Fagus Orientalis Research Articles

Species and Structural Diversity of Coniferous-Broadleaved Mixed Forests of the Pshekha River, North-Western Caucasus

The article presents the species and structural diversity of coniferous-broadleaved forests of the Pshekha river – the largest tributary of the Kuban river. All in all, 7 main types of forest were identified and described: fir-beech fern-forb forest, fir-hornbeam blackberry-forb forest, aspen-hornbeam honeysuckle-small-herb forest, hornbeam-black alder nitrophilic-tall-herb forest, hornbeam-oak rhododendron-blackberry forest, hornbeam-beech blackberry-forb forest and hornbeam honeysuckle-blackberry forest. The composition of the forest flora of the Pshekha river includes 270 species, including 221 species of vascular plants and 49 species of mosses. Floristic diversity of coniferous-broadleaved forests of the Pshekha river is inversely related to the crown density of the stand and the proportion of oriental beech (Fagus orientalis). The highest species saturation was noted in the hornbeam-black alder nitrophilic-high-grass forest type, the lowest – in the fir-beech fern-forb type. Ecological and coenotic structure of coniferous-broadleaved forest types of the Pshekha river depends on the height above sea level, which determines the indicators of the average annual precipitation and average annual temperature – with a decrease in altitude above sea level. m. the proportion of boreal species in the composition of the flora decreases, while the proportion of nemoral and meadow-edge species increases. In the coniferous-broadleaved forests of the river. Pshekha, 11 species of earthworms were identified, belonging to four morpho-ecological groups: epigeic, epi-endogeic and endogeic, as well as anecic. In forests with a high quality of litter (hornbeam-dominated), the greatest contribution to the biomass is made by epigeic (up to 41%) and endogeic (up to 45%) groups of earthworms. In forests with low quality litter (fir- and beech-dominated), the share of endogeic earthworms is high (up to 66%). Anecic worms are mostly confined to forests on moist soils. In all types of forests, Crimean-Caucasian endemics make a large contribution to biomass and abundance: polymorphic species D. schmidti, anecic D. mariupolienis, as well as Mediterranean species: litter D. attemsi (often inhabiting oak and hornbeam deadwood) and proper soil A. jassyensis. Cosmopolitan species (D. r. tenuis, D. octaedra) are numerous among the epigeic worms and often inhabit deadwood of coniferous tree species.

Waterlogged wood remains found in a Late Bronze Age settlement (İnönü Cave) on the Western Black Sea coast of Türkiye

The remains of wooden structures belonging to the Late Bronze Age were unearthed during the excavations carried out in the İnönü Cave, which is located approximately 25 km inside the Ereğli district of Zonguldak, on the western Black Sea coast of Türkiye. Thanks to the special conditions of the cave, the woods that makes up the structures that have survived until today has been examined within the scope of this study. All wood flooring elements examined in this study consist of water-filled wood, except for one example (NNDK-1), which has semi-water-filled properties. In the construction of the wooden floor, one oak species from the white oak group (probably Quercus petraea (Matt.) Liebl.) and one pine species from the Sylvestris group (probably Pinus nigra Arnold), Alnus glutinosa (L.) Gaertner and Acer L. sp. were used. In addition, the most used genus in its construction was oak (Quercus L., section Quercus). The inhabitants of İnönü cave in the Late Bronze Age must have met their wood needs from nearby local resources. Wood anatomical analysis pointed out the occurrence of riverine forests formed by Black alder along the streams and temperate broadleaf and mixed forests formed by Sessile oak, maple, and Black pine in İnönü cave and its vicinity. These, together with others like Fagus orientalis Lipsky, Carpinus betulus L., Carpinus orientalis Mill., Salix alba L., and Populus nigra L., are the genera/species present in the region today.

Evaluation of the mechanical performance of chairs without fasteners constructed of wood–based panels

According to the literature review, limited studies were performed related to the production of "without fastener and ready to assemble (RTA)" furniture made of wood-based panel materials with Computer Numerical Control (CNC) machines and the evaluation of their strength. The aim of this study was to evaluate the cyclic loading performance of different types of RTA chairs without fastener which produced with CNC machines by using engineering design approach and product engineering methods including performance tests. In the production of chairs, 18 mm thick oriented strand board, medium density fiberboard and Oriental beech plywood were utilized as wood-based panels. Within the scope of the study, 4 different chair types without fasteners were designed and produced, and performance tests were carried out in 3 different loading directions (front to back, back to front and side thrust) with cyclic stepped increasing loading method according to the principles of American Library Association specification. Totally, 108 real size chairs without fastener were prepared and tested. As a result of the study, it was concluded that the chairs produced from Oriental beech plywood gave the best performances, while the chairs produced from medium density fiberboard gave performance values close to Oriental beech plywood, except for the side thrust test. However, the mechanical performance values of the chairs constructed of oriented strand board were very low. In conclusion, it could be said that the chairs constructed of Oriental beech plywood and medium density fiberboard without fastener have been found to have sufficient mechanical performance.

Predicting and Mapping Dominant Height of Oriental Beech Stands Using Environmental Variables in Sinop, Northern Turkey

The dominant height of forest stands (SDH) is an essential indicator of site productivity in operational forest management. It refers to the capacity of a particular site to support stand growth. Sites with taller dominant trees are typically more productive and may be more suitable for certain management practices. The present study investigated the relationship between the dominant height of oriental beech stands and numerous environmental variables, including physiographic, climatic, and edaphic attributes. We developed models and generated maps of SDH using multilinear regression (MLR) and regression tree (RT) techniques based on environmental variables. With this aim, the total height, diameter at breast height, and age of sample trees were measured on 222 sample plots. Additionally, topsoil samples (0–20 cm) were collected from each plot to analyze the physical and chemical soil properties. The statistical results showed that latitude, elevation, mean annual maximum temperature, and several soil attributes (i.e., bulk density, field capacity, organic carbon, and pH) were significantly correlated with the SDH. The RT model outperformed the MLR model, explaining 57% of the variation in the SDH with an RMSE of 2.37 m. The maps generated by both models clearly indicated an increasing trend in the SDH from north to south, suggesting that elevation above sea level is a driving factor shaping forest canopy height. The assessments, models, and maps provided by this study can be used by forest planners and land managers, as there is no reliable data on site productivity in the studied region.

Developing a Structural Complexity Index for Oriental Beech Forests in Northern Iran

Abstract The structural complexity index (SCI) has become an important metric for forest managers to monitor ecosystem services and conservation value in a wide variety of forest types. In this study, we developed an SCI for an unmanaged mixed Fagus orientalis Lipsky forest in northern Iran, which incorporated structural information specific to mature and old-growth forests. Our results showed that we were able to develop an SCI for this forest that would assist managers to make conservation decisions in a forest where large overstory trees and small understory trees are equally important. The SCI was significantly positively correlated with the density of five minor tree species (Acer velutinum Boiss., Acer cappadocicum Gled., Tilia begoniifolia Chun & H.D. Wong, Quercus castaneifolia C.A. Mey., and Prunus avium L.) and the density of large ([50 cm < diameter at breast height {DBH} < 75 cm]) and very large (DBH > 75 cm) overstory trees. The SCI remains a highly flexible tool for forest conservation and decision making and may assist with decisions about forest management in response to climate change and shifting disturbance regimes. Study Implications: Forest managers have begun to use the structural complexity index (SCI) to assess the successful achievement of conservation management objectives. In many mature, mixed-species forests, large trees, minor species, and understory tree species are important structural components. In this study, we demonstrate that reduction of the minimum diameter used for sampling trees and careful selection of the variables used to calculate SCI results in a valuable metric for making conservation decisions. The advantage of SCI as a forest decision tool is that forest managers are able to adjust the inputs used to calculate SCI to reflect specific management objectives or monitoring goals.

The Effect of Bleaching Agents on Color Change in Different Section Shapes in Beech And Fir Woods

Aim of study: It is an investigation of the effects of bleaching processes on the color change in the wood of tree species. Tree species Eastern Beech (Fagus Orientalis Lipsky.) and Eastern Black Sea Fir (Abies Nordmanniana subsp.) were used in the study. Sodium hydroxide-hydrogen peroxide, oxalic acid, peracetic acid diluted 1/3, peracetic acid diluted 1/6 were used as bleaching agents. Trial samples were prepared in accordance with standards and color change measurements were made.
 Area of study: Surface treatments on wooden materials
 Material and methods: In the study, two wood species and one varnish type were used; Color changes were tested by applying various bleaches to the wooden material by rubbing method.
 Main results: As a result of the study, differences were observed in all cross-section shapes in beech wood bleaching measurements with 1/6 diluted peracetic acid, and differences were observed in cross-section shapes in fir wood bleaching measurements. The best bleaching of fir wood was achieved with peracetic acid.
 Main results: As a result of the study, differences were observed in all cross-section shapes in the beech wood bleaching measurements with 1/6 diluted peracetic acid, and in the cross-section shapes in the fir tree bleaching measurements. The best bleaching of fir wood was achieved with peracetic acid.
 Highlights: The bleaching process allows the wooden material to easily acquire a homogeneous color. Since the cell arrangements are different in different cross-sectional shapes, the bleaching rates are different from each other. While there is not much difference in the color changes in the wood material when bleached with oxalic acid, the samples are bleached as a result of bleaching with sodium hydroxide-hydrogen peroxide and peracetic acid. Significant changes have occurred in color changes. The reason for this difference is due to the different degrees of corrosion of bleaching agents.

Drivers of tree-related microhabitat profiles in European and Oriental beech forests

Tree-related microhabitats (TreMs) provide a quantitative indicator of habitat heterogeneity in forests, including beech (Fagus) forests. However, systematic analyses of the factors driving TreM diversity and composition in Fagus sylvatica and F. orientalis forests are lacking. In this study, the TreMs of beech forests on 203 plots of 22 forest sites (production and old-growth forest) across the full longitudinal range of both species were assessed following a standardized TreM protocol. A unified diversity and ordination framework based on Hill numbers was applied to account for unobserved TreM types and to extend the sensitivity of our findings focusing from rare to dominant TreMs. The composition of TreM assemblages was mostly determined by Fagus species and elevation, a surrogate for climate, and with focus on dominant TreMs by DBH, whereas old-growth versus production forest had no effect. The coverage of detected TreMs per plot increased with the number of trees assessed and DBH, but was lower in old-growth than in production forests. When standardized for sampling coverage, the diversity of rare and dominant TreM types was higher in old-growth than in production forests, but increased with elevation only focusing on dominant TreMs. These findings corroborate regional studies showing a higher TreM diversity in old-growth forests. Moreover, they demonstrate the importance of focusing conservation efforts on forests of both Fagus species and at different elevations, covering the full range of TreM assemblages. Future studies comparing TreM diversity in different forests should standardize diversity by sample coverage, as currently done in many biodiversity studies.

Physical, mechanical, and thermal characteristics of alkaline copper quaternary impregnated oriental beech wood

The physical, mechanical, and thermal properties of Oriental beech (Fagus orientalis), which had been impregnated with the water-based, copper-containing Korasit KS material from the Alkaline Copper Quaternary group, were investigated in this study. According to ASTM 1413-07el (2007) standard, the wood samples used in the investigation were impregnated with 3 % and 6 % aqueous solutions of Korasit KS. The modulus of rupture, thermal, and water absorption tests were performed on samples of Oriental beech after they had been impregnated. Oriental beech's modulus of rupture values decreased as a result of Korasit KS impregnation. Additionally, Oriental beech had lower modulus of rupture values at greater concentrations of Korasit KS. In every water absorption period, the water absorption values of the Oriental beech impregnated with Korasit KS were higher than those of the control group. Our results showed that Korasit KS impregnation enhanced thermal properties of Oriental beech. Moreover, higher concentration levels of Oriental beech yielded better thermal characteristics of Oriental beech.

The effect of silvicultural systems on soil function depends on bedrock geology and altitude

Soil quality and function in forest environments are influenced by the interaction of soil-forming parameters and silvicultural systems. Hyrcanian forests were recently accepted as a UNESCO World Heritage Site, which extends across an area of approximately 1.8 million hectares and ascend to an elevation of 2800 m above sea level (m.a.s.l). In these woodlands, Oriental Beech (Fagus orientalis Lipsky) is the predominant tree species and could be observed at 700–1500 m.a.s.l., and occur on different parent rocks. Shelterwood and single-tree selection techniques have been the primary management methods for beech forests for the past forty years. Studies investigating the impacts of silvicultural systems have not yet been done on soil and forest floor features on different bedrock geology and altitudes. Therefore, in this study, we examined the influence of single-tree selection and shelterwood methods, 25 years after employing those methods, on soil quality and function compared to control areas (intact forests) in Hyrcanian beech stands. For this purpose, 15 forest floor (30 × 30 cm) and topsoil (0–10 cm depth) samples in each silvicultural systems (i.e., single-tree selection and shelterwood methods and control zones) × 4 regions (including Rasht, Nowshahr, Sari and Gorgan) × 4 altitude levels (with averages of 800, 1000, 1200 and 1400 m.a.s.l.) were considered. According to our findings, the investigated forest regions, forest floor and soil characteristics across various locations spots could be separated by principal component analysis output, and more than 85% of the variance was explained by the first and second axes. The structural equation model showed that the region, altitude and silvicultural systems had an effective role in the changes in soil biological activities by influencing the forest floor, and the soil physicochemical features. Based upon the network model, the C/N ratio, the sand content, the soil aggregate stability, the available K, the fulvic acid, and the Acarina density were found to be prominent factors with regard to soil function. In the control sites, increased soil organic material fractions, microbial/enzyme and biota activities were detected, particularly at the lower altitudes of the Nowshahr site, which had geological formations of dolomite and calcic layers. Taken together, it seems that the single-tree method, commonly referred to as the close-to-nature technique produces more suitable conditions for soil functioning compared to the shelterwood management approach. Silvicultural systems, bedrock geology and altitude can have major detrimental effects on soil function and fertility, over the long-term, impacts may increase with harvest intensity.

Determination of the amount of litterfall according to the development stages and of the carbon stock input into the litter in the oriental beech forests in the Marmara Region

Bu çalışma Marmara Bölgesi’ndeki doğu kayını ormanlarında gelişim çağlarına göre dökülme miktarlarını ve bu yolla ölü örtüye giren karbon stoklarını ortaya koymak amacıyla yapılmıştır. Denemeler, b (d1,3=8,0-19,9 cm), c (d1,3=20,0-35,9 cm) ve d (d1,3=36,0-51,9 cm) gelişim çağında bulunan, bakı, yükselti, eğim, yamaç konumu ve meşcere gelişimi bakımından farklılık gösteren toplam 18 alanda tesis edilmiştir. Her deneme alanına beş adet 50×50 cm ebadında kapan kurulmuş ve üç yıl boyunca aylık olarak dökülme materyalleri toplanmıştır. Araziden alınan dökülme materyalleri laboratuvarda bileşenlerine (yaprak, dal, kabuk, diğer) ayrılarak 65 °C’de sabit ağırlığa ulaşıncaya kadar kurutulmuş ve tartılmıştır. Daha sonra öğütülen örneklerde karbon analizi yapılmıştır. Kapanlardan elde edilen dökülme bileşenlerine ait kütleler hektara çevirme katsayısı kullanılarak bir hektar alandaki dökülme miktarları elde edilmiş daha sonra bu değerler analizler sonucu elde edilen karbon yoğunlukları ile çarpılarak bir hektar alanda dökülme sonucu ölü örtüye katılan karbon stokları hesaplanmıştır. Elde edilen veriler varyans, korelasyon ve aşamalı çoklu regresyon analizleri ile değerlendirilmiştir. Araştırma sonuçlarına göre, gelişim çağının ilerlemesine bağlı olarak dökülme miktarı artmış ve toplam dökülme 3959 ile 5698 kg/ha/yıl arasında değişmiştir. Dökülmeye ait ağırlıklı karbon oranı %50,3 olarak belirlenmiştir. Toplam dökülme ile ölü örtüye giren C stoku gelişim çağlarına göre 1988-2857 kg/ha/yıl arasında değişmektedir. Kayın ormanlarındaki toplam dökülme meşcere özellikleri, iklim özellikleri ve fizyografik faktörler ile tahmin edilmiştir. Elde edilen modeller kullanılarak yöredeki ve benzer yetişme ortamlarındaki kayın meşcerelerinde yıllık dökülme miktarı tahmin edilebilir. Bu araştırma ile ortaya konulan bulgular arazi kullanımı, arazi kullanımı değişikliği ve ormancılık sektörünün uzun dönemli hedefleri arasında yer alan modelleme çalışmalarında kullanılabilir.

Change of Cr, Co, and V concentrations in forest trees by species, organ, and soil depth

Heavy metal pollution is one of the most important environmental problems threatening living organisms and environmental health. Thus, there is much research interest in monitoring and reducing heavy metal pollution. Plants’ potential to accumulate heavy metals in various organs differs greatly. Therefore, it is necessary to determine the most suitable species and organs first and acquire knowledge of the subjects such as the transfer of heavy metals within plants and their particular intake into plants. This study investigated Cr, Co, and V, which are among the most important and dangerous heavy metals, and are listed in the primary pollutant list of the Agency for Toxic Substances and Disease Registry. Their concentrations were studied at different depths of soils where Pinus nigra, Pinus sylvestris, Fagus orientalis, and Abies nordmanniana subsp. bornmüelleriana species are grown, in the leaves, cones, wood, bark, and roots. The results showed that the intake of these elements into plant bodies generally occurs through the soil. Additionally, the highest concentrations in both leaves and roots were generally obtained in Fagus orientalis and Abies nordmanniana subsp. bornmüelleriana species. It can be stated that those species are the most suitable species to monitor and reduce heavy metal pollution.

Oriental beech roots improve soil aggregate stability and reduce soil detachment rate in forest lands

In many forestlands, such as Saravan Forest Park, the high capacity of soil detachment from deforestation and subsequent ecological restoration are important issues that need detailed information about plant and tree species for the objectives of soil conservation. To determine if some species are more helpful for the stability of soil aggregates and thus reducing soil erosion, we examined Oriental beech species, compared to three other species (Crataegus ambigue, Primula heterochroma and Rubus persicus) in the Saravan forest park, and measured how root characteristics (root biomass, root length and root weight density) influenced mean weight diameter of aggregates (MWD) and soil detachment rate (Dc). For measuring Dc, undisturbed samples collected from soils under the four studied species and subjected to five slopes (from 4.8 to 31.4%) and five water discharges (from 0.26 to 0.65 l m−1 s−1) by a hydraulic flume. Results showed that Oriental beech roots can significantly influence soil aggregate stability. MWD was greater in soil under Oriental beech species characterized by high values of root biomass, root length and root weight density. Moreover, Dc was significantly lower in soils with Oriental beech species compared to three other species. Pearson's correlation matrix showed a strong positive correlation between MWD and the root characteristics (P < 0.01) (R2 = 0.8). Also, the clustering of soils among the studied species by the principal component analysis (PCA) revealed a clear difference based on the root characteristics and MWD. Generally, this study showed that, compared with other species, the root system of Oriental beech is more effective in the stabilization of slope by the binding effect on the soil, thus improving aggregate stability and reducing soil detachment rates.

Comparison of plant diversity between managed and unmanaged forests in Haftkhal, Mazandaran Province, North of Iran

Abstract. Kiasari MSh, Sagheb-Talebi Kh, Rahmani R, Ghelichnia H. 2023. Comparison of plant diversity between managed and unmanaged forests in Haftkhal, Mazandaran Province, North of Iran. Asian J For 7: 106-113. The relationship of plant diversity with silvicultural practices has not been fully understood for the oriental beech forests (Fagus orientalis Lipsky), which is a widespread forest tree in the Hyrcanian Region, Iran. The implementation of appropriate forestry practices in the oriental beech forests is therefore crucial in terms of sustainable forest management. Hence, assessing the impacts of silvicultural practices on plant diversity is essential with the regard to sustainable forest management. This study aimed to compare plant species diversity between two managed and unmanaged forest stands in Mazandaran Province, Iran. Forest inventory in an area of 131 ha was performed using in a systematic random sampling with a 150 × 200 m grid size. In addition, the area of sampling was 100 m2 (10 × 10 m). Twenty and thirty sampling plots were established in managed (compartment No. 8) and unmanaged (compartment No. 36) forests, respectively. Shannon-Wiener and Simpson Indices were used to calculate plant species diversity, while Margalef and Sheldon indices were used to determine species richness and evenness, respectively. The results revealed that 50 and 56 plant species were found in managed and unmanaged forests, respectively. Rosaceae, Asteraceae, and Fabaceae were the main families in these studied areas. This study showed that the diversity and richness of plants in the managed forest slightly increased compared to the unmanaged forest. On the other hand, the evenness of plants in the managed forest slightly decreased compared to the unmanaged forest. Changes in plant diversity indices between managed and unmanaged forests were not statistically significant. This research showed that forest management of oriental beech forests using the single-tree selection cutting has not reduced or weakened the diversity of plant species in the managed forest compared to the unmanaged forest.

Effect of fungal infection on physico-mechanical resistance of WPC made from thermally treated wood/PP

The effect of fungal decay on the physico-mechanical characteristics of thermally treated wood flour-plastic composites was determined. Firstly, the wood chips (Fagus orientalis L.) were treated thermally for 30 and 120 minutes at various temperatures (120, 150, and 180 °C) under saturated vapour in a steaming vessel and they were ground by Wiley mill machine. Then, polypropylene, thermally treated wood flour, and MAPP as compatibilizer were used by melt compounding and injection molding process. Some physical and mechanical parameters were measured prior to and after fungal (Trametes versicolor) infection for 6 weeks. The flexural strength, flexural modulus, and impact strength of undecayed and decayed WPCs at 180 °C for 120 min and at 150 °C for 30 min increased, respectively, but the water uptake and thickness swelling of WPCs decreased at 180 °C for 120 min. The wood particles of WPCs treated at 180 °C for 120 minutes had the least mass loss. The mechanical property parameters were reduced after fungal infection. Moreover, the results showed that the moisture sorption and thickness swelling for all formulations of unrotted specimens were significantly lower than that of white-rotted specimens.

Properties of thermally modified Scots pine (Pinus sylvestris L.), Kazdağı fir (Abies equi-trojani Asch. et Sint.), and Eastern beech (Fagus orientalis Lipsky)

Surface roughness and discoloration of thermally modified Scots pine (Pinus sylvestris L.), Kazdağı fir (Abies equi-trojani Asch. et Sint.), and Eastern beech (Fagus orientalis Lipsky) were evaluated. The surface roughness and discoloration of the samples sanded with 60, 80, and 120-grit grades were evaluated at temperature levels of 160, 180, 200, and 220 °C. Findings were subjected to multiple analysis of variance and Duncan’s homogeneity tests; using the SPSS package program, single, double, triple, and quadruple interactions were analyzed. The highest surface roughness values were found in Eastern beech samples with radial cross-section (12.4 µm) finished with 60-grit sandpaper. The lowest roughness value was found in Kazdagi fir samples that were heat-treated in 200 °C and processed with 120-grit sandpaper (2.03 µm). The lowest discoloration evaluation (∆E) value was found eastern beech samples 32.43, and highest ∆E values 46.86 found at Scots pine.

Investigation of color parameters in pine, limba, sapele, iroko, oak, and beech wood species exposed to outdoor conditions in Van city, Turkey

Sapele, pine, limba, iroko, beech, and oak wood species are important species used indoors and outdoors, as supplied by furniture companies. It is known that the color changes in wood material when exposed to the external environment. This is an important factor for the outdoor use of wood material. In this study, the color parameters of Scotch pine (Pinus sylvestris L.), oriental beech (Fagus orientalis L.), limba (Terminalia superba Engl. et Diels), sapele (Entandrophragma cylindricum), sessile oak (Quercus petraea L.), and iroko (Milicia excelsa) wood species, which are used in both indoor and outdoor woodworking industries in Van city, Turkey were investigated after exposing them to natural weather conditions for 9 months in outdoor conditions. Each type of wood exhibited a different color behavior in outdoor conditions. In sapele and limba wood species, b* and a* values increased and L* values decreased with increasing weathering time. It was observed that ∆E* increased with increasing time of exposure in all tree species. At the end of 9 months of weathering, the highest ∆E* value was determined in pine wood, followed by beech, sapele, limba, iroko, and oak wood species, respectively.

Weathering Performance of Oriental Beech (Fagus orientalis L.) Wood Impregnated with Glycerol and Glyoxal

This study aimed to improve some surface properties such as color, gloss, and surface roughness changes of Oriental beech (Fagus orientalis L.) wood impregnated with some water repellent chemicals such as glycerol (GR) and glyoxal (GX) after weathering. Oriental beech wood specimens were impregnated with a 4 % aqueous solution of GR, GX, and a mixture of GR and GX (1:1; weight : weight) (GR+GX) and then exposed to weathering in Muğla Province in Turkey. Results showed that [delta]L* values of all wood specimens were decreased after weathering. Moreover, the decreases in the control specimen were higher than in the impregnated wood specimens. Oriental beech wood specimens showed a greenish and yellowish tendency, giving -[delta]a* and +[delta]b* values, respectively. Total color changes of GR impregnated Oriental beech was the lowest after weathering. The gloss of all Oriental beech test specimens decreased after weathering. The control specimen gave the lowest value in all three surface roughness parameters (Ra, Rz, and Rq) after weathering. Among the impregnated specimens, the groups impregnated with GR had, in general, the highest value in all three roughness degrees and showed the most negative results in surface roughness.

Properties of heat-treated beech laminated veneer lumber reinforced with carbon fiber fabric

Carbon fiber fabric reinforced laminated veneer lumber (RLVL) pieces were prepared by using heat-treated beech (Fagus orientalis Lipsky) veneers with polyurethane (PU) adhesive as the binder. Carbon fiber fabric was tested in three different locations with solid material and non-reinforced samples (on the bottom adhesive line, upper adhesive line, and upper and bottom adhesive lines-symmetrical). Prior to the manufacture of LVL and RLVL, heat treatment was conducted in a laboratory oven at three temperatures. These temperatures were 150, 170, and 190 °C. Tests were performed on LVL and RLVL to determine their air-dried density, modulus of rupture (MOR), and modulus of elasticity in bending (MOE). Experimental test results showed that reinforcement with carbon fiber increased the air-dried density, MOR, and MOE. In addition, carbon fiber fabric placed symmetrically close to bottom and upper surfaces gave the highest MOR and MOE values. However, locating the carbon fiber fabric closer to the bottom surface tended to give higher mechanical properties for the reinforced LVL.

Ultraviolet light and natural weathering vs. the compression strength of laminated wood

Effects of protective measures were evaluated relative to the compression strength in the direction parallel to the grain of laminated veneer wood (LVL). For this purpose, laminated panels were prepared from Scots pine, Oriental beech, Castanea sativa, and sessile oak wood veneer by gluing them with Desmodur vinyl trie ketonol acetate (D-VTKA), polyvinyl-acetate (PVAc) dispersion D4 adhesive, resorcinol formaldehyde (RF), and melamine formaldehyde (MF). The samples were impregnated with a mixture of wax, linseed oil, and coated with a synthetic-based translucent varnish. The control samples (without the treatment described above), impregnated samples, and varnished samples were kept in the external environment for 1 y and in an ultraviolet (UV) environment for 240 h. The samples were tested to determine the air-dried density, retention amount, and compression strength. The results indicated that, in terms of outdoor conditions, the varnished proceeding provided better protection compared to the impregnated proceeding. The best result for compression strength was obtained on the Oriental beech samples with RF and MF glues. The ratio of the UV environment to represent the external environment was 89%.

Decay resistance of Oriental beech wood treated with fire retardants and coated with epoxy and polyurea resins

Bu çalışmada, yanmayı geciktirici özellikteki kimyasal maddelerden, borik asit, boraks ve amonyum sülfat ile emprenye işlemi uygulanan ve epoksi (Sika floor 156) ve poliürea (Sikalastic®-851 R) reçineleri ile kaplanan Doğu kayını (Fagus orientalis L.) odununun beyaz ve kahverengi çürüklük mantarlarına karşı direnç özelliklerinin geliştirilmesi amaçlanmıştır. Çalışmada, deney örnekleri borlu bileşikler ve amonyum sülfatın %3’lük sulu çözeltisiyle emprenye edilmiştir. Ardından bu örneklere poliürea ve epoksi reçineleri ile kaplama işlemi uygulanmıştır. Daha sonra örnekler 12 hafta boyunca kahverengi (Postia placenta) ve beyaz çürüklük (Trametes versicolor) mantar saldırılarına maruz bırakılarak, ASTM D 1413–07 (2007) standardına göre toprak blok (soil-block) testi gerçekleştirilmiştir. Elde edilen sonuçlara göre, emprenye ve kaplama işlemi gören tüm deney örnekleri için ağırlık kayıplarının kontrol örneğine göre daha düşük çıktığı belirlenmiştir. Çalışmada kaplama öncesi borlu bileşiklerle emprenye işlemi her iki mantar çürüklüğüne karşı, örneklerin çürüklük direncini istatistiksel anlamda önemli ölçüde artırmıştır.