对森工企业内部锯材原木合理造材的探讨

本文对当前森工企业内部锯材原木的造材方法进行了分析,探讨了森工企业内部锯材原木的合理造材法。     

锯材商们希望原木价格能有所缓和

法国：一些锯材厂商希望今年的原木购买成本能有昕缓和。目前的交易市场,锯材商开始大规模购买橡木原木。目前法国大型榉木锯材商对价格调整漠不关心,以致原木统材及齐边材产品和板材及产品的销售价格保持稳定。然而,一些小型厂家,特别是原木统材厂家,显然已再次压低价格。     

谈提高伐区内原木合理造材质量的措施

论述和分析了造材生产中存在的不合理因素,提出加强伐区内原木合理造材的措施。     

谈提高伐区内原木合理造材质量的措施

论述和分析了造材生产中存在的不合理因素,提出加强伐区内原木合理造材的措施。     

浅谈畜力集材

集材作业是伐区木材生产的重要工序，集材成本约占伐区木材生产总成本的２／３左右．集材方式的选择对集材任务完成的好坏、提高效率、降低生产成本至关重要．目前，由于“天保工程”的实施，可采森林资源逐渐减少，承包经营的发展，使畜力原木集材方式转变为重要的集材方式．山河电林业局于１９８５年后全部采取伐区造材、畜力原木集材作业方式。现结合多年的生产实践，对畜力原木集材的特点、措施、发展方向探讨如下：ｌ畜力集材的特点 畜力集村适用于伐区坡度大、森林资源分散、公顷出材量小、集材距离长的林相。畜力集材具有机动灵活；…     

伐区招投标出材量误差原因及解决对策

对广东省乳阳林业局伐区招投标设计与实际采伐出材量存在较大误差的原因进行了分析,并提出了相应的解决对策,从而对切实加强乳阳林业局今后的森林采伐管理招投标工作,具有十分重要的意义。     

非洲

西非木材价格和木材市场动向西非地区的原木价格稍有上扬,而大部分价格保持稳定。欧洲原木采购量很小,大部分原木销到了亚洲,最大买主中国,还有印度,在市场上仍很活跃。虽然一些商人称部分树种库存很少,满足一般质量订货的能力已有限,但欧洲锯材市场仍表现清淡,尽     

干基腐朽材量材设计新方法的探讨

本文作者根据在张广才岭境内制材厂跟踪调查结果,提出对干基腐朽材的量材设计时,一般树种可按墩根和造短材的习惯量材法的进行划尺,但对可做特级原木或胶合板原木的树种,一定要掌握好腐朽深度,将腐朽部分墩掉,使下节原木变为特级原木或胶合板原木。这种最材新方法对国家和企业都大有好处。     

原条造材及原木售价的承包与计算

贮木场生产和经营管理的好坏,是影响林业企业经济效益的重要环节。因此,有必要对原条造材及原木售价的承包与计算问题提出如下意见,供林业企业工作参考。我们认为,林业局或林场确定贮木场第二年的造材出材率(指平均出材率)和原木平均售价,从而确定其总产值并承包给贮木场,可根据贮木场前一年的原条造材出材率、原木平均售价和第二年的伐区资源状况来确定。林业     

美国阔叶材市场

1.木材供应 与前几个月相比,2002年12月的阔叶材产量较低.秋季是木材采伐的旺季,12月(尤其在圣诞节前),术材采伐量明显减少.随着冬季潮湿、雨雪季节的来临,木材采伐受阻,更加剧了原木供应紧张矛盾.目前,许多制材厂难以维持足够的原木库存,将来也难以保障库存.这样,原木短缺致使原木和新鲜锯材(生材)价格上扬.原木涨价使得销售原木有利可图,因而不是将原木锯解成锯材出售.与此相似,新鲜锯材与窑干锯材间的价格差越来越小,锯材干燥厂为了获利的锯材销售所承受的困难日益加大,有的干燥厂只好临时关闭干燥炉.     

Integrated harvesting for conventional log and energy wood assortments: a case study in a pine plantation in Western Australia

Biomass or energy wood harvesting can be integrated with conventional log harvesting (saw log or pulpwood production) to allow more cost-effective energy wood supply. The efficiency of an integrated energy wood harvesting system was evaluated and compared with conventional log harvesting in a 32-year-old Pinus radiata plantation (radiata pine) located in south-west Western Australia. The harvesting system consisted of a harvester and a forwarder. The study included two treatments: a conventional log-harvesting operation where merchantable sawlogs and pulp logs were produced at the stump by the harvester and extracted by the forwarder; and an integrated energy wood operation where the harvester produced sawlogs, pulp logs and energy wood at the stump that were extracted by the forwarder. In the integrated energy wood harvesting plot, 37 m3 ha?1 of energy wood was extracted in addition to the sawlog and pulp log volumes. Extracting the additional energy wood reduced the productivity of the forwarder and increased the cost of extraction (AU$2.7?m?3) compared with the control plot (AU$2.2?m?3). Harvesting system cost was not significantly impacted, with a cost of AU$3.18?m?3 in the control plot and AU$3.23?m?3 in the integrated energy wood harvesting plot. Diameter at breast height (DBH) was a significant factor influencing the working time of the harvester, whereas load volume, extraction distance and extraction type (sawlog, pulp logs, and pulp log/energy wood) significantly impacted forwarding time. Increasing DBH resulted in longer working cycles for the harvester. Heavier loads and longer forwarding distances increased forwarding cycle time, while extracting sawlogs was least expensive and energy wood extraction was the most expensive. The marginal cost of the energy wood was approximately AU$10.2?m?3 (AU$7.0 extraction and AU$3.2 harvesting), which is about double the cost of the sawlogs. Additional material recovered in the integrated energy wood plot resulted in less residual residues on the plot (103.2 green metric tonnes per hectare [GMt ha?1]) than the control plot (144.2 GMt ha?1).     

Identifying the inter-market relationships of forest products in the Pacific Northwest with cointegration and causality tests

We identify various inter-market relationships of forest products using cointegration and causality tests together. Of the six Douglas fir domestic sawlog, export sawlog, and lumber markets in the Pacific Northwest, we find that the two log markets and the two lumber markets are integrated, respectively. However, the two export log markets are not, nor is any cross-grade combination. In conjunction with cointegration restrictions, our causality tests demonstrate that export and lumber prices lead the movement of domestic sawlog prices; and similarly, the movements of domestic lumber prices follow the movements of export log prices. A close examination further reveals that export log prices for Region 1 lead the price formation process in all the lumber markets and log markets. We believe that these results have significant implications for understanding and thus dealing with forest products market behavior and price forecasting.     

我国进口俄罗斯木材趋势分析

对我国进口俄罗斯木材的历史数据进行分析,并根据灰色预测GM（1,1）模型理论,建立我国进口俄罗斯原木、锯材、板材预测模型,以此预测2015年我国对俄罗斯原木、锯材、板材的进口数量以及未来几年我国进口俄罗斯木材的总体趋势,从而为我国木材流通领域的宏观调控提供依据,保证整个社会经济的协调发展。     

桉树无节材修枝技术研究进展与展望

本文综述了国内外桉树人工林无节材培育修枝技术的理论和研究。为了满足当今社会对高品质木材的大量需求,人们开始将桉树纸浆材人工林栽培向更高价值含量的锯材转化。众多研究表明,影响桉树木材外观等级的主要因素是节子。要从根本上解决木材质量的问题,合理而科学的修枝理论和实践显得尤为重要。修枝直接影响树冠动态发展,而树冠动态与树木的生长直接相关。尽管桉树自然整枝能力较强,但不能靠它获得大量无节材,修枝措施必不可少。修枝对树木生长和木材材质都会产生影响。合理的修枝强度会促进树木生长,而科学的修枝技术对高品质无节材的形成相当关键。为了使修枝达到最大效益,在非生长季节以及树冠郁闭前修去小枝活枝,并且保证修枝伤口平滑和注意伤口保护是最合适的修枝处理。伤口的愈合与诸多因素有关。     

高温高湿处理对落叶松锯材树脂脱除及分布影响分析

对落叶松锯材进行高温高湿处理是其木材干燥中一个重要过程。通过高温高湿处理,可使落叶松锯材中所含的树脂固体成分受热软化,粘度降低,流动性增强,在热力作用下向表面移动进而从木材中溢出。本研究通过对落叶松锯材进行不同时间高温高湿处理和不同后期处理条件的干燥试验,分析被处理的落叶松锯材树脂脱除和分布规律,为探讨合理落叶松脱脂工艺提供基础依据。通过试验分析,得出对落叶松锯材进行高温高湿处理的时间在8h以内时,木材中树脂从芯部向表层移动和从表面溢出明显。处理时间达到8h后,树脂分布变化和溢出变化不明显。     

Wood‐rotting basidiomycetes are a minor component of fungal communities associated with Acacia hybrid trees grown for sawlogs in South Vietnam

Acacia hybrid (Acacia mangium × Acacia auriculiformis) clones are widely planted in Vietnam with a total of approximately 400,000 ha to meet the demand for pulpwood, sawn timber and wood chip exports. Silvicultural techniques such as pruning and thinning have been applied to improve productivity and sawlog quality of Acacia hybrid plantations. However, those techniques may also create opportunities for wood decay fungi to enter the Acacia hybrid stems through wounds and cause stem defects that reduce sawlog quality and the value of the plantation. The presence of fungal decay agents in Acacia hybrid trees was examined in two Vietnamese plantations. In July 2011, just prior to a second thinning, discoloured wood samples were taken from a three‐year‐old Acacia hybrid plantation at Phan Truong Hai for the isolation of fungi. In July 2012, approximately 18 months after pruning and thinning treatments, discoloured wood samples were taken from a three‐year‐old Acacia hybrid plantation at Nghia Trung for the isolation of fungi. DNA sequencing of the rDNA ITS identified the isolates. In May 2015, approximately 4 years after thinning and fertilizer treatments, discoloured and decayed wood samples were taken from the above (7‐year‐old) Acacia hybrid plantation at Phan Truong Hai for fungal identification. DNA was extracted directly from discoloured and decayed wood samples and fungal rDNA ITS amplicons sequenced on a Roche 454 sequencer. The results showed that silvicultural treatments did not affect the fungal communities associated with discoloured and decayed wood of Acacia hybrid plantation at Phan Truong Hai. A total of 135 fungal species or OTUs (operational taxonomic units) were identified, including 82 members of Ascomycota and 52 Basidiomycota.     

Yield Potential of Quercus robur Stands in Finland

Yield potential of common oak (Quercus robur L.) stands in Finland was examined by estimating the site index value with a Swedish model of a sample of 23 existing stands in southern Finland, and studying its correlation with site fertility and geographical location. Stand structure and yield parameters were compared with those suggested by the Swedish management regimes to assess their condition and potential for quality oak production. External wood quality and sawlog volume were examined in sample tree data. The study stands scored high site index values on the reference site index curves from southern Sweden. The most fertile sites showed an average site index value of H ₁₀₀=28-30 m, and the common Oxalis-Myrtillus type H ₁₀₀=24-26 m. In the absence of thinning and pruning, the external quality of the trees was poor. Defects had reduced the sawlog proportion on average by 40% from the estimated maximum allowed by tree dimensions.     

Structural changes in sawlog and pulpwood markets in Finland

This paper presents a short‐term econometric model for the sawlog and pulpwood markets in Finland. More specifically, the effects of structural changes in the market on the success of short‐term market modelling are investigated. Wood prices and quantities traded are stationary. Therefore, valid statistical inference using the levels of these variables is possible. Pulpwood prices were found to be directly proportional to sawlog prices during the study period, and the cross‐price effects were not statistically significant. The results indicated that the price sensitivity of wood supply in Finland increased during the 1980s and early 1990s. Nationwide collective price agreements were found to have increased the level of pulpwood supply and demand from private forests, but to have had no effect on either supply of or demand for sawlogs. Due to a structural change in the 1970s, the models estimated for the whole period cannot be used for short‐term forecasting in the 1990s. Higher‐than‐annual frequency data should be used in developing accurate short‐term forecasting models.     

Predicting probability of A-quality lumber of Scots pine (Pinus sylvestris L.) prior to or concurrently with logging operation

Knot properties have a profound influence on the suitability of wood for many wood products leading to significant value differences between different quality grades. It would therefore be rather advantageous to maximise the volume of good quality timber attained from the logs. The objective of this study was to assess how well A-quality lumber of Scots pine derived from log tomography features can be predicted with characteristics measured prior to or concurrently with the logging operation. The study is based on field experiments and X-ray scanning of 204 stems from southern Finland in 2014. We employed mixed logistic regression techniques to model the relationship between the main stem characteristics and probability of A-quality lumber. From the tree characteristics that can be measured or detected from standing trees, the height from the ground level to the lowest dead branch was found to be the best predictor of A-quality lumber. From the characteristics that could, at least in theory, be detected and measured at the moment of harvest, early growth rate and size of tree were found to be the best combination for predicting the probability of A-class quality.