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Staffan Berg Janine Schweier Franka Brüchert Marcus Lindner Erik Valinger 《Scandinavian Journal of Forest Research》2014,29(5):485-498
The forest sector is important for the German Federal State of Baden-Württemberg (BW) and the Västerbotten (VB) County in Sweden. Their forestry wood chains (FWCs) are of similar magnitude and supply forest industries. This study provides a regional comparison of the performance of FWCs from roundwood harvesting, including hauling, to mill gate concerning the factors that impact sustainability and assess different sustainability indicators for alternative supply chains, in particular fully mechanized chains in comparison to motor-manual operations. The harvest volumes are similar but operational conditions differ. Analysis of sustainability indicators demonstrated that the total costs for roundwood to industry are similar. Higher harvesting costs in BW are compensated for by lower transport costs to the mills. Employment per unit is higher in BW because of the high share of labour in felling. Due to smaller machinery and shorter transport distances in BW, energy use and greenhouse gas emissions per unit are lower than in VB. Areas for improvement are the technologies for logging in BW and the logistics of timber transport in VB. 相似文献
3.
在归纳总结潮湿立地上的采伐作业对林地土壤、水质以及保留树木影响的基础上,评述了目前用于潮湿地的采伐设备与系统。提出在潮湿立地上减少环境破坏的采伐工艺类型主要是原条、长原木以及这2种工艺类型的一些改进;潮湿立地环境友好的森林采伐作业技术通常包括良好的伐区规划设计、机械设备的合理选用以及加强作业检查监督3个方面。 相似文献
4.
《Scandinavian Journal of Forest Research》2012,27(8):800-806
Abstract While motor-manual short-wood harvesting still dominates Italian forest operations, there is a growing interest to introduce mechanization in order to reduce logging costs and increase work safety and comfort. Against this background, a survey was conducted for determining the attitudes of North Italian logging contractors towards mechanized Cut-to-Length (CTL) technology and to evaluate the potential of machine simulators when introducing mechanized harvesting for prospective users. A total of 90 persons were interviewed, after they tested a forwarder simulator; 74 interviews were valid and accepted into the study for statistical analysis. This sample was younger and contained a larger proportion of employers compared with the overall population of North Italian logging contractors. Respondents are aware of the significant potential of mechanized CTL technology, and of its notable safety benefit. People working with firewood seem to be keener than the others. The main obstacles to the expansion of mechanized CTL technology in Italy are financial, rather than technical. Harvester manufacturers trying to increase their sales in Italy may want to focus on simplified low-cost machines, suitable for application to general purpose prime movers and especially designed for firewood contractors. They should also target younger contractors, who are more familiar with computer technology. Forest machine simulators can help introducing CTL technology to Italy, but one needs to think about new ways to deploy them. 相似文献
5.
Raffaele Spinelli Mark Brown Rick Giles Dan Huxtable Ruben Laina Relaño Natascia Magagnotti 《Agroforestry Systems》2014,88(3):479-487
The authors tested two harvesting systems especially designed for mallee agroforestry plantations on farmland. Both systems were based on versatile forest technology commonly used for conventional logging operations. They differed especially for the felling technology: small-scale drive-to-tree or industrial swing-to-tree equipment. Both systems were tested side-to-side on 12 experimental plots each. The resulting harvesting cost was 22 and 27 AU$ t?1, for the industrial and the small scale system, respectively. Chipping represented between 60 and 80 % of the overall harvesting cost, and offered much room for improvement. The industrial system always offered the lowest harvesting cost, regardless of annual usage, when equipment mobilisation costs were not considered. The productivity of conventional forestry equipment was strongly dependent on belt stocking and tree size. If the diameter at ankle height dropped below 10 cm, economic viability decreased very rapidly. 相似文献
6.
As forests of the eastern United States become fragmented into smaller ownership parcels, there is a growing need for timber
harvesting contactors who can economically harvest timber and perform silvicultural operations on small tracts. Traditional
large-scale harvesting operators are ill-suited for work on small parcels, due to their high fixed costs. By contrast, small-scale
operators, characterized by few workers and low capital investment, offer an opportunity to serve this landowner segment.
This paper presents financial and productivity results from a small-scale timber harvesting pilot study conducted on small
forested parcels in western Maryland, USA. Acceptable financial performance is possible for these operations, provided that
the operator pays close attention to the important factors determining productivity and profitability, including: (1) average
tree volume, (2) net delivered price, (3) time utilization, and (4) distance to the site. Although profitable harvesting of
saw log quality trees on parcels less than 10 ha is possible, harvesting of small or poor-quality trees remains economically
unattractive. 相似文献
7.
《Southern Forests》2013,75(4):195-200
At least 200 000 m3 of timber is harvested annually using semi-mechanised harvesting systems on the Viphya forest plantations in Malawi. Although these systems have long been used on the Viphya, no investigation on their productivity has so far been reported. Additionally, the absence of localised productivity analyses in Malawi has created a paucity of information on appropriate timber harvesting systems for production maximisation and cost minimisation. The objective of this study was to compare the production rates and operational costs of chainsaw/grapple skidder (semi-mechanised) and feller-buncher/grapple skidder (mechanised) harvesting systems in order to determine the economic feasibility of mechanised systems in the Viphya forest plantations. The study was conducted in Pinus kesiya compartments at the Kalungulu and Champhoyo forest stations of the Viphya forest plantations. A work study approach was followed to capture harvesting time and volume data for the semi-mechanised system. Secondary work study data were used to simulate productivity of the mechanised system on similar compartment conditions. A timber-harvesting costing model was used to analyse the results. The study showed that the simulated mechanised system was associated with lower operating costs and inventories with higher production rates than the semi-mechanised system. The cost marginal difference was US$0.89 m–3. It was therefore established that migration to mechanised systems could optimise timber harvesting productivity on the Viphya in future, if optimal volumes are available to ensure the efficient application of the mechanised harvesting system. 相似文献
8.
The use of small-scale harvesting equipment continues to grow in forestry in many regions of the world. This equipment includes various devices and methods used to harvesting that generally are smaller, less expensive and less productive than advanced forestry machines. The objective of this study is to compare the efficiency of five alternative extraction methods implemented in a harvesting unit located in a mixed beech and oak forest ecosystem in northwestern Turkey. A continuous time study was conducted during primary transport operations that included skidding with animal power, skidding with farm tractor, hauling with farm tractor, hauling with forest tractor, and extraction by skyline. Timber was skidded uphill on a skid trail, and an average skidding distance of 100 m for all haulage methods was considered. Average slope of the harvesting unit ranged from 20 to 40 %. Average productivities for respective haulage methods were 3.80, 6.25, 2.80, 5.25 and 10.09 m3/h. Significant differences were found between productivity of haulage methods using one-way analysis of variance. The extraction by skyline, skidding with farm tractor, and hauling with forest tractor were determined to be the most statistically different methods, the productivity of these methods was found significantly higher than the other methods. Skid trails are useful for shortening distances during forest operations and skidding with farm tractor is a productive method in small-scale forestry of Turkey. 相似文献
9.
《Southern Forests》2013,75(2):109-115
Operator impact on productivity and cost using similar processor machines was addressed in this case study. The study had two objectives: (1) determine the extent of operator productivity variation between six processor operators in a harvesting operation; and (2) determine potential cost implications associated with operator productivity variation. The study was carried out on the Zululand coastal plains near Kwambonambi. A multistem mechanised harvesting system, working in Eucalyptus grandis × camaldulensis pulpwood stands (with an average rotation length of seven years) was observed. The operators had all been operating their respective processors for 18 months; i.e. since the inception of the harvesting operation and had received similar in-house training. Time studies were carried out on the processors’ cycle times, and note taken of the respective operators working the machines during the time studies. Cycle time for each machine was measured as the time between a delimbed and debarked tree length leaving the processor head and the following tree length leaving the head. The required number of observations per processor was determined by cycle time and work element time variation. It was found that operators varied by up to 58% in terms of productivity, 24% in terms of utilisation and 70% in terms of cost. The potential difference in cost between using the cheapest operator and the most expensive operator was R9.34 m?3, R4 438 d?1 and R1 384 752 y?1. 相似文献
10.
Yuri Gerasimov Victor Senkin Kari Väätäinen 《European Journal of Forest Research》2012,131(3):647-654
A field-based study was carried out to broaden our knowledge of fully mechanized cut-to-length harvesting productivity in
naturally grown forests in the northern European part of Russia (NEPR). The recorded data comprised 38 midsized single-grip
harvesters (JD 1270D) in clear-cutting operations in the Karelia, Komi, Vologda, Leningrad, Tver, and Kirov regions in NEPR,
4.3 million felled trees, and 1.4 million m3 u.b. (under bark) of processed timber. Harvesting operations were conducted in forest stands composed of spruce (48% on average),
pine (19%), birch (22%), and aspen (11%), with an average stem volume 0.31 m3 u.b. The cut-to-length harvesters produced from 4.3 to 14.9 m3 u.b./productive machine hour (PMH) and 16.0–49.5 m3 u.b./stem processing machine hour (S
proc
MH). A machine evaluation analysis and a regression analysis were used to formulate models for predicting cutting productivity
of modern single-grip harvester. The regression models were developed to estimate the productivity of the harvesters in the
regions taking into account two significant factors influencing the productivity: the stem volume and tree species of the
felled trees. Productivity/cubic meter u.b. of processed timber/PMH was calculated according to stem volume and tree species distributions in most forest-covered NEPR regions. Further research
is suggested to improve the developed productivity models and to allow prediction of system performance over a broad range
of stand and site conditions. 相似文献
11.
A. R. Proto G. Macrì R. Visser H. Harrill D. Russo G. Zimbalatti 《Small-Scale Forestry》2018,17(1):71-87
Most timber harvesting operations in the southern Mediterranean area of Italy can be considered to be in an early stage of mechanization. It is mainly based on agricultural tractors that are sometimes equipped with specific forest-related accessories such as winches, hydraulic cranes, or log grapples. In recent years, there has been an increase of specialized forestry machines working in Calabria, southern Italy, including forwarders, skidders and cable yarders. This study assesses the efficiency and costs of extraction using forwarders, as a mechanized alternative to agricultural tractors and horse logging. Time studies were conducted to quantify the productivity and operational cost of log forwarding for two John Deere forwarders in two different coniferous stands: (A) Calabrian pine and (B) silver fir. The empirical time study included 100 forwarding cycles (i.e., 50 for each site) that were broken down into four different work phase elements. Models for cycle time, total productivity and individual work phases were calculated. The average load per cycle was 11.8 m3 in stand A and 9.97 m3 in stand B and the average one-way forwarding distance was 306 m in A and 597 m in B. The average productivity per scheduled machine hour (SMH) was 14.4 m3 in A and 15.7 m3 in B, while the costs, calculated to be 3.60 €/m3 in A and 4.90 €/m3 in B, were considered lower respect traditional methods. 相似文献
12.
《Southern Forests》2013,75(3-4):149-154
Australia is at an early stage of exploring the use of forest biomass to generate energy. This study evaluated the biomass yield and the productivity rates of equipment for harvesting biomass in a poor-quality eucalypt plantation. The operation consisted of a tracked feller-buncher, grapple skidder and mobile chipper. Time study methods were used to measure the harvesting operation. A multiple regression model was constructed to predict skidding productivity. Biomass production was 63.9 t ha?1 based on the recorded load weight of eight trucks. Delays were documented and analysed. The average delay for all equipment was about 30% of working time. The study results will help guide biomass harvesting managers to estimate productivity and cost of similar operation sites. 相似文献
13.
Mohammad Reza Ghaffariyan Ramin Naghdi Ismael Ghajar Mehrdad Nikooy 《Small-Scale Forestry》2013,12(2):181-192
Time equations are derived for felling with chainsaw, skidding with cable wheeled skidder, loading with grapple hydraulic loader and trucking of logs within a cut-to-length harvesting method. The continuous time study method was applied to collect data for felling, skidding, loading and a transportation model. Multiple regression analysis via SPSS software was applied to develop the time models. Felling time was found to be highly dependent on diameter at breast height. Skidding distance, winching distance, slope of the trail and piece volume were significant variables for the skidding time prediction model. The loading time model was developed considering piece volume. Transportation distance and load volume were used as independent variables in modeling the transportation time. The net production of felling was estimated at 12 trees/h (56.65 m3/h). The net production rates for skidding, loading and traveling averaged 18.51, 41.90 and 3.32 m3/h respectively. The total cost of harvesting from stand to mill was estimated 19.70 €/m3. The skidding phase was the most expensive component of the cut-to-length method. The bucking and delimbing components were less costly than the other logging phases. The results of this study can be used for harvesting planning and productivity optimization. 相似文献
14.
Excessive slash loading could pose a problem for the regeneration of the serotinous lodgpole pine especially in forests at higher elevation where soil temperature is limiting. In the past, these forests have commonly been harvested using full-tree harvesting where trees are processed at roadside; however, recently cut-to-length harvesting has become a more frequent harvesting method. In cut-to-length harvesting the harvested trees are processed in the block, as a result slash accumulation is much higher on these cutblocks. In an experimental field trial, the cone distribution, natural lodgepole pine regeneration, and the growth and establishment of planted lodgepole pine were evaluated in response to slash load, drag scarification, and mounding after cut-to-length harvesting of high elevation lodgepole pine stands in the Rocky Mountains. Twelve sites were established, each contained six plots which were randomly assigned to six treatment combinations of two slash removal (slash and slash removed) and three mechanical soil preparation treatments (no soil preparation, drag scarifying, and mounding). The slash removal reduced slash volume by more than 50% but also reduced the number of lodgepole pine cones available for regeneration by over 33%. However, soil mechanical treatments offset this effect as fewer cones were necessary to achieve high natural pine regeneration densities. Drag scarification of plots resulted in 12 times the number of pine seedlings compared to the non-prepared plots. Although slash removal did not have an effect on the number of naturally regenerated lodgepole pine seedlings, it had a positive effect on their growth performance. Conversely, planted pine seedlings had lower mortality and better growth in soils that had been mechanically prepared and had the slash removed; however, the growth effects became only apparent 4 years after planting. While slash removal and mechanical soil preparation did increase soil temperatures; the slash removal treatment had a more transient effect on soil temperatures than soil preparation. Differences in soil temperature decreased over time which appeared to be mostly driven by a warming of the soils in the plots with no soil preparation, likely a result of the decomposition of the finer slash and feathermosses. Overall, it appears that surface disturbance on these high elevation sites had a far greater effect on lodgepole pine regeneration and growth than the increased accumulation of slash as a result of cut-to-length harvesting. 相似文献
15.
《Scandinavian Journal of Forest Research》2012,27(7):701-709
AbstractThe study explored the effect of tree-selection pattern on harvesting productivity, under specific site conditions typical of mountain forestry and suitable for mechanized cut-to-length harvesting. In particular, the experiment tested two different single-tree-selection principles, namely, uniform spatial distribution across the whole site and clustered distribution, where selection trees were concentrated along presumed strip roads. The test was conducted on two different sites, representative of two different stand-development stages. Ten plots were located on each site, and randomly assigned to the two spatial distribution treatments (uniform and clustered). Great care was taken to maintain even conditions for the test. Mean tree size and removal intensity were the same on all plots from the same site; all plots were harvested by the same harvester and forwarder team; data were collected by the same researchers in all plots. Under the specific conditions of the study, the spatial distribution of harvest trees had no significant effect on harvesting productivity and cost. In contrast, harvesting performance was affected by tree size and possibly removal intensity. Anecdotal evidence about the effect of spatial distribution on harvesting cost may derive from its possible association with the other above-mentioned factors (e.g. tree size or removal intensity). 相似文献
16.
在直接扑救森林草原火灾时,个人安全防护装备可以最大限度地保护扑火人员的人身安全,提高扑火效率。文章阐述森林草原消防人员安全防护装备国内外标准化组织建设、防护装备研制及相关标准制订情况。通过综合分析森林草原消防人员发生伤亡事故的主要原因,提出大力开展个人安全防护装备一体化研究,阐明了需要解决的一系列关键技术难题;明确了个人安全防护装备一体化配备标准和技术指标要求;探究目前我国森林草原消防人员防护装备存在的共性问题。结合我国森林草原消防人员安全防护装备现状,针对安全防护装备一体化发展趋势,“十三五”安全防护装备研发课题组研制了新型森林防火头盔、森林防火特种防护服及森林防火救生罩,用以丰富现有安全防护装备体系,有效保障扑火人员的生命安全。 相似文献
17.
Environmentally acceptable and economical forest operations are needed for sustainable management of forest resources. Improved methods for harvesting and transporting timber are especially needed for wet sites. As the demand for hardwood lumber continues to increase, improved and alternative methods are needed to ensure acceptance of timber harvesting for the wet site conditions that are typical of bottomland hardwoods. Some alternative technological developments include grapple saw feller-bunchers, wide tires, larger forwarders, clambunk skidders, two-stage hauling, mats, cable systems, helicopters and towed vehicles and air-cushioned vehicles. These developments have the potential to improve the performance of the harvesting system and to reduce the negative effects of conventional operations on conventional sites and on difficult sites such as wet areas. Although many of these new alternatives are now operational, others are just concepts or evolving prototypes. More research is still needed to optimize these alternative technologies and to reduce costs associated with their implementation. 相似文献
18.
From the early 2000s there has been a general shift in South Africa in harvesting and extraction systems from the use of semi- to fully-mechanised systems. Any increase in mechanisation, as is occurring in Zululand, will need to take into consideration damage to stumps and the subsequent ability to regenerate by coppice. In 2002, four types of harvesting and extraction systems, arranged in a randomised complete block design, were used to clearfell a stand of E. grandis × E. urophylla. A motor-manual harvesting system was used to carry out the manual harvesting system (Man). The fully mechanised system (Mech) consisted of a single-grip harvesting head used with a tracked excavator to carry out all felling and processing operations. Two additional systems (Man_Mech_3W and Man_Mech_Flexi) had increased levels of mechanisation over that of the Man treatment. Both these harvesting systems made use of a Bell debarker, with loading carried out by a Bell three-wheeled loader in the Man_Mech_3W, and by a Flexiloader in the Man_Mech_Flexi treatments. Data collected from these four treatments were used to determine the effects of mechanised harvesting systems on type and severity of stump damage, coppicing potential and coppice growth over the rotation. Irrespective of harvesting system, more damage occurred to the top than bottom half of the stump, with a significant decrease in coppice regrowth with increasing stump damage. Most damage and least coppice regrowth occurred in the extraction rows where the damage recorded could be attributed to vehicle movement, tear-outs and/or log stripping. There was no significant difference between the harvesting systems in terms of stump mortality, final stem stocking and rotation-end volume. Thus, individual components within each harvesting system can have a larger impact than the overall harvesting system used. Future research should focus on these components, and where associated damage occurs for a specific component, this should be lessened through management intervention, training or technological improvements. 相似文献
19.
Adrian Enache Martin Kühmaier Rien Visser Karl Stampfer 《Scandinavian Journal of Forest Research》2016,31(4):412-427
Timber production is an important ecosystem service of European mountain forests. This paper aimed to assess the current practices in logging operations and to identify the efficiency gaps in timber production. The study was located in 7 case study areas from representative European mountain ranges, where 632 logging operations were analysed. The focus was on road infrastructure, transport systems, harvesting methods and extraction technologies. Often inappropriate technology was used in steep terrain; there was no correlation between the average slope and the selection of harvesting systems (HS). Skidding was the most common extraction method (75%), while cable yarding and forwarding had shares of 15% and 8%. The mean road density was 18.5?m?ha?1. The mean extraction distance was 501?m. The mean harvesting and extraction productivity were 9.0 and 10.2?m³?h?1; the mean costs were 11.1 and 11.7?€?m?³, respectively. Non-mechanized and obsolete HS reported the lowest efficiency and the highest environmental footprint, while fully mechanized systems reported the highest efficiency, the lowest number of accidents and the lowest stand damage. Cable yarders are the appropriate extraction technology in steep terrain, but they require a well-developed road network. Higher mechanization degree, improved quality of the road networks, knowledge transfer to practice and training of forest workers are some of the necessary measures to overcome the efficiency gaps in timber production in European mountain forests. 相似文献
20.
森林采运系统动力学模型研究 总被引：1，自引：0，他引：1
为了分析森林采运系统的效率和成本,本文选择系统中关键的采—集过程,利用系统动力学的方法建立模型,进行计算机仿真模拟。结果显示,以特定时间范围内完成一定工作量为前提,系统运行的效率和成本与初始设备的投入量关系不大,与设备条件、外部条件、林木条件等关系很大。但初始采造设备的投入量会影响集材设备的运行效率和成本。在实际生产中,首先应根据林木条件和外部条件选择合适的设备,这样才能使得运行效率最高而成本最低;其次在设备的安排上,应充分保障采造设备,但也不应使其生产力与集材设备的生产力相差过大,否则会造成后期集材设备需求激增等问题。 相似文献