双循环新格局视角下我国木质人造板高质量发展路径研究北大核心

根据2001-2021年我国木质人造板产量、进出口贸易等数据,利用对外依存度等指标,考察我国木质胶合板、纤维板、刨花板双循环的状况,寻求木质人造板高质量发展的路径。结果显示:胶合板国内、国际市场发展空间受限,亟待转型升级;纤维板国内、国际市场双萎缩,提高产品质量是其高质量发展的关键;增加产量以满足国内需求和开拓国际市场,是构建刨花板双循环新格局的重点。最后探讨了我国木质人造板高质量发展的核心问题。     

我国人造板行业的稳步发展及调整升级

总结我国人造板行业近10年的发展状况,解析我国现行林业产业发展相关国家政策,特别是人造板生产、进出口、原料林基地建设投融资等政策,指出:当前我国人造板行业正处于稳步发展的关键时期,国家为林业产业的发展制定了扶持政策,企业应抓住机遇,改变单纯重视加工制造的思维定势,坚持技术创新,加快结构调整、装备升级和营销网络建设,提高品牌创建能力,加快在全球价值链上的升级,从人造板生产大国转变为人造板增值产品制造强国.     

木质人造板产品质量安全风险及评估方法初探

分析我国木质人造板产品质量安全现状,说明进行木质人造板产品质量安全风险评估的必要性;借鉴风险评估的基本原理和程序,结合木质人造板产品的具体情况,明确木质人造板产品生产及使用过程中的主要风险及其来源,并对我国木质人造板产品质量安全风险评估方法和步骤进行探讨。     

中国木质林产品贸易发展问题与对策

近年来,随着相关自贸区协定的签署,我国木质林产品国际贸易迎来了市场机遇,然而部分国家进出口关税的增加,也使我国木质林产品贸易面临挑战。我国木质林产品进出口贸易量世界第一,然而原料进口价格的不稳定性,出口产品附加值不高,仍是亟需解决的问题。在此大背景下,我国木质林产品贸易的发展水平有待进一步提高。概述了我国木质林产品贸易规模,分析了制约我国木质林产品贸易发展的不利条件,提出了优化我国木质林产品贸易的措施。     

我国人造板工业生产、贸易现状与展望

通过回顾近年我国人造板工业发展历程,分析了人造板用途以及生产、进出口贸易现状.针对受金融危机影响、用材资源受制约、以及非关税贸易壁垒等问题,提出应加强技术创新、质量环保意识,进一步细分市场和企业整合,增加政策扶持,在危机中实现我国从人造板大国到人造板强国的转变.     

中国木质家具对外贸易现状及问题分析

以木质家具为分析视角,在概述其生产现状的基础上,分别从总量、结构和来源上重点分析了中国木质家具进出口贸易现状;最后,立足于木质家具贸易的发展状况,指出其存在的主要问题并进行了对策分析。     

中国木质能源进出口贸易特征分析

依据联合国贸易数据库2003～2012年10年的进出口数据,分析了中国的薪材、木炭、木片或木粒、木质剩余物4种主要木质能源进出口贸易情况。中国木质能源进出口贸易呈现以进口为主的规模特征,贸易规模不断扩大,10年来中国木质能源的进口量年平均增长达到37％;中国木质能源的进出口市场结构存在一定的差异,进口来源国以发展中国家为主,而出口市场集中于发达国家。探讨了中国木质能源净进口趋势的原因,特别是木片或木粒的净进口原因及其负面影响,并指出了提高木质能源的利用率是产业发展的重点和难点。     

废弃木质材料回收利用方式的分析

1废弃木质材料回收利用的现实意义随着我国建筑业和房地产业的迅速发展,木材消费市场也在大幅度增长。到2010年底,我国人造板产量已达15 360.83万m~3;据国家统计局统计,到2011年底,人造板的总产量已超过2亿m~3。随之而来的便是作为生产生活所需的木制品与日俱增,因此废弃木质材     

GB/T 35601-2017《绿色产品评价 人造板和木质地板》解读

对目前林业行业唯一的GB/T35601-2017《绿色产品评价人造板和木质地板》标准的编制原则、主要内容进行解读。该标准的颁布实施,对促进我国人造板和木质地板产业转型升级、引领绿色消费和扩大绿色产品贸易的意义重大。     

关于召开第二届广州国际木材、人造板产业进出口贸易洽谈会的通知

<正>为整合国内外木材资源,缓解我国木材供需矛盾,拉动内需,拓展人造板及木制品国际市场;加强世界木材与人造板贸易信息交流与业务合作,与全球行业权威专家强强对话;搭建商务洽谈和信息交流平台,给木业供销企业提供更广阔的贸易空间。中国林产工业协会将于"2015第四届广州国际木业展"期间举办"第二届广州国际木材、人造板产业进出口贸易洽谈会"(以下简称"广洽会")。会议时间为2015年5月9~10日,会议地点在中国进出口商品交易会(广交会展馆)。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.