Turkish Journal of Forestry

255-267

Authors: Hakan DURGUN H. Oğuz ÇOBAN Mehmet EKER

Remote sensing data and techniques are widely used in modern forestry studies. Today, aerial photographs taken with remote sensors on Unmanned Aerial Vehicles (UAV) can be processed by using softcopy photogrammetry to produce data such as point cloud and orthomosaic. Therefore, it is possible to make some remote measurements in forest ecosystems. It may be necessary to predict stem volumes of trees cut down in a forest area or felled for any reason in a practical way. In this study, it is aimed to predict the over-bark stem volumes by measuring the diameter and height of cut brutian pine trees (Pinus brutia Ten.) in orthomosaic and point cloud data produced from UAV photographs. The study was carried out in 2 different brutian pine stands located within the borders of Çandır Forestry Chief of Sütçüler Forestry Directorate in Isparta Regional Directorate of Forestry. In these areas, the diameter at breast height (d1.3) and total height of 175 cut brutian pine trees were measured on the point cloud and orthomosaics, tree volume predictions were made from these values obtained by various methods and the results were compared with the references data based on field measurements. In the study, the diameter and height measurement results calculated depending on the ground sampling distance of the aerial photographs were also compared. According to the findings, the lowest correlation value of 0.78 and the highest 0.92 for diameter measurements, the lowest 0.96 and highest 0.99 correlation values in height measurements, the lowest 0.70 and the highest 0.93 correlation values in stem volume predictions were obtained between UAV photogrammetry and reference data. As a result, it has been understood that UAVs, which are preferred as a practical remote sensing tool today, can be used to measure the diameter and height of pine trees lying on the ground and stem volumes can be successfully predicted by UAV photogrammetry.

278 - 289

Authors: Mehmet EKER Eray ÖZTÜRK

In this research, the use of the motosoyar, which was previously developed by mounting a peeling device on a brush cutter, in the field and the determination of the resulting efficiency; in addition, it was aimed to determine the implementation potential of the motosoyar by comparing the work productivity of the motosoyar with the chainsaw-mounted debarking equipment and the axe. In addition, it was aimed to compare the debarking quality of these three tools by accepting the amount of bark remaining on the log surface as an indicator. A certified employee; in the same field conditions, in the same stand, in the same tree species (Pinus brutia Ten.), cut and sorted on the same dates, the bark of logs of similar height and different diameters was stripped with these three tools. Work efficiency was determined through time studies; debarking quality was calculated over the amount of bark remaining on the log. In debarking operations of logs with an average diameter of 25 cm, medium diameter and 3 m length, the chainsaw was more efficient in all time periods (3.65 m3/h), motosoyar (3.06 m3/h) was found to be efficient compared to the axe (1.25 m3/h), but inefficient compared to the chainsaw. In terms of debarking quality, it has been determined that the axe peels more cleanly (remaining shell amount; 1.65%), the chainsaw follows it with a rate of 2.73%, and the motosoyar peels at a level of 3.42%. With the improvement of the system structure (arrangement of belt and shaft arm) of motosoyar, it has shown a performance that can be as efficient and useful as a chainsaw. It has been revealed that Motosoyar has implementation potential as well as theoretical, technical, economic and ergonomic potential in debarking works.

299-304

Authors: Vedat ÇAVUŞ Fatih MENGELOĞLU

In this study, it was aimed to determine the stress and relaxation behavior of wood plastic composites produced by using magnesiumoxysulphate and lignocellulosic filler. For this purpose, test specimens were produced by using 10% and 20% magnesiumoxysulfate, lignocellulosic filler (Pinus brutia Ten.), 3% wax and maleic anhydride grafted polypropylene (MAPP) into the polymer matrix. Extrusion and injection molding methods were used in the manufacturing of test specimens. In order to determine the stress relaxation behavior of wood plastic composites in tensile, a total of 15 test samples, 3 for each variable parameter of each production code, were prepared in depend on the ASTM D 638 (2004) standard. The stress-relaxation behaviors of test samples were determined at 600 Newton force, tensile speed of 5mm/min and tensile for 2 hours. The experiments were carried out in room conditions and the temperature of the room where the experiment was conducted was adjusted with air conditioning. According to the test results; It has been determined that the ratio and type of filler materials have a significant effect on the stress relaxation values. It has been determined that the Synthetic and lignocellulosic filler participation rates are effective on the stress relaxation values of the test samples and the stress relaxation values decrease significantly as the participation rate increases. It has been determined that the filler ratio reduces the mobility of the polymer chains between them, this delays the relaxation and as the amount of filler increases, the relaxation decreases. In applications where stress relaxation behaviour it is important, specific care should be paid on the selection of filler amount.

313-319

Authors: Mesut UYSAL Orhan EREN Halil KARATAY Doğan MEMİŞ

In this study, flexural strength and modulus of elasticity (MOE) of cross-laminated timber (CLT) made of the Uludag fir and black pine wood, which are domestic coniferous tree species included in the scope of the EUROCODE 5, and polyvinyl acetate (PVAc) adhesive were investigated. CLTs, prepared with three layers, were pressed under the pressure of 0.4 N/mm2, the temperature of 35°C and the time of 150 min. Three-point bending tests were applied to determine flexural strength and MOE by obtaining load-deformation curves of solid wood and CLTs made of the Uludag fir and black pine wood. The average flexural strength of the solid Uludag fir and black pine was 65 N/mm2 and 83.8 N/mm2. The average flexural strength of the CLTs made of the Uludag fir and black pine wood was 38.4 N/mm2 and 64.6 N/mm2, respectively. Those of MOEs were 9093.5 N/mm2, 11068.8 N/mm2, 5273.4 N/mm2 and 8657.0 N/mm2, respectively. It resulted that solid wood and CLT made of black pine wood had more strength than those of Uludag fir. Analysis of variance also showed that wood species have a statistically significant effect on flexural strength and MOE of the materials. Consequently, the acquisition of domestic coniferous trees, the production of the CLTs made of these woods and the determination of their mechanical properties are vital in the structural analysis and member design of these materials in the wood construction industry in Turkey.

328 - 334

Authors: Muhammed Zakir TUFAN Tuğba YILMAZ AYDIN Ergün GÜNTEKİN Birol ÜNER

In this study, physical and chemical properties of heat treated cedar (Cedrus libani A. Rich.) wood were investigated. Heat treatment was carried out at four different temperatures (120, 150, 180 and 210 °C) and three different time period (2, 5 and 8 hours). The chemical properties of the obtained samples were determined using FT-Infrared spectroscopy. Heat treatment generally causes changes in the cell wall, hemicellulose degradation and reduction, long chain molecule modification, and accessible OH groups in wood. The hydroxyl group changes (H1429/897) were determined, and the crystal structure after 8 hours of heat treatment was 1.21, 1.33, 1.25, and 1.14, respectively. Changes in the cellulose chains were detected at the peak (A1370/670) and showed differences with the control sample at four different temperatures (120,150, 180, and 210°C) and in an 8-hour time period (3.13, 3.60, 3.33, 1.29) values were obtained. Carbonyl peaks at 1740nm increased with time and heating periods. The most apparent changes takes place at 180 and 210 °C for 8 hours treatment.

341 - 347

Authors: Ibrahim Halil HATİPOGLU Erdi EKREN

As the basic component of urban open green areas, plants are extremely important not only with their aesthetic appearance but also with the ecosystem services they provide. In order for plants to provide the expected benefits from them, their characteristics must be known and the planting design must be planned and applied correctly. The plant taxa selected in the design of urban open and green areas should be evaluated as a whole with both their physiological and morphological characteristics. Therefore, in addition to the aesthetic properties of the plant material to be used in planting design studies to be made in cities, its aromatic properties, toxicity status and pollen spreading properties that may cause allergic reactions on humans should be examined and choices should be made accordingly. Within the scope of the study, 85 plant taxa were identified in the open and green areas of Haliliye district of Şanlıurfa province. These plants were evaluated in terms of life form, leaf condition, flowering period, aromatic properties, poisonous parts and allergen rates. As a result of this evaluation, it was determined that the use of natural plants was insufficient, deciduous and evergreen plant species were used in a balanced way, and there was an important richness in terms of aromatic plant diversity. In addition, it has been determined that there are a significant number of plant taxa containing poison, as well as the use of many allergenic plants in open green areas. As a result, various suggestions were developed regarding the use of plant species in planting design applications, and observation notes made in open green areas were shared.