3种棕榈藤藤材防变色的研究

目前,棕榈藤(rattan)主要用作家具、工艺品,其产品具有很高的商品价值.藤制品在使用过程中色调逐渐加深(变色),尽管变色对材质材性影响不大,但对色调有损伤,直接影响制品的外观,降低商品价值.因此,抑制藤材的变色对保持产品外观和商品价值具有重要意义.     

印度尼西亚为棕榈藤主要出口国

2008年,印尼棕榈藤贸易占全球市场份额的80%,其中藤材和藤家具出口位居世界首位,藤垫、藤席及其他藤编织物的出口仅次于中国居全球第二位。印尼棕榈藤出口贸易的首要目的地是     

我国推荐性林业行业标准《棕榈藤藤材缺陷》

藤材缺陷标准的制定是制定藤材分等规则的基础,也是建立藤材质量评价标准体系的第一步,对于规范棕榈藤市场,提高藤材使用价值,有效保护棕榈藤资源等具有十分重要的意义。本文首先对国内外现有棕榈藤材标准编制情况进行了简要综述,基于我国多年来的棕榈藤材相关研究成果和技术,制定了我国推荐性林业行业标准——棕榈藤藤材缺陷。该标准规定了棕榈藤材缺陷的分类、定义、术语和图谱,适用于棕榈藤材在生产实践中的各种可见缺陷。     

世界棕榈藤引种驯化进展

棕榈藤是热带和南亚热带地区重要的非木材产品,用途广泛,可编织、食用、作家具,特别是藤家具在国际市场上很受欢迎,但藤工业所需的原材料正面临着短缺的危险。至今藤家具工业的用藤主要来自于天然棕榈藤资源,由于过度采收和热带森林的破坏,天然棕榈藤资源日益锐减,使棕榈藤生物多样性受到严重侵蚀并威胁到棕榈藤家具工业。文中提出棕榈藤引种驯化对天然棕榈藤资源的保护和藤家具工业的发展具有重要意义,并分别介绍了印度尼西亚、马来西亚、菲律宾、印度、孟加拉国、斯里兰卡和中国等主要产藤国和其它一些国家的棕榈藤引种驯化历史,最后阐述了棕榈藤引种驯化在保护棕榈藤资源和发展棕榈藤家具工业中的作用。     

木、竹、藤材的变色防治

对木材变色的机理、类型、成分和影响因素, 木材变色的预防和消除以及生物防治等研究的最新成果进行了概括总结, 综合论述了木材、竹材和藤材的变色防治研究现状, 得出以下几点结论:(1)低毒或无毒、高效、多功能的防变色剂的研制开发仍是木材工业变色防治研究的重要研究方向。(2)开展色变脱除, 恢复已变色材原有颜色和价值方面的研究很有必要。(3)以菌治菌的生物防治, 污染小, 成本低, 应加强其理论研究和实践应用。(4)通过热处理或光辐射等手段, 诱导木、竹、藤材变色, 进行调色处理, 将成为新的研究方向。(5)与木材相比, 竹材、藤材变色的研究落后, 尤其是藤材变色, 应得到进一步加强。     

中国大陆藤工业现状及发展对策

通过实地调研和资料收集,综合分析了我国大陆藤工业的发展现状。分析认为,近年来我国大陆藤工业持续低迷,出口额和国内市场逐年下降,藤企业处境艰难,其主要原因包括发达国家的经济危机、东南亚产藤国的竞争、国内房地产调控政策以及劳动力成本上涨等。建议我国积极开发藤材替代品,摆脱对藤材的高度依赖性,同时发展同印度尼西亚的双边关系,争取更多藤材进口。     

3种棕榈藤藤材的化学组成

棕榈藤加工业在我国区域经济中的重要性已为人所知(许煌灿等,1999).近20年来,我国对棕榈藤从天然分布及利用(许煌灿等,1993)、种质资源收集保存和引种驯化(尹光天等,1993)、组培栽培技术(许煌灿等,1984;1994b;张方秋,1993)、生态生物学特性(许煌灿等,1994a;尹光天等,1998)到藤茎解剖学特性(林文豹,1983;蔡则谟,1994;腰希申等,1998)都做了大量的研究工作.通过研究,掌握了我国棕榈藤资源及其分布、用途、生物学特性、生长环境、资源储量和产量,建立了多个棕榈藤藤种园,研制出多个藤种的组培技术.     

3种棕榈藤叶片叶绿素荧光特征分析研究

棕榈藤作为热带、亚热带植物中重要的森林资源,优质的藤材是重要的加工利用材料,具有重要的经济价值。叶片光合能力对藤材的形成具有重要影响,利用叶绿素荧光仪测定黄藤(Daemonorops jenkinsiana)、大白藤(Calamus faberii)、小白藤(C.balansaeanus)的叶绿素荧光参数,为研究逆境条件下棕榈藤的光合能力和选择适宜的栽培条件提供参考。结果表明,在实验室条件下3种棕榈藤的光系统Ⅰ(PSⅠ)实际光量子效率Y(Ⅰ)为小白藤 > 大白藤 > 黄藤,光系统Ⅱ(PSⅡ)的Y(Ⅱ)为大白藤 > 黄藤 > 小白藤;非光化学猝灭系数qN由高到低依次为大白藤、黄藤和小白藤;而光化学猝灭系数qP则是小白藤最高,黄藤次之,大白藤最低;PSⅠ的电子传递效率ETR(Ⅰ)是小白藤 > 大白藤 > 黄藤,而PSⅡ的ETR(Ⅱ)值则是小白藤 > 黄藤 > 大白藤;PSⅡ最大光量子产量F_v/F_m维持在0.78~0.8范围内,且大白藤显著高于黄藤和小白藤(P < 0.05)。由此可见,在实验室条件下小白藤的光合效率在这3种藤中最高,其次为黄藤,大白藤最低;且光保护能力为大白藤最高,黄藤次之,小白藤最低。     

越南是欧盟藤家具和藤编织品的供应国

2008年,越南出口藤家具量的80%和藤编织品量的近50%供应给欧盟市场（主要是德国和法国）,出口值达4500万美元。同年,越南出口的藤产品消耗藤材约2.1万t。     

现代藤家具加工工艺

合理的加工工艺,是保证产品质量,提高生产效率的重要条件。当然,正确的工艺是建立在对结构深入透析的基础之上。笔者以现代藤家具的加工为切人点,研究探讨其加工工艺技术。1藤材的制备(藤皮、藤芯)原藤的加工处理,通常由藤料加工厂完成,然后发     

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.