金樱子离体培养植株高效再生体系的建立

以金樱子带芽茎段为外植体, 对消毒时间、基本培养基、激素配比等方面进行了研究.结果表明:选用浓度为0.1%HgCl2消毒5 min最佳;MS作为基本培养基腋芽萌发整体效果较好,萌芽率达到62.1%;最佳腋芽诱导培养基为MS+0.5 mg/L 6-BA+0.1 mg/L NAA,萌芽率达80.28%;最佳芽增殖和继代培养基为MS+3.0 mg/L 6-BA+0.1 mg/L NAA,增殖系数可达到4.42;最适生根培养基为1/2MS+IBA 0.2 mg/L,生根率达61.34%.     

龙脑樟愈伤组织诱导及增殖研究

以龙脑樟的茎段作为外植体,进行腋芽的诱导获得无菌苗,继而腋芽小叶被用于愈伤组织的诱导并进行增殖培养。结果表明外植体适宜的灭菌方法为：0.1%升汞灭菌10 min,污染率为21.6%;腋芽小叶愈伤组织诱导最佳培养基配方为：MS＋BA 4.0 mg/L＋NAA 0.1 mg/L,诱导率可达72.7%,较佳增殖培养基组合为：MS＋BA 5.0 mg/L＋NAA 0.5 mg/L。     

虎眼万年青离体快繁体系及无糖生根培养

以虎眼万年青的叶片为外植体,对不同激素浓度的愈伤组织和不定芽的诱导情况以及再生芽的无糖培养情况进行了研究.结果表明:适于愈伤组织诱导及不定芽分化的培养基为MS+BA1.0mg/L+NAA0.1mg/L,适宜的继代培养基为MS+BA0.5mg/L+NAA0.1mg/L;用无糖培养体系进行生根培养时,基质中NAA浓度为0.1mg/L时,再生芽的生根率达94%,种苗质量优于常规组培.     

牡丹组培快繁技术研究

以牡丹的当年生茎尖为外植体进行簇生芽诱导,对牡丹的快繁技术进行改良研究。结果表明,诱导簇生芽时,在MS 6-BA2.0mg/L NAA0.2mg/L 200mg水解乳蛋白培养基上的诱导效果较好,分化率达100%;继代培养时,以MS 6-BA1.0mg/L KT0.5mg/L NAA0.1mg/L 200mg水解乳蛋白培养基的增殖倍数最高,达11.8倍;再生苗在1/2MS NAA0.1mg/L 200mg水解乳蛋白培养基上生长良好;在炼苗中,移栽基质以蛭石 草炭土较好,其有助于小苗的后期生长。     

野生柱穗醉鱼草嫩芽的组培技术研究

以野生柱穗醉鱼草的嫩芽为外植体,分诱导培养,茎芽增殖,继代培养,生根培养4个阶段进行其组培技术研究,结果表明:外植体消毒用0.1%升汞液浸泡7 min效果较好;最佳的诱导培养基是MS 6-BA 0.5 mg/L NAA0.02 mg/L;茎芽增殖培养基是MS 6-BA 0.5 mg/L NAA0.02 mg/L;继代培养基是MS 6-BA 0.5 mg/L;生根培养基是MS 6-BA 0.5 mg/L NAA 0.02 mg/L AC 0.3%。     

神仙草组织培养快繁技术的研究

以神仙草的茎段和叶片为外植体,研究神仙草在添加了不同的激素成分及不同浓度的培养基中对不定芽诱导、继代增殖和生根培养的影响,结果表明:初代培养的适宜培养基是MS+BA 1.0 mg/L+NAA 0.1 mg/L;继代增殖适宜培养基是:MS+BA 2.0 mg/L+NAA 0.1 mg/L;生根适宜培养基是:1/2MS+NAA 1.0mg/L。     

俄罗斯耐寒蓝靛果忍冬组织培养技术研究

以俄罗斯耐寒蓝靛果忍冬的腋芽为外植体,诱导腋芽分化及增殖的最佳培养基是1/2MS+NAA 0.1mg/L+6-BA 1.0 mg/L,增殖系数可达7.4;最佳生根培养基为WPM+NAA 0.5 mg/L,生根率能够达到100%。     

玫瑰海棠的组织培养

以玫瑰海棠的幼嫩组织作外植体,在含不同植物激素的培养基上进行丛生芽的诱导、芽的继代增殖、芽生根与移栽研究,以快速获得再生植株.结果表明,丛生芽诱导培养基以MS＋6-BA 1.5 mg/L＋NAA 0.1 mg/L较好,诱导系数达12;增殖培养基以MS＋6-BA1.5 mg/L＋IAA 0.1 mg/L较好,增殖系数达11.3,且增殖芽生长好;生根培养基以1/2MS＋NAA 0.5 mg/L为最佳,生根率达100%,幼苗生长势旺.     

水栀子的组织培养和快速繁殖

以水栀子茎切段为外植体,进行植株再生和快速繁殖研究。结果表明在以MS BA3mg/L NAA0.4mg/L的培养基上,不定芽诱导效果较好,分化率达100%;增殖培养时,在MS BA1mg/L IAA0.2mg/L GA30.3mg/L的培养基上效果较好;再生苗在1/2MS IAA(0.1～0.5)mg/L的培养基上生根效果较好。     

大别山冬青苗木的组织培养

以大别山冬青带腋芽幼嫩茎段为外植体,研究大别山冬青组织培养中外植体选择、芽的诱导、继代增殖和生根诱导技术.结果表明:大别山冬青的最适外植体来自1年生扦插苗的腋芽.运用正交试验筛选出大别山冬青腋芽诱导的培养基为MS+6-BA 0.5mg/L+KT0.05 mg/L+NAA 0.05 mg/L+GA 30.1 mg/L,腋芽萌发速度快,萌发率高;继代增殖培养基为MS+6-BA 0.3g/L+NAA 0.02 mg/L+GA 30.3 mg/L,增殖系数达5.78;生根培养基为1/2MS+0.2 mg/L 6-BA+0.4mg/L IBA.     

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.