The construction and maintenance of forest roads are the activities that require the highest financial investment in the extraction of forest products. In addition, the cost of transporting forest products from landing to storage area can be significant proportion of the total extraction cost. For this reason, forest engineers are obliged not only to reduce the cost of road construction and maintenance, but also to prepare the most appropriate transportation plan to minimize total costs. Computer aided models can be used to solve complex transportation problems that require the evaluation of many alternative routes and selection of the alternative with least cost. In this study, the Network 2000 program based on the shortest path algorithm was used in transportation planning of forest product, and then the solution capacity of the method was examined in a sample application. As a study area, two Forest Enterprise Chiefs (FECs) of Pasalar and Sarnic were selected from Mustafakemalpasa Forest Enterprise Directorate (FED) in the border of Bursa Forest Regional Directorate. The transportation cost of the road sections, forest product types, location of landing and forest depots were entered into the Network 2000 program after being digitized with ArcGIS 10.2 software. In the solution process, firstly, the route that minimized the transportation cost was investigated, and then, the route with the maximum net profit was determined by taking the sale prices of forest products into consideration. According to results, the transportation cost mostly depends on the transportation time, hourly truck cost and load capacity of the truck.
{"title":"Using Network 2000 Program for Transportation Planning of Forest Products","authors":"Hande Egemen Suslu","doi":"10.33904/ejfe.427547","DOIUrl":"https://doi.org/10.33904/ejfe.427547","url":null,"abstract":"The construction and maintenance of forest roads are the activities that require the highest financial investment in the extraction of forest products. In addition, the cost of transporting forest products from landing to storage area can be significant proportion of the total extraction cost. For this reason, forest engineers are obliged not only to reduce the cost of road construction and maintenance, but also to prepare the most appropriate transportation plan to minimize total costs. Computer aided models can be used to solve complex transportation problems that require the evaluation of many alternative routes and selection of the alternative with least cost. In this study, the Network 2000 program based on the shortest path algorithm was used in transportation planning of forest product, and then the solution capacity of the method was examined in a sample application. As a study area, two Forest Enterprise Chiefs (FECs) of Pasalar and Sarnic were selected from Mustafakemalpasa Forest Enterprise Directorate (FED) in the border of Bursa Forest Regional Directorate. The transportation cost of the road sections, forest product types, location of landing and forest depots were entered into the Network 2000 program after being digitized with ArcGIS 10.2 software. In the solution process, firstly, the route that minimized the transportation cost was investigated, and then, the route with the maximum net profit was determined by taking the sale prices of forest products into consideration. According to results, the transportation cost mostly depends on the transportation time, hourly truck cost and load capacity of the truck.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44515505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Turkey, extraction of forest products is mostly carried out by forest villagers and/or forest villages development cooperatives. Due to their limited equipment availability, many activities conducted during timber extraction are still done by human power based (manual) systems. However, the work force in forestry sector has recently decreased because young people in the forest villages tend to head for different job opportunities. Besides, manual systems are not favorable in terms of loading time, which directly effects overall efficiency of timber extraction. In recent years, development cooperatives have begun to turn to small-size mechanization systems in timber loading operation. Electric powered winch located at the rear end of the truck platform is one of the methods that can provide development cooperatives with low-cost and time-saving timber loading system. In this study, it was aimed to compare productivity of two loading systems including traditional manual loading and electric powered winch systems. The time and motion study was carried out during loading of round wood materials at the landing area located in Bahce Forest Enterprise Chief in the city of Osmaniye. Loading operation was divided into specific work stages and time measurements were made in the field using with a chronometer. Based on the productivity analysis, it was found that the average productivity for manual loading and electric winch loading were 3.40 m 3 /hr and 4.25 m 3 /hr, respectively. As a result, electric power winch system, which is affordable for forest villages development cooperatives, can be an efficient alternative method for loading operations particularly when there are limited equipment availability.
在土耳其，森林产品的开采主要由森林村民和（或）森林村发展合作社进行。由于设备可用性有限，木材开采过程中进行的许多活动仍由人力（手动）系统完成。然而，林业部门的劳动力最近有所减少，因为森林村的年轻人倾向于寻找不同的工作机会。此外，手动系统在装载时间方面并不有利，这直接影响木材提取的整体效率。近年来，发展合作社已开始在木材装载作业中转向小型机械化系统。位于卡车平台后端的电动绞车是为开发合作社提供低成本、省时的木材装载系统的方法之一。在本研究中，旨在比较两种装载系统的生产率，包括传统的手动装载系统和电动绞盘系统。在Osmaniye市Bahce Forest Enterprise Chief的着陆区装载圆木材料期间进行了时间和运动研究。装载操作被划分为特定的工作阶段，并使用计时器在现场进行时间测量。根据生产率分析，发现手动装载和电动绞盘装载的平均生产率分别为3.40 m 3/小时和4.25 m 3/小时。因此，森林村发展合作社负担得起的电力绞车系统可以成为装载作业的有效替代方法，尤其是在设备可用性有限的情况下。
{"title":"Comparison of Timber Loading Productivity between Manual System and Electric Powered Winch System","authors":"Neşe Gülci, O. Erdaş","doi":"10.33904/EJFE.423511","DOIUrl":"https://doi.org/10.33904/EJFE.423511","url":null,"abstract":"In Turkey, extraction of forest products is mostly carried out by forest villagers and/or forest villages development cooperatives. Due to their limited equipment availability, many activities conducted during timber extraction are still done by human power based (manual) systems. However, the work force in forestry sector has recently decreased because young people in the forest villages tend to head for different job opportunities. Besides, manual systems are not favorable in terms of loading time, which directly effects overall efficiency of timber extraction. In recent years, development cooperatives have begun to turn to small-size mechanization systems in timber loading operation. Electric powered winch located at the rear end of the truck platform is one of the methods that can provide development cooperatives with low-cost and time-saving timber loading system. In this study, it was aimed to compare productivity of two loading systems including traditional manual loading and electric powered winch systems. The time and motion study was carried out during loading of round wood materials at the landing area located in Bahce Forest Enterprise Chief in the city of Osmaniye. Loading operation was divided into specific work stages and time measurements were made in the field using with a chronometer. Based on the productivity analysis, it was found that the average productivity for manual loading and electric winch loading were 3.40 m 3 /hr and 4.25 m 3 /hr, respectively. As a result, electric power winch system, which is affordable for forest villages development cooperatives, can be an efficient alternative method for loading operations particularly when there are limited equipment availability.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49186232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Farm tractors equipped with necessary attachments have been widely used in skidding of forest products in Turkey. There are number of different types and sizes of farm tractors that are employed in forest operations. For appropriate logging plans and better machine selections in mechanized forest operations, it is important to analyze the efficiency of farm tractors during skidding operations. In this study, it was aimed to analyze the productivity of timber skidding operation with farm tractor. Time study was used to estimate productivity and then the effects of specified factors (volume, number of piece) on productivity were investigated by using statistical analysis. Logging operation took place in a black pine stand located in the province of Koycegiz in Mugla. Time data of work stages during uphill skidding operation were collected for two skidding trails with different slope classes (20% and 30%) while average skidding distance was kept constant. It was found that the average productivity for two slope classes were 5.72 m 3 /hr and 4.30 m 3 /hr, respectively. The results indicated that the productivity increased as the volume of skidded logs per turn increased for both slope classes. On the other hand, increasing number of pieces transported in each turn caused reduction in productivity of the tractor skidding operation. The most time consuming work stage was skidding followed by move-out unloaded and choker setting stages.
农用拖拉机配备了必要的附件，已广泛用于土耳其林产品的打滑。在森林作业中使用的农用拖拉机有许多不同类型和大小。分析农用拖拉机在打滑作业中的效率，对制定合理的采伐计划和选择机械设备具有重要意义。本研究旨在分析农用拖拉机打滑作业的生产效率。采用时间研究方法估算生产率，并采用统计分析方法考察了特定因素(体积、件数)对生产率的影响。伐木作业发生在穆拉的科伊切吉兹省的一个黑松林。在保持平均滑行距离不变的情况下，对2条不同坡度等级(20%和30%)的滑行道进行上坡滑行作业各阶段的时间数据采集。两个坡类的平均生产力分别为5.72 m 3 /hr和4.30 m 3 /hr。结果表明，两种坡度的生产率都随着每轮打滑原木数量的增加而增加。另一方面，由于每转弯运输的件数增加，导致拖拉机打滑作业的生产率降低。最耗时的工作阶段是打滑，其次是移出卸载和扼链设置阶段。
{"title":"Productivity Analysis of Timber Skidding Operation with Farm Tractor","authors":"S. Gülci, Halit Büyüksakalli, I. Tas, A. Akay","doi":"10.33904/EJFE.428397","DOIUrl":"https://doi.org/10.33904/EJFE.428397","url":null,"abstract":"Farm tractors equipped with necessary attachments have been widely used in skidding of forest products in Turkey. There are number of different types and sizes of farm tractors that are employed in forest operations. For appropriate logging plans and better machine selections in mechanized forest operations, it is important to analyze the efficiency of farm tractors during skidding operations. In this study, it was aimed to analyze the productivity of timber skidding operation with farm tractor. Time study was used to estimate productivity and then the effects of specified factors (volume, number of piece) on productivity were investigated by using statistical analysis. Logging operation took place in a black pine stand located in the province of Koycegiz in Mugla. Time data of work stages during uphill skidding operation were collected for two skidding trails with different slope classes (20% and 30%) while average skidding distance was kept constant. It was found that the average productivity for two slope classes were 5.72 m 3 /hr and 4.30 m 3 /hr, respectively. The results indicated that the productivity increased as the volume of skidded logs per turn increased for both slope classes. On the other hand, increasing number of pieces transported in each turn caused reduction in productivity of the tractor skidding operation. The most time consuming work stage was skidding followed by move-out unloaded and choker setting stages.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45098230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Turkey, the use of mechanized harvesting technology in forestry has recently increased due to demands of private forest industry for large amounts of woods . In order to implement these systems effectively and efficiently, their applications should be well planned considering the factors that affect the performance of harvesting equipment. Performances of the mechanized harvesting systems are mainly influenced by factors such as tree size, tree formations, terrain conditions, operator motivation and skills. In this study, a single-grip harvesting operation was evaluated by using time and motion study analysis. Also, the main factors that affect harvesting operation were evaluated using statistical analysis. The study was implemented during a clear-cut operation in Brutian pine ( Pinus brutia ) stands located in Osmangazi Forest Enterprise Directorate in the city of Bursa, Turkey. Three stages of harvesting operation were evaluated; harvester moving to the trees, grabbing and felling trees, and processing (i.e. delimbing and bucking) trees. The average time of the work stages was examined, and the results indicated that most of the time was spent on tree processing. The productivity of the harvesting operation was found to be 24 m 3 /hr ranging between 6 m 3 /hr to 57 m 3 /hr. This productivity was mostly affected by the tree size, which directly influenced the total processing time of the felled trees in the study area. According to the statistical analysis results, it was found that there is a significant relationship between tree volume and the time spent on tree processing stage. The results from this study cannot be generalized but it suggests that mechanized harvesting using a harvester should be well planned ahead taking into considering the volume and size of the felled material in order to operate the harvester with optimal efficiency. Optimum machines and configurations should be selected based on machine specifications and stand characteristics.
{"title":"Performance Analysis of a Harvester during Timber Extraction Activities in Bursa, Turkey","authors":"E. Bi̇li̇ci̇, Dalia Abbas","doi":"10.33904/EJFE.426171","DOIUrl":"https://doi.org/10.33904/EJFE.426171","url":null,"abstract":"In Turkey, the use of mechanized harvesting technology in forestry has recently increased due to demands of private forest industry for large amounts of woods . In order to implement these systems effectively and efficiently, their applications should be well planned considering the factors that affect the performance of harvesting equipment. Performances of the mechanized harvesting systems are mainly influenced by factors such as tree size, tree formations, terrain conditions, operator motivation and skills. In this study, a single-grip harvesting operation was evaluated by using time and motion study analysis. Also, the main factors that affect harvesting operation were evaluated using statistical analysis. The study was implemented during a clear-cut operation in Brutian pine ( Pinus brutia ) stands located in Osmangazi Forest Enterprise Directorate in the city of Bursa, Turkey. Three stages of harvesting operation were evaluated; harvester moving to the trees, grabbing and felling trees, and processing (i.e. delimbing and bucking) trees. The average time of the work stages was examined, and the results indicated that most of the time was spent on tree processing. The productivity of the harvesting operation was found to be 24 m 3 /hr ranging between 6 m 3 /hr to 57 m 3 /hr. This productivity was mostly affected by the tree size, which directly influenced the total processing time of the felled trees in the study area. According to the statistical analysis results, it was found that there is a significant relationship between tree volume and the time spent on tree processing stage. The results from this study cannot be generalized but it suggests that mechanized harvesting using a harvester should be well planned ahead taking into considering the volume and size of the felled material in order to operate the harvester with optimal efficiency. Optimum machines and configurations should be selected based on machine specifications and stand characteristics.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46604441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1080/08435243.2001.10702761
C. Blinn, Anne-Marie Alden, P. Ellefson
Abstract Forestry Best Management Practices (BMPs) prevent or minimize the impact of forestry operations on water quality. Relatively little is known about the net financial effect to timber harvesters from applying water quality BMPs. A survey of Minnesota timber harvesters found them to be well acquainted and willing to comply with the state’s water quality BMP program. Although the BMP program was officially implemented in 1990, many practices were apparently being widely applied prior to the program’s initiation. These practices were probably already providing important financial benefits to timber harvesters. From 1990 through 1994, however, most timber harvesters (75 percent) reported increased costs associated with applying 40 individual water quality BMPs. Only 16 percent reported financial gains from applying the individual BMPs. When looking at the net financial effect across all 40 BMPs studied, 87 percent reported a net increase in costs from applying those practices. A number of recommendations are provided to assist BMP policy makers, program designers, and educators.
{"title":"Timber Harvester Perceptions of Costs and Benefits from Applying Water Quality BMPs in North-central USA","authors":"C. Blinn, Anne-Marie Alden, P. Ellefson","doi":"10.1080/08435243.2001.10702761","DOIUrl":"https://doi.org/10.1080/08435243.2001.10702761","url":null,"abstract":"Abstract Forestry Best Management Practices (BMPs) prevent or minimize the impact of forestry operations on water quality. Relatively little is known about the net financial effect to timber harvesters from applying water quality BMPs. A survey of Minnesota timber harvesters found them to be well acquainted and willing to comply with the state’s water quality BMP program. Although the BMP program was officially implemented in 1990, many practices were apparently being widely applied prior to the program’s initiation. These practices were probably already providing important financial benefits to timber harvesters. From 1990 through 1994, however, most timber harvesters (75 percent) reported increased costs associated with applying 40 individual water quality BMPs. Only 16 percent reported financial gains from applying the individual BMPs. When looking at the net financial effect across all 40 BMPs studied, 87 percent reported a net increase in costs from applying those practices. A number of recommendations are provided to assist BMP policy makers, program designers, and educators.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":"118 1","pages":"39 - 51"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90376752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1080/08435243.2001.10702758
R. Björheden
Abstract Payload development in truck hauling of tree sections was studied, using production statistics from central Sweden. An increase of payload weights over four years was observed. Factors influencing productivity may be divided into groups connected to a) technology, b) human skills, c) work object properties and d) working conditions. Apart from varying weather and seasonal climactic change, no productivity change or development could be observed associated with technology, work object properties or working conditions during the course of the 49-month study. The operators studied were all experienced roundwood hauling contractors, but had no previous experience with tree section hauling. Their experience of the work studied and on the equipment increased during the study. Under the stable conditions of this study, the most important factors influencing payload variation are increased operator skill and varying weather and climate. Meteorological data explained more than 70 per cent of the variation but a logarithmic increase of payloads along with a decreasing sensitivity to weather conditions remained unexplained. Hypothetically, this is accredited to growing operator skill including an increased ability to judge and compensate for varying characteristics of tree sections handled. If so, the learning phase might be longer than generally assumed. To shorten this low-productivity period is an important aim for vocational training for workers and contractors in forestry. Some methodological problems connected with the interpretation of production studies are also discussed.
{"title":"Learning Curves in Tree Section Hauling in Central Sweden","authors":"R. Björheden","doi":"10.1080/08435243.2001.10702758","DOIUrl":"https://doi.org/10.1080/08435243.2001.10702758","url":null,"abstract":"Abstract Payload development in truck hauling of tree sections was studied, using production statistics from central Sweden. An increase of payload weights over four years was observed. Factors influencing productivity may be divided into groups connected to a) technology, b) human skills, c) work object properties and d) working conditions. Apart from varying weather and seasonal climactic change, no productivity change or development could be observed associated with technology, work object properties or working conditions during the course of the 49-month study. The operators studied were all experienced roundwood hauling contractors, but had no previous experience with tree section hauling. Their experience of the work studied and on the equipment increased during the study. Under the stable conditions of this study, the most important factors influencing payload variation are increased operator skill and varying weather and climate. Meteorological data explained more than 70 per cent of the variation but a logarithmic increase of payloads along with a decreasing sensitivity to weather conditions remained unexplained. Hypothetically, this is accredited to growing operator skill including an increased ability to judge and compensate for varying characteristics of tree sections handled. If so, the learning phase might be longer than generally assumed. To shorten this low-productivity period is an important aim for vocational training for workers and contractors in forestry. Some methodological problems connected with the interpretation of production studies are also discussed.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":"22 1","pages":"18 - 9"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88403504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1080/08435243.2001.10702765
Audrey Martin, N. Holden, P. Owende, S. Ward
Abstract The purpose of this study was to evaluate differential global positioning system (DGPS) positional accuracy on Irish forest roads with typical peripheral canopies. The peripheral canopy obstruction at 20 forest road sites in Roundwood State Forest, was determined using a handheld clinometer and magnetic compass. This simple field technique permitted quantification of the canopy obstruction using graphical means and resulted in a graphical skyplot of each site. The equipment, one Trimble ProXRS DGPS unit and two Trimble 4000SSi units permitted determination of the DGPS accuracy (average of 2.9 m) and precision (average of 2.1 m) with a range of peripheral canopies. DGPS performance was quantified in terms of the average absolute error in positional dilution of precision (PDOP) (DPDOP = 1.6). The relationship between DPDOP and percentage of open sky was found to be statistically significant (r = 0.706, r = 0.001). Statistical analysis also indicated a strong relationship between relative precision and DPDOP (r= 0.796, r= 0.000). Satellite constellation in the measurement period was not the sole factor affecting DGPS useability. Three distinct classes of peripheral obstruction at road sites were defined (Class I: 100-66 %; Class II: 65-33 %; Class III: 32-0 % obstruction) and it was found that both DGPS accuracy (3.70 m, 3.23 m, 1. 91 m, respectively) and precision (4.10 m, 2.43 m, 0.83 m, respectively) improved with decreasing peripheral obstruction. These classes may be used as a means of predicting signal attenuation which might be expected under particular forest canopy conditions elsewhere.
摘要本研究旨在评估差分全球定位系统(DGPS)在爱尔兰典型外围树冠林道上的定位精度。采用手持式倾角仪和磁罗经测定了朗德伍德国家森林20个林道站点的林冠外围障碍物。这种简单的现场技术允许使用图形手段对冠层阻塞进行量化，并生成每个站点的图形天际图。该设备，一个Trimble ProXRS DGPS单元和两个Trimble 4000SSi单元允许确定DGPS精度(平均2.9米)和精度(平均2.1米)，具有一系列外围遮罩。用定位精度稀释的平均绝对误差(PDOP) (DPDOP = 1.6)来量化DGPS的性能。DPDOP与开放天空百分比的关系有统计学意义(r = 0.706, r = 0.001)。统计分析还表明，相对精度与DPDOP之间存在较强的相关性(r= 0.796, r= 0.000)。测量期内的卫星星座并不是影响DGPS可用性的唯一因素。定义了三种不同类型的道路周边障碍物(I类:100- 66%;II类:65- 33%;III级:32- 0%阻塞)，发现DGPS精度分别为3.70 m, 3.23 m, 1。精度(分别为4.10 m、2.43 m、0.83 m)随着周围障碍物的减少而提高。这些分类可用作预测信号衰减的一种手段，这种衰减可能在其他地方的特定森林冠层条件下发生。
{"title":"The Effects of Peripheral Canopy on DGPS Performance on Forest Roads","authors":"Audrey Martin, N. Holden, P. Owende, S. Ward","doi":"10.1080/08435243.2001.10702765","DOIUrl":"https://doi.org/10.1080/08435243.2001.10702765","url":null,"abstract":"Abstract The purpose of this study was to evaluate differential global positioning system (DGPS) positional accuracy on Irish forest roads with typical peripheral canopies. The peripheral canopy obstruction at 20 forest road sites in Roundwood State Forest, was determined using a handheld clinometer and magnetic compass. This simple field technique permitted quantification of the canopy obstruction using graphical means and resulted in a graphical skyplot of each site. The equipment, one Trimble ProXRS DGPS unit and two Trimble 4000SSi units permitted determination of the DGPS accuracy (average of 2.9 m) and precision (average of 2.1 m) with a range of peripheral canopies. DGPS performance was quantified in terms of the average absolute error in positional dilution of precision (PDOP) (DPDOP = 1.6). The relationship between DPDOP and percentage of open sky was found to be statistically significant (r = 0.706, r = 0.001). Statistical analysis also indicated a strong relationship between relative precision and DPDOP (r= 0.796, r= 0.000). Satellite constellation in the measurement period was not the sole factor affecting DGPS useability. Three distinct classes of peripheral obstruction at road sites were defined (Class I: 100-66 %; Class II: 65-33 %; Class III: 32-0 % obstruction) and it was found that both DGPS accuracy (3.70 m, 3.23 m, 1. 91 m, respectively) and precision (4.10 m, 2.43 m, 0.83 m, respectively) improved with decreasing peripheral obstruction. These classes may be used as a means of predicting signal attenuation which might be expected under particular forest canopy conditions elsewhere.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":"6 1","pages":"71 - 79"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86193729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1080/08435243.2001.10702760
M. Sirén
Abstract Tree damage in a one-grip harvester operation was assessed by observing the number of contacts with standing trees and damage resulting from these contacts. The processing phase for a single tree was called a cycle. On average, 19.3% (14.5–25.4%) of cycles involved contacts with standing trees. One third of the contact trees were removed during harvesting. Of the struck trees left standing, 28.2 % were damaged. The probability of contact damage was 1.5 times higher in the summer than in other seasons. Mean damage percentage in the study stands was 3.4 ( range 0.0–8.6%). Contacts with standing trees were explained by machine operator, stem volume of processed tree and the number of trees on the working area. The probability of damage resulting from contact was explained by harvesting season and size of processed tree. A model was developed to predict tree damage. The model consisted of a contact model and a damage model formulated using logistic regression. The tree damage model and the productivity models can be used, for example, in comparing different thinning regimes in model stands. The operator had considerable influence on both the harvesting quality and productivity, and there was a large variation between machine operators. High productivity and a good silvicultural result were highly correlated.
{"title":"Tree Damage in Single-Grip Harvester Thinning Operations","authors":"M. Sirén","doi":"10.1080/08435243.2001.10702760","DOIUrl":"https://doi.org/10.1080/08435243.2001.10702760","url":null,"abstract":"Abstract Tree damage in a one-grip harvester operation was assessed by observing the number of contacts with standing trees and damage resulting from these contacts. The processing phase for a single tree was called a cycle. On average, 19.3% (14.5–25.4%) of cycles involved contacts with standing trees. One third of the contact trees were removed during harvesting. Of the struck trees left standing, 28.2 % were damaged. The probability of contact damage was 1.5 times higher in the summer than in other seasons. Mean damage percentage in the study stands was 3.4 ( range 0.0–8.6%). Contacts with standing trees were explained by machine operator, stem volume of processed tree and the number of trees on the working area. The probability of damage resulting from contact was explained by harvesting season and size of processed tree. A model was developed to predict tree damage. The model consisted of a contact model and a damage model formulated using logistic regression. The tree damage model and the productivity models can be used, for example, in comparing different thinning regimes in model stands. The operator had considerable influence on both the harvesting quality and productivity, and there was a large variation between machine operators. High productivity and a good silvicultural result were highly correlated.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":"110 1","pages":"29 - 38"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76096797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1080/08435243.2001.10702766
E. S. Drews, B. Hartsough, J. A. Doyal, L. Kellogg
Abstract Two harvesting systems were compared for reducing fuel loadings in overstocked conifer stands in eastern Oregon; forest managers also set a high priority on minimizing soil disturbance. Both employed cut-to-length (CTL) harvesters; one used a forwarder and the other a small skyline yarder. Both systems produced very similar and acceptable results in terms of fuels reduction and soil disturbance, but at different stump-to-mill costs: $46/green ton for the forwarder system versus $80/green ton for the yarder system.
{"title":"Harvester-Forwarder and Harvester-Yarder Systems for Fuel Reduction Treatments","authors":"E. S. Drews, B. Hartsough, J. A. Doyal, L. Kellogg","doi":"10.1080/08435243.2001.10702766","DOIUrl":"https://doi.org/10.1080/08435243.2001.10702766","url":null,"abstract":"Abstract Two harvesting systems were compared for reducing fuel loadings in overstocked conifer stands in eastern Oregon; forest managers also set a high priority on minimizing soil disturbance. Both employed cut-to-length (CTL) harvesters; one used a forwarder and the other a small skyline yarder. Both systems produced very similar and acceptable results in terms of fuels reduction and soil disturbance, but at different stump-to-mill costs: $46/green ton for the forwarder system versus $80/green ton for the yarder system.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":"24 1","pages":"81 - 91"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77402057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-01-01DOI: 10.1080/08435243.2001.10702763
C. LeDoux, N. K. Huyler
Abstract We compared production rates, operating costs, and break-even points (BEP) for small and large cut-to-length (CTL) harvesting systems operating at several machine utilization rates (MUR) in mixed hardwood and softwood stands in Vermont. The small CTL harvester produced 11. 08 m3 [391.4 ft3] per productive machine hour (PMH) compared to 14.83 m3 [523.80 ft3] per PMH for the large harvester. The impact of average tree size (volume) on cost was substantial but similar for both CTL systems. At a fixed stump-to-landing logging cost of about $14.12/m3 or [$0.40/ft3], the BEP tree size was 0.14 m3 [5.0 ft3] for the small harvester and 0.26 m3 [9.33 ft3] for the large system at the 85 percent MUR. At an MUR of 70 and 85 percent, the processing cost for trees that averaged 0.08 m3 [3.0ft3] was $22.19 and $18.28/m3 [$0.6285 and $0.5176/ft3], respectively, for the small CTL harvester. Results were similar for the large harvester. Either CTL system would be effective in helping managers meet forest management goals in eastern hardwood stands.
{"title":"Comparison of Two Cut-to-Length Harvesting Systems Operating in Eastern Hardwoods","authors":"C. LeDoux, N. K. Huyler","doi":"10.1080/08435243.2001.10702763","DOIUrl":"https://doi.org/10.1080/08435243.2001.10702763","url":null,"abstract":"Abstract We compared production rates, operating costs, and break-even points (BEP) for small and large cut-to-length (CTL) harvesting systems operating at several machine utilization rates (MUR) in mixed hardwood and softwood stands in Vermont. The small CTL harvester produced 11. 08 m3 [391.4 ft3] per productive machine hour (PMH) compared to 14.83 m3 [523.80 ft3] per PMH for the large harvester. The impact of average tree size (volume) on cost was substantial but similar for both CTL systems. At a fixed stump-to-landing logging cost of about $14.12/m3 or [$0.40/ft3], the BEP tree size was 0.14 m3 [5.0 ft3] for the small harvester and 0.26 m3 [9.33 ft3] for the large system at the 85 percent MUR. At an MUR of 70 and 85 percent, the processing cost for trees that averaged 0.08 m3 [3.0ft3] was $22.19 and $18.28/m3 [$0.6285 and $0.5176/ft3], respectively, for the small CTL harvester. Results were similar for the large harvester. Either CTL system would be effective in helping managers meet forest management goals in eastern hardwood stands.","PeriodicalId":36173,"journal":{"name":"European Journal of Forest Engineering","volume":"99 1","pages":"53 - 60"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79142736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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