行业内外

“全国林纸一体化工程建设”目标确定“全国林纸一体化工程建设”具体目标为:“十五”期间,全国新增制浆生产能力280万t,(其中木浆生产能力210万t,竹浆生产能力70万t),造纸生产能力330万t,造纸林基地200万hm2(其中木材基地176万hm2,竹材基地24万hm2)。木浆新增能力180万t,竹浆60万t,纸及纸板300万t,基地可产木材1000万m3、竹材400万t,实现造纸工业用材由靠商品材供应向造纸林基地供应逐步过渡。2005年我国纸及纸板消费预测总量为5000万t,木浆比重要达到25%。其中国产木浆比重达到10%,产量达380万t,要增加木浆产量180万t,相应木材需求量为190…     

“全国林纸一体化工程建设”目标确定

“全国林纸一体化工程建设”具体目标为：“十五”期间，全国新增制浆生产能力280万t，(其中木浆生产能力210万t，竹浆生产能力70万t)，造纸生产能力330万t，造纸林基地200万hm^2(其中木材基地176万hm^2．竹材基地24万hm^2)。木浆新增能力180万t，竹浆60万t，纸及纸板300万t，基地可产木材1000万m^3、竹材400万t，实现造纸工业用材由靠商品材供应向造纸林基地供应逐步过渡。     

优化产业区域布局 实现公司、基地、农户三方共赢

杨树木材是优质的木浆造纸原料。目前木浆造纸原料缺乏,市场容量极大。据中国制浆造纸工业部门的行业规划和预测,中国2000年纸和纸浆总消耗量达3400万吨,其中木浆造纸比重为18%;2010年将达到5000万吨,其中木浆造纸比重为22%;木浆进口由2000年的4.8%下降到2010年的1.1%。因此,林     

关于木片造纸问题的调查

一、我国造纸情况我国纸的品种较多,但其原料主要分为木材纤维和非木材纤维两类。近年来,制浆造纸工业逐步重视木材纤维造纸,对木材原料的需要量已日益增多。我国1981年生产的纸浆中,草浆约占58%,木浆和生打浆(废纸浆)约各占21l%。普通纸、中档纸及一般包装纸板以草类原料为主,而一些工业和文化用纸由于对纸的质量要求较高,历年     

美国市场纸、纸板和纸浆的生产能力小幅下降

美国：林纸协会（AF＆PA）3月30日发布的《纸、纸板和纸浆生产能力第52次年度调查》指出,美国2011年的纸和纸板生产能力为8970万t,同比下降了1．4％。这个降幅略小于2010年的降幅（3．1％）。2012年,纸和纸板的总生产能力预计还会下降1．0％,2013年和2014年预计将分别下降0．6％和0．5％。     

中国林产品化学利用概况

林产品化学利用是指以木质和非木质林产品为原料,经化学加工制备国民经济所需的各种产品.主要包括木材制浆造纸、木质活性炭、松脂化学加工、植物单宁、林产精油、植物提取物等.近年来中国林产化学工业发展较快,特别是建设林纸一体化工程,为发展木材制浆工业,改变中国制浆造纸工业原料结构创造了良好的条件,按计划2005年木浆产量将达380万t,2010年达750万t.松香产量已超过50万t/a,出口约30万t/a.木质活性炭产量达6万t/a.随着我国经济的发展对林化产品的需求将进一步扩大.     

发展竹浆造纸 节约木材资源

随着社会经济水平的发展,中国纸及纸板的现有产品结构已不适应纸张消费市场的变化与发展,加剧了国内市场对进口纸及纸板的依赖性。竹材纤维细长,是制浆造纸的优质原料。竹浆纸的开发有利于节约木材资源,有利于环境保护。中国竹资源丰富,发展竹浆造纸的市场前景非常广阔。因此,在造纸工业中实现以竹代木,建立林纸一体化的竹浆生产基地,将成为节约木材资源,减少纸及纸浆的进口,使制浆造纸工业得以持续发展的有利途径。     

综合利用“三剩” 大力发展木片生产

目前,我国的纸和纸板的产量、品种和质量都不能满足社会要求,每年要进口纸、纸浆和纸板100万吨以上。究其根源主要是木质纤维原料短缺造成的,因为我国现在每年每人平均木材消耗量只有0.2立方米,拿不出更多的木材用于造纸工业。要想改变造纸工业的落后状况,只能走“林纸结合”的道路。而造纸用的原料主要是靠从“采伐剩佘物”中制取工业木片,作为造纸浆的木质纤维原料。 如果把小头直径4厘米以上、长     

纸浆竹林集约栽培技术

纸在生产建设和人民生活中都有着广泛的用途。据统计 2 0 0 2年全国纸和纸板产量 3470× 10 4 t,同年进口纸和纸板以及纸浆、纸制品、废纸合计 1874 .5 8× 10 4 t,占到全国纸和纸板总产量的 5 4% ,耗费大量外汇并影响到了国民经济的安全性和稳定性。我国又是一个木材资源匮乏的国家 ,发展造纸业举步维艰。竹材是除针叶材外的制浆造纸优质原料 ,适宜制造各种中高档纸张。我国是一个竹子生产大国 ,竹林相对于其它林木具有产量高、砍伐周期短和适宜永续经营等优势。发展我国的竹材制浆造纸 ,有利于缓解我国严重的木材供需矛盾 ,实现造纸工业的…     

中国林产品化学利用概况

林产品化学利用是指以木质和非木质林产品为原料．经化学加工制备国民经济所需的各种产品。主要包括木材制浆造纸、木质活性炭、松脂化学加工、植物单宁、林产精油、植物提取物等。近年来中国林产化学工业发展较快，特别是建设林纸一体化工程．为发展木材制浆工业，改变中国制浆造纸工业原料结构创造了良好的条件，按计划2005年木浆产量将达380万t,2010年达750万t。松香产量已超过50万t／a，出口约30万t／a。木质活性炭产量达6万t／a。随着我国经济的发展对林化产品的需求将进一步扩大。     

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.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

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。     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Growth of Mixed Birch-Coniferous Stands in Relation to Pure Coniferous Stands at Similar Sites in South-eastern Norway

Mean age, mean and top heights and yield were studied in 20 mixed stands of birch ( Betula pubescens Ehrh. and B. pendula Roth) and Picea abies (L.) Karst. and nine mixed stands of birch and Pinus sylvestris L. in south-eastern Norway. Each mixed stand and the adjacent pure coniferous stand (control) were growing under the same site conditions and had not been commercially thinned. There were no significant differences in mean age at breast height or in top heights between birch and conifers in the mixed stands, while mean height was significantly higher for birch than for spruce. A growth index was calculated based on total volume and age at breast height. For the spruce sites the growth in young mixed stands (birch < 17 m) was superior to that of pure spruce, while the difference was insignificant in older stands. The growth index correlated positively with the ratio between generatively and vegetatively regenerated birch trees, and negatively with the age of the oldest species in the mixture and with site quality. For the pine sites there was no significant difference in the growth index between mixed birch-pine and pure pine stands. A mixture effect of birch on the volume yield of spruce or pine could not be demonstrated.     

Defoliation by the Needle-shortening Pine Gall Midge,Thecodiplosis brachyntera,on Pines in Central Sweden

An outbreak of the needle-shortening pine gall midge, Thecodiplosis brachyntera , occurred on Scots pine, Pinus sylvestris (L.) and lodgepole pine, P. contorta (Dougl.) in central Sweden during 1995-1998. The larval feeding of T. brachyntera kills current-year needles and heavy infestation causes severe defoliation. A pattern of fluctuating defoliation among years and sites was found on both pine species. Defoliation was evenly distributed in the crown of P. sylvestris during years of high as well as low infestation; apical whorls had as much defoliation as basal whorls. In P. contorta , however, there was a tendency for defoliation to be concentrated on branches in the most apical whorls. Growth ring increments on P. sylvestris with high levels of defoliation (71%) did not differ from trees with moderate levels (26%) of defoliation. Shoot lengths were significantly shorter, however, on heavily infested trees the year after defoliation.