彩叶扶芳藤扦插繁殖生根剂比较试验

采用不同生根剂用不同浓度和浸蘸方法进行彩叶扶芳藤扦插比试验。结果表明:采用"森生2号"生根剂500×10-6、穗条基部浸泡2s,生根率达87.96;采用"森生1号"生根剂500×10-6、穗条基部速蘸2s,生根率达84.26。在此基础上,组装成彩叶扶芳藤扦插繁殖配套技术。     

花叶扶芳藤扦插繁殖技术

以花叶扶芳藤枝条为试材,研究不同配比的泥炭、珍珠岩、蛭石和河砂混合基质以及不同质量浓度的NAA、IAA和IBA速浸插条基部对生根的影响。结果表明:以泥炭-珍珠岩-蛭石(4∶3∶3)为基质扦插花叶扶芳藤的成苗率和平均根数最高;扦插前用3种植物生长调节剂快速浸蘸插条基部,均能显著地提高花叶扶芳藤扦插成苗率、根长和生根数。但以NAA 200~400 mg/L浸蘸插条基部,成苗率最高,达91.05%;以半木质化枝条扦插生根率较高。     

秤锤树扦插繁殖技术

秤锤树已经作为濒危树种列入中国植物红皮书.为了更好地保护这个南京的乡土树种,需要通过快速的扩繁来增加其数量.通过对比试验(不同的扦插基质、扦插方法及激素水平)发现,利用500 mg/L IBA浸泡插条基部2 h后扦插在混合基质中,全光照自动间歇喷雾条件下,1 a生嫩枝扦插的生根率最高,可达到87.78%;1 a生硬枝扦插的生根率次之,达到83.33%.由此可知,秤锤树扦插繁殖的生根率很高,完全可以上述方法扩繁.     

卫矛属植物组织培养无菌苗的方法研究

以卫矛属3种植物为试验材料,研究了取材方法、取材时间和不同品种对组培污染率的影响;采用茎段、小茎尖和嫩梢培养对卫矛属植物进行消毒处理,以其获得无菌苗。结果表明,宽瓣扶芳藤在春季3~4月腋芽萌发时进行消毒处理效果最好;胶东卫矛的消毒最为容易;以嫩梢培养方式进行消毒处理效果最佳。     

茶花砧木的培育与嫁接

茶花的繁植方法有种子繁殖、嫁接繁殖、扦插繁殖三种方法。种子繁殖的茶花后代变异性大,不能保持原品种的特性,加之一些品种不能结实,所以、种子繁殖法只作为育种用。扦插繁殖法近年来随着先进科学手段的应用,已获得成功,但经目前的实践证实,扦插成活率较高的只是一般品种,而大多数中档以上的品种成活率都很低或根本不生根。     

金叶钝齿冬青等彩叶灌木新品种扦插育苗试验

通过对金叶钝齿冬青等彩叶灌木新品种的全封闭扦插育苗试验，掌握了各树种的扦插难易程度。金叶连翘、花叶柳最易扦插成活，金叶钝齿冬青、红叶石楠、金叶锦熟黄杨次之，而金边构骨扦插较难成活，在扩繁方式上应采用嫁接繁殖，繁殖系数会更高。从生根类型上来看，芽间生根的树种最易扦插成活，且生根率较高，芽基生根次之，而愈伤组织生根的成活率一般比前二者低，生根时间也晚一些。全封闭扦插育苗方法始终要保持床内饱和的湿润状态是此项技术成败的关键。     

红椿无性系嫩枝扦插繁殖试验

为解决优质家具材树种红椿苗木快繁的问题,开展了红椿无性系嫩枝扦插繁殖试验.结果表明:10个无性系穗条扦插生根率变幅为47.4％ ～91.5％,TC01、TC04和TC08这3个无性系扦插生根率最高,无性系间的生根率有极显著差异;穗条带2片叶可显著提高穗条的生根率;不同浓度GGR对穗条生根率有显著影响.     

杏扁小拱棚嫩枝扦插育苗技术

杏扁是我国北方地区的主要经济树种,"龙王帽"、"一窝蜂"是张家口市优选的主栽乡土杏扁品种,具抗寒、抗旱、丰产特性,成为我市出口创汇的主要产品. 多年来,杏扁苗木繁殖采用播种、嫁接繁殖.杏属难生根树种,杏枝扦插在国内外报刊杂志很少报道.1999年以来,张家口市林科所承担了"张家口市百万亩杏扁基地建设项目",科研人员以"龙王帽"、"一窝蜂"为试验材料,进行了杏扁苗木快繁系列试验,其中本文作者作为项目负责人进行的"杏扁小拱棚嫩枝扦插快繁试验"取得了关健技术突破,"龙王帽"、"一窝蜂"两个杏扁品种嫩枝扦插成活率达到85%以上.此项技术弥补了杏枝扦插技术空白,改写了杏属扦插难生根的说法.此项技术的成功对其它难生根树种扦插育苗具有指导性和推广价值.     

油料植物南美油藤扦插技术研究

以2 a生南美油藤枝条作为穗条研究不同生根剂种类、生根剂浓度、穗条根部生根剂浸泡时间、穗条不同木质化程度以及以0.5年生枝条作为穗条研究不同品种对南美油藤扦插生根效果的影响。结果发现:南美油藤扦插7 d左右出现愈伤组织,10左右愈伤组织出出现白芽点,12 d左右开始生根,20 d可以移栽。不同生根剂种类、生根剂浓度、穗条根部生根剂浸泡时间对南美油藤扦插生根率具有显著影响,生根剂IBA,浓度500~1 000 mg/L,浸泡时间20~60 s对南美油藤扦插生根效果最优;木质化程度低的枝条作为穗条扦插效果优于完全木质化枝条,已经驯化的南美油藤V扦插效果优于其他几个品种。     

滇丁香非试管智能化快繁技术研究

滇丁香是一种具有较高开发价值的园林观赏树种,利用植物非试管智能化快繁技术进行其扦插苗的规模化快繁,具有生根快、生根率高、移栽成活率好的优势。试验结果证明,滇丁香扩繁最佳的扦插方法是采用其半木质化枝条作为插条,用200 mg/kg的ABT2处理2 h后扦插;其次是用200 mg/kg的NAA或国光生根处理2 h后扦插。在规模化生产中,采用国光生根2 000 mg/kg快速沾根2~5 m in的方法,也可达到生根率90%左右的效果;同时电磁场处理苗床具有杀菌及提高生根率的作用。用非试管扦插快繁方法将未生根植株进行回插,1个月后仍可获得90%以上的生根效果,该特点与其他树种扦插苗的表现显著不同,有利于提高滇丁香扦插苗的生产效率。     

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.