Quercus Petrea Research Articles

<em>Viscum album</em> Mother Tinctures reduce the activity and expression of Na+/K+ ATPase in cells of the proximal tubule of porcine kidney

Viscum album (VA) preparations have been used over the years to treat various diseases1. In homeopathy, VA mother tinctures and yours dynamized are described for cardiovascular diseases2. Nonetheless, the molecular mechanisms involved in the VA anti-hypertensive activity are poorly described. In this sense, the objective of this work was to investigate the cytotoxicity, the Na+/K+ ATPase activity and expression and also the generation of Reactive Oxygen Species (ROS) induced by winter and summer VA mother tinctures (TMVA) and their dynamized samples (6cH, 12cH and 30cH), in porcine proximal tubule renal cells (LLC-PK1). The cytotoxicity was performed by the MTT method after 24h of treatment with TMVA and yours respective dynamized samples (from Quercus petrea, Malus domestica, Ulmus carpinifolia, Pinus sylvestris and Abies alba), at 0.5% to 2.5% (V/V). Morphological alterations were evaluated by optic and transmission electronic microscopy. For the Na+/K+ ATPase and ROS assays, the cells were treated only with the concentration of 1.5% (V/V) of the samples. The MTT assay showed a dose-dependent cytotoxicity only for the summer Quercus robur TMVA (p<0.05). Considering the cytotoxic effect of this VAMT, it was not considered in the further experiments. Furthermore, no cellular alteration was detected in the LLC-PK1 cells after treatment with the selected TMVA and no significant effects were triggered neither by TMVA nor by the potentized samples (p>0.05) in the ROS generation (n=5). Only the TMVA of Abies alba summer reduced approximately 50% of the Na+/K+ ATPase activity (n=9). Also, the TMVA from Abies alba and Pinus sylvestris prepared with winter VA demonstrated capacity to reduce the expression of the enzyme Na+/K+ ATPase. The homeopathic potencies did not presented effect in the cytotoxicity and ROS generation and further analyses need to be performed to investigate its potential to reduce the Na+/K+ ATPase activity and expression.

The composition of trees from Straseni forest compared with the productive potential

In the present article it is studied the composition of stands by species and their correspondence with the productive potential offered, in the conditions of the central area of the Republic of Moldova, located in the Straseni district, Straseni forest entity. The most valuable natural and fundamental trees were preserved here. The main species is present – the Quercus petrea, followed by the Quercus robur. Deviation of current compositions from optimal ones is the resoult of of poor forest management in the past. Accurately establishing the reason for the deviation from the optimal compositions will ensure the comparisons also made according to climatic conditions. The species structure of the volume reflects the ability to capitalize on the natural conditions of the territory where it is installed.

Dendrochemical indicators of tree rings reveal historical soil acidification in Swiss forest stands

The deposition of acidifying nitrogen and sulphur compounds from agriculture and fossil fuel combustion has drastically altered the chemical balance of forest soils in many regions of the world, leading to soil acidification with negative impacts on nutrient availability and thus also on tree vitality. The change of nutrient concentrations in the soil solution can be assessed by long-term investigations, however meaningful indicators, reflecting environmental changes, are needed to compare the current nutrient status with past values. We used dendrochemical indicators in stem wood of different tree species to access the impact of acidifying depositions on soil quality and tree nutrition. We selected 328 stem wood samples from 96 trees of Norway spruce (Picea abies), European beech (Fagus sylvatica), Sessile oak (Quercus petrea) and English oak (Quercus robur) from 22 forest sites, which are part of the long-term Intercantonal Forest Observation Program in Switzerland. Four time periods of 20 years were defined according to the emissions of air pollutants between 1910 and 2017. Our results showed a trend of increasing Al concentrations in tree rings of spruce peaking in the most recent time period (2000–2017). Mn and Ca concentrations in spruce and beech wood have decreased significantly throughout the time period 1910–2017. These dendrochemical indicators depended on the soil pH, with higher Al and lower Mn and Ca concentrations for soils with a low pH (pH<4.2). In oak trees the observed dendrochemical changes are confounded with dendrochemical differences between heartwood and sapwood. K and Mg showed inconsistent patterns in all three tree species, which are probably caused by translocation within the stem discs. With the use of piecewise structural equation models (SEM) we highlighted the direct and indirect influences of N deposition on element concentrations in stem wood. The data suggest a relation between increased N deposition and lower base saturation values in the forest soils for all three tree species, which were linked to higher Al concentrations in spruce and lower Mn concentrations in spruce and beech. The relation between Al concentrations in tree rings of Norway spruce and measured base saturation was used to reconstruct past soil base saturation values. It revealed a progressive soil acidification in the long-term forest observation sites. These reconstructed base saturation values were further used to validate modelled values from dynamic biogeochemical models such as SAFE/ForSAFE. This comparison pointed out possible shortcomings such as the lack of organic complexation in those models. Taken together, our analyses showed that element concentrations of Al, Mn, Ca in Norway spruce and European beech stem wood were suitable dendrochemical indicators of environmental change due to soil acidification, as they reflect both direct and indirect effects of air pollutants and chemical soil properties.

Interspecific Growth Reductions Caused by Wild Ungulates on Tree Seedlings and Their Implications for Temperate Quercus-Fagus Forests

Ungulate impacts on forest understory alter tree species composition, with cascading effects on forest functions and resilience against future climate conditions. Indeed, the ungulate browsing pressure on tree seedlings is species-specific and causes contrasted growth reductions that alter tree recruitment rates. Untangling the effects of browsing from the effects of the other factors driving regeneration success is required to guide the forest and ungulate management. In particular, Fagus sylvatica L. strongly dominates temperate Quercus-Fagus forests close to their climax, and it remains unclear if controlling ungulate populations can maintain tree species diversity in naturally regenerated forests. We addressed this question by monitoring 734 pairs of fenced and unfenced 6-m2 plots across a broad gradient of Cervus elaphus L. abundance in Belgian Quercus-Fagus forests managed by continuous cover forestry. Seedling height, density, and vegetation cover were monitored from 2016 to 2021. Species diversity and ecological affinity for light, temperature, and atmospheric humidity conditions were computed from these measures. With ungulates, the mean growth of Betula pendula Roth. and Sorbus aucuparia L. was negligible, whereas, without ungulates, their growth was higher than the growth of other species. With ungulates, the growth of Fagus sylvatica L. and Picea abies (L.) H. Karst was higher than other species. Quercus (Quercus petreae (Matt.) Liebl and Quercus robur L.) growth was the lowest in all conditions. Finally, Carpinus betulus L. was heavily browsed but still grew higher than its competitors with ungulates. Ungulate browsing can then severely affect seedling growth and likely reduce the diversity of future recruited trees. In the study area, browsing unfavored the regeneration of the species that are less shade tolerant, more-drought tolerant, and more-heat tolerant. It thus accelerates the natural succession and reduces forest resilience to heat and drought events. Such an observation was found valid over a wide study area encompassing contrasting levels of Cervus elaphus L. abundance. Combining further reductions of ungulate populations with foodscape improvement is likely required to maintain species diversity in these forests.

Maintaining the protective function of mountain forests under climate change by the concept of naturalness in tree species composition

In Swiss mountain areas, the protective function of forests is the predominant ecosystem service having high cultural and economic significance. It is assumed that natural forests or close-to-natural forests, i.e., forests being in the equilibrium with environmental conditions are the most resilient and resistant in regard to disturbances and hence best protecting people and assets on the long run. Here, we estimated the naturalness of the tree species composition by comparing Swiss National Forest Inventory (NFI) data with current and future potential Natural forest Site Types (NST). Based on this analysis, we identified species that are under or over-represented in protective mountain forests and derived the subsequent potential for management interventions. The urgency of management interventions is expected be small if all predominant tree species of the idealized potential natural forests are present and only their relative portions in the stand need adjustment. In contrast, interventions are advisable, if predominant tree species of the current and future potential natural forests are absent. Based on NFI data, the tree species composition of 47% of the protective mountain forests were classified as “natural” or “close-to-natural,” while the remaining 53% were classified as “not natural” or “partly natural.” Norway spruce [Picea abies (L.) H. Karst.] and European larch (Larix decidua Mill.) were the two most over-represented species under current and even more so under predicted future climatic conditions. To date, silver fir (Abies alba Mill.) and European beech (Fagus sylvatica L.) were the two species most frequently absent in protective mountain forests, in which they should prevail. Apart from European beech, the most prominent increase in prevalence is predicted for oak (sessile oak and pubescent oak; Quercus petrea Liebl., Q. pubescens Willd.) and small-leaved lime (Tilia cordata Mill.). These species were currently missing from more than 75% of the stands, in which they are expected to be dominant under future conditions. Our analysis indicates the need to transform tree species compositions of protective mountain forests to optimize fitness under future climates. Some of these transformations will take place naturally, incited by disturbances, others—the majority of them—will need active management interventions.

Çataldağ (Balıkesir-Bursa) bölgesindeki yaşlı çökük geniş yapraklı ağaç türlerinde bulunan saproksilik böcek türlerinin (Coleoptera) belirlenmesi üzerine araştırmalar

With this study, Cataldag province extending at the provincial borders of Balıkesir and Bursa, the field studies were performed at 11 different study areas per three weeks using pitfall traps and window traps with old and hollow seven different original forest tree species (Alnus glutinosa, Carpinus betulus, Platanus orientalis, Fagus orientalis, Quercus petreae, Q. cerris, Q. cerris x Q. infectoria) in between April and November months during 2014-2015. At the result of the study, 112 saproxylic beetles species belonging to 83 genus of 25 families were identified. Anobium hederae Ihssen, Gastrallus corsicus Schilsky, Hemicoelus canaliculatus (Thomson), Cryptophagus pubescens Sturm, Symbiotes gibberosus (Lucas), Triplax russica (Linnaeus), T. scutellaris Charpentier, Hylis cariniceps (Reitter), Isorhipis marmottani (Bonvouloir), Phloiotrya tenuis (Hampe), Litargus balteatus (LeConte), Sacodes flavicollis (Kiesenwetter), Tetratoma desmarestii Latreille and Synchita undata Guérin-Méneville are the new records for Turkish beetles fauna. 89 saproxylic beetles of 22 families are recorded for Balıkesir and Bursa provinces for the first time. 35 species in red list prepared for endangered saproxylic beetle species in Europe and Mediterrenean basin were determined. Podeonius acuticornis endangered (EN), Cardiophorus gramineus, Megapenthes lugens, Mycetochara quadrimaculata near threatened (NT), Ischnodes sanguinicollis and Lucanus ibericus vulnerable (VU) categories are included. 88 saproxylic beetle species were determined in Susurluk and the most species were collected from P. orientalis (32 species), nonetheless 56 saproxylic beetle species were determined in Mustafakemalpaşa and the most species were collected from Q. cerris (20 species). Saproxylic beetle species were collected with 82 % window trap and 25 % pitfall trap.

SAPSIZ MEŞENİN (Quercus petrea (Matt.) Liebl) TOPRAK ORGANİK KARBON VE AZOT STOKLARI ÜZERİNDE GELİŞİM ÇAĞLARININ ETKİSİ: TAŞKÖPRÜ, KASTAMONU ÖRNEĞİ

This study aimed to determine the effects of four different development stages of sessile oak (Quercus petrea (Matt.) Liebl) stands on soil organic carbon (SOC) and total nitrogen (TN) stocks in northwest Turkey. According to the diameter at breast height (dbh), sessile oak stands were classified into four development stages namely: a development stage (&amp;lt;8cm), b development stage (8 to 19.9 cm), c development stage (20 to 35.9 cm) and d development stage (36 to 51.9 cm). Soil samples were taken from three different soil depths (0-10, 10-20, and 20-30 cm). Total 72 soil samples were collected from all development stages. Forest floor litters were also sampled from each development stage. Results showed that soil organic carbon varied significantly between the four development stages (R2=0.714, p=0.000) with the highest stocks under the d development stage (55.0 Mg ha-1) and the lowest under the b development stage (10.6 Mg ha-1). Total N stock was highest under the a development stage (3.39 Mg ha-1), whereas it was lowest under the b development stage (1.18 Mg ha-1). About 71% of SOC was deposited in the upper 30 cm of the soil. The forest floor litter also varied between the four development stages with the highest values under the b development stage and the lowest under the a development stage. As a result, the results of the study indicated that sessile oaks can play a significant role in storing organic carbon and nitrogen in the soil. On the other hand, amounts of SOC and TN stocks can be significantly varied according to stand development stages.

Taze ve Doğal Yaşlanmış Ağaç Malzemeye Uygulanan Üç Çeşit Verniğin Yüzey Sertliği

Aim of study: This study was carried out to determine the surface hardness values of some varnishes applied to the surface of naturally aged wood material.&#x0D; Material and methods: Acrylic, polyurethane and water-based varnish was applied to the surface of the experimental samples prepared from naturally aged and fresh Scots pine (Pinus sylvestris L.), sessile oak (Quercus petrea L.) and chestnut (Castanea sativa M.) wood materials. A total of 360 test samples, 10 for each wood type, cutting direction, age period, and varnish type were prepared then the surface hardness values of these samples were determined.&#x0D; Main results: As a result of the experiments, the effect of the age period on the surface hardness of the varnish layer was found to be insignificant. The highest surface hardness value in wood material was obtained in the tangential section of oak wood and the difference between oak wood and chestnut wood was statistically insignificant. As a varnish type, the highest surface hardness value was obtained in polyurethane varnish, followed by acrylic varnish and water-based varnish, respectively. In addition, the surface hardness of the varnish layer in the tangential section of the wood material was found to be higher than that of the radial section.&#x0D; Highlights: In cases where high surface hardness is required in the varnish layer, polyurethane varnish can be preferred. As a result of the experiments, water-based varnish with a low surface hardness value will be able to give a working performance compatible with wood material with a hygroscopic structure, thanks to its high elasticity. For this reason, wood with a high amount of dimensional change can be used to protect the material against external influences.

Cellulose in Foliage and Changes during Seasonal Leaf Development of Broadleaf and Conifer Species.

Stable isotope approaches are widely applied in plant science and many improvements made in the field focus on the analysis of specific components of plant tissues. Although technical developments have been very beneficial, sample collection and preparation are still very time and labor-consuming. The main objective of this study was to create a qualitative dataset of alpha-cellulose content of leaf tissues of arboreal species. We extracted alpha-cellulose from twelve species: Abies alba Mill., Acer pseudoplatanus L., Fagus sylvatica L., Larix decidua Mill., Picea abies (L.) Karst., Pinus sylvestris L., Quercus cerris L., Quercus petrea (Matt.) Liebl., Quercus pubescens Wild., Quercus robur L., Tilia platyphyllos Scop. and Ulmus glabra Huds. While these species show an increase in cellulose yield from bud break to full leaf development, the rates of increase in cellulose content and the duration of the juvenile phase vary greatly. Moreover, the veins display significantly higher alpha-cellulose content (4 to 11%) compared to blade tissues, which reflects their different structural and biochemical functions. A guide for the mass of sample material required to yield sufficient alpha-cellulose for a standard stable isotope analysis is presented. The additional benefits of the assessment of the mass of required sample material are reduced sample preparation time and its usefulness in preparing samples of limited availability (e.g., herbarium material, fossil samples).

The impact of stain removal and bleaching on the adhesion strength of water-based varnish layers in oak

The aim of this study is to determine the performance of water-based varnish adhesion on the process of stain removal, bleaching and impregnation applied to wood surfaces. In order to accomplish this objective, the selected sessile oak (Quercus petreae Mill.) wood samples were firstly contaminated with grease and PVAc glue, after they were cleaned. Then, the wood samples were bleached by using oxalic acid (C2H2O4) and hydrogen peroxide (H2O2). Secondly, preprocessed specimens impregnated with imersol aqua (IA) and wood protective chemicals (WP) and together both these chemicals (IA+WP). Finally, adhesion strength performance of the wood samples were tested after they covered by single component primary resin (SCPR), double component polyurethane modified with acrylic (DCAP) and double component elastic polyurethane (DCEP). The adhesion resistance of varnish layers is determined according to ASTM 4541 principles. As a result, the oil stain removal and the protective chemical applications decreased the adhesion strength on the wood surface of water-based varnish layers. Contrary, the glue stain removal and the C2H2O4 and H2O2 bleaching increased the adhesion strength. Also, it was determined that DCEP applications have the highest value in oak wood samples.

Diagonal Tension Performance of Impregnated Woodworking Corner Joints

In this study, the effects were examined of wood species, processing types and processing time on diagonal tension performance of woodworking corner joint with double tenon and mortise. Test samples were prepared by using Scots pine (Pinus sylvestris Lipsky), sessile oak (Quercus petreae Lipsky) and black locust (Robinia pseudoacacia L.). Poly vinyl acetate (PVAc) adhesive was used to join the tenon and mortise corner joints. The samples were impregnated by using the method of immersion for 20 and 40 min with a mixture of wax / linseed oil (3 % paraffin, 10 % linseed oil, 87 % white spirit) and Imersol-Aqua. The test of diagonal compression was used to test 120 samples. In this study, the minimum strength decrease of around 68 % was obtained for Scots pine impregnated with Imersol-Aqua for 40 min and the highest strength increase of around 10 % was obtained for sessile oak samples impregnated with Imersol-Aqua for 40 min. The highest diagonal tension performance of 879.734 N·m was obtained for oak samples impregnated with Imersol-Aqua for 40 min., the lowest diagonal tension performance of 189.111 N·m was obtained for Scots pine samples impregnated with Imersol-Aqua for 40 min.

Isıl İşlem Görmüş Ahşap Kullanılarak Çeşitli Koşullar Altında Yapışma Performansının İncelenmesi

In this study, the adhesion performance of oak (Quercus petrea Liebl.) And Scotch pine (Pinus Silvestris L.) wood samples that were heat treated and glued with 1K-PUR adhesive were kept under different conditions (A1-A4-A5) and moisture contents (20°C /% 35, 20°C /%65 ve 20°C /% 95), and then the adhesion performance was investigated.Rough sized pieces of both types of wood were heat treated at 195°C for 2 hours. Test samples were prepared from untreated and heat treated blanks (DIN EN 204). Tensile tests according to DIN EN 204 were applied to samples kept at 20°C/35%, 20°C/65% and 20°C/95% temperature and relative humidity, respectively, and the adhesion performance was determined in three climatic conditions.At the end of these tests, it was found that the holding environment and climatic conditions have a significant effect on the adhesion resistance. It was observed that the samples that were kept under A1 conditions and tested had wood rupture (error) between 70% and 100%, and the samples tested after holding in A4 and A5 conditions mostly broke off from the glue joint.

Investigation of Bonding Performance of Polyurethane (Pur) Based Adhesives to Different Climate Conditions

This study was carried out to determine suitable wood type and glue to be used in wet-hot places (in the construction of saunas, baths and various marine vehicles), to determine the changes in adhesion performance at variable temperatures and sequential and individual processes by keeping the relative humidity constant in these areas. For this purpose, as wood material, Scotch pine (Pinus sylvestris Lipsky) and stemless oak (Quercus petrea spp.), glue as polyurethane based PA300 and PA301 adhesives were preferred. Wood material was supplied by random method.Test results in terms of bonding strength; sequential process adversely affected and decreased by 7 percent compared to the individual process. As wood type, 14 percent higher resistance was obtained in pine than oak. In terms of elasticity modulus; sequential process negatively affected and decreased by 1.4 percent compared to the individual process. As wood type, it was 10.5 percent with respect to oak, and 32.6 percent with higher elasticity than PA300 glue as glue type. In terms of elongation deformation in glue line; the sequential process adversely affected and reduced by about 19 percent compared to the individual process.

Finite Element Modeling of Fiber Reinforced Polymer-Based Wood Composites Used in Furniture Construction Considering Semi-Rigid Connections

In this study, control samples of pine (Pinus slyvestris L.), beech (Fagus orientalis L.) and oak (Quercus petreae L.) species were obtained by using fi ber reinforced finger corner joints. Teknobont 200 epoxy and polyvinyl (PVAc) adhesives were used as glue. Bearing in mind the critical loads that may affect their use, experimental samples were tested under diagonal loads. Experimental samples were also analyzed by a computer program using the finite element method (FEM). Finally, experimental data were compared with the results of FEM. The comparisons clearly showed that experimental results and finite element solutions (SAP2000 V17) including semi-rigid connections are in good agreement. As a structural analysis program in furniture engineering designs, FEM can be preferred in terms of reliability and cost.

The use of oak chips during the fermentation process: effects on phenolic compounds profile and antioxidant activity in Syrah young wines

The oak chip is an alternative to the traditional barrels in winemaking in order to improve the aged quality of the red wines. This study investigated the influence of adding of oak chips during the fermentation process in phenolic compounds profile and antioxidant activity. The American (Quercus Alba) and/or French (Quercus Petreae) oak chips were added (4g L−1 doses) in the alcoholic fermentation and malolactic fermentation or solemnly in the malolactic fermentation. Results indicated that Syrah tropical wines presented higher levels (≥265,44 mg L−1) of phenolic compounds compared to wines fermented with oak chips (222,71–254,36 mg L−1). However, the wine with French oak chip added during malolactic fermentation showed a higher antioxidant activity for ORAC method. This study offers a practical application of oak chips in winemaking process as an alternative to produce quality young red wines with low cost to the wineries in places of oak barrels.

Determination of modulus of elasticity and bending strength of wood material impregnated with nanoparticle silicon dioxide (SiO2)

The purpose of this study is to determine the effects of the nano-particulate silicon dioxide (SiO2) material on the bending strength and modulus of elasticity in bending of some wood species. Oriental beech (Fagus orientalis L.) and sessile oak (Quercus petrea L.) woods species which are commonly used in the furniture industry were used in this study. Impregnation was carried out with the preparation of SiO2 at concentrations of 1% and 3% according to ASTM-D 1413-76 (1976) standards. According to the results, while solution concentration was increasing in both wood species, total retention (kg/m3) and percentage retention (%) values increased; air dry density (12%), bending strength and modulus of elasticity in bending decreased. The maximum mean values of bending strength and modulus of elasticity was in control samples of oriental beech and the minimum were in sessile oak wood with 3% concentration. These results can be related to the fact that the higher density of oriental beech wood (0.630-0.685 g/cm³). In both species of wood, impregnation with SiO2 resulted loss of about 3-5% in bending strength and 0.6-9% in modulus of elasticity.

Long-term experimental management in Swedish mixed oak-rich forests has a positive effect on saproxylic beetles after 10\xa0years

Secondary succession in protected oak-rich temperate forests reduces variation in habitats and leads to denser, shadier sites. Long-term experimental studies of the effects of conservation management alternatives are needed for such forests. Here we present a rare follow-up study of the response of beetles (a highly diverse taxon with many red listed species) to conservation thinning, an action that could favour biodiversity. We previously harvested about 25% of the tree and shrub basal area in a treatment plot, and no trees and shrubs in a nearby matched minimal intervention plot, in each of eight oak-rich (Quercus robur and/or petrea) forest reserves. After two seasons, thinning had led to an increased number of species of both herbivorous and saproxylic beetles. In the present study, we examined the 10-year response of the beetle groups at the same sites. For herbivorous beetles, the initial positive effect of thinning on the number of species had disappeared after 10 years, presumably because of regrowth. In contrast, saproxylic beetles showed a further positive response after 10 years, increasing in the number of species by a third compared to before thinning. We found no change in species composition of either group due to the thinning, but many saproxylics were unique to thinning plots. Overall, our results suggest that in mixed oak-rich forests, saproxylic beetles seem to benefit from conservation-oriented thinning for at least 10 years.

Effects of Different Joint Angles and Adhesives on Diagonal Compression Strengths

ABSTRACT This study was performed to determine the effects of different joint angles and adhesives on diagonal compression strengths of the box-type furniture made from solid wood and MDF (medium density fiberboard). After drilling joints of 75o, 78o, 81o, 84o, and 87o degrees on Oriental beech (Fagus orientalis Lipsky), European oak (Quercus petreae Liebl.), Scotch pine (Pinus sylvestris Lipsky), and MDF samples, a diagonal compression strength test was applied on corners glued with polyvinyl acetate (PVAc) and polyurethane (Desmodur-VTKA = Desmodur-Vinyl Trieketonol Acetate) according to ASTM D 1037 standard. Consequently, the highest compression strength was obtained in Oriental beech (0.321 N.mm -2 ) with Desmodur-VTKA glue (0.268 N.mm -2 ) and joint angle of 84o (0.302 N.mm -2 ), while the lowest value was obtained in MDF (0.154 N.mm -2 ) with PVAc glue (0.252 N.mm -2 ) and joint angle of 78o (0.207 N.mm -2 ). Considering the interaction of wood, adhesive, and joint angle, the highest compression strength was obtained in Oriental beech with joint angle of 81o and Desmodur-VTKA glue (0.445 N.mm -2 ), whereas the lowest compression strength was determined in MDF with joint angle of 87o and PVAc glue (0.132 N.mm -2 ). In consequence, Desmodur-VTKA as glue and 81o as joint angle could be recommended to obtain some advantageous on the dovetail joint process for box-type furniture made from both massive wood and MDF.

Determination of surface roughness parameters of heat-treated and untreated scotch pine, oak and beech woods

Heat treatment is an industrial application that changes the physical, mechanical and chemical properties of wood. In addition, the smell, color and surface roughness of the heat treated wood also varies. The objective of this study is to investigate surface roughness properties (Ra, Rz and Rq) of heat treatment and untreated some wood types. In this study, wood specimens prepared from Scotch pine (Pinus sylvestris L.), oak (Quercus petreae L.) and beech (Fagus orientalis L.) wood species were heat-treated according to ThermoWood® method at 212oC for 1 hour and 2 hours in Bolu - Gerede, Turkey. Caliber sanding machine with 180 grinding were applied untreated and heat-treated specimens after heat treatment. Surface roughness parameters (Ra, Rz and Rq) according to ISO 4287 (1997) standard were determined for all samples. According to obtained data, it was observed that the Ra, Rz and Rq parameters decreased when the heat treatment time increased. It was determined that the surface roughness of all wood materials was changed by the applied heat treatment process.

Invasive oaks escape pre-dispersal insect seed predation and trap enemies in their seeds.

Species introduced to habitats outside their native range often escape control by their natural enemies. Besides competing with native species, an alien species might also affect the native herbivores by introducing a new source of different quality food. Here, we describe the case of northern red oak (Quercus rubra) invasion in Europe. We collected data on insect (moth Cydia spp. and weevil Curculio spp.) seed predation of northern red oak in its native (USA, North America) and invasive (Poland, Europe) range, as well as for sessile oaks (Quercus petrea) in Europe. We also evaluated the quality of acorns as hosts for weevil larvae by collecting infested acorns and measuring weevil developmental success, and quantifying acorn traits such as seed mass, tannins, lipids and protein concentration. We used DNA barcoding to identify insects to the species level. The predation by moths was similar and very low in both species and in both ranges. However, red oaks escape pre-dispersal seed predation by weevils in Europe. Weevil infestation rates of northern red oak acorns in their invasive range were 10 times lower than that of sessile oaks, and also 10 times lower than that of red oaks in North America. Furthermore, even when weevils oviposited into northern red oaks, the larvae failed to develop, suggesting that the exotic host created a trap for the insect. This phenomenon might gradually decrease the local abundance of the seed predator, and further aid the invasion.