苹果枣组培快繁技术研究

以ＭＳ为基本培养基，取苹果枣萌蘖苗茎段作外植体进行离体快繁研究，筛选出最佳分化培养基的激素配比是６－ＢＡ６．０ｍｇ／Ｌ＋ＮＡＡ０．１ｍｇ／Ｌ，生根培养基ＩＢＡ用量以０．６ｍｇ／Ｌ较好。试管苗繁殖系数达６．２，生根率达９１．６％，移栽成活度达９８％。     

樱桃矮化砧木SD——13组培快繁技术研究

利用ＳＤ－１３樱桃矮化砧木的嫩茎梢作为外植体，进行离体培养，研究出其生长分化的基本培养其为ＭＳ，最佳分化培养基为ＭＳ＋ＢＡ０．６ｍｇ／Ｌ＋ＮＡＡ０．０５ｍｇ／Ｌ，分化率达９４％，最佳生根培养基为１／２ＭＳ＋ＮＡＡ０．０４ｍｇ／Ｌ，生根率达９２％，移栽成活率达９５％。     

乌克兰大樱桃的组培快繁试验

对引进的乌克兰大樱桃以早春刚萌动未展叶的饱满芽，或刚抽生的嫩茎为外植体进行组培快繁试验，筛选出适宜的分化培养基为ＭＳ＋ＢＡ１．５＋ＩＡＡ０．３＋ＧＡ０．５，增殖培养基为３／４ＭＳ＋ＢＡ１．０＋ＩＡＡ０．５和生根培养基为１／２ＭＳ＋ＩＢＡ０．２＋ＮＡＡ０．１。研究了植物激素对试管苗芽的萌动，分化，增殖，生根的影响，选择合适的移栽基质，成活率在９０％以上。     

马尾松离体培养条件下的微繁殖和菌根的形成*

以马尾松种胚作外植体进行不定芽诱导。基本培养基的种类对外植体不定芽的诱导起着决定性的作用，在ＧＤ附加２．０ｍｇ／ＬＢＡ的培养基上，外植体不定芽诱导率达７０％以上。ＩＡＡ或ＮＡＡ的加入不利于外植体不定芽的诱导。在不定芽生长培养基中，加入适量的ＩＢＡ能促进不定芽的伸长生长。伸长至０．５ｃｍ以上的嫩枝在１／２ＧＤ附加４．０ｍｇ／ＬＩＢＡ的培养基上，生根状况良好。生根后的小植株，在１／２ＧＤ培养基上接种Ｒｔ４９菌根真菌，菌丝侵染进入根部，形成组培菌根植株。     

蓝桉组织培养的研究

用蓝桉（Ｅｕｃａｌｙｐｔｕｓｇｌｏｂｕｌｕｓ）离体芽器官诱导培养，分化形成丛生芽，年繁殖系数３￣（１２）。０．１～０．５ｍｇ／Ｌ的６－ＢＡ或０．５～０．８ｍｇ／Ｌ的ＫＴ诱导外植体（带节茎段）腋芽萌动的效果最佳，诱导率分别达８０．３％和８１．５％。１．５～２０ｍｇ／Ｌ的６～ＢＡ或２０～２．５ｍｇ／Ｌ的ＫＴ分别与０．５～１．０ｍｇ／Ｌ的ＮＡＡ组合，对于促进腋芽分化形成丛生芽及继代培养中芽的增殖具有最佳效果。培养基中的无机盐浓度、蔗糖含量对蓝桉试管苗的生根具有显著影响；ＩＢＡ促进蓝桉试管苗的生根。至目前为止，在１／２ＭＳ无机盐培养基＋ＩＢＡ１．２～１．４ｍｇ／Ｌ＋Ｓ５ｇ／Ｌ中诱导生根，生根率最高可达２６．４％。     

马尖相思离体培养再生植株的研究

用马尖相思（Ａｃａｃｉａ ｍ ａｎｇｉｕｍ ）１０ 年龄树芽器官为外植体,通过组织培养直接诱导不定芽产生,并获得根茎叶齐全的试管苗。剪取当年枝条的自顶芽往下依次带节的茎段培养,以第二、第三节茎段诱导芽萌动率高而快;芽诱导培养基为改良ＭＳ＋ ６－ＢＡ ２ ｍ ｇ／Ｌ＋ ＮＡＡ ０．５ ｍ ｇ／Ｌ,芽诱导率９０％ ;芽增殖培养基为改良ＭＳ＋ ６－ＢＡ ０．５ ｍ ｇ／Ｌ＋ ＮＡＡ ０．２５ ｍ ｇ／Ｌ＋ ＶＢ２ ５ ｍ ｇ／Ｌ＋ Ｖｃ ４ ｍ ｇ／Ｌ,芽增殖倍数４．８ 倍;生根培养基为１／２ ＭＳ＋ ＡＢＴ ２ ｍ ｇ／Ｌ＋ ＩＢＡ ０．２ ｍ ｇ／Ｌ＋Ａｃ ０．１％ ,生根率９７．０％ ;黄心土为试管苗最佳移栽基质,成活率达到８５％ 。     

金脉连翘的组培快速繁育研究

通过对金脉连翘的组培快繁试验,研究了外植体不同取材部位及不同激素种类、浓度对芽诱导及增殖的影响。结果表明,采用母树嫩茎的中部茎段作外植体诱导率高,分化增殖系数大;在做不同种类的激素对茎增殖比较中,生长素在其中起着决定作用。同时筛选出最佳分化培养基ＭＳ＋６－ＢＡ３．０＋ＮＡＡ０．１,根的诱导培养基１／２ＭＳ＋ＮＡＡ０．３或１／２ＭＳ＋ＡＢＴ２．０～３．０。     

毛白杨离体快速繁殖简报

以河北省易县毛白杨为试材，对其离体快速繁殖过程中的各阶段进行了较为系统的观察分析。结果表明： 幼树半木质化新梢中部单芽茎段为最佳外植体材料； 启动培养基以改良培养基 Ｂ５＋ ０２ ｍ ｇ／ Ｌ Ｎ Ａ Ａ为最好； 试管苗的叶片可与腋芽及茎尖同时作为继代培养的材料， 最佳分化培养基为 Ｍ Ｓ＋ ０２５ ｍ ｇ／ Ｌ Ｂ Ａ＋ ０２５ ｍ ｇ／ Ｌ Ｚｔ＋ ０２５ ｍ ｇ／ Ｌ Ｉ Ａ Ａ；最佳生根培养基为１／２ Ｍ Ｓ＋ ００２ ｍ ｇ／ Ｌ Ｎ Ａ Ａ＋ １０ ｍ ｇ／ Ｌ Ｖ Ｂ１＋１５％ 蔗糖， 生根率可达１００％ ， 生根数量为４ 条。     

杜仲组织培养技术的研究

为了提高杜仲的繁殖系数,以杜仲种子无菌发芽后的胚轴为外植体进行了不定芽的诱导。在添加ＮＡＮ０．８ｍｇ／Ｌ、ＮＡＡ０．１ｍｇ／Ｌ的ＭＳ培养基上愈伤组织生长较快,愈伤组织诱导率为１００％。２０ｄ后出现了芽的分化,其分化率为２５．６％。在探讨谷氨酸氨对芽分化的影响中,添加谷氨酰氨的培养基中能促进不定芽的分化。在根的诱导中,以 ＭＳ（１／２Ｎ）为基本培养基,在添加 ＩＢＡ１． ５ ｍｇ／Ｌ时,根系生长粗壮且生根率达 ９５％。     

绿宝石蔓绿绒离体培养繁殖技术研究

绿宝石蔓绿绒离体培养繁殖技术研究结果表明：①冬春两季的茎尖、带芽茎段是理想的外植体材料；②外植体用７５％ 酒精消毒１５ ｓ，再用０１％ 升汞浸泡５ ｍ ｉｎ，可达到较好的消毒效果；③最佳分化增殖培养基ＭＳ＋ ＢＡ２ ｍ ｇ／Ｌ＋ ＮＡＡ０３ ｍ ｇ／Ｌ，可使增殖倍数达７５０；④最佳生根培养基濎濚ＭＳ＋ ＮＡＡ０５ｍ ｇ／Ｌ＋ ＩＡＡ０１ｍ ｇ／Ｌ＋ 蔗糖２０ｇ／Ｌ＋ 活性炭２ｇ／Ｌ，达到９６２％ 的瓶苗生根率；⑤组培苗按照最佳移栽程序，可获得９１２１％ 的移栽成活率。     

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.