基于最优轮伐期模型的超限额采伐现象及其约束机制分析

文中将最优轮伐期模型应用于对超限额采伐现象的研究,认为由于国有森工企业的利润大多来自于木材销售收入,而企业领导的任期是有限的,他们只关心自己任期内的业绩,导致企业经营的目标实际上是短期木材收益的最大化,而不是我们所期待的可持续木材与生态综合收益最大化,甚至也不是私人拥有森林时所追求的长期木材收益的最大化。他们会设法突破政府设定的采伐限额,增加采伐量,造成森林资源加速衰退的不良后果,不仅生态功能迅速萎缩,木材产量也无法长期维持下去。同样的情形在国有林场短期租赁给私人经营时也极易发生。为尽量杜绝这种现象,有必要通过建立有效的监督和惩罚机制使超采所带来的额外收益小于被发现时上缴罚款的数学期望值,以此从根本上遏制住企业超限额采伐的动机。     

Attitudes towards mechanized Cut-to-Length technology among logging contractors in Northern Italy

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.     

Profiles of forestry contractors and development of the forestry-contracting sector in Sweden

Abstract

Contractors perform the majority of forestry activities in Sweden, yet little is known about the development of their company structures and strategies. By analyzing data from the Swedish Forest Agency's yearly survey to forestry contractors for 2006–2009 and comparing the results with previous data for 1993–1998, we examined the current profiles of Swedish forestry contractors and their recent development. For 2006–2009, responses were received from 700 to 770 forestry contractors, corresponding to ca. 20% of the estimated total number of Swedish forestry contractors. In 2009, 60% of contractors were mainly performing logging activities, whereas 30% were mainly performing silvicultural activities. Between 1993 and 2009, the number of contractors increased by ca. 80%, while the number of forestry working contractors and their employees increased by 157%. These increases were mainly due to increased silvicultural activities. Although one-person enterprises still dominate among Swedish forestry contractors, most logging work is performed by small-sized enterprises, whereas most silviculture work is performed by large-sized enterprises. Our study suggests that there is an increased dependency upon contractors and forestry contractors have become more diversified, but still specialized, in the type of work they perform.     

Growth and fruit production of the tree <Emphasis Type="Italic">Caryocar brasiliense</Emphasis> in the Cerrado of central Brazil

Caryocar brasiliense is a native tree found throughout the Cerrado savanna biome in central Brazil, and is exploited by rural population as food and industry. Although the abundance and popularity of this species in Cerrado have been an important component of local extractive economy, several aspects of sustainability as fruit production per tree size and growth rate have received little attention. We monitored, during two growing seasons, the stem growth rates and fruit production of tree in a wild population in Distrito Federal, central Brazil. The results showed a low growth rate of trees. The proportion of adult population fruiting was higher in 2006 than in 2007. For the smallest size (7.3-cm stem diameter) to begin fruiting, the estimated age was between 30 and 51 years old, and for tree with the largest stem diameter in the plot (43-cm diameter) the age was estimated to be between 110 and 153 years old. The whole fruit production by hectare was highly variable between years and was associated with differences in annual precipitation. The total fruit production was 1,004 fruits per ha (72.9 kg ha⁻¹) in 2006, and 299 fruits per ha (21.7 kg ha⁻¹) in 2007. The fruit production per tree was significantly positively correlated between 2006 and 2007 fruit season. Although an estimated fruit yield for whole Cerrado region is more than enough to support the actual demand, the slow growth rates and intensive harvesting indicates that more attention to sustainable management is required to avert demographic collapse of this cornerstone of the Cerrado extractive economy.     

集聚和出口对中国造纸企业全要素生产率的影响

造纸业作为中国传统制造业之一,亟需通过提高全要素生产率实现产业转型升级。文中基于我国1999—2007年企业层面的面板数据,测算了中国造纸企业的全要素生产率,进而考察集聚和出口对中国造纸业全要素生产率的影响。测算结果表明,中国造纸企业1999—2007年处于规模报酬递减阶段,企业全要素生产率没有太大变动。实证分析发现,产业集聚对造纸企业的全要素生产率有显著的正向影响,出口企业的全要素生产率显著低于内销企业,而且产业集聚对内销企业全要素生产率的提升幅度显著高于出口企业全要素生产率的提升幅度;集聚和出口都能影响企业研发创新,进而影响企业全要素生产率。     

Cooperation in private forestry of post-soviet system: Forest owners’ cooperatives in Lithuania

The current state of cooperation in private forestry in Lithuania is examined, with a focus on the analysis of objectives, organisational structure and the ways forest owners’ cooperatives operate. A postal survey has been used as a main research instrument, the questionnaire consisting of a series of multiplechoice close-ended questions. This paper provides insights into the state forest enterprises and other private companies operating in the private forestry sector, and places forest owners’ cooperatives in a broader context of the private forestry sector. A typical forest owner’s cooperative in Lithuania has up to 10 members and about 20 clients to whom services are provided. The leaders of cooperatives indicate that the optimal number of clients using their services should not exceed 40. The main stated objectives of cooperatives are the provision of services to their members under the most attractive conditions, uniting members, and earning a profit for the members. These activities of cooperatives revolve around timber harvesting and trade. It is concluded that the process of cooperation of private forest owners in Lithuania is rather slow, although positive development can be observed.     

Forestry contracting in northern Scotland: a survey report

This paper reports results from a survey of forest contractingfirms (‘contractors’) in Northern Scotland, carriedout as part of a tripartite 1991–94 study of forestryin rural development in Scotland, Northern Ireland and the Republicof Ireland. Aspects of the overall study focused upon the structureand activities of the contractor sector of the Scottish forestryindustry, in par-ticular its sources of business, employmentcharacteristics, capital assets and future prospects. Resultsshow that the sector in 1992 was highly fragmented, while sub-contractingwas common.Harvesting and general contractors were heavily relianton the Forestry Commission for con-tracts, while silviculturalcontractors mostly relied on forest management companies andfarmers. During the last 12 years, employment has increasedonly in the general sector, while workers directly employedtended to live closer to the firm's address than sub-contractors.Finally, most harvesting and silvicultural firms in the aa were,at the time of survey, pessimistic as to the future survivalof their businesses     

技术改造:人造板企业兴旺之举──刨花板企业技术改造要点

人造板行业已由幼稚期转入成长期，供需矛盾基本缓解，买方市场初现，市场竞争加剧，全行业盈利下滑，许多企业陷入困境。出路只有依靠技术进步，进行技术改造，以先进的手段投入经营，扩大生产规模，提高产品质量，降低生产成本，才能在竞争中立于不败之地，再现昔日之辉煌。     

比较优势在林业发展中的地位和作用

林区或林业企业应从产品绝对比较优势、产品相对比较优势和资源比较优势３个层面上进行优化产业结构或资源配置的努力。政府应根据林区比较优势的动态变化制定出旨在发挥新的比较优势的产业政策，诱导林业企业进行产品结构升级。解决初级林产品价格低下的正确途径是开放市场，简单地延长产业链并不能成为开放市场的替代选择。     

Reorganisation of wood production for improved performance: a swiss forest district case study

An extremely fragmented timber supply, high harvesting costs, low profitability, high subsidies and insufficient competitiveness characterise forest enterprises in Switzerland. In a case study using a forest district in the state of Solothurn as an example, it was sought to identify strengths and weaknesses of wood production and to formulate possible improvement opportunities. The results indicate that there is considerable potential for industry rationalisation. The greatest handicaps are the small sized forest holdings, excessive numbers of staff, insufficient use of modern harvesting technology and costly business administration. The most eminent of the proposed improvement measures are those which aim to increase concentration of timber supplies and reduce production costs. These include greater centralising of timber sales as well as planning and steering of production, making full use of modern harvesting systems, reducing transaction costs, supporting administration, planning and steering of wood production with modern information technology and reducing input on stand tending. In principle, amelioration can be best achieved by close cooperation with neighbours or even merger of enterprises. Consequently, there is a need for related business tasks to be combined in functions. The paramount prerequisite for success is the willingness and readiness of all affected stakeholders to make changes. The situation described is typical for Swiss forestry and the proposed solutions could well be used as models for a wide range of Swiss forest districts.     

林业企业的可持续增长率

由于规模化优势和财务杠杆的作用，使得林业企业超常增长可带来丰厚的利润，但企业的增长必须与资金的增长相平衡，否则，企业会因增长过快而资金增长不足陷入财务困境，林业企业在经营活动中应适度地把握可持续增长率，采取相应的管理财务策略，实现企业的平衡增长。     

Economics and Employment Generation of Bamboo-Based Enterprises: A Case Study from Eastern Bangladesh

An exploratory survey was carried out to assess economics and employment generation of the trade of bamboo and bamboo-based secondary products in the eastern Bangladesh, to obtain reliable information about their status, socio-economic significance, production and marketing. The study was undertaken over 30 bamboo-based enterprises in a suburban market of eastern Bangladesh, to investigate regional product details, economic profitability and employment opportunities. The sample entrepreneurs, corresponding to about 25% of the bamboo enterprise population were interviewed using a semi-structured questionnaire. About 202 full and part-time workers were employed in the factories, under categories of artisan (who manufactured secondary products). The average number of worker’s in the large, medium and small factories were 9 (artisan 40%), 6.45 (artisan 35%) and 5 (artisan 25%) respectively. The study revealed that there was always a satisfied demand of skilled artisans. Most of the workers were relatively newly employed (not more than 5 years). The daily wage rate varied between 70 and 130 Tk. ($US 1 equals approximately 70 Bangladeshi Taka (Tk.), as at December 2008). Bambusa balcooa was the most utilized species (39.96%) in terms of monetary value. The price of a single B. balcooa culm in the local market was Tk. 160–210. Nine sizes of articles under seven bamboo categories were identified, these being bera (36″ × 120″ and 72″ × 96″), bookshelf (36″ × 24″), chaluni (12″ × 12″), chatai (48″ × 60″ and 36″ × 48″), jhuri, rickshaw hood and tukri. Net average profit per article was the highest for rickshaw hoods (Tk. 400 at the retailer stage). The total expected annual income for an enterprises from all articles types sold was estimated to be Tk. 85,800. Three distinct marketing channels were identified for selling bamboo and value-added secondary products. The study also generated policy implications for effective management of bamboo-based enterprises.     

Impact of forest harvesting on river runoff in the Xiaoxing’an Mountains of China

Using the runoff experiment method in a large basin combined with the contrast experiment in a small watershed, and based on the runoff and forest resources data for the past 35 years, this paper studied the serial changes of river runoff in the Xiaoxing’an Mountains after forest harvesting. The results showed that the river flow increased in the initial ten years after forest harvesting, but decreased gradually with the growth and crown closure of the Larix gmelini plantations. The river flow tended to be the same or even lower than the level before harvesting. The river runoff had a close correlation with annual rainfall, the size of forest harvesting and regeneration. A significant positive correlation was observed between the annual flow and the size of forest harvesting, which resulted in the increase of river runoff after forest harvesting. Forest harvesting could also significantly increase the peak flood and snowmelt runoff. There was a negative correlation between the regenerated forest area and annual flow, and thus, forest regeneration would decrease annual flow. __________ Translated from Chinese Journal of Applied Ecology, 2005, 16(12): 2,259–2,262 [译自: 应用生态学报]     

A comparison of genetic diversity and differentiation in five Chinese pines using cpSSR and AFLP markers

Gene diversity and genetic differentiation in five Chinese pines, Pinus henryi, P. tabulaeformis, P. yunnanensis, P. taiwanensis and P. massoniana, were compared using amplified fragment length polymorphism (AFLP) and simple chloroplast sequence repeat (cpSSR). High genetic differentiation and median gene diversity with cpSSR markers were found both at population and species level, while median differentiation and higher gene diversity in AFLP data. Measures of subdivision that consider similarity between haplotypes offered better information on the geographic structure of plants than the standard subdivisions. Among several methods analyzed in AFLPs, the square root method provided downwardly biased estimates of the genetic parameters, while the Lynch and Milligan method over-estimated genetic diversity due to a small sample size. The Bayesian statistic was the most accurate and popular method for these dominant species and its value of species differentiation (θ ^B = 0.1035) was close to the parameter given by analysis of molecular variance (AMOVA). __________ Translated from Acta Botanica Boreali-Occidentalia Sinica, 2007, 27(12): 2385–2392 [译自: 西北植物学报]     

Rational Harvesting Policy and Sustainable Development of Community in Forest Regions

INTRoDUCTIoNManyforestentcrpriscslnHeiIonaiiangForestRcgion,Chinaarefacingx`ithseriousproblemsoffi-nanceshortageandresourccrapidly'dccrcasingtoday.Highdemandoftimberandotl1erforestproductsintI1epastresultedinoverharvestingandi111proPerharvesting.Thishasbe…     

Phosphorus supply and cycling at long-term forest monitoring sites in Germany

In this study, the supply and input–output balances of phosphorus (P) were investigated for a 10-year-period at 85 long-term monitoring sites in German forest ecosystems under the European Level II programme. These sites encompass 23 European beech (Fagus sylvatica L.) stands, 9 oak stands comprised of common oak (Quercus robur L.) and/or sessile oak (Quercus petraea Liebl.), 20 Scots pine (Pinus sylvestris L.) and 33 Norway spruce (Picea abies H.Karst.) stands. We quantified P concentrations in needles and leaves, P inputs from the atmosphere, P outputs through leaching and harvesting, and total P in the soil and humus layers. The P concentrations in European beech leaves from two sites (>1 mg P g⁻¹ dry weight), and in Norway spruce needles from four sites (>1.2 mg P g⁻¹ dry weight), were deficient over several years. In contrast, the oak and Scots pine sites were well supplied with P. When P removal through harvesting was disregarded, P balances were positive or stable (median 0.21 kg P ha⁻¹ a⁻¹). With harvesting, balances were mostly negative (median −0.35 kg P ha⁻¹ a⁻¹), with long-term P removal from the forest ecosystems.     

金融危机下中国林业企业的发展战略研究

随着金融危机对世界经济造成巨大冲击,中国林业企业也受到了较大的影响。主要表现为：林业行业产出下降、就业减少、进出口受阻、库存增加以及利润下降。究其原因,主要是由于我国林业企业对外依存度高,产业化程度低,自主创新能力差,缺乏品牌意识。本文基于林业企业受到的影响,分析了中国林业企业受到重创的主要原因,提出企业的应对对策。     

林产工业信息管理系统的研究

介绍了林产工业信息管理系统的建设目标、建设原则、总体构架、主要功能及主要管理模块。该系统应用到黑龙江省森工生产中 ,可以加强企业生产中供、销、存业务活动和数据分析管理能力 ,帮助企业系统地梳理物流、资金流、信息流。以达到对企业宏观监控、规范和管理的目的 ,避免企业违法 ,提高经济效益     

加快转变经济发展方式 推进行业平稳较快发展

对木工机械行业"十二五"规划进行解读,指出未来五年是加快木机行业转型发展、产业转移突破发展的关键五年,要坚持把结构调整和科技创新作为未来五年木机行业发展的重要支撑,要紧跟市场需求变化,向结构优化、技术先进、清洁安全、附加值高的新型产业转向,要扩大企业知名品牌,推进强强联合,做大做强,要重视企业的人力资源、企业文化、内部管理等软实力建设,增加企业发展的无形财富,实现企业长久发展。     

Mechanized thinning of walnut plantations established on ex-arable land

The study compares two product strategies—chips versus firewood—and two technological levels—manual versus mechanized—as applied to the thinning of walnut agroforestry plantations, established on ex-arable land. Such plantations are widespread all across Europe, and their establishment was subsidized under the provisions of EU Directive 2080/90, and of regional grant schemes. Field test data were used to build a simple deterministic model for estimating thinning productivity and cost under varying work and economic conditions. This model can assist prospective users when checking the profitability of an operation, or when assessing the competitiveness of alternative options. Removing nurse alder from young walnut plantations yields between 25 and 50 t of fresh biomass per hectare and is crucial to the good development of the stand. The study shows that the removal of nurse alder from walnut plantations is economically viable, and it can also offer some profits if stand and market conditions are favourable. As a rule, the average DBH of removal trees should not be smaller than 12 cm. Best results are obtained with mechanized harvesting, which does not seem to cause heavier stand and soil damage than manual harvesting. Manual harvesting is preferable only if the annual utilization of machinery is very low, and in this case it should be geared to firewood production. The manual whole-tree harvesting (WTH) method used in this study offers the lowest performance under all conditions, and should be replaced with some other manual alternative to WTH. Mechanized WTH offers a significant cost reduction over mechanized short-wood (SWS) harvesting, but this difference is still rather limited: hence, other parameters come into play when deciding what system to apply, and namely product price and mass output. In this respect, one also has to consider the cost of managing the harvesting residue, and that of fertilizing, if soil nutrient depletion is to be feared.