainable recovery processes of useful compounds from forestry and/or wood industry wastes were evaluated. Four species of interest in industrial and environmental fields (Quercus cerris, Quercus ilex, and Robinia pseudoacacia from Central Italy, Quercus petraea from France) were submitted to neutral extraction and analyzed by gaschromatography, with mass spectrometry identification of low-molecular-weight phenols. Moreover, Quercus petraea heartwood samples were submitted to three extraction/hydrolysis protocols in an alkaline environment, and the byproducts from the lignin degradation were identified and evaluated. The recovery of bioactive phenols from forestry wastes by applying eco-friendly extractive protocols may reveal a precious strategy for rethinking the management of such wastes, in line with the fundamentals of “circular economy”.