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    A Comparison of Two Felling Techniques Considering Stump-Height-Related Timber Value Loss
    (Zagreb Univ, Fac Forestry, 2023) Gulci, Nese; Gulci, Sercan; Akay, Abdullah E.; Sessions, John
    Harvest from plantations can provide both industrial wood and forest residues for bioenergy, including stumps. The literature suggests that the choice of cutting system can affect the division between industrial wood recovery and remaining stump volume. In this study, two felling techniques - motor-manual chainsaw and feller-buncher, were compared based on stump-height-related timber value loss for four ground slope classes: high, medium, low, and flat. The economic value loss of wood material for three products - sawlogs, pulpwood, and fiber-chip wood, was determined based on the estimated volume of stumps left in the woods. The results indicated that the average stump height for the motor-manual chainsaw and feller-buncher was 17.16 cm and 8.69 cm. The economic value loss of wood material per stump was higher in felling by manual chainsaw as compared to the feller-buncher operation (log: (sic)0.60 up arrow, paper wood: (sic)0.29 up arrow, fiber-chip: (sic)0.15 up arrow). However, volume loss due to high stumps could contribute to wood for bioenergy if stumps are subsequently removed. Additional research is needed to evaluate the benefits and costs of stump removal for bioenergy as part of a total supply chain to provide both industrial wood and wood for bioenergy.
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    ANALYSIS OF A SAMPLE APPLICATION FOR WHOLE TREE EXTRACTION USING SkylineXL 24.1: A CASE STUDY FROM KAHRAMANMARAS, TURKIYE
    (2025) Gülcı, Neşe; Sessions, John; Gülci, Sercan; Akay, Abdullah Emin
    In mountainous areas, timber extraction operations are commonly carried out using skylines. Transporting forest products with a skyline is an efficient method commonly used in mountainous areas with challenging terrain conditions and in areas where environmental factors are crucial. There are four main types of cable systems: Highlead, Standing, Running, and Live Skyline. Because of reduced lift, Highlead is not a skyline system, but rather a method suitable for shorter yarder distances at steep terrain. Standing, Running, and Live Skylines are cable logging systems that have a suspended cable used for suspending and yarding products. The installation stages of these skylines require expertise and need to be carefully planned. The payload and cable tensions are very important factors for preventing work accidents and ensuring efficient cable logging operations. There are various software programs developed for analyzing skyline systems. This study aimed to analyze a sample logging application using one of the well-known software, SkylineXL 24.1. The study was implemented in the KSU Başkonuş Research and Application Forest in Kahramanmaras, Turkiye. According to the results for the standing system, the minimum required skyline length was 540 m, while the Koller yarder capacity was 579 m. The maximum allowable tension of the skyline (10.584 kg) has been reached at each terrain point in this study.
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    Planning Optimum Logging Operations through Precision Forestry Approaches
    (EJFE, 2015) Gülci, Neşe; Akay, Abdullah Emin; Erdaş, Orhan; Wing, Michael G.; Sessions, John
    In this study, it was aimed to determine optimum logging operations by using Geographical Information System (GIS) techniques as one of the effective tools of a precision forestry approach. In the first stage of the application process, a high resolution Digital Elevation Model (DEM) of the study area was produced by using Real Time Kinematic GPS in the field. Then, the DEM was used to classify the area into slope classes specified by the International Union of Forest Research Organizations (IUFRO). A map for the optimum logging operations was generated for two scenarios (i.e. maximum productivity and minimum residual stand damage) considering current terrain conditions. Four different logging methods were evaluated: ground skidding logs using a portable winch integrated with skidding cone, winching logs by using a farm tractor, downhill sliding of logs by chute system with gravity, and controlled sliding of logs downhill by chute system integrated with portable winch. During the assessment of logging methods, the results from the previous empirical studies conducted in similar stand characteristics and topographical conditions were used. For both scenarios, results indicated that skidding by portable winch integrated with skidding cone was the optimum logging method for more than half of the study area, followed by downhill sliding by chute system and controlled sliding by chute system integrated with portable winch.
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    Productivity of a Portable Winch System Used in Salvage Logging of Storm-Damaged Timber
    (Zagreb Univ, Fac Forestry, 2019) Bilici, Ebru; Andiç, Güryay Volkan; Akay, Abdullah Emin; Sessions, John
    Storm damages result in serious losses in many regions, primarily by stem breakage or blow-down. Extraction of storm-damaged trees often requires more difficult than normal skidding activities due to obstacles created during the storm. In this study, the productivity of a portable winch was evaluated as a possible alternative to recover storm-damaged timber. Field measurements were conducted in the Alabarda Forest Enterprise Chief located near the city of Kutahya in western Turkey, where storm damage often occurs during the winter season. The time study was implemented in two slope classes (35% and 55%) and two skidding distances (40 m and 60 m). All timber was skidded uphill. A regression mode was developed that related productivity to log volume, ground slope and skidding distance. The highest percentage of total cycle time was observed for skidding logs to the landing. The highest productivity (3.96 m(3)/hour ) was found at the shorter skidding distance (40 m) and the lower ground slope (35%). Statistical analyses indicated that productivity was most highly affected by log volume, followed by skidding distance and ground slope. Larger log loads increased productivity, while both longer skidding distances and steeper slopes reduced productivity.