A Comparison of Productivity in Five Small-Scale Harvesting Systems

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.     

Energy Audit of Wood Harvesting Systems

A computer-based model for the evaluation of energy use in mechanized wood harvesting systems (EnergyCalc) was developed with aid of life cycle analysis methodologies. The system boundaries were determined "from stump to roadside" with wood volume over bark (m³) as the functional unit. The computer model (based on a database system) used a Visual Basic program, and the energy audit was based on fuel and oil consumption, and the energy consumed in the manufacture of the machines and replacement parts. The general scenario from the literature, results from Sweden and a preliminary study from Ireland are presented. In the overall energy audit of mechanized wood harvesting systems in Ireland, fuel consumption was the most significant item (82%), followed by oils (7%) and machine repairs and replacement (11%). The mean energy use from the data for Ireland was found to be 16% higher than the equivalent in Sweden (120 vs 103 MJ m^?3). An energy reduction strategy that has the potential to reduce overall energy consumption for Irish systems by up to 13% was suggested.     

Productivity and Costs in Shelterwood Harvesting

Harvesting costs have a significant influence on the application and potential use of the shelterwood system. These costs are strongly related to the time needed for the logging operations. In this study, which was carried out in Norway spruce [Picea abies (L.) Karst.] stands in northern Sweden, the effective time (E ₀) of a single-grip harvester in shelterwood cutting, thinning of shelterwoods and clearcutting was measured. Based on these data the costs of shelterwood harvestings and clearcutting were calculated and compared. It was found that (1) the time per tree in shelterwood cutting and thinning of shelterwoods was greater than in clearcutting, (2) the time per cubic metre was higher in sparse shelterwoods than in dense shelterwoods, (3) most of this increase was due to longer driving time because fewer trees were harvested, and (4) the longer time and higher logging costs in the shelterwood system (compared with the clearcutting system) were mostly related to the establishment of the shelterwood. It was concluded that the shelterwood alternative is especially competitive when it is desirable to maximize the share of saw logs at the expense of pulpwood.     

Performance,Capability and Costs of Small-Scale Cable Yarding Technology

The authors tested two mini-yarders, one for uphill and the other for downhill extraction. The two machines were modern commercial models, offering state-of-the-art yarding technology on a miniature scale and at a much lower cost than required for purchasing a full-size tower yarder. The two units must not be regarded as alternative, but rather as complementary, since they offer different capabilities and advantages. Both machines were tested while harvesting firewood from the thinning of young beech stands in Central Italy. The tests indicated that both units can reach a productivity between 1.5 and 2.4 m³ SMH⁻¹, including all delays, as well as set-up and dismantle time. Calculated extraction cost ranged between 24 and over 30€ m⁻³. The authors calculated a set of regression equations for estimating machine productivity as a function of the main work conditions. The performance of the studied mini-yarders does not seem much inferior to that achieved by professional light tower yarder under the same work conditions, but the lighter construction of the small-scale units may result in a lower resistance to wear and abuse. In any case, mini-yarders seem ideal for deployment under the typical conditions of small-scale forestry, offering a good solution to wood extraction on steep terrain, competitive with animal and winch logging in terms of productivity, cost and operator comfort.     

Tree Seedling Production Systems in Northern Mindanao, Philippines

This paper examines seedling production systems for small-scale forestry in northern Mindanao, particularly the constraints and opportunities to sustain the operation of smallholder nurseries. Various types of nurseries were identified to examine issues and concerns operators face, and data collected through a survey of nursery operators, discussion with government and NGO personnel, and literature review. Many smallholders in northern Mindanao have been engaged in seedling production, for farm needs and sale in local markets. The interest of smallholder to sustain seedling production depends on market demand and incentives, which translates to financial benefit on sound nursery practices and of reliable access to profitable markets. Activities that will assist smallholder nurseries to achieve full potential have been identified as: available nursery technologies to produce high quality planting materials in sufficient quantity; building farmer groups to facilitate seedling production and enhance the scale of product marketing; building partnerships with various service providers and other stakeholders to address technical, institutional, marketing and policy issues that may hamper the operation of smallholder nurseries; access to markets and market information; and provision of incentives and policy support. Associated benefits from small-scale seedling production accrue to the government, wood processors and to the public in general.     

全球林产品生产、贸易和消费格局

总结了世界林产品的生产、贸易和消费格局.分析了锯材、木制人造板、木浆和纸制品的主要生产国的状况,并比较了它们的效率和生产侧重,讨论了几个涉及林产品生产的理论问题.对中国林产品工业的发展提出了几点建议.     

Profitability, Liquidity and Solvency of Wood Harvesting Contractors in Finland

In order to respond to global competition challenges, the wood-processing industry in Finland and elsewhere is outsourcing roundwood harvesting to harvesting contractors. The industry also seeks to negotiate with fewer, larger and more diverse contractor enterprises. The weak profitability, liquidity and solvency of harvesting contractors and the consequent difficulty in hiring qualified machine operators make networking and enterprise growth a complicated process. Financial data of 1,060 Finnish wood harvesting contractors from the period 2001 to 2007 were studied using the ‘closing of the accounts’ data. The material represents most of the full-time contractors. For 2007 net profit was about 6%, credit share of turnover over 50% and median financial reserve €18,000. High machine depreciation and interest expenses together with low solidity make it difficult for small enterprises to absorb seasonal variations and to cope with recessions. Profitability varies considerably amongst smallest enterprises, which most often are sole-operator enterprises. Moreover, even the median profit of the smallest enterprises tends to be negative, which means that enterprise capital will be consumed and many enterprises are at risk of failure. Larger enterprises are more likely to be limited liability companies. Their median profit is clearly positive and the profit varies relative little between enterprises.     

An Economic Evaluation of a Small-Scale Timber Harvesting Operation in Western Maryland, USA

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.     

2008年日本胶合层积材生产情况

根据日本胶合层积材产品协会对胶合层积材生产的调查结果,2008年国内胶合层积材的总产量达129．28万m^3,比前一年增长了4％。自2003年以来,2006年是胶合层积材产量最高的一年,其产量高达168万m^3。然而,由于2007年房屋开工量的减少,结构用胶合层积材产量迅速下降,并且这种趋势还将继续。2008年胶合层积材的进口量也下降到了49.2万m^3,比前一年下降了36．7％。     

清洁生产及其在木材工业中的应用

介绍了清洁生产产生的背景,清洁生产的定义、内容和推行清洁生产的意义,以及我国目前实施清洁生产的情况。建议我国应在木材工业中宣传推广清洁生产,改善现有的木材工业环境管理体系。     

我国森林资源采伐消耗特点分析

通过第八次森林资源清查成果分类汇总,分析我国森林资源采伐消耗的现状、结构及区域分布特点,以历次森林资源清查结果分析我国森林资源采伐消耗动态变化趋势及特点,提出了加强林木采伐管理、科学经营森林、提高木材供给能力的对策、措施和建议。     

Impact of Changes in the Sociological Characteristics of Small-Scale Forest Owners on Timber Harvesting Behavior in Quebec,Canada

Owing to the economic, social and environmental impacts associated with timber harvesting by small-scale forest owners, a number of studies have characterized their profiles, motivations and activities at a given time. However, little research has focused on how timber production has been affected by changes in the prevalence of types of forest owners over time. A 2012 telephone survey of Quebec (Canada) small-scale forest owners reveals relationships between level of harvesting and socio-demographic factors, and an evolution of these factors by examining the results of surveys conducted in 1973 and 1985. Within the same population, property size, distance between owners’ forest and homes, possession of a forest management plan, gender, education level, the length of ownership are correlated with how likely respondents were to harvest timber on their forest. Furthermore, comparison with results from previous surveys of the same population show an increase in the prevalence of characteristics associated with owners who place less importance on timber harvesting in their management decisions. Overall, since the initial survey of forest owners conducted in 1973, the size of forest holdings in Quebec has decreased, respondents’ education level has improved and the proportion of forests owned by women have increased. However, these changes are occurring at a relatively slow rate, giving government authorities time to implement policies to encourage harvesting among the new generation of forest owners.     

改性低毒木材胶粘剂在非织造布生产中的应用

通过试验表明，在非织造布绣花衬的生产中所用的胶粘剂以热固性的低毒脲醛(以下简称为1^#)和热塑性的丙稀酸乳胶(以下简称2^#)以1：(1．2—1．5)比例配比最佳；1^#胶在使用时须加迟缓剂，适当延长固化时间；1^#胶和2^#胶混合后pH值调整为弱酸性，并加一些其它辅料，适合各种客户的需要；没有使用完的胶须及时用碱处理，以延长其活性期。     

木材工业用胶黏剂生产现状、存在的问题与对策

近年来随着木材工业,特别是人造板工业的迅猛发展,我国木材工业用胶黏剂产量大增,按人造板产量推算,主要胶种UF、PF、MF的2004年消耗量300万t以上。但是胶黏剂行业存在着生产单位过于分散,规模小等问题,因而产品质量有较大差异,产品研发能力不足。笔者建议发展规模经营和专业化生产以促进木工胶黏剂行业的健康发展。     

原木采集生产的生物质流特征分析

在原木采集生产系统中,木质和非木质生物质流为主要的物质流.通过现场试验,针对闽西北马尾松、杉木、桉树3种速生人工林,测量其立木的树根、树干、树枝、树叶、树皮各组成部分的干质量以及灌木、草本、枯枝落叶的干质量,得出伐区生物质的分布比例.按采集生产作业的工艺流程,分析采集生产过程中立木生物质流的原木单位耗材、原木单位产品的排放量、立木资源效率和各工序的工序材比系数.针对木质和非木质生物质流的时空分布,建立相应的时空网络图.采用网络分析方法,推导最小木质材料损耗、最大迹地剩余生物量的工艺方案,进而分析各工艺方案的木质材料、剩余生物质在采伐迹地、集材道和集材楞场的空间分布.木质和非木质生物质流的时空分布揭示了原木采集生产物质流的重要特征.时空网络图可用于分析原木采集生产物质流的特征和相应的投入产出效益.将伐区地理信息系统与木材生产时空网络图结合,可开发出林木采伐更新作业系统的模拟、优化工具.     

Intercrop of olive trees with cereals and legumes in Chalkidiki,Northern Greece

Agroforestry Systems - It is estimated that olive groves cover an area of 700,000 ha in Greece, with 124,311 ha forming agroforestry systems combined with various crops or...     

Adaptation to Change and Re-designing of Governance Systems: Cases from Small-Scale Rural Forestry

Changes in small-scale forest governance as a reaction to global changes are viewed from the system dynamics perspective, focused on two levels of dynamic systems: the policy system with sets of interactions at the national level and the management system at the local level. These interactions are considered through permanent adaptation and re-shaping of stakeholders’ networks and positions provoking further changes in the systems. Empirical evidence has been obtained from two case studies related to small-scale rural forestry in distinct contexts—France (the Territorial Forestry Charters) and Kyrgyzstan (collaborative forest management and leasing of forest plots)—and viewed through a theoretical framework of social-political systems dynamics. The changes caused by the systems’ capacity for adaptability and resilience are expressed through a double spiral of decision-making, characterising the interactions between national policies and local management practices. The analysis leads to a conclusion that changes are basically determined by the formal and informal stakeholders’ strategies developed in a specific context and their mutual adaptation aimed at system resilience.

桂北桉树生长与材性的比较研究

以广西黄冕林场的几个桉树树种为研究对象,对比分析不同树种生长、立木材性以及林分密度对其影响。结果表明：各树种的生长（树高、胸径、单株材积、冠幅、树皮厚度）和材性（立木Pilodyn值、应力波波速、基本密度）性状均差异显著。比较3种不同林分密度的邓恩桉发现,林分密度对其生长、材质形成等产生显著影响,适宜的林分密度有利于林木生长和材性形成。对各性状采用主成分分析法进行了树种评价,结果表明：巨桉林木生长量大,大花序桉和本沁桉生长量相对较少,但木材材质相近,表现为坚硬,而粗皮桉、柳桉、邓恩桉均低于对照尾巨桉。从林木生长、立木材性方面看,适合于该地区发展的树种有巨桉、大花序桉和本沁桉,其中巨桉最适宜。     

防腐木材生产过程中的质量控制

我国木材防腐产业近年来发展迅猛,在短短的10年内产量递增3倍以上,呈现了可喜的发展势头。但是,也出现很多负面的问题:随着企业数量迅速递增,其中不少追求短期效应的企业也进入了该行业,而其技术力量明显地跟不上,有些甚至自身不掌握技术反而认为该行业技术含量低;市场恶性竞争越来越激烈,     

板式家具生产中的合理排料

三聚氰胺板式家具是指以人造板为基材,表面覆贴三聚氰胺浸渍纸,经下料、封边、钻孔等工序加工制成的家具。具有款式多,色彩变化快,拆装方便,节约