国产丛生竹类资源与利用

合轴丛生竹是国产竹林资源重要组成部分,计有16个属160余种,其分布呈现很强的地域性和不确定性,以云南种质资源最为丰富.全国合轴丛生竹林80余万hm2,年产竹材500万t以上,主要用作制浆造纸和劈篾编织.     

“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。     

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…     

印度竹材制浆造纸

印度竹材造纸发展较早，于1951年建立了第一座竹浆厂，至19世纪50年代中叶．竹浆产量曾达到全国纸浆总产量的73．6％。虽然之后一段时间处于下降趋势，随着竹产业的变革发展，目前印度是世界上使用竹材造纸最多的国家。在该国牡竹是造纸的主要原料。全国近百个造纸厂中1／2以上是以竹子为原料。估计竹材在造纸原料中的比例为45％-60％。20世纪80年代中期竹浆产量为310万t。     

中国竹浆造纸的潜力与发展

中国竹子资源丰富，分布广泛，发展竹材制浆造纸产业，对于缓解木浆原料短缺现状具有重要意义。根据对竹浆的理化性能分析，竹材是较好的造纸原料，竹材的纤维形态及化学组成表现出较好的制浆性能，仅次于针叶木，接近于阔叶木。从竹材应用于竹浆造纸的角度，综述了竹材的物理化学性能、现行的竹浆造纸工艺、竹浆造纸设备，并就竹浆造纸的发展潜力与发展方向提出了个性化观点，以期为探索绿色、低碳、环保的竹资源利用新途径，为开发高技术含量和高附加值竹产品提供借鉴，从而促进中国竹产业可持续发展。     

竹材造纸的发展前景

随着我国纸制品市场需求的迅速扩大和天然林资源保护工程的不断深化，造纸行业产品需求与原料供应的矛盾日益突出。本文简要分析了我国造纸原料结构调整的必要性，介绍了竹材纤维的制浆造纸性能，分析了竹材造纸的优势所在，指出了在当前及今后一段时期内利用竹材造纸是调整我国纸业原料结构的有效途径。     

求购竹浆造纸机械设备

在纸浆工业中实现以竹代木,建立林纸一体化的竹浆生产基地,成为节约木材资源,减少纸浆的进口,使制浆造纸工业能持续发展的有利途径。据调查,中国80％的纸浆靠进口,中国又是竹材生产大国,如果利用竹材作为“第二木材”,在造纸工业中实现以竹代木,是中国急待解决的问题。近年来,经常有业内人士寻求关于能生产竹浆造纸的成套设备,年产在2万t左右。欢迎生产竹浆设备的企业和个人随时与本编辑部联系。     

撑绿杂交竹丰产林营造技术

撑绿杂交竹是由撑篙竹与大绿竹杂交培育出来的一种笋材两用竹子新品种,具有生长快、产量高之优点.其竹材是造纸的优良原料,竹笋味甜爽口.我们经过多年的种植和研究,总结出了一套撑绿杂交竹丰产林营造技术,造林3年后可进入盛产期,每年每公顷可产竹材45～75 t,经济效益显著.     

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…     

关于加快发展我国竹材制浆造纸的一些看法

我国木材资源匮乏，每年都要耗费大量外汇进口纸和纸浆，进口量占了我国纸和纸板产量的一半以上。竹材是制浆造纸的优质原料，充分利用我国产竹大国的优势，发展竹材制浆造纸，有利于缓解我国严重的木材供需矛盾和造纸工业的可持续发展，有利于森林资源和生态环境的保护，认为竹材制浆造纸亏本的观点是不符合实际的。当前，随着我国经济建设的快速发展和经济结构调整，竹材制浆造纸正在跨入一个大发展的新时期，需要统一认识，顺应市场发展的需要，努力建设好竹材制浆原料基地，推动我国竹材制浆造纸快速发展。     

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.