重组竹材模拟室外防霉性能的研究

利用不同防霉剂处理重组竹材后模拟室外霉变试验,分析了不同浓度不同防霉剂处理后重组竹材的吸药量,对重组竹材模拟室外防霉试验后的防治效力进行了评价。结果表明:同一浸渍时间条件下,重组竹材的吸药量随防霉剂浓度的增加而逐渐增大,尤其当浓度到达0.7%时,吸药量有大幅度提升,不同的药剂浓度对重组竹材的吸药量影响显著;经同一浓度的ZJFC-I防霉剂处理后,ZJFC-I、ZJFC-I+名饰及ZJFC-I+欧诗木,均随着霉变时间的增加,霉变等级而随之升高;经不同浓度的ZJFC-I防霉剂处理后,在同一时期内,ZJFC-I、ZJFC-I+名饰及ZJFC-I+欧诗木均随着浓度的增加,霉变等级而随之降低,且浓度越高,降低程度越大;不论室内还是室外防霉试验,先用水性防霉剂浸渍重组材,再在其表面均匀刷涂一层油性防霉剂或保护剂,防霉效果均优于其他处理工艺。     

几种防霉剂对丛生竹防霉效果研究

采用4种不同防霉剂(CCA/SMR、DDAC/IPBC、NCM/IPBC和NCM)对丛生竹梁山慈竹进行防霉处理,研究了防霉剂种类、防霉处理工艺对竹材防霉效果的影响,同时对3种防霉效果检测方法包括实验室培养皿法、野外遮荫法和野外暴露法进行了对比。研究结果表明,本试验条件下CCA/SMR和NCM防霉剂的防霉效果约为2个月,使用浓度分别为1.5%/0.3%和5.0%,可用于竹材贮存、运输、加工过程中的防霉;混合防霉剂DDAC/IPBC和NCM/IPBC的防霉效果更好,可考虑用于竹制品使用过程中的防霉;采用加压处理工艺的竹材,其防霉效果明显优于浸泡处理工艺;3种防霉效果测试方法得出的处理竹材的防霉结果基本一致,但测试的侧重点、针对的霉菌种类和环境影响因素有所不同。对于户外用竹制品防霉效果的测试,以野外暴露测试为主;室内用竹制品或竹材贮运过程中的防霉效果的测试,以实验室培养皿和野外遮荫法测试为主。     

竹材防霉染色处理的初步研究

以铜化物、硼化物、新洁尔灭的质量分数为因素,按正交试验方案组成不同配比的复合防霉药剂,分别加入到质量分数为1%的酸性染料溶液中,在一定温度下对竹材进行防霉染色处理;同时测定防霉染色处理竹材与染色处理竹材的色度指数,并评价其变化.结果表明:将该复合防霉剂与酸性大红染液复配,不仅能提高染色竹材的防霉性,而且防霉剂的配比对竹材的染色效果基本无影响.     

竹材的防霉试验研究报告

本研究根据竹材防霉效力值,试验五种配方对竹材的防霉效果。结果:0.1％MBT和0.5％DP的防霉效果不次于2.5％BP(主剂为Na-PCP),尤其是MBT,使用浓度较低,高效,有可能代替氯酚类防霉剂;0.5％苯菌灵和3.0％季胺盐化合物的防霉效果较差,建议可用作竹材的短期防霉。     

DP防霉剂对竹材防霉效果的研究

DP防霉剂是近年新开发的高效低毒的药剂,经对竹材防霉效果的试验,采用DP水溶液具有较好的防霉效果,药液使用浓度以0.5—1.0％为佳,浸渍处理时间以1—3小时以上为宜。根据试验结果,DP防霉剂在竹材防霉方面有希望代替目前使用面较广而毒性较大的五氯酚钠。     

无机复配防霉剂对木竹材性能的影响

为获得低成本、低毒环保、工艺简便且高性能的木竹材防霉剂,采用无机试剂硫酸铜、硼酸及双氧水复配防霉剂,对杨木和毛竹材进行浸渍处理,并考察其防霉功效,同时探究试剂对木竹材物理力学性能的影响,结果表明:浓度为1%硫酸铜、1.5%硼酸与6%双氧水复配的无机试剂抑菌效果较好,且对杨木及毛竹17 d的防治效力达到100%;复配防霉剂对试材的物理力学性能影响不大,但会导致试材表面色差增加。研究结论为低毒无机木竹材防霉剂的开发和应用提供基础理论依据。     

八种防霉剂对橡胶木和竹材霉菌及蓝变菌的毒性试验

霉菌和蓝变菌是橡胶木和竹材变质的主要原因之一。八种防霉荆对上述木竹材霉菌及蓝变菌的毒性试验结果表明：祛霉乐防霉剂对霉菌的最低抑制浓度为２～１０ＰＰｍ，和ＭＥＣＴ相当，对蓝变菌有特效，防治橡胶木或竹材霉菌和蓝变菌的最低有效浓度为０．２％，可替代五氯酚钠和进口防霉剂。     

竹材霉变与防霉处理

本文介绍了竹材霉变及防霉作用机理,主要防霉剂及其选择与使用方法,防霉效果评价方法与影响防霉效果的主要因素及今后的研究方向。     

户外用竹材重组材防霉性能研究

采用竹束浸渍、重组竹材浸渍及直接涂刷三种处理,对比分析同等浓度不同药剂及处理方式对重组竹材的霉腐防治效力。结果表明:华科-108强力杀菌防霉剂和ZJFC-I型水剂防霉剂都具有良好的霉菌抑制效果。而氟酚合剂、硼酚合剂,对试验霉菌具有一定的抑制效果,防治效力中等;3种水性防霉剂采用竹束浸渍处理和竹重组材浸渍处理后,防霉效果差异显著。对竹重组材进行防霉处理的效果显著优于对其制造单元(竹束)进行防霉处理。使用扫描电子显微镜(SEM)和傅立叶红外光谱仪(FTIR)对霉变前后毛竹重组材的解剖结构和化学组成进行观察和分析,结果发现竹重组材未经防霉处理,纤维素、半纤维素、木质素均发生不同程度的降解,纤维素和半纤维素降解程度较大,振动趋势有明显改变,说明竹材易发生霉变。而经过ZJFC-I和华科-108防霉处理后的竹材,降解程度稍弱,说明经过这两种防霉剂处理对三大素的降解具有一定的抑制作用。     

竹材防霉剂筛选试验

本试验以毛竹为试材,对九种防霉剂进行筛选试验,筛选出四种高效低浓度防霉剂,它们是:75号工业防霉剂、DP防霉剂、硼酚合剂与氟酚合剂。防霉效果稍次的有三种:甲基托布津、多菌灵、福美双、使用浓度稍高于1%。防霉效果欠佳的有杜香油与新洁尔灭硼化合剂。     

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.