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1.
俄乌地缘政治冲突对全球针叶材供需格局的影响   总被引:1,自引:1,他引:0       下载免费PDF全文
文中构建涵盖19个经济体的全球针叶材区域价格均衡模型,模拟分析俄乌冲突引发的全球针叶材供需格局变化与调整。结果表明,俄乌冲突导致显著的贸易转移效应,俄罗斯和白俄罗斯2国对欧盟针叶材出口合计减少900万m3,对中国、埃及、土耳其出口合计增加543万m3;乌克兰对欧盟出口增加255万m3,对中国、土耳其出口则合计减少183万m3。俄罗斯和白俄罗斯的中国市场份额将分别达到29%和3%。俄白2国退出欧盟市场造成6%的供应空缺,而乌克兰可以填补其中的一半。俄乌冲突造成木材贸易出超方和入超方利益分化,全球整体福利受损,俄罗斯福利下降约1亿美元,中国、美国、日本等木材贸易赤字方分别减少4 300万美元、2 400万美元、600万美元,加拿大、欧盟、新西兰等木材贸易盈余方分别增加2 700万美元、2 200万美元、1 300万美元,全球总福利下降2亿美元。  相似文献   

2.
In this study, the combustion properties of wood pellets were evaluated using a cone calorimeter, which is usually used to verify the fireproof performance of architectural materials. In contrast to the conventional methods including combustion calorimetry and thermogravimetric analysis, a cone calorimeter can estimate various combustion parameters, e.g., changes of heat release rate (HRR), weight decrease during burning process, ignition time, and flame-out and burn-out time as well as combustion heat, in a single experimental run with no pretreatment for sample size reduction. The following results were obtained by the combustion test of Japanese cedar (Cryptomeria japonica) and larch (Larix kaempferi) wood pellets having various volume densities. Ignition time of wood pellet became slower with increasing volume density of the pellets. However, burn-out time was not clearly correlated to volume density. The heat release values measured by cone calorimeter could be comparable to those from the conventional combustion calorimeters, and flaming heat values of the bark pellets were always lower in comparison with pellets made of xylem, although total heat release was almost the same.  相似文献   

3.
Mitigating international trade in illegally harvested wood (products) is an international priority. To support this priority, the European Timber Regulation prohibits placing illegally harvested or traded timber on the EU market, requiring companies to undertake due diligence in sourcing wood (products). To take effect, this regulation needs to be implemented in all European member states.Although Germany is one of the first member states to transpose and enact the regulation's provisions, its implementation has recently been portrayed as “weak” and ineffective. This article aims to answer why this perception emerged. It scrutinizes implementation performance of the EUTR in Germany.Based on rich empirical data from stakeholder interviews, documents, and participant observation, this study argues that EUTR performance in Germany is not generally perceived as ineffective. Instead, stakeholder perceptions vary. As stakeholders face major uncertainties connected to market structure and company behaviour, they tend to base their assumptions about the implementation process on two major heuristics. Both focus on the question how to change company behaviour. One stresses the need to pursuade companies to comply, the other stresses the need to coerce them. These heuristics are based on the two larger objectives pursued by different stakeholder groups during policy making of the EUTR: (1) global sustainable forest management and (2) image improvement of the EU wood importing industry.Based on these different policy objectives, the EUTR does not provide clear guidance on which policy instruments should be given priority. As a consequence, national implementation is turned into a policy-making process. The outcome of this struggle will likely affect the future trajectory of EUTR implementation in other EU member states and in countries exporting wood into the EU.  相似文献   

4.
According to the United Nations International Panel on Climate Change good practice guidance, an annual forest biomass carbon balance (AFCB) can be estimated by either the stock-difference (SD) or the gain–loss (GL) method. An AFCB should be accompanied by an analysis and estimation of uncertainty (EU). EUs are to be practicable and supported by sound statistical methods. Sampling and model errors both contribute to an EU. As sample size increases, the sampling error decreases but not the error due to errors in model parameters. Uncertainty in GL AFCB estimates is dominated by model-parameter errors. This study details the delta technique for obtaining an EU with the SD and the GL method applicable to the carbon in aboveground forest biomass. We employ a Brownian bridge process to annualize the uncertainty in SD AFCBs. A blend of actual and simulated data from three successive inventories are used to demonstrate the application of the delta technique to SD- and GL-derived AFCBs during the years covered by the three inventories (SD) and rescaled national wood volume harvest statistics (GL). Examples are limited to carbon in live trees with a stem diameter of 7 cm or greater. We confirm that a large contribution to the uncertainty in an AFCB comes from models used to estimate biomass. Application of the delta technique to summary statistics can significantly underestimate uncertainty as some sources of uncertainty cannot be quantified from the available information. We discuss limitations and problems with the Monte Carlo technique for quantifying uncertainty in an AFCB.  相似文献   

5.
郭东升  朱典想  牛前明  朱江 《木材工业》2008,22(1):34-36,42
木质颗粒燃料是一种可再生、清洁和成本稳定的燃料,可由农作物秸秆、木、竹加工剩余物及普通的废旧木料等可再生的物质制成,北美和欧洲正在大量使用.本文介绍了木质颗粒燃料产业的发展现状,产品特点、用途和制造工艺,并分析了这种燃料在我国的发展前景.  相似文献   

6.
Japan and China have been two leading importers of wood products in the global market, and the trade pattern for China since 1993 has largely repeated that for Japan in the 1960s. In this study, the import demand of wood products in Japan and China between 1995 and 2013 by product type and source is assessed using the translog cost function and cointegration analysis. Wood products are classified into three main types by the degree of processing and transformation on wood fiber: roundwood, sawnwood, and wood-based panels. The own-price elasticities are overall inelastic, but they can become very elastic for some source-differentiated products (e.g., sawnwood import by Japan and roundwood import by China from the United States). Clear substitutability across product types and supplying sources is identified. Wood products with a different degree of processing or from different sources can be substituted with each other when they are used by wood-utilizing industries in the importing countries. The substitute relation will continue to present both opportunities for economic development and challenges for global environment protection.  相似文献   

7.
Ecotourism is a sustainable use of forest resources, as compared to traditional uses such as logging or mining. However, whether turning forests into tourist sites can generate incomes comparable to the lucrative traditional activities is less clear. We estimated the recreational values of the Belum-Temengor Rainforest Complex (BTRC) in Perak, Malaysia, and compared it with the alternative of one-time consumptive revenues from logging. Based on data from an on-site survey of 367 visitors to BTRC, direct non-consumptive use values were computed using the individual travel cost approach and the truncated Poisson count data model. The annual direct non-consumptive use value was RM14.66 million based on the estimated number of nights spent and willingness-to-pay per trip. The future cash flows of recreation demand were RM614 million, RM970 million, and RM1.86 billion for the next 30, 50, and 100 years, respectively. Own-price, cross-price, and income elasticities of recreation demand were also computed. Visitors’ on-site travel cost, alternative-site travel cost, income, ethnicity (Malay), and marital status (Single) were associated with recreation demand. Our main conclusion is that the direct non-consumptive use values from recreation demand and other indirect use and non-use values from forest conservation exceed the one-time consumptive revenues from logging.  相似文献   

8.
Enhanced productivity in the logging industry is one of the key factors that determine the competitiveness of the forest products sector. Policy measures to improve efficiency must therefore start at the timber harvesting stage. This study analyzed and compared the production technologies in the timber harvesting industries of British Columbia (B.C.), Ontario, and Quebec, which are Canada's largest timber producing provinces. The study used annual data of log output and four inputs: labour, capital, energy, and materials from 1961 to 1999. Six models, encompassing different restrictions on the long-run translog cost function, were applied to each industry to determine the best technology for that industry. The cost function that best described each industry's technology was used to estimate own- and cross-price elasticities, input substitution elasticities, scale effects, technological change and bias, and total factor productivity. The production technologies of B.C. and Quebec were best described by homothetic, linearly homogeneous functions, while that of Ontario was found to be non-homothetic. Based on the Morishima elasticities of substitution, the results in general indicated inelastic substitution among all the four factor inputs. As a result the industries had limited options to make input adjustments with respect to changes in relative input prices; and hence required output levels were maintained at higher production costs. All three provincial industries exhibited biased technological changes, saving on capital and labour, and intensively using energy and materials. Labour and capital therefore recorded higher productivity than energy and materials over all provinces; consequently, efforts at improving the efficiency of the logging industries should focus on increasing the productivity of the latter inputs. Scale effects ranged from 2.17 in B.C. to 1.44 in Quebec implying that the timber harvesting industries appeared to have had the greatest potential for cost reduction through output expansion. In a competitive market structure, the strategic policy implication of these scale effects is that low-cost producers force high-cost industries out, leading to industrial concentration. The low levels of technological change in the timber harvesting industries observed in this study may reflect these industrial concentration problems. Policies that reduce the rental cost of capital, such an increase in investment tax credits and cuts in the corporate income tax rates have the potential to increase productivity and hence improve on the timber industry's competitive position.  相似文献   

9.
木质颗粒成型能耗分析   总被引:1,自引:0,他引:1  
生物能源是一种重要的再生能源,生物能源木质颗粒比其他生物能源更容易实现大规模生产和使用,在国外应用已经相当普遍。我国在木质颗粒产品推广应用中,存在诸多问题,其中最棘手的问题是生产木质颗粒中制粒能耗高、设备损耗大。通过分析木质颗粒生产的国外制粒工艺、国内自主研发的制粒工艺和引进技术改进的制粒工艺的单位产量能耗,我们认为:引进制粒生产技术是合理可行的方法。  相似文献   

10.
《Southern Forests》2013,75(2):121-131
Evaluation of a series of spotted gum (Corymbia citirodora) progeny trials, established in the subtropical region of Queensland, Australia, was undertaken to provide information for the development of advanced-generation breeding populations suitable for pulp production. Measurements of growth at two ages were combined with assessments of wood density and pulp yield from a selected sample of provenances to provide comparisons between provenances, to generate genetic parameter estimates and to predict genetic gain potential. Although growth at this age was moderate relative to other eucalypts, the near-infrared predictions of average wood density of 756 kg m?3 and pulp yield of 55% indicate the species has considerable potential as a pulpwood crop. A pulp productivity breeding objective was used to identify production populations using a range of selection trait weightings to determine potential genetic gain for pulp productivity. Genetic parameters indicated (1) levels of genetic control were moderate for all traits and higher for wood property traits, (2) genetic improvements could be achieved by selection among and within provenances with greater levels of improvement available from selection within populations, (3) genotype by environment interactions were negligible, (4) genetic correlations between traits were favourable, and (5) selection of volume production alone would maximise improvements in pulp productivity.  相似文献   

11.
  • ? Variation in wood basic density and its correlation with tree growth were investigated at 13 years in a provenance/progeny test of Prosopis africana in Niger. The test included progeny from 256 trees sampled from 24 provenances in the Sahelian ecozone of Burkina Faso and Niger.
  • ? Variation in wood density was significant due to provenances and families within provenances. Individual tree heritability was higher for wood density than for growth traits. Provenance means for wood density increased from the more humid to the drier parts of the sample region. Phenotypic correlations indicated that larger trees tended to have denser wood.
  • ? Clines suggest that natural populations of P. africana from the drier parts of the sample region have the genetic capacity to produce denser wood, compared with populations from the more humid parts of the region. Correlations and heritability estimates suggest that selection of faster-growing trees may produce a small gain in wood volume but little (if any) gain in density in the subsequent generation. Multi-location provenance/tests are needed to confirm this tentative conclusion.
  •   相似文献   

    12.
    Abstract

    Several uncertainties are associated with the future development in Russia. The aim of this study is to analyse the effects of some of them on the forest sectors in Russia and the European Union. In particular, we examine the impacts of increasing prices set on atmospheric CO2 emissions and the changing investment climate in Russia on the use of forests in the EU and Russia as well as on the export of forest products from Russia to the EU. In the analysis, we use a numerical forest sector model, EUFASOM. The results suggest that a more intensive utilisation of the vast forest resources in Russia call for rapid improvements in the investment climate. Otherwise, the growth of pulp and paper production in Russia would mainly be directed at satisfying the domestic demand. It is hard to penetrate the EU markets which are suffering from excess capacity and a slow demand growth. Russia's importance as a supplier of energy wood to the EU is likely to increase, unless for instance export tariffs or tighter climate policies in Russia hinder such a development. The results demonstrate large differences in the harvesting and use of wood in the EU and Russia across the alternative future scenarios.  相似文献   

    13.
    Summary The probability of bond between wood components and glyoxal was examined by means of a mechanical method, infrared (IR) spectrometry, and solid state 13C-nuclear magnetic resonance (NMR) spectrometry. The successive fixation of a compressed wood by the glyoxal treatment suggested the formation of cross-linkings between wood components and/or wood structures. The IR spectra showed that ester bond as well as ether bond was formed between wood components and glyoxal. The existence of linkages between glyoxal and cellulose was indicated also from the NMR spectra. The addition of glycol to the glyoxal solution was investigated from the viewpoint of stabilizing effect of the linkages. When 0.2 mole ratio of glycol was added to 5–10% glyoxal solution, weight gain and antiswelling efficiency (ASE) were largest, however the addition of excessive amount of glycol did not advance further the weight gain and ASE. When an appropriate amount of glycol was added to the impregnation solution, both weight and ASE did not largely reduce even by the repeated hot water soaking. By the treatment without glycol, the dimensional stability after water soaking was attributed to only restraint of the swelling. On the other hand, when the glycol was added, the dimensional stability was developed not only by the restraint of the swelling but also by the buckling effect.We would like to thank Associate Professor Dr. Umezawa, Wood Research Institute, Kyoto University, for his invaluable support in NMR analysis. Thanks are also due to Dr. Inoue, Wood Research Institute, Kyoto University, for his preparing the wood specimens.  相似文献   

    14.
    In order to examine the contribution of wood components to the acetylation of wood, we acetylated wood meal that had been partially delignified. The results were analyzed in terms of the reaction kinetics. The first-order rate equation was successfully adjusted to the weight gain data. The rate constant for acetylation initially increased with progress of lignin elimination and then turned to decrease; the apparent activation energy showed the reverse tendency and ranged from about 90 to 130 kJ/mol. These results suggest that lignin elimination brings not only separation of lignin but also drastic change of the chemical and/or physical structure in the residual lignin, and this affects the reactivity of wood meal as a whole. The ultimate weight gain estimated by the regression of the rate equation showed a minimum when lignin was moderately eliminated, which was explained in terms of enhanced reactivity of lignin and lower accessibility for holocellulose than predicted. The equilibrium moisture content had a maximum when lignin was moderately eliminated. This tendency is the opposite of that observed for the ultimate weight gain, and suggests that the sites for acetylation do not always correspond to those for moisture adsorption. Part of this report was presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004  相似文献   

    15.
    The distributions of boron in Japanese cedar (Cryptomeria japonica D. Don) sapwood blocks treated with aqueous or methanolic boric acid [B(OH)3] solutions were explored through Raman spectroscopy and prompt gamma-ray analysis (PGA). B(OH)3 was the sole boron species observed in Raman spectra of the wood blocks treated with either solution. Plots of weight gain of the treated wood blocks versus boron concentration in treatment solutions were found to be linear. The results indicated that the methanolic solution makes it possible to impregnate wood with much larger amounts of boron than the aqueous solution. PGA confirmed that B(OH)3 was highly enriched near the end grains of the treated wood blocks. Raman measurements suggested that boron content in the bulk of the wood block is not as large as expected from the weight gain of the treated wood blocks when an ordinary air-drying method is used. It was concluded that the aqueous solution impregnates the cell walls of wood with boron more easily than the methanolic solution. Part of this report was presented at the 55th (Kyoto, March 2005) and 56th (Akita, August 2006) Annual Meetings of the Japan Wood Research Society. This article follows the previous rapid communication “Analysis of boron in wood treated with boric acid solutions using Doppler broadening method of prompt gamma-rays.” J Wood Sci (2006) 52:279–281  相似文献   

    16.
    Acetylated wood meals of Sugi (Cryptomeria japonica D.Don) wood were prepared by mechanochemical processing using a high-speed vibration rod mill. Weight percent gain (WPG) of the acetylated wood meals ranged from 7.0 to 35.5 %. Wood–plastic composites (WPCs) containing 50 % acetylated woods were produced by an injection molding technique. The polymer matrix used was polypropylene homopolymer. Maleic anhydride-grafted polypropylene (MAPP) was also used as a compatibilizing agent. The mechanical properties of WPCs in bending and tensile tests were independent of WPG of acetylated wood meals, and the test values for WPCs containing acetylated wood meals were lower than that of unmodified wood meal. The use of MAPP increased bending and tensile strength, but no effect on bending modulus was found. An increase in WPG significantly decreased water absorbability and thickness swelling of WPCs as measured by dimensional stability tests. These results demonstrated that mechanochemical processing is a promising technique for preparing WPC material with improved dimensional stability. The future challenge is to inhibit the decreases in mechanical properties of WPCs containing acetylated wood meals.  相似文献   

    17.
    Growth and stem straightness are the two main selection criteria in the French maritime pine breeding programme. In this contribution, our objective was to study the possibility of selecting for wood density assessed at an early stage. We measured X-ray wood density, in three progeny tests, on more than 1 900 breast high increment cores. High relative expected genetic gain (from 3 to 9%) was found for wood density at mature stage. Juvenile and adult wood density estimations were well-correlated; the relative efficiency of early selection reached about 80% at 12 years old. As it would not be realistic to use the X-ray densitometer at an operational scale in a breeding programme, we tested the efficiency of using the Resistograph, an indirect method to assess wood density on live trees. High correlation between the Resistograph and density data (R 2 = 0.93 on familial data) was found, suggesting that wood density through Resistograph assessment could be soon integrated as a new selection criterion in our breeding programme.  相似文献   

    18.
    For overcoming disadvantages of wood, an esterification process was employed and tetrabromophthalic anhydride (TBPA) was used as a reactive chemical agent to prepare an esterified wood with the high dimensional stability, flame resistance, and resistance to biodegradation from water-leaching. The experimental results indicated that esterification of wood plus maleic anhydride / tetrabromophthalic anhydride / glycerol could endow wood with dimensional stability, the antiswelling efficiency during water absorption (ASEw), reduction in water absorptivity (RWA), antiswelling efficiency during moisture absorption (ASEm),moisture excluding efficiency (MEE), and oxygen index (OI) of treated wood increased with an increase in the weight percent gain(WPG). And the treated wood showed great decay resistance and resistance to water leaching, too.  相似文献   

    19.
    马尾松种子园优良无性系的选择与评价   总被引:4,自引:2,他引:4  
    通过对马尾松种子园132个无性系种子产量性状调查与木材比重测定及种子园自由授粉子代8年生生长性状调查,在统计分析、相关分析基础上采用综合评分法进行优良无性系的选择,入选率为20%。结果表明:对马尾松种子园无性系再选择,以营建改良代种子园是可行的。8年生子代材积可获得改良增益10.6%,木材比重可获得4.6%的增益,种子园单株产种量可获得增益37.5%,选择效果明显,达到提高种子园产量、增加改良增益的目的。  相似文献   

    20.
    The effects of molecular weight of PF resin on the deformation behaviour of NaClO2 treated resin-impregnated wood during compression were investigated. Blocks of Japanese cedar were subjected to 2% NaClO2 aqueous solution. This was repeated up to four times resulting in a weight loss of 28%. Treated and untreated samples were impregnated with PF resin having different molecular weight. With increasing molecular weight, weight gain and volume gain decreased for untreated PF resin-impregnated wood, while NaClO2 treated wood impregnated with high molecular weight PF resin showed almost double the weight gain compared to untreated condition. NaClO2 treatment has shown considerable potential for high compression of PF resin-impregnated wood at lower pressing pressure regardless of the molecular weight of the resin. Low to high molecular weight resin was shown to penetrate into NaClO2 treated wood as estimated by weight gain contributing to the plasticization of cell wall considerably and thus resulting in cell wall collapse at low pressing pressure. The density of NaClO2 treated wood impregnated with high molecular weight resin attained a value of over 0.8 g/cm3 which is close to the density of untreated wood impregnated with low molecular weight resin. Such compressed wood exhibited high dimensional stability after boiling for 3 h. Thus, the penetration of resin into wood contributes to highly compressed dimensional stable resin-impregnated wood at low pressing pressure.  相似文献   

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