Turkish Journal of Forestry

268-277

Authors: Ceyhun GÖL Serhat MEVRUK

The objective of this study is to investigate the effects of representative land use types and land cover (LUT/LC) of heavily deforested areas on soil properties in semi-arid region of Türkiye. Some of the soil properties have been measured on a grid with a 50 m sampling distance on the top-soil (0-15 cm depth). Data has been analyzed by using Ordinary Kriging/Spherical geostatistical model. Results indicated that the soil properties differed in terms of organic carbon (SOC), pH, bulk density, and the amount of sand, depending on the land uses in the study areas. The SOC concentration of top-soil layers has referred a significant difference (P<0.05) according to the land use type. Top-soil SOC concentrations in the four LUTLCs have been in the following order: cultivated areas < grasslands < Scotch pine stands = Uludağ fir stands. The impacts of LUTLC change on SOC and soil properties have not been restricted to the soil surface; however, relative changes have equally been high in the sub-soil, stressing the importance of sufficiently deep sampling. Furthermore, it has been determined that some physical and chemical characteristics of the natural forest soil have been significantly changed after long term and continuous cultivation. SOC loss is remarkable under the land use conversion while cropland has considerable potential to sequester SOC.

290-298

Authors: Ahmet Bora KIRKLIKÇI Tarık GEDİK

The negative aspect of the COVID-19 pandemic, whose impact in the economic field began to be felt much more especially after the third quarter of 2020, has emerged in every sector. Institutionalized businesses have been less affected by the pandemic than other businesses. With this study, it has been tried to analyze the crisis management plans of the forest products industry enterprises, which are institutionalized at a certain level or on the way to institutionalization, in the COVID-19 process. The data obtained by using individual in-depth interviews with business managers were coded, described, analyzed and interpreted in accordance with the combined qualitative research reporting criteria. According to the results obtained from fourteen different forest products industry enterprises, managers defined the need to be prepared for the crisis and stated that this preparation should be done by the top management. According to managers, the pandemic process has caused major changes in consumer behavior. The managers stated that the period caused the most loss of workforce and loss of jobs and markets (economic loss). Business managers are advised to make risk assessments, prepare contingency plans and develop crisis management models in order to minimize the effects of the COVID-19 pandemic in their businesses.

305-312

Authors: Ömer Ümit YALÇIN

In this study, it was investigated some properties of gypsum particleboards which is produced with olivine mineral. Wood particles were added as reinforcement in different proportions (70% and 30%) to two types of plasterboard. The effects of inorganic olivine mineral added to these two types of boards were evaluated in terms of their physical and mechanical properties, thermal conductivity, and combustion behaviour. Subsequently, tests were carried to determine their water absorption, thickness swelling, internal bonding, bending strength, modulus of elasticity, thermal conductivity, and combustion performance. The properties of the boards were then examined using Fourier-transform infrared spectroscopy and thermogravimetric analysis. The Fourier-transform infrared analysis revealed the typical traces of cellulose, hemicellulose, and lignin in the wood material, traces of gypsum as the binder, and varying traces of olivine, according to the additive ratio, were also observed. Thermal analysis determined the positive contribution of olivine to the basic stability of both types of boards. It can be concluded that olivine, when added in different proportions, is a suitable reinforcement material for improving the technical properties of gypsum particleboard.

320 - 327

Authors: Abdullah CANIYILMAZ Samim YAŞAR

In the present study, heat-treatment was applied to brutian pine (Pinus brutia Ten.) wood samples at 120, 160 and 200oC, and then the samples were pressed in the ratio of 25% and 50% for densification. Fourier transform infrared (FTIR) spectroscopic and thermal properties of heat-treated samples were investigated. The physical and mechanical properties of the heat-treated and densified samples were evaluated. FTIR spectroscopic findings showed that there was no remarkable change in the crystallinity index of the samples due to heat-treatment. It was observed that the heat-treated samples had lower material loss than the control samples at the main decomposition phase in the thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) curves. However, according to the TGA and DTG findings, it was determined that a significant level of holocellulose loss occurred in the samples with the increase of the temperature applied in the heat-treatment. In the results obtained, it has been seen that it can be recommended to apply heat treatment before densification, if the thermo-mechanically densified brutian pine samples are considered to be used in environments where they can come into contact with water. In addition, heat-treatment and densification methods can be recommended to be used together for increase the usability of wood materials in load-bearing applications and outdoor (siding, park and garden furniture, etc.) or indoor (paneling, parquet, sauna, furniture elements, etc.) applications, as well as partially fire-resistant structures.

335 - 340

Authors: İlhami Emrah DÖNMEZ Koray BAŞOL Sezgin Koray GÜLSOY

Citrus trees are pruned at certain periods in order to increase yield, to protect the trees from diseases or to give form to the tree, and thus lignocellulosic residues emerge. These residues are called pruning residues and cannot be used other than burning. There are many species in the citrus family throughout Turkey and it is one of the leading countries in terms of fruit production. In this study, the cell-wall main components, side components and fiber properties of orange (Citrus sinensis), tangerine (Citrus reticulata), lemon (Citrus limon) and grapefruit (Citrus paradisi) wood and bark, which are pruning residues in citrus orchards and evaluated as waste material, were revealed. In chemical analyses, the amount of holocellulose was found to be between 66.45% and 80.82%, the amount of α-cellulose between 41.54% and 55.24%, and the amount of klason lignin between 14.37-19.67%. Solubility values were determined close to each other in wood and bark samples. While the 1% NaOH solubility ranged between 19.38-78.17%, the amount of soluble substances after hexane extraction was found to be between 2.61-8.24 mg/g. Fiber length and width were determined as 0.64-0.77 mm and 13.00-14.90 µm, respectively.

163-177

Authors: İrem TÜFEKCİOĞLU, Gökhan ERGAN, Burçin KAYNAŞ, Nursema AKTEPE, Çağatay TAVŞANOĞLU

The Mediterranean Basin is a biogeography shaped by fires for millions of years. For the restoration of burned areas in the Mediterranean Basin, therefore, planning should increase resistance and resilience of plant communities to fire by considering adaptation strategies of plant species to fire. In this study, following the fire of 2021, affected approximately 12,500 hectares in Marmaris region, a rapid assessment method and post-fire restoration prescriptions were developed for the Datça-Bozburun Special Environmental Protection Area. By using EFFIS and Sentinel-2 satellite images, the burned area was determined and classified to fire severity with normalized burn ratio difference The regeneration potential of burned areas was revealed by counting the number of serotinous cones of Turkish red pine (Pinus brutia) and estimating potential coverage of maquis species in sampling areas based on stand type and burn severity levels. Open pine stands had the highest serotiny and high resprouting potential following maquis vegetation, while the young pine stands have the lowest level of serotiny. Considering results and slope degrees, six restoration prescriptions were developed for burned areas. While 6% of the burned area was recommended to be left unmanaged, natural regeneration + laying out branches with cones and natural regeneration with additional seeding, and artificial regeneration by planting saplings after terracing and tillaging were foreseen for the remaining areas. This simple and cost-effective methodology developed in this study is highly applicable to local practitioners and decision makers, as it can be carried out within two months following the fire.

187-195

Authors: Onur ALKAN, Ramazan OZÇELİK

Black pine (Pinus nigra JF Arnold.) is one of the most economically and ecologically important tree species in Turkey. In this context, reliable and accurate information about the current status, growth and yield characteristics of these forests is needed for the sustainable management of black pine forests. One of the most important components of growth and yield models is the height-diameter relationships. Diameter and height variables are also the most important measurement tools in forest inventory studies. Since the height of a standing tree cannot be measured as easily as the breast height diameter, tree height is often estimated as a function of diameter in forest inventory studies. For this reason, accurate and reliable estimation of tree height has a great importance for forestry activity. In this study, a height-diameter model was developed for natural black pine stands in Eğirdir region using Quantile Regression (QR) techniques. The measured data were randomly divided into two equal groups. Chapman-Richards height-diameter model was chosen as the base model for both methods since this model has been provided successful results in previous studies. QR models are developed based on three quantile (3, 5 and 9 quantiles) sets in this study. The most important advantage of QR approach over other estimation methods is that QR allows the calibration of the model with extra sample tree heights. For this purpose, different calibration alternatives were tested using a number of trees ranging from 1 to 10 in each sample plot. As a result of the study, it was seen that the 3QR approach performed better than both 5QR and 9QR approaches in terms of describing the height-diameter relationships. In addition, it has been determined that the calibration with five sample trees in each sample plot is appropriate in terms of both the estimation precision of the models and the sampling costs

203-211

Authors: Gülser PATLAR, Mustafa AVCI, Şükran OĞUZOĞLU

Field studies were carried out during the April-November period of 2018-2019 in order to determine the phytophagous and predatory insect species living on ornamental trees and shrubs in Burdur city center parks. 15 parks located in the city center were chosen as the study area. The parks were visited three-four times throughout the year and specimens of insects and host plants were collected and brought to the laboratory for preparation and diagnosis. A total of 34 plant taxa were examined throughout the study. As a result, totally 55 phytophagous insect species were identified from three orders and 19 families [Pseudococcidae 1, Diaspididae 4, Marchalinidae 1, Tingidae 3, Psyllidae 2, Cicadellidae 3, Miridae 7, Lygaeidae 6, Coreidae 2, Rhapolidae 2, Pentatomidae 4, Cixidae 1 (Hemiptera), Apionidae 3, Chrysomelidae 4, Curculionidae 8, Malachiidae 1, Elateridae 1 (Coleoptera), Tortricidae 1, and Notodontidae 1 (Lepidoptera)]. Among them, the most common and abundant species was Marchalina hellenica (Gennadius, 1883) from the Marchalinidae family. We report Anthocomus equestris (Fabricius, 1781) from the Malachiidae family as a new record from Turkey. Totally 18 predator species were identified from seven families [Nabidae 1, Miridae 1, Anthocoridae 2, Coccinellidae 10, Cantharidae 2, Srypidae 1, and Forficulidae 1]. We identified 83 interactions between phytophagous insects and host plants, and 26 interactions among phytophagous insects, host plants, and predator species.

218-230

Authors: Şahin PALTA, Perihan YÜCESOY

The aim of this study was to determine the ecological characteristics of natural rangelands. For this purpose, four different natural pastures were studied in Nebioğlu region in Zonguldak province. When the studies on the subject were examined, it was determined that, while studies were carried out on pastures in almost every region of our country; such a study has not been conducted in the Nebioğlu region before. This situation increases the original value of the research. Vegetation cover in the study areas were identified and the botanical composition was checked at the family level, including Fabaceae, Poaceae and other genus. Soil sampling was done in pasture areas. A total of 40 soil samples, compiled from 10 randomly taken samples from each study area, were subjected to some physical, chemical and biological analyses. In the collected soil samples, soil texture class, actual pH (H2O), lime content, electrical conductivity, total nitrogen, organic carbon, available phosphorus and available potassium contents were analyzed. According to the results of the study, one way-Anova analysis of variance was performed in the SPSS program in order to understand if the Fabaceae, Poaceae, other genus ratios and soil properties are different among the research areas. Duncan test was applied to determine different groups. According to the results of the study, the canopy coverage of vegetation was calculated as 100% in all pasture areas. The highest rate of legumes was in Hallaç rangeland with 48.7%, grasses rate was in Gölyanı range with 39.8%, other genus rate was 30.8% in Alçak and Hallaç pastures; The lowest rate of legumes was found in Alçak pasture with 38.3%, the rate of grasses in Hallaç with 20.5%, and the rate of other families in Gölyanı range with 20.1%. According to the results of the soil analysis, it was determined that the soils in all pasture areas were in the clayey soil class, slightly alkaline and had low electrical conductivity.

243-254

Authors: Hasan ALKAN, İsmail ARAÇ

This research was carried out to determine the opinions of the implementing personnel regarding electronic sales methods, which have started being used in the sale of wood-based forest products. Within the scope of the research, a survey was conducted with 323 personnel working in various units of the General Directorate of Forestry and working in electronic sales. Basic statistical tests and the chi-square test were used in the analysis of the research data. According to the research findings, the use of electronic sales in the sales of forest products, which started in 2019 with the reflection of technological developments in forestry, has become widespread with the Covid -19 pandemic period. Electronic sales, which were approached cautiously at the beginning by practitioners, were adopted due to the curfews during the pandemic process, the risks born with doing business face-to-face, the ease, reliability, speed and fairness etc. of the method and the consideration that it was more advantageous compared to in-person sales. It is thought that the method plays a role in the increase in the sales prices of forest products along with other reasons. The most negative aspect of the method is the reduction of direct communication-interaction with customers.

103-105

Authors: Musa TATAROĞLU Yusuf KATILMIŞ

Barbotinia oraniensis (Barbotin, 1964) is here reported for the first time from Turkey. The cynipid wasp has recorded in Mediterranean region, Northern Africa and some European countries. The galls of the species were collected from the seed capsules of Papaver rhoeas L. (Papaveraceae) in April 2022. Photos of the gall, and data on the distribution, and biology of the new record species are provided.

116-127

Authors: Nur DİKTAŞ BULUT, İsmet DAŞDEMİR

Trabzon province attracts foreign tourists from Arab countries, and forest recreation areas are used extensively. This study aimed to determine the consumer profile, recreational use of forest resources, user and recreational demand characteristics for recreational areas, and consumer preferences and expectations of Arab tourists coming to Trabzon. In the study, a face-to-face survey was conducted with the random sampling method for 400 Arab tourists using 10 forest recreation areas in Trabzon. In the survey, questions such as visitor characteristics of foreign tourists, use of forest resources, recreational suitability, deficiencies, and reasons for site preference were included. The obtained data were evaluated with descriptive statistics, analysis of variance, and the Duncan test. According to the analyzes and evaluations, it was found that approximately 83% of Arab tourists coming to Trabzon for forest recreation tourism came from Kuwait, Jordan, United Arab Emirates, Oman, and Iraq. The most common activities in forest recreation areas were determined as walking on forest roads, chilling, watching the scenery, taking fresh air, and taking pictures. The reasons considered very important for the preference of forest recreation areas by Arab tourists were determined natural and aesthetic values, the beauty of forests, and clean and cold water to drink, respectively. The most important variables affecting the utilization of forest recreation areas are inadequate facilities and services (4 points), environmental pollution (3.41 points), crowdedness (3.38 points), adverse weather conditions (3.34 points), noise pollution (3,12 points), security (2.86 points), transportation problem (2.59 points), and inadequate pandemic measures (1.35 points). In addition, the demand for forest recreation areas differs at 95% confidence level according to age, gender, education, family size, natural and aesthetic values, clean and cold water, the beauty of forests, tour program, friend recommendation, desire to be alone with nature, pandemic measures, lack of another place to go around the city, pollution situation, promotion and facility, and service adequacy. In the study, some suggestions were made for the sustainable management of forest recreation areas, increasing the quality of recreational services, tourist satisfaction, and tourism development for Arab tourists.

135-140

Authors: Arif Caglar KONUKCU

This study aimed to investigate the influence of density on the fracture behavior of southern yellow pine (Pinus taeda L.) wood in radial-longitudinal crack propagation direction under mode I loading. The density of the crack-tip location for each fracture test block was determined by using an X-ray density profile analyzer. Three fracture parameters were obtained from the load-deformation curve of each fracture test block, namely fracture toughness, initial slope, and specific fracture energy. In general, the results showed that the fracture parameters were strongly influenced by the density. Crack-tip locations with higher density were found to be more resistant to crack initiation. The initial slope of the load-deformation curve increased as the crack density in the wood increased. As a result of the regression analysis, it was observed that there were positive and strong correlations between density and each fracture parameter.

146-155

Authors: Emine KILIÇ, E. Seda ARSLAN

Basins formed by ecological resource have several indispensable natural values for human well-being as a part of natural landscapes. In this context, determining the different ecological characteristics of the basins is important for the sustainability and management of ecological life. In this study, infrastructures approach was applied to analyze topography and land use of the Burdur Basin. At this point, the study area was determined as green, blue, yellow, and grey infrastructures and analyzed with the topography, slope, and aspect features of the study area. Image classification utilized as a part of remote sensing of Sentinel-2A satellite images, and because of the accuracy analysis, the Kappa were calculated 0.86. In the study, NDVI, NDWI and SAVI indices were used and analyzed with infrastructure systems to determine the infrastructure identification potential of these indices. As a result, it has been determined that yellow infrastructures cover more area compared to other infrastructure types, green, blue and grey infrastructures and the yellow infrastructure, respectively. According to the indices, the NDVI index has the most infrastructures identification potential for the study area. Consequently, the dominant infrastructure type in the study area was found to be yellow infrastructure. Yellow infrastructure is followed by green, blue, and gray infrastructures respectively.

11-20

Authors: Mehmet ÇALIKOĞLU, Ali Cem AYDIN, Alper Ahmet ÖZBEY

In this study, the response rate of provenance trial efforts was estimated in terms of tree growth in Turkish red pine plantations. Investigations were executed at six different Pinus brutia provenance trials in Western Mediterranean Region of Turkey according to breast height diameter (dbh) at the end of the 30th year. Trials were established in randomized complete block design with 3 replications. In two best provenances according to dbh in each site, two trees nearest to plot mean in each block were cut and divided into one-meter stem sections. 5 years values of dbh over bark, dbh inside bark and basal area were calculated by stem analyses. Tree heights by ISSA method and stem volumes by Smalian Formula were estimated for same years. Growth of each characteristics over the years was compared with guide curves of site indexes in the Pinus brutia plantation yield table. As a result, in this study, the growth performances of the afforestations made by selecting superior provenances, according to the site classification of the existing Turkish red pine plantations were revealed.

30-37

Authors: Mustafa AVCI, Zeynep Eda AKINCI, Şükran OĞUZOĞLU

Neodiprion sertifer (Geoffroy, 1785) (Hymenoptera: Diprionidae) is an important pine insect that is distributed naturally in Asian and European continents and as an invasive species in North America. In this study, the effects of the outbreak caused by pine sawfly on the diameter increment of trees in 2005 in Sarıköy brutian pine (Pinus brutia Ten.) forests situated in the province of Afyonkarahisar, district of Başmakçı were determined. The annual ring widths for 2000-2014 were evaluated in the increment cores taken from the trees that were damaged and not damaged by insects. Diameter increment was found to decrease by 42.7% in trees that were damaged by the insects and by 20.8% in the trees that were not damaged in 2005 compared to 2004. While a decrease of 7.1% persisted in the damaged trees in 2006 compared to 2005, while there was an increase of 9.7% in the undamaged trees. The damaged trees had an increase of 53.8% in 2007 compared to 2006 while a decline of 25.5% was found in the undamaged trees. A statistically significant difference was found in the mean annual ring widths of the damaged trees between 2004 and 2005 when the damage occurred and the following year, 2006 (p<0,05). The effects of precipitation and drought on the diameter increase in the trees damaged by the insect were investigated in 2005 and 2006. It was concluded that the decline in the diameter increment of the trees was related to the insects whereas precipitation and drought did not have any impact.

51-57

Authors: Ufuk YILMAZ, Ufuk KILLI, Mustafa Batuhan KURT, Ahmet TUTUŞ, Sinan SÖNMEZ

Paper-Cardboard production sector renews itself day by day and evaluates alternative options to increase quality. At the same time, it has closely adapted to technological developments in the printing industry and has now managed to enter every home or office thanks to digital printing. Digital printing (inkjet-electrophotographic) has come to a level where it can replace some conventional printing techniques as a result of the quality prints it provides. Considering the ease of use and cost advantage, it becomes inevitable that this printing technique is one of the most common printing methods. In this study, the properties of corrugated cardboard with different coating properties in electrophotographic printing are investigated with parameters such as printing chroma, hue angle and gloss values. According to the results of the research, it is determined that corrugated cardboards coated with precipitated calcium carbonate (PCC) gave more positive results in terms of both optical properties and electrophotographic print quality.

64-68

Authors: Gonca DÜZKALE SÖZBİR, İbrahim BEKTAŞ, Müberra DEMİRBÜK

Cemented wood composites are among the high strength materials formed by combining the good qualities of cement and the high advantages of wood compared to other traditional materials and it is high moisture and fire resistance, easy to workability, high resistance to fungus and termites. In the study, composite boards were produced by using 20% of red pine wood timber wastes according to the amount of cement and by adding 2.5%, 5% and 10% active wood carbon as an additive, and the effect of different ratios of activated carbon on the board properties was investigated. The humidity, oven dry density (g/cm3), air dry density (g/cm3), water absorption, thickness swelling, bending strength (N/mm2), modulus of elasticity (N/mm2) and heat transmission coefficient values of the cemented wood composite board were determined. It was determined that as the amount of activated carbon added to the produced boards increased, the amount of moisture, water absorption and thickness swelling increased, and the amount of full dry density and air dry density decreased. While there was no effect on the nail holding resistance from mechanical properties, it increased the screw holding resistance, bending resistance and modulus of elasticity values. In addition, it was determined that the additive decreased the heat transfer coefficient value.

79-89

Authors: Nilgün GÜNEROĞLU, Sabriye PEKTAŞ

Green spaces are decreasing day by day due to population growth and technological developments. For this reason, ecological design solutions have come to the fore in order to protect existing resources and support natural processes in cities. In this sense, edible gardens not only provide users with healthy and fresh food in urban green areas, but also attract attention with their economic features. Edible gardens, which are very important with their aesthetic features such as color, form and texture in their leaves, flowers, fruits and stems, are special areas that encourage users to learn and socialize. The aim of this study is to determine the edible woody plant taxons in Karadeniz Technical University Kanuni campus and to investigate the landscape importance of these species. In the study, 46 different plant taxa belonging to 16 families were determined in the campus area. According to the data obtained, the taxa with the best spring coloring with flower beauty are the Rosacea Family. In addition, it has been determined that these plants are used intensively in parks and gardens as solitary and group. Laurocerasus officinalis, Corylus colurna, Crataegus monogyna and Crataegus oxyacantha were evaluated as the plants with the highest potential for use in landscape designs with their edible fruit feature.

362 - 365

Authors: Gökhan AYDIN

The study was carried out to compare the biodiversity parameters of the insect species in natural and un-natural habitats in Gölcük Nature Park (Isparta Province) between 2018 and 2019. Two natural and two unnatural habitats (impact of tourism) were selected to realize mentioned aim. Totally 40 pitfall traps (10 traps for each habitat) were set up to sample Coleoptera species. Species richness was found higher in natural habitats than unnatural ones. Diversity index (both Shannon-Wiener and Simpson) were calculated higher in natural habitats and as expected, dominancy inversely proportional to diversity was measured lower in natural habitats. Shannon Evenness, population density due to individual of the species showed mostly evenly distributed on the graphs in natural habitats. The Sörenson Coefficient results showed that selected natural and unnatural habitats groups were found similar to each other. The results of the study showed that human activity plays an important role in habitat destruction. It has been revealed that species richness and diversity are negatively affected in habitats with human impact.

371 - 374

Authors: Burak AYIN, Musa AZMAZ, Yusuf KATILMIŞ

Field studies were conducted between 2018 and 2019 in Antalya province in order to reveal the parasitoid wasps associated with cynipid galls (Hymenoptera: Cynipidae). As a result of these studies, a total of 13 parasitoid wasp species were identified belonging to four families; Eupelmidae, Eurytomidae, Torymidae, and Ormyridae. Among them, Torymus scutellaris (Walker, 1833) is a new record for Turkey. Data are given on the distribution of the species, their associated galls, and host plants.

386 - 394

Authors: Murat ÖZEN, Hasan ALKAN

In this study, the opinions of the students of Isparta University of Applied Sciences, Faculty of Forestry, Department of Forestry Engineering on the distance education process were investigated. Questionnaire and interview techniques were used to collect data. In this context, an online questionnaire was applied to 235 students. Interviews were conducted with some selected students and instructors. Basic statistical tests and chi-square test were used to evaluate the data. According to the research findings, students think that formal education in forest engineering education is much more appropriate than distance education. The three features that students are satisfied with in distance education are respectively; having the opportunity to watch the lessons again, being cheaper than formal education, not having to attend school. The three issues that cause dissatisfaction among students are respectively; difficulty in attending classes due to problems in internet access, increase in the number of homework and assignments that take a lot of time and there is not a suitable place for the lesson in living spaces.

408 - 416

Authors: Onur ALKAN, Ramazan OZÇELİK

Four taper estimating systems were evaluated for Cilicica fir (Abies cilicica Carr.) in Turkey to demonstrate statistical and practical considerations that should be used when selecting a taper estimating system for forest inventory purposes. The four equations selected were: Kozak et al. (1969), Demaerschalk (1972), Max and Burkhart (1976), and Clark et al. (1991). Tested models have been compared using evaluation statistics like as: mean difference (MD), standard error of the estimate (SEE), and Fit index (FI). Clark et al. (1991)’s segmented taper model was superior in predicting Cilicica fir stem form and stem volume than the other models. However, since this model also requires the measurement of the upper stem diameter value at 5.30 m for stem diameter and volume estimations, it was concluded that Max and Burkhart (1976) model is more suitable for practical forestry purposes among the models tested. Clark et al.’s, Max and Burkhart’s, and Demaerschalk’s models showed consistent prediction performances for both the whole stem and different parts of the stem in terms of MD and SEE values in diameter and volume estimates. Average diameter and volume prediction errors were less than 2.0 cm and 0.01 m3, respectively. All models produced reliable results for diameter and merchantable taper volume estimates at any point, based on 10 different relative height classes.

426 - 431

Authors: Samim YAŞAR, Gürcan GÜLER

In the present study, hemicelluloses were isolated from black poplar (Populus nigra L.) sawdust, which is generated by the wood industry in large quantities as lignocellulosic waste. The monosaccharide composition of hemicelluloses was determined by gas chromatography. Xylose was the predominant monosaccharide unit, at 81.13%. Isolated hemicelluloses were then esterified with octanoyl, decanoyl, and lauroyl chloride, and the produced derivatives were characterized in terms of percent yield, degree of substitution (DS), solubility, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Hemicellulose derivatives had DS values ranging from 0.83 to 0.97, and percent yields ranging from 61.54% to 62.31%. FTIR analysis confirmed esterification. TGA indicated that the hemicellulose derivatives offered lower thermal stabilities than native hemicelluloses. Solubility analysis indicated that esterification increased the hydrophobic capacity of hemicelluloses. Generally, the hemicellulose derivatives obtained could be used to make biodegradable and environmentally friendly plastics, resins, films, and coatings for industrial utilization.

439 - 443

Authors: Naile ANGIN, Murat ERTAŞ

Natural pine resin, produced from coniferous species with different techniques is a very valuable and ancient biochemical product. It has wide uses in the chemical industry, paper, road paint, plastic, medicine and cosmetic industries. In recent years, legal restrictions all over the world on consumption of synthetic resin lead the industry to biodegradable products. Although there are suitable forests for natural resin production in Turkey, commercial manufacturing and scientific studies on this subject are not at the desired level today. The aim of this study is to examine the effect of different solvent types on the yield and chemical properties of crude wood resin. As a result of the analysis, extraction yields were found between 16% and 22%, and the highest yield was obtained in the ethanol-benzene solvent system. Collaterally to the yield, the highest acid and saponification numbers were found in alcohol-benzene extracts as 174,87 and 180,33 mg KOH /g, respectively. In order to evaluate our national resources and our current potential in crude wood rosin production, more detailed and effective studies should be carried out on the physical and chemical factors that affect the yield and quality of crude wood rosin.

449 - 456

Authors: Oruç ARAS, Sait Dündar SOFUOĞLU

In this study, the effect of machining parameters on the surface quality of the machining of different surfaces of the Oriental beech (Fagus orientalis Lipsky) tree species used in the woodworking and furniture industry was investigated and it was aimed to determine the optimum machining parameters. The experiments were carried out at two different dept of cut (depth of cut 3.33 mm or 2.5 mm per machining, total 10 mm dept of cut) by using two different 8 mm diameter cutters at 8000, 12000 and 16000 rpm at feed rates of 1000, 1500 and 2000 mm/min. Surface roughness measurements were made according to ISO 4287 by using a test device with the stylus method on the surfaces obtained in different sections. Ra and Rz roughness measurements were performed on the surfaces obtained as a result of machining. It has been observed that the machining parameters have an effect in different rates on the surface roughness and the results are evaluated by comparing with the literature. The lowest average roughness (Ra=5,18 µm) value was obtained in 3-layer processing, 1000 mm/min feed rate at 16000 rpm, cutter type 2 for measurements perpendicular to the fibers on floor surfaces. The lowest values (Ra=2,84 µm) on the side surfaces were obtained as 4-layer machining, 1000 mm/min feed rate at 16000 rpm, cutter type 1 for measurements perpendicular to the fibers.