Turkish Journal of Forestry

353 - 361

Authors: Mahmut REİS, Seda TAT, Bülent ABIZ

Erodibility is a property that results from the various properties of soils in their own structure and shows their resistance to erosive factors or their tendency to erosion. Soil properties affecting soil erodibility are significantly originated parent material. Thus, different parent materials form soils having different erodibility properties. In this study, the effects of some parent material on soil erodibility and soil properties influencing soil erodibility was investigated. The study was carried out Cemrengec Watershed within city of Kahramanmaras in Turkey. Soil characteristics such as texture, organic matter, structure, moisture equivalent and permeability, and soil erodibility indices was determined by taking samples from soils developed from limestone, sandstone, quartzite and mica schist in the watershed. Soil erodibility indices values, dispersion ratio, erosion ratio, colloidal moisture equivalent ratio, clay ratio and soil erodibility factor were calculated. So, erodibility values of soil were examined by taking 5 different erodibility indices into account. And then, whether or not there were differences among soil erodibility values was investigated. Soil properties having influence on soil erodibility indices were statistically compared by variance analysis and correlation test. According to results, soil erodibility values of parent materials ranged as sandstone>quartzite>mica schist>limestone. Besides, clay percentage was the most important soil property affecting soil erodibility taking soil properties into account.

366 - 370

Authors: Ayşe DELİGÖZ, Esra BAYAR

The increase in the duration and severity of summer droughts due to global climate change will adversely affect forests, and it is very important to examine the drought stress that trees are exposed to as a species due to increasing drought and to understand the response of the species. In this study, the effects of drought stress on physiological (midday water potential, relative water content, gas exchange parameters) and biochemical (total soluble sugar content) characteristics were investigated in Quercus trojana P.B. Webb. seedlings. Under greenhouse conditions, two treatments were applied to 1+0 old seedlings: control (2-3 times a week for watering) and drought stress (no watering for 30 days). Drought stress was repeated twice, consecutively. At the end of the two-month stress cycle, drought stress decreased the midday water potential, relative water content, net photosynthesis rate, stomatal conductance and transpiration rate, while increasing the water use efficiency and total soluble sugar content. In the study, strong relationships were found between midday water potential, net photosynthesis rate, stomatal conductance, transpiration rate and total soluble sugar content.

375 - 385

Authors: Mehmet EKER, Yasin KURT

The aim of the study is to compare the android-based “time measurement and recording tool" (ZÖKA) application which has been developed to be used in time studies in forestry works and the "time analysis" (TA) program, which is a Windows operating system-based time recording software, with each other and with a digital stopwatch in terms of data precision and usage characteristics. This study was carried out in order to eliminate the questions about the performance of ZÖKA and TA program developed for the purpose of time studies, their positive and negative aspects compared to the chronometer, and which one could be more effective. During the wood-based harvesting activities, the working times of the debarking work were recorded with real-time by video recorders. The recorded images were watched with the help of video player software and the actual times of the work elements (which were later used as control data) were determined by the indirect observation method. Time measurements were made on the same images with the same surveyor using a digital stopwatch, ZÖKA application and TA program. The obtained data were compared with the control data and with each other in terms of data sensitivity. A simple comparison was made by considering the usage features of the stopwatch, ZÖKA application and TA program, and the structural characteristics of these three tools. It has been determined that the ZÖKA application can measure and record more sensitive data and is more effective with eye-hand and ear-hand coordination in time measurements of jobs with short-term work periods (3 seconds and less). It has been revealed that the TA software is also more sensitive than the digital chronometer and has the advantage of recording data, especially in cases where the duration of the work slices exceeds 5 seconds and especially indirect observations are made. ZÖKA application can be used with precision in time studies, especially in measuring short-term work cycles.

395 - 407

Authors: Ahmet USLU

Protected areas have become important tourism destinations in terms of nature-based tourism and recreation activities. Real-time data on the behavior and preferences of visitors are needed for the management of protected areas. Social media data provides a unique and on-site source of information about human existence and activities in nature when collecting visitor information is laborious and costly. In this study, it is aimed to determine the temporal and spatial changes of visitors to Ihlara Valley by using geotagged photographs on Flickr. Detailed analysis of visitor behavior and preferences was carried out with trend charts and density maps created from geotagged photo data. The results of the study revealed that Flickr data is a useful resource for evaluating the characteristics of protected areas, analyzing visitor behavior and preferences from a temporal-spatial point of view, and providing new opportunities for future research.

417 - 425

Authors: Mehmet KORKMAZ, Ozan Arif ADIGÜZEL

Climate change will affect forest resources and the continuity of ecosystem services more in the future. In this respect, it is an important requirement to ensure the adaptation of forest resources management to climate change. In this article, the knowledge levels of forest engineers on climate change, the effects of climate change on forest resources and their perceptions and opinions of current and foreseen forestry management and practices within the scope of adaptation processes were evaluated. In this context, survey studies were conducted with 241 forest engineers. According to the results of the study, possible changes regarding the impact of climate change on forest resources; abiotic and biotic damages will increase and there will be changes in species composition over time. Existing national forestry policies were found to be insufficient to prevent the negative effects of climate change, at the same time, it was stated that the transfer of some existing policies to forestry practices was not sufficient, and that forest resources management should be changed to adapt to climate change. In this context, encouraging the establishment of mixed stands, including species that can better adapt to the future climate in afforestation and monitoring forest health have come to the fore as the most important preventions.

432 - 438

Authors: Tuğba YILMAZ AYDIN

Heat treatment is one of the environmentally friendly and cost-effective modification methods applied for improvements of wood properties. However, influences of exposure duration and temperature should be known to provide balanced improvements for properties. In this study, effect of temperature (80, 120, 150, 180, and 210°C) and exposure duration (2, 5, and 8 h) on the longitudinal ultrasonic wave velocity, density, dynamic Modulus of Elasticity-MOE (Edyn), MOE in bending, and Modulus of Rupture (MOR) properties of Taurus cedar (Cedrus libani) was figured out. Edyn was predicted using ultrasonic wave velocity of 2.25 MHz longitudinal ultrasonic wave propagated through the longitudinal axis. The three-point bending test was performed to determine static mechanical properties. According to results, the highest adverse effects of extended duration and temperature were observed for MOR and followed by Edyn, and MOE in bending. Up to 150°C and 8 h treatment levels, some remarkable increases (15.3%) were observed particularly for MOE in bending. Coefficients of determinations were calculated as 0.83, 0.38, and 0.37 for Edyn vs MOE in bending, Edyn vs MOR, and MOE in bending vs MOR, respectively.

444 - 448

Authors: Ahmet Ali VAR, Aykut YALÇINDAĞ

This study investigated the preventive effectiveness of geothermal resource waters on the volumetric shrinkage and swelling properties (working property) of wooden. For this purpose, Turkish red pine (Pinus brutia Ten.) wood samples were treated by immersion method with nine different geothermal source water from Turkey's three different geothermal fields (Afyonkarahisar, Denizli, Kütahya). A higher performance against shrinkage and swelling was observed in wood samples treated with Denizli’s geothermal resource waters. Also, all treated wood samples had lower swelling and shrinkage values compared to untreated ones. These reductions in swelling and shrinkage values show that geothermal resource waters could be effective in reducing the volumetric working property of wooden.