Difference in mass concentration of airborne dust during circular sawing of five wood-based materials

The object of this study was to compare the mass concentration of airborne dust during circular sawing of five wood-based materials: solid sugi (Cryptomeria japonica) lumber, tropical hardwood plywood, softwood plywood, particleboard, and medium-density fiberboard. Specimens were sawn at a constant feed per tooth (0.05 mm) using two saw speeds. The mass concentration of airborne dust of diameter 7.07 μm or less (respirable dust) was measured with a light-scattering dust monitor. The mass concentration showed a log-normal distribution, and the geometric means of mass concentration at saw speeds of 2000 and 3000 rpm were 2.33 and 2.89 mg/m³ for tropical hardwood plywood, 1.13 and 2.84 mg/m³ for particleboard, 0.91 and 2.28 mg/m³ for medium-density fiberboard, 1.09 and 1.38 mg/m³ for softwood plywood, and 0.32 and 0.66 mg/m³ for sugi lumber. The mass concentration for all five wood-based materials increased with the revolution speed of the circular saw.     

Long-term effects of eliminating illegal logging on the world forest industries, trade, and inventory

We assessed the impact on the world forest sector of a progressive elimination of illegal logging. The analysis compared predictions from 2007 to 2020, with and without a gradual reduction of illegally logged industrial roundwood from 2007 to 2011. A large part of the curtailment of timber supply due to the stoppage of illegal logging would be compensated by increased legal production incited by higher prices. As a result, without illegal logging the world annual production of industrial roundwood would decrease by no more than 1%, even though it would decrease by up to 8% in developing countries. World prices would rise by 1.5 to 3.5% for industrial roundwood and by 0.5 to 2% for processed products, depending on the assumption on illegal logging rates. World consumer expenditures for wood products and producer revenues would rise by 1 to 2% without illegal logging. World value added in forest industries would remain the same. However, the changes in consumer expenditures would be more than double the changes in producer revenues in countries dependent on illegally logged timber of domestic or foreign origin such as Indonesia and China. Symmetrically, changes in producer revenues would be almost twice the changes in consumer expenditures in countries with little illegal logging and efficient industries, such as Canada, Germany and the United States. Value added in forest industries would decrease most in countries with heavy illegal logging (12% in Indonesia and up to 9% in Brazil), and it would increase most in Germany, Canada (4%), and the United States (2%). Without illegal logging, the world forest inventory would increase slightly, as the increase in developing countries would more than compensate the decrease in developed countries.     

The long-run determinants of U.S. lumber imported from Canada revisited

This paper examines the effects of the lumber price, the housing starts, and the bilateral exchange rate on U.S. softwood lumber imports from Canada in a cointegration framework. To that end, the Phillips-Hansen fully-modified cointegration (FM-OLS) procedure is applied to monthly data for the period from January 1994 through June 2009. Results show that there exists the long-run equilibrium relationship between the U.S. lumber imports from Canada and the selected macroeconomic and market variables. We also find that the U.S. lumber price and housing starts are more important than the bilateral exchange rate in influencing U.S.-Canada softwood lumber trade.     

装饰单板贴面胶合板与杉木复合制造地板技术

为了降低实木复合地板生产的材料消耗和成本,直接采用装饰单板贴面胶合板与杉木组合制造实木复合地板.结果表明,按改进工艺制造的复合地板不仅具有国标所要求的物理力学性能,而且可降低材料成本30%左右.     

Seasonal physiology and growth of planted oaks with implications for bottomland hardwood restoration

New Forests - Afforestation and reforestation of once dominant bottomland hardwood forests in the southeastern United States can provide ecosystem services and wildlife habitat. However, challenges...     

Analysis of trade in illegally harvested timber: Accounting for trade via third party countries

The paper presents a model to analyse trade in illegally harvested timber with a particular focus on trade via third party countries. The model is deduced from the conventional input–output-analysis. In contrast to this type of analysis, inverse export coefficients are introduced to analyse the effect of a certain amount of country-specific supply, e.g., of illegally harvested timber, to the use of wood and wood products of all other countries, based on trade relationships. A database has been compiled especially for application of the model. It comprises data on industrial round-wood production in terms of industrial wood harvested and removed from the forest; recovered wood fibre in the form of recovered paper and waste wood; bilateral trade of 272 wood-based commodities in m³ raw wood equivalent (rwe), and domestic use of those commodities. Two scenarios expressing high and low estimates of illegal harvesting for all countries have been employed in the model. The model reveals the trade linkages between all countries of the world and allows quantification of the global supply and use arising from illegal harvesting. Furthermore it allows calculation of the import of illegally harvested timber for each country of the world. And finally, the model likewise allows the quantification of domestic use of illegally harvested timber for each country of the world.The results show that international trade increases the global domestic supply of illegally harvested timber by more than 70% in each scenario. In particular industrial round-wood from Papua New Guinea, Malaysia, Indonesia and Myanmar passes through many countries until it ends in form of finished wood products in the country of final destination. Not only due to suggested illegally harvested timber in the own country, but also due to strongly developed trade relationships, China holds the lead in total supply and use of illegally harvested timber. However this result must be seen against the background of the large population in China. This aspect also helps to explain the predominant position of China, Brazil and Russia with regard to the domestic use of illegally harvested timber. A comparison of import of illegally harvested timber on the basis of “simple” (covering only bilateral trade) and inverse export coefficients demonstrates the model's merit. The hitherto usually simple approach underestimates the “real” trade by a third up to a half.     

Maximum entropy modeling of mature hardwood forest distribution in four U.S. states

In the eastern United States, mature hardwood forest provides habitat for many species of native flora and fauna, but is much less common now than historically. This study examined the utility of maximum entropy modeling and spatial application to identify ecosystem types like mature hardwood forest. I performed pilot modeling in Charles County, Maryland, where I compared fine-scale geographic data available locally to coarse-scale data available nationally. As expected, a model constructed with the best locally available data, including LiDAR-derived canopy height and fine-scale soil maps, outperformed a model constructed with nationally consistent data. However, the model using national data nevertheless accurately identified most mature hardwood forest sites and excluded most young forest. I then applied the coarse-scale approach to four states: Pennsylvania, Ohio, Kentucky, and Tennessee. Average test AUC (area under the receiver operating curve) based on 10 replicates varied from 0.76 to 0.80 when comparing mature hardwood forest locations to general forest locations. The maximum training or test sensitivity plus specificity threshold, depending on the state, captured 78-79% of positive locations while rejecting 74-81% of negative locations. The maximum entropy approach is versatile, and can be applied to other ecosystems and species.     

柞、硬阔叶树与软阔叶树原条材种出材量(率)表的编制

我国50～60年代初期,林业部综合队曾编制红松(Pinus koraiensis Sieb.et Zucc.)、云杉(Picea spp.)、马尾松(Pinus massoniana Lamb.)、兴安落叶松(Larix gmelini(Rupr.)Rupr.)、白桦(Betula platyphylla Suk.)等树种材种出材量表,70～80年代各省(区)市、规划院、科研等单位对杉(Cunninghamia lanceolata Hook.)、落叶松、山杨(Populus davidiana     

Determinants of illegal logging in Indonesia: An empirical analysis for the period 1996–2010

Illegal logging is a significant problem in Indonesia, which is one of the few countries with a large forest area. In this study, we investigate the factors that affect harvesting and supply of illegal timber from Indonesia to China and Japan. Moreover, we investigate the factors that lead to the demand of Indonesian illegal timber from China and Japan. A simultaneous-equation econometric model of illegally logged timber demand and supply is developed and tested using the annual data over the period 1996–2010. We find that corruption and decentralization in Indonesia have significant and positive impacts on the illegally logged timber supply while excess demand in Japanese construction and furniture industries as well as Japan’s housing starts are the significant factors that affect the illegal logging in Indonesia. The law enforcement or policies aimed at reducing illegal harvesting in Indonesia are found to be more effective than the policies targeting the import of illegally logged timber into Japan and China.     

Examining hardwood pulp and ethanol prices for improved poplar plantations in Canada

Temporal variation in prices is an important factor that influences returns on investments and decisions made by policy makers. This study investigates the behaviour of two output prices potentially associated with growing improved poplars in Canada: hardwood pulp and ethanol. Time series techniques are used to assess the processes and volatility of hardwood pulp and ethanol price series. The findings indicate that price series for hardwood pulp and ethanol are best characterized by mean reverting processes around constant averages, indicating more predictability for poplar producers than would be the case for random walks. However, the results from the volatility analysis suggest substantial uncertainty for producers. The volatility of both markets is found be to be highly related to past volatilities, and therefore persistent. To the extent that future prices are more volatile, the importance of producers considering multiple product options for pulp plantations increases, as do complexities for policy makers to predict the impacts of policies to support biofuels.     

Impacts of the currency value change on the forest products import quantities in Korea

This study estimated the impacts of the currency value change on the forest products import quantities in Korea using vector autoregressive model. The first objective is to analyze whether there is any causal relationship between change in the currency value and changes in the import quantities of forest products in Korea. Assuming that there is any causal relationship, the second objective is to evaluate the dynamics of the impacts of the currency value change on the forest products import quantities in Korea. The causal relationship was analyzed by the causality test of Granger. The relationship between the currency value and the import quantity was represented by vector autoregressive model. And the dynamics were evaluated by variance decomposition analysis and impulse response analysis. Change in the currency value causes change in the hardwood roundwood import quantity in Korea. In the model of the hardwood roundwood import quantity, after 6 months, the currency value change accounts for approximately 10% of variation in the import quantity. On the other hand, the impact of a shock to the currency value is significant for approximately 10 months on the import quantity of hardwood roundwood in Korea.     

Plywood frame corner joints with glued-in hardwood dowels

This paper presents research on plywood frame corners jointed to glulam beams and columns by means of glued-in hardwood dowels. The frame corner was made of a solid block of ordinary plywood of the same width as the glulam beams and with plies parallel to the plane of the frame to avoid splitting due to stress perpendicular to the grain. Hardwood dowels with a diameter of 12mm and a maximum glued-in length of 120mm were glued into drilled holes in the plywood corner and glulam beam ends parallel to the grain direction of the beams to form a momentresisting joint. Static bending tests were conducted of frame corners with 100 X 200mm² and 120 X 420mm² beam cross sections. Bending capacities of the joints corresponding to a modulus of rupture of the jointed glulam beams of about 30MPa were obtained for both closing and opening moments for the small cross sections, and about 22MPa was obtained for the large cross sections. Simple design models for calculation of joint strength and rotational stiffness are also presented.     

加拿大林产工业的最新进展

加拿大是世界林产品生产大国和贸易大国。文中概述了加拿大近几年锯材、人造板、纸浆、纸和纸板等主要林产品的生产情况, 以及2004年的林产品出口情况。在此基础上, 归纳出加拿大林产工业的6个特点。     

我国胶合板生产和贸易的现状和展望

通过回顾我国胶合板发展历程,分析了胶合板用材资源、加工和使用特点以及生产分布、进出口贸易现状.针对用材资源受制约、薄型中纤板竞争以及非关税贸易壁垒等问题,提出我国应大力培育人工林,保持一定的木材进口量,加强技术创新,质量意识、环保意识、品牌意识和专业化意识,进一步细分市场和企业整合,向胶合板强国迈进.     

Impacts of log export restrictions in southeast asia on the Japanese plywood market: An econometric analysis

Seen worldwide, many restrictive policies on timber harvests or log exports have been enforced in the major timber-exporting countries in the last two and half decades. This study aims to assess the impacts of the log export restrictions in the Southeast Asian countries on the Japanese plywood market, whose supply mainly comes from Southeast Asia and the domestic plywood industries. Both plywood industries process tropical raw logs. This econometric analysis reveals the followings; the log export restriction of Indonesia, along with its policy to promote the plywood industry, increased plywood exports to Japan, leaving the amount of log supply rather unchanged. Sabah’s log export restriction and Sarawak’s log export cutback policies decreased the amount of log exports from Southeast Asia to Japan significantly. Furthermore, the producer surplus of Southeast Asian plywood industries increased notably after the log export restriction of Indonesia. The consumer surplus in the Japanese plywood market increased accordingly. On the other hand, the producer surplus of the Japanese plywood industry decreased significantly as a result of Sabah’s log export restriction and Sarawak’s log cutback policies. Consequently, these log export restrictions led to large profits for the plywood industries of Southeast Asia, and that, enforced costs were levied on Japanese plywood industry. This study was supported by a Grant-in-Aid for International Scientific Research (No. 08041048) from the Ministry of Education, Science, Sports, and Culture of Japan.     

《雷斯法案》修正案对中美木质家具出口影响及对策分析

首先分析美国<雷斯法案>修正案的历史沿革、出台的背景以及修订的主要内容;接着从中美木质家具贸易现状出发,研究<雷斯法案>修正案对中美木质家具出口的影响,指出由于出口难度加大、出口成本提高和贸易保护主义等原因,将减少我国木质家具出口.在此基础上,文章最后针对我国家具出口企业如何应对挑战提出了一些合理化建议.     

A review of the utilisation of hardwoods for LVL

This review on the use of hardwoods for the production of LVL revealed that a large number of research studies have been carried out, particularly in North America and three Asian countries (Japan, Malaysia and China). However, the studies have been restricted to species of low to medium density, i.e. 290 to 693 kg/m³. Two major potential uses of hardwood LVL have been investigated in these studies: domestic and industrial structures, and various furniture components. The production of structural LVL in North America and Asia was based predominantly on low density hardwoods. A study currently carried out in Europe aims at using medium density hardwoods for structural LVL. The LVL used for furniture components was produced from medium density hardwoods. No work has been undertaken outside Australia on the use of high density species for LVL. In Australia, studies undertaken on the production of LVL and hardwood plywood from eucalypts revealed that there were significant problems in gluing the dense raw material which often had a high level of extractives. Peeling low quality, small diameter eucalypt logs also created problems when the traditional plywood processing techniques were used. Received 7 July 1997     

胶合板厂技术改造和单板层积材生产

本文阐述了我国胶合板工业现状和存在的问题;介绍了单板层积材产品及其和实体木材及胶合木间的区别,着重论述了对胶合板生产线进行改造的可行性方案及在我国发展单层板层积材的必要性和生产单板层积材的可行性。     

Some observations on sawn hardwood exports form Tanzania

Sawn hardwood exports from Tanzania have declined drastically from a peak of 24 000 m³ in 1969 to 640 m³ in 1984. Factors influencing this trend include scarcity of fine hardwoods which have been overexploited, production and distribution problems which have led to very high free-on-board supply prices, and unprofitable shipments for export. In addition, inadequate export handling facilities and the absence of direct shipping routes to many potential markets have worsened export prospects, at least for the immediate future.     

Long-term effects of single prescribed fires on hardwood regeneration in oak shelterwood stands

One of the arguments against using prescribed fire to regenerate oak (Quercus spp.) forests is that the improvement in species composition of the hardwood regeneration pool is temporary and multiple burns are necessary to achieve and maintain oak dominance. To explore this concern, I re-inventoried a prescribed fire study conducted in the mid-1990s to determine the longevity of the effects of a single prescribed fire on hardwood regeneration. The initial study was conducted in three oak shelterwood stands in central Virginia, USA. In 1994, each stand was divided into four treatments (spring, summer, and winter burns and a control) and the hardwood regeneration was inventoried before the fires. During the burns, fire intensity was measured and categorized in each regeneration sampling plot. Second-year postfire data showed marked differences in species mortality rates, depending on season-of-burn and fire intensity: oak and hickory (Carya spp.) regeneration dominated areas burned by medium- to high-intensity fire during the spring and summer while yellow-poplar (Liriodendron tulipifera) and red maple (Acer rubrum) seedlings dominated unburned areas and all areas treated with low-intensity fire regardless of season-of-burn. The treatments were re-inventoried in 2006 and 2007 to determine whether these fire effects were still present. The new data show that the species distributions by season-of-burn and fire intensity found in 1996 still existed 11 years after the treatments. The fact that fire effects in oak shelterwood stands can last at least a decade has important management implications for resource professionals interested in sustaining oak forests in the eastern United States.