ABSTRACT Background: In recent years, mechanized logging equipment has become more frequently used in topographically suitable and intensively managed forest areas. However, the rut depths caused by this logging equipment can cause serious deformation problems in the forest soil. In this study, the physical impacts of a skidder on forest soil were evaluated using Unmanned Aerial Vehicle (UAV) based digital imagery. The research was conducted in the Saros Forest Enterprise Chief located in the city of Çanakkale in Türkiye, where rut depth formations were comparatively analyzed using manual ruler method and UAV data. Rut depths were determined for two slope classes (0-20% and 20-50%) and during the fifth, tenth, and fifteenth turns of the skidder. Results: The results indicated that the rut depths calculated from UAV imagery were highly consistent with those obtained from manual measurements. It was observed that rut depths were greater on steeper slopes (20-50%) and increased with the number of turns. In addition, bulk density and hygroscopic moisture tended to increase in low-slope areas while decreasing in steep slopes. Conclusion: The UAV-based method provides a quick and reliable approach for monitoring soil deformation caused by a skidder during logging operations. This UAV-based method can help predict the environmental impacts of logging equipment and support more sustainable timber extraction planning. Moreover, the proposed methodology can be applied to evaluate the physical effects of other mechanized logging equipment on forest soil.

İnsansız Hava Araçları (İHA) destekli uzaktan algılama verilerinin doğruluk düzeyindeki iyileşmelere paralel olarak ormancılık çalışmalarındaki kullanımı yaygınlaşmıştır. Son yıllarda İHA tabanlı üç boyutlu (3B) nokta bulutu verileri kullanılarak tek ağaç parametreleri hesaplanabilmektedir. Bu çalışmada, Bursa Teknik Üniversitesi (BTÜ) Mimar Sinan Kampüsü’ndeki fıstık çamı (Pinus pinea, L.) alanında, İHA verileri kullanılarak ağaç parametrelerinin (ağaç boyu ve tepe tacı genişliği) belirlenmesi amaçlanmıştır. Örnek sahadan alınan İHA görüntüleri üzerinde 3B nokta bulutu yöntemi kullanılarak ağaç boyu ve tepe tacı genişliği parametreleri elde edilmiştir. İHA tabanlı yöntemin başarısını değerlendirmek için klasik yersel ölçüm cihazları kullanılarak çalışma alanındaki ağaçların boy ve tepe tacı genişliği verileri elde edilmiştir. Çalışmada, yersel ölçümlerle ve İHA verileri ile belirlenen ağaç parametreleri arasındaki ilişkiler istatistiksel analizlerle incelenmiştir. Ayrıca, her iki yöntemle elde edilen ağaç parametreleri Ortalama Kare Hatası (Mean Squared Error-MSE) ve Kök Ortalama Kare Hatası (Root Mean Squared Error-RMSE) yöntemleri ile karşılaştırılarak İHA tabanlı yöntemin etkinliği değerlendirilmiştir. Ağaç boyu için hata değerleri, MSE ve RMSE, sırasıyla 0,057 ve 0,427 olarak belirlenmiştir. Tepe tacı genişliği için ise hata değerleri sırasıyla 0,239 ve 0,653 bulunmuştur. Ağaç boyu ve tepe tacı genişliği parametreleri kendi arasında karşılaştırıldığında ağaç boyunun daha yüksek doğrulukla belirlendiği görülmüştür.

To effectively combat wildfires, ground teams must reach the fire site via road network within critical response time. However, low-standard forest roads can reduce firetruck speeds and delay fire response times. This study aimed to investigate how improving road standards affects firefighting access within critical response time and contributes to reducing timber losses. This study was conducted in Antalya, the city most affected by wildfires in Türkiye. In the study, highly fire-prone forests were first identified based on a fire probability map of Antalya, developed through a GIS-based MCDA model incorporating the Fuzzy-AHP method. Then, the highly fire-prone forests and their corresponding timber volume were determined. Finally, the economic value of timber saved from fire and the present net value of total road costs were determined. As a result of improving forest roads, the forest areas that could be reached in time increased by 11.04%, making an additional 81,867.53 hectare of highly fire-prone forests accessible. The amount and economic value of timber products saved in this area were 971,195.55 m3 and €37,689,301, respectively. The cost of improved roads was €37,386,622 while the resulting positive net economic value of €302,679 indicates that investing in forest roads improvements is a viable option.

Mechanical harvesting equipment used in forestry operations increases productivity; however, they may cause significant physical impacts on the soil. Among the most noticeable of these effects are wheel ruts caused by logging vehicles. Such effects can disrupt the physical structure of the soil, increase the risk of erosion, and damage forest ecosystems. In this study, wheel rut depths formed during ground-based skidding operations were analyzed comparatively using both a manual measurement method and a 3D image-based method implemented via Unmanned Aerial Vehicles (UAVs). The fieldwork was conducted during a skidding operation in the Dağtekke Forest Enterprise Chief in the city of İzmir. Manual measurements were performed using a ruler and a lath along skidding trails. For image-based method, aerial images of the study area were captured using UAV, and then used to generate Digital Surface Model (DSM). The results obtained from both methods were compared using correlation analysis and paired sample t-tests. The findings showed a high correlation between manual method and UAV-assisted method, indicating that UAV photogrammetry offers a fast and reliable alternative for rut depth monitoring. The UAV-derived measurements of rut depth showed a high level of accuracy, achieving a Mean Absolute Percentage Error (MAPE) of 16.86%. This study presents a novel application of UAV-based method for high-resolution, remote measurement of rut depth. It offers a cost-effective alternative to traditional methods while providing valuable insights into assessing the environmental impacts of mechanical equipment in forestry operations.

Forest fires have increased in frequency, intensity, and extent significantly worldwide due to climate change and human activities, particularly in the Mediterranean region. Fire-prone areas should be determined primarily to take precautions against forest fires and reduce their ecological, economic, and social impact. This study aimed to determine the spatial distribution of forest fire probability for the Antalya Regional Directorate of Forestry (RDF), highly vulnerable to forest fires. The forest fire probability map was generated using the GIS-based Fuzzy-AHP method, prioritizing decision criteria, including stand characteristics, topographic features, meteorological parameters, and proximity to anthropogenic structures. The results indicated that the most important factors influencing the fire were tree species, development stage, and proximity to road networks. The generated map showed that 45.82% of the forests in Antalya RDF were in the very high class, while 15.82% were in the high-level class. The fire probability map, validated using the "Area Under Curve" (AUC) method, offered promising and acceptable results above 0.7. The Fuzzy-AHP method, when integrated with GIS techniques, effectively predicts fire probability levels in fire-sensitive forests. This method will empower fire managers to develop and implement strategies that enhance forest fire resilience by predicting areas with high fire probability.

The term "cutting residue" is a widely used term in Turkey, which refers to the leftover pieces of logs in the forest after cutting, except for the logs. As of yet, there is no specific expression and explanation for the term "slash" in Turkish forestry. Turkey carries out intensive forestry activities based on industrial wood production, primarily in mature stands and damaged after disasters such as fire or storm fall. Products that do not carry industrial woodiness in the stand, such as branches, roots, and tips that are not suitable for industrial production, are considered firewood and used for energy production or left in the stand. As a result, it is observed that the collected cutting residues from the fields that are sufficient in terms of benefit and cost is burned to generate electricity in electricity generation stations. Due to the demand for forest-based wood raw materials in recent years, some domestic companies have begun converting thick branches into industrial products such as paper and chipboard production. Additionally, some studies have been conducted to reduce transportation costs in bringing cutting residues to the economy, focusing on the storage and processing of forest cutting residues on the landing sites. In this regard, small-scale chipping machines have been produced by the domestic industry. Therefore, slash disposal and mechanization have a very limited place in Turkish forestry. Decision makers need to prepare action plans in this regard and provide support to joint research projects with academic units.

In Turkiye, insufficient technical standards of the forest roads limit the speed of the fire truck, leading to increase in the arrival time of the initial response team to the fire areas. Improving forest road standards will increase the design speed and expand the accessible forest areas within the critical response time. In this study, the effect of improving forest road standards on expanding accessible forest areas was investigated. Considering the forest areas in Antalya Forestry Regional Directorate in Turkiye, accessible areas by the stationary initial response teams (103) and mobile teams (71) were determined from the existing road network, and then, the possible increase in the accessible forest areas was investigated when the road standards are improved. Within the scope of the study, the impact of mobile teams used in emergencies on forest areas reached during the critical response period was also evaluated. According to the results, in the scenario where current road standards and stationary teams were evaluated, it was determined that only 59.54% of the forest areas could be reached by initial response teams during the critical response time. When the road standards were improved, this rate increased to 71.69%. On the other hand, when the current road standards and stationary and mobile teams were evaluated together, it was determined that initial response teams could reach 70.40% of the forest areas during the critical response time, and if road standards were improved, this rate increased to 78.17%. Also, utilizing mobile teams increased the accessible forest areas within the critical response time by 9.03%. The results have shown that improvements in road standards and the presence of mobile teams have a very effective role in combating forest fires.

Some soil behaviors change significantly as water content varies over time. The particle size distribution of soils has a direct impact on mechanical properties such as soil water content, resistance to dispersion, swelling-shrinkage, fluidity, plasticity, and stickiness. This study was conducted to investigate the usability of Atterberg limits, consistency index and coefficient of linear extensibility (COLE) in the temporal planning of ecosystem restoration activities such as silvicultural interventions, tillage, afforestation, and the construction of forest roads, etc. Surface soil samples were collected from the sections numbered 263, 264, 266, 268, 317, 318, 319, 323, 324,325 and 366 of the degraded forest of the And & imath;r & imath;n forestry operations department. The COLE, liquid limit (LL), plastic limit (PL), plasticity index and consistency index values of soil samples were determined. The LL values ranged from 17.5 to 62.4%, the PL values from 8.2 to 46.8% and the PI values from 6.4 to 15.5. The highest COLE value (0.13) was recorded in the section 318, while the lowest COLE value (0.03) was in section 325.The LL and PL values have a positive linear relationship with clay and organic matter content. All sections have karstic characteristics, but the mechanical characteristics of the soils differ significantly between the sections. Silvicultural interventions carried out especially in section 318, which had the lowest consistency index (Ic = 0.70), and sections 263, 264, 317 and 319, where the consistency index is >2,should take mechanical properties into account, and the planting time intervals should be determined, accordingly for sustainable forestry.

Soil erosion, one of the most serious phenomena in watershed management, can be estimated based on various criteria. Land use change is one of the most important factors affecting the susceptibility of soil erosion. In this study, the effect of land use change on soil erosion risk in two plan periods (2005 and 2017) was investigated using Analytical Hierarchy Process (AHP) and Geographic Information Systems (GIS) for the forest planning units in the Doğancı Dam Watershed, located in Bursa, Türkiye. Eight criteria were evaluated including erosion-related slope, bedrock type, land use/land cover, precipitation, relative relief, aspect, drainage frequency, and density. According to the results, the most effective factor in soil erosion was slope (0.29), while bedrock type and land use/land cover ranked second with 0.19. It was found that full closure forests were characterized by high erosion resistance (0.3), while bare land was characterized as the most sensitive area to erosion (0.39). In terms of spatio-temporal changes in a 12-year period, the areas in the medium and high erosion risk decreased, while low and very low-risk areas increased. The ROC method showed a satisfactory accuracy of 72.8% and 80.2% for the 2005 and 2017 erosion risk maps, respectively.

Timber extraction is a time-consuming and difficult stage of producing the wood-based forest products, involving economic and ecological sensitivity. In this study, it was aimed to determine the optimum extraction methods in terms of productivity and environmental effects by integrating the analytical hierarchy process (AHP) method with geographic information systems (GIS). The study was implemented in the coniferous stands located within the borders of Baharlar Forest Enterprise Chief (FEC) in Ayvac & imath;k Forest Enterprise Directorate (FED) in Bal & imath;kesir in T & uuml;rkiye. The main criteria in AHP were slope, skidding (transporting) distance, soil factor, stand age and yield. In the study, tractor skidding, tractor winching, chute system and skyline yarding methods were evaluated by considering environmental effects including residual tree damage and potential impacts on forest soil. In the solution phase, a total of eight suitability maps were produced for four extraction methods for productivity and environmental effects assessment. After the suitability maps were generated, digital data layers of working time were produced for each extraction method using equations about machine working times obtained from previous studies. As a result of the study, it was determined that skidding distance and slope were the criteria with the highest impact in almost all extraction methods for productivity and environmental aspects. In tractor skidding, it was found that soil factor and skidding distance have the highest impact in terms of environmental effects. When considering productivity, the results showed that the most commonly preferred extraction method was the tractor winching (43.30%), followed by the tractor skidding (25.34%). While the chute system was preferred in approximately 20.92% of the area, the least preferred method was the skyline yarding (10.44%). When evaluated in terms of environmental effects, it was determined that tractor skidding (34.02%) was widely preferred, followed by chute system (26.95%), tractor winching (20.96%) and skyline yarding (18.07%).

With recent technological development, photo-optical measurement systems in mobile devices have been increasingly used for automatic wood volume estimation because of their ease of use and efficiency. This study aimed to evaluate the use of photo-optical mobile apps for measuring solid wood volume of the stack in Turkish forestry practices. For this study, 21 log stacks were measured using the traditional technique and two photo-optical mobile apps - iFovea Pro and Timbeter. A strong correlation was found between the traditionally measured solid wood volume of the stack and the volume estimated using both photo-optical apps, the number of logs in the stack, and the mean diameter of the stack. The estimated number of trees from the two apps and manual measurement were not statistically different. However, statistical differences were observed between all three measurement approaches for the mean diameter of the stack. Also, statistical test results indicated mixed results for estimated solid wood volume in the stack. In addition, the study tested whether both apps correctly measure the diameter of the logs in the stack. Thus, manually measured diameter of the randomly selected 50 trees within 21 stacks was compared to the log diameters measured automatically using both mobile apps. The results indicated no statistical difference between the three measurement approaches. The study results are promising for using photo-optical mobile apps in Turkish forestry in terms of transition to digital forestry. However, there are still opportunities to improve the capabilities of the method through further analysis of estimating stack volume using the image from both sides of the logs considering different quality and diameter classes with bark conditions.

The aim of this study was aimed to estimate the economic value of timber products from the forest stands that are potentially saved from wildfires after improving road standards. The study was implemented in the Alanya Forest Enterprise Directorate (FED) in the Mediterranean city of Antalya, Turkey. In the solution process, the possible increase in the accessible forest areas with improved forest road standards was investigated by using GIS-based network analysis methods. In the next step, the timber production in the forest areas potentially saved from the wildfire was calculated based on parameters such as site index, rotation period, and stand structure. Then, the economic value of timber product types was calculated using market prices. The results indicated that increasing the design speed on improved forest roads reduced the arrival time of firefighting teams to the forests, which consequently increased the accessible forest areas within the critical response time. It was found that the accessible forest areas within the critical response time increased from 47,231 hectares to 59,354 hectares when standards of the forest roads were improved. This saved 12,123 hectares of additional forest area from the wildfire in the Alanya FED. The cost of road improvement activities was estimated at US$ 2,286,998. It was calculated that the total timber products obtained from the forest area potentially saved was about 94,721 m3, and worth US$7,545,579 at market prices. The results can be used by policymakers in determining the potential investments in improving forest road standards to enhance the efficiency of firefighting activities.

As far as numerous researchers are concerned, the main source of sediment in forests is roads and their related elements. Due to the importance of this issue, research has been conducted extensively in this regard. Therefore, the main purpose of this research was to evaluate the efficiency of the WARSEM model in the study area. To achieve this goal, in addition to determining the appropriate correction factor to calibrate the model, evaluating the effect of fill slope factors on the accuracy of the results of WARSEM model in the study area was desirable as well. The study area was a part of the Hyrcanian forests in the Northwest Iran. After recording fixed information along the road, fieldwork was done for a whole year because it was decided to utilize natural rainfall showers in the study process. The field observations indicated that the amount of sediment in the study area was high; nevertheless, the WARSEM has about a 19% overestimate in the study area. Thus, the calibration index for the study area was supposed to be 0.81, based on bringing the R2, NS, and RMSE closer to acceptable values. Also, the results showed that the amount of fill slope sediment does not cause a significant change in the overall results. Therefore, the opinion of the model designers is also valid in the study area. Moreover, the results indicated that road gradient and delivery factor are more effective than other factors in changing the result of the model.

Turkiye is located in a region sensitive to forest fires due to its climate, vegetation characteristics, and topography. Every year, forest fires, for various reasons, cause burning of thousands of hectares of forest area. Fires damage the ecosystem and have economic consequences. The Mediterranean, Aegean and Marmara coasts, where the Mediterranean climate and fire-sensitive tree species dominate, are at primary risk against forest fires. For an effective fight against forest fires, it is crucial to identify zones with fire risk based on various parameters such as forest structures (tree species, crown closure, stand development class), topographic features (slope, aspect), climate, and proximity to certain points (such as roads, settlements, agricultural areas). Fire risk data will shed light on the measures that can be taken against fire. In this study, GIS (Geographic Information Systems) based Analytical Hierarchy Process (AHP) method, one of the well know Multi-Criteria Decision Making Analysis (MCDA) methods, was used to develop the fire risk map of Mersin Forestry Regional Directorate (FRD) within the Mediterranean region of Turkiye. Then, the accuracy of the fire risk map was evaluated by taking into account the previous fires in the regional directorate. As a result, the findings showed that 13.87% of the study area was classified as very high, 25.87% as high, 24.68% as medium, 22.44% a low, and 13.14% as very low risk areas. The results also indicated that tree species are the most influential risk factor in forest fires, and followed by stand development class factor. The accuracy of the fire risk map was evaluated by using the location information of a total of 562 forest fires in Mersin FRD between 2003-2022. In order to determine the accuracy of the fire risk map, the Receiver Operating Characteristic (ROC) curve method was used in the ArcGIS environment. As a result, the Area Under Curve (AUC) value was approximately 74%, which showed that the fire risk map developed for Mersin FRD was moderately reliable. With this study, it has been demonstrated that it is possible to produce reliable fire risk maps in a short time using the GIS-based AHP method.

Computer-assisted forest road design mainly relies on a high-resolution digital elevation model (DEM), which provides terrain data for supporting the analysis of road design features. The resolution and accuracy of the DEM in representing the terrain structures vary depending on the preferred dataset, which then reflects some of the essential road features such as alignment, road slope, and earthwork. In this study, three forest road sections were designed by using high-resolution DEMs generated from UAV photogrammetry data, GNSS-GPS data and Total Station data. NetCAD 7.6 software, developed in Turkey and mostly used in road design applications, was used to perform the road design while calculating horizontal profiles, vertical profiles, curves, cross sections, and earthwork. The DEM generation capabilities for three datasets were compared based on spatial resolution, data collection and data processing stage. Then, the differences between three road sections were evaluated by considering specified road features such as alignment properties, road slope, and earthwork. The results indicated that the UAV (Unmanned Aerial Vehicles) based DEM generation method provided the highest resolution (10 cm), followed by the Total Station (56 cm) and GNSS-GPS (61 cm) based methods. When comparing the time for data collection procedure, it took 14 minutes, 70 minutes, and 110 minutes for UAV data, GNSS-GPS data, and Total Station data, respectively. On the other hand, UAV based method falls into a disadvantageous situation in data processing stage, due to high data processing time (3 hours). However, GNSS-GPS and Total Station based methods work only with spatial point data, so they require less processing time of 15 minutes and 25 minutes, respectively. The results indicated that road lengths were 294.8, 272.4 and 282.1 m and the average road slopes were 3.41%, 3.39%, and 3.31% for the road sections designed by using UAV, GNSS-GPS, and Total Station based DEMs, respectively. The excavation and landfill volumes were 369.16 m3 and 166.98 m3, 285.86 m3 and 201.83 m3, and 433.17 m3 and 183.95 m3, respectively. The results indicated that UAV photogrammetry data generates high-resolution DEMs that can be effectively used to design forest roads.

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: €0.60­, paper wood: €0.29­, fiber-chip: €0.15­). 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.

Small-scale forestry operations, which are used in non-industrial and site specific forestry, provide alternative logging methods suitable for precision forestry approach. In this study, a small-scale cable yarding system integrated with a portable winch was considered as alternative timber extraction method compared to a standard tower yarder. It was aimed to evaluate productivity of this yarding method, which was implemented during commercial harvesting activities performed in a 10.74 ha black pine stand located in Bursa province of Turkey. The main factors (i.e. slope, yarding distance, lateral pulling distance, log volume, log length), significantly affecting the productivity, were evaluated based on two slope classes (34–50% and 50–70%) and two yarding distances (100 m and 200 m). The results indicated that the average productivity was 0.95 m3/PMH and 0.90 m3/SMH. It was revealed that the productivity of the small-scale cable yarding decreased as the ground slope and the yarding distance increased. Statistical analysis indicated that there was a significant (p<0.001) relationship between productivity and log volume and length in four applications. On the other hand, it was found that there was a significant (p<0.05) relationship between productivity and lateral pulling distance in only the first application (34–50% slope; 100 m yarding distance). Considering the volume classes of the logs, it was determined that the productivity increased from the low volume class to the high volume class.

As forestry approaches have been formed according to the demands and aspirations of the society, the forest sector implies different concerns such as social, economic, and environmental. Harvesting and extraction of wood at low cost, protection of stands against degradation and changes in land use, proper implementation of afforestation and forest extension, conservation of endemic species, preservation of soil, providing jobs, and supporting national and domestic development have a different priority for foresters, depending on the time and area conditions. Of course, all of these have always been discussed by the shareholders in the forest sector with the main attention to forest sustainability. However, the question is: Are forestry approaches compatible with the changes in the world today? With increasing environmental concerns, as discussed at the Glasgow 2021 Conference, the importance of forests and their protection has doubled, and it seems that forestry practices in the world need a new approach. In addition to climate change, increasing human population and regional and global economic changes affect the use of forests and the form of forest management and utilization. This paper aims to take an analytical look at this issue and examine the current situation in five countries (Iran, Germany, Croatia, Turkiye and Italy). It was also targeted with the help of the DPSIR Framework to elaborate on the social consequences of the situation, and an analysis was presented about what to do or not. This paper emphasizes that forest managers and policymakers need to modify and adapt the plans and methods in a way that is appropriate to the progress of time and its changes, while protecting forests and ensuring their sustainability, limiting non-professionals from involving directly in the decision-making process.

Cable yarding is one of the most preferred timber extraction methods in steep and mountainous terrain conditions. In recent years in Turkiye, mid-size cable yarders have begun to be used frequently in steep forest areas where intensive forestry is carried out. In order to make more effective use of cable yarders and achieve maximum productivity, timber extraction operations must be planned most appropriately and implemented in the field accordingly. The productivity of mechanized equipment used in harvesting operations is mainly determined by using time study analysis. In traditional methods, time measurements are carried out by observing the work stages with time recording devices (stopwatches) in the area where the machine operates. Since timber extraction by using a cable yarder occur in steep and rugged terrain conditions, difficulties may be encountered in applying time analysis in the field. In this study, it was aimed to obtain high-resolution digital video images of the activities of cable yarding operation with an Unmanned Aerial Vehicle (UAV) and to calculate productivity through time study analysis on these images. For the study, the Tajfun MOZ 500 GR model mid-size cable yarder was evaluated during a timber extraction operation in Köyceğiz Forest Enterprise Chief (FEC), located in Muğla City, Turkiye. Besides, statistical analysis was performed to estimate the effects of factors such as average product length, product diameter, lateral yarding distance, number of pieces, and total product volume per turn on the productivity of the cable yarder. The results indicated that UAV video images can be an effective alternative method to conduct time study analysis and productivity estimations. It was found that the productivity of the mid-size cable yarder was 11.76 m3/hour. During the operation, the pulling mainline to the product and choker setting were the most time-consuming work stages, followed by the time-loaded carriage reaching the landing. The statistical analysis indicated a significant relationship (p<0.001) between product length, product diameter, total volume and productivity of the cable yarder. The results showed that there was a negative relationship between lateral yarding distance and productivity. The regression model regarding the productivity of the cable yarder and the independent variables was also significant.