北美红杉组培苗工厂化育苗技术

阐述北美红杉组培苗的工厂化育苗技术。以萌生条茎段为材料，采用多菌灵、新洁而敏、升汞等药剂处理外植体，以降低污染率；采用以芽繁芽的方式进行试管增殖，从而减少变异；通过壮芽及生根培养，获取大量适宜生根的试管苗；试管苗移植2～3年后，以便进一步培育北美红杉扦插苗，并为生产部门提供大量优质的穗条。     

激素对菊花组织培养的影响

以菊花花瓣为外植体,研究了不同浓度的6-BA和NAA对愈伤组织诱导和分化的影响,实验结果表明:菊花花瓣诱导培养适宜的培养基为MS+1.0mg/L 6-BA+0.3mg/L NAA;分化培养最佳培养基为MS+1.5mg/L 6-BA+0.05mg/L NAA;无菌苗接种到生根培养基MS+0.3mg/L NAA中,植株的生根情况较好,生根率为100%。     

菊花组织培养中的光质效应研究

光质在菊花培养过程中具显著的生物学效应。试验表明,绿色光可促进菊花试管苗的生长,绿色、红色、蓝色光能部分解除60Co γ射线照射试管苗后所产生的抑制生长作用,红色光有利于花瓣愈伤组织的形成。菊花在组织培养过程中的光质效应,尚与品种有关,表明品种间存在光质敏感性的差异。     

蓝花楹组培技术研究

以蓝花楹实生苗茎尖作为外植体的组培技术研究结果表明,其组培中的启动培养基宜为MS 6-BA1.0 mg/L NAA0.2 mg/L;增殖培养基宜为MS 6-BA2.0 mg/L NAA0.4 mg/L或MS 6-BA2.0 mg/L NAA0.5 mg/L;生根培养基宜为1/2 MS NAA0.5 mg/L.其试管苗适宜的移栽基质为营养土 蛭石(比例1:1),移栽成活率为55.10 %.有利于其试管苗增殖的光照条件为3 000 lx.继代次数对其试管苗的增殖和生根均有影响,而适宜转向生根培养的继代数最少为9代.     

库拉索芦荟组织培养技术研究

以美国库拉索芦荟初接种试管苗为材料,MS为基本培养基,研究了不同配方培养基对库拉索芦荟试管苗生长的影响,筛选出了适宜于库拉索芦荟试管苗生长的培养基,结果表明：继代培养基中,BA浓度以2．0～3．0mg·L^-1、蔗糖浓度以3％为宜,继代培养基以MS＋BA3．0mg·L^-1＋NAA0．5mg·L^-1为最佳,茅增殖系数为5．2;生根培养中,NAA激素对试管苗生根率和生根数都有极显著的影响,生根培养基以MS＋NAA0．5mg·L^-1为最佳,生根率达100％,平均生根数6．3条;试管苗炼苗3—7d后移栽到营养土：沙土=3：1的基质上,移栽成活率可达70％以上。     

北美红杉组培苗工厂化育苗技术

阐述北美红杉组培苗的工厂化育苗技术。以萌生条茎段为材料,采用多菌灵、新洁而敏、升汞等药剂处理外植体,以降低污染率;采用以芽繁芽的方式进行试管增殖,从而减少变异;通过壮芽及生根培养,获取大量适宜生根的试管苗;试管苗移植2～3年后,以便进一步培育北美红杉扦插苗,并为生产部门提供大量优质的穗条。     

杜鹃花组织培养技术研究

杜鹃花组织培养，基本培养基宜选用Andersson改良MS培养基，外植体材料灭菌剂选用氧化性较低的饱和次氯酸钙上清液或5％次氯酸钠溶液。细胞分裂素以ZT的诱芽效应较为显著：初始培养时在培养基中加入ZT5mg／L NAA0．1mg／L，增殖培养时在培养基中加入ZT5mg／L NAA0．1mg／L效果均佳。培养周期以45d为宜。在生根培养基中添加2g／L的活性炭，有利于试管苗生根，培养周期30d。试管苗移栽基质以泥炭土 珍珠岩(或蛭石)，按1：1混合为好。     

柽柳的组织培养研究

以野生耐盐变异柽柳植株的萌动芽为材料,进行了不同植物生长调节剂及浓度对萌动芽生长、生长芽分化、不定芽生根的影响及试管苗的移栽、扦插、移植试验,成功建立了耐盐野生变异柽柳植株的无性系。结果表明:MS+BA 0.1 mg.L-1+GA 0.5 mg.L-1+IAA 0.2 mg.L-1是暗培养条件下培养芽生长的理想培养基;MS+AgNO31.0 mg.L-1+BA 1.0mg.L-1+NAA 0.1 mg.L-1是不定芽分化培养的理想培养基;1/2MS+IAA 0.4 mg.L-1是试管苗生根培养的理想培养基;移植到海边沙滩上的试管苗保持了耐盐变异性状,并且生长旺盛,根系发达。     

不同固化物对中华猕猴桃胚乳试管苗生根的影响

用蛭石、河沙、珍珠岩、琼脂培养其诱导中华猕猴桃胚乳试管苗产生根。试验结果表明，以蛭石诱导的试管苗生根最快，生根率达９２％，其次是珍珠岩达７３％。由此，缩短了试管苗移植土壤的时间。     

核桃试管苗生根培养的研究

以新疆绵核桃为试材,对继代培养无根试管苗的生根进行了研究.结果表明：生根诱导方法、外源IBA水平及IBA处理时间、光周期以及试管苗发育状态等均对不定根发生具有明显影响.选取生长旺盛、节间较长,叶片嫩绿的幼态苗,采用间接诱导生根法,即用50～80 mg/L IBA浸渍处理试管苗基部60～90 min,然后转至不含生长调节物质的1/2 DKW培养基,先黑暗诱导14 d,再在16 h/d光照下培养,可诱导试管苗生根率达60%以上.     

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.