浅析红叶石楠夏季扦插技术

正红叶石楠在我国分布广泛,主要集中分布于华东、中南及西南等地区。随着城市园林绿化的蓬勃发展,在湖南、湖北、云南、安徽、山东、河北等地均有引种栽培。红叶石楠的繁殖主要方法是扦插,以夏插成活率最高。扦插时间红叶石楠在长江中下游地区的扦插时间一般为春插3月上旬、夏插6月上旬和秋插9月上旬。以夏插成活率最高,但夏插时一定要处理好排水、保湿和病虫害的防治工作。穗条剪取穗条应选择当年半木质化的嫩枝作为插条。因为半木质化的嫩枝     

罗田垂枝杉不同材料扦插试验研究

为探索罗田垂枝杉的无性繁殖,以大树侧枝和基部萌条及采穗圃穗条为试验材料进行扦插,分析不同材料、不同系号及不同激素处理生根差异。结果表明:20 a以上的大树Ⅱ级侧枝的扦插生根率较低,为48.11%,而Ⅰ级侧枝的扦插生根率可达65%以上;萌条扦插生根率(88.86%)要远高于优树侧枝扦插生根率(48.01%),两者差异达到极显著水平(p0.01),黄化未木质化穗条扦插生根率仅为6.67%,远低于其他萌条86.94%~91.67%的生根水平,不同系号间萌条生根率从51.57%~98.77%不等;激素处理的采穗圃穗条生根率都在91.57%以上,粉剂1处理后生根数量最多,与其余三种处理差异达到显著水平。可见侧枝扦插要显著差于萌条扦插,而激素处理可以有效提高扦插生根率。     

红叶石楠扦插育苗技术研究

从影响红叶石楠扦插穗条生根的因素展开研究,应用对比分析和方差分析找出适合红叶石楠扦插的基质种类、植物生长剂浓度、穗条年龄和长度。结果表明:红叶石楠属于愈伤组织生根型;8 cm~10 cm长的穗条是较为合适的长度;1 a生穗条的扦插生根率高于2a生穗条的扦插生根率;同一植物生长剂,浓度高的生根率大于浓度低的生根率;扦插的基质以棕壤较好。     

红叶李嫩枝扦插剪穗母条对成活率的影响

为探讨剪穗母条对扦插生根的影响,以红叶李为试材,在6月份分别不同年龄母树、母树不同部位、枝条不同部位上剪取母穗,进行扦插育苗试验,结果表明,嫩枝扦插采穗时要选择生长旺盛、无病虫害的幼树上当年生萌生枝条。树龄最好不要超过10年生以上。在条源缺乏时,在大龄树上采条时,尽量选择基部和中部萌生枝条。     

南天竹扦插快繁技术

从红叶南天竹采穗圃剪取穗条进行分级,采用不同浓度的植物催根剂,进行扦插对比试验。结果表明:于3月上旬剪取上一年的秋梢,将穗条分粗细2级进行扦插,采取"森生1号"植物催根剂1g对水300 mL,穗条基部速蘸2秒;穗条基部切口直径小于4 mm,木质化程度介于硬枝与半木质化之间的细级穗条,扦插繁殖效果较好,从扦插到测定,经108天培育,生根率可达75.33%、平均根幅5.53 cm、平均根长7.80 cm、平均新叶片数3.24片,可以用来上盆培育容器苗。     

红锥采穗圃营建及其穗条的扦插育苗试验

红锥是我国极具推广和开发价值的南亚热带优良速生珍贵用材树种。为了获取红锥大量扦插繁殖用的穗条,营建其采穗圃,经大量的试验研究,探索到了较为完备的红锥采穗圃营建技术。通过对所采穗条开展的扦插育苗试验,探明了不同的穗条处理方式、不同扦插季节、不同扦插基质、不同生根药物和采穗母株对其穗条扦插生根的难易。致使红锥穗条的扦插生根率最高可达90%以上。     

野牡丹采穗圃建立和扦插繁殖技术研究

经过2年来对野牡丹采穗圃的建立和管理及穗条的不同药剂浓度、不同扦插时间、穗条所处不同部位、不同的修剪方式试验研究,结果表明:(1)苗圃中选择的优树建立的采穗圃当年每株母树采穗量达18条～54条,丛生性母株留低桩1 cm～2 cm采穗量最大,达到54条/株;(2)穗条用200 mg.L-1GGR6生根粉处理后的扦插效果最好,生根率达到88.5%,清水处理的穗条扦插效果最差,生根率为68.5%;10月中旬是扦插野牡丹的最佳时间,成活率可达90.5%;枝条上部的穗条扦插成活率最高,可达91.5%;穗条的不同修剪方式对扦插成活率影响不明显,平均成活率80.4%。     

红叶石楠不同取穗部位对扦插生根的影响

于夏季进行了红叶石楠树冠不同取穗部位(树冠上部、中部、下部)及枝条不同取穗部位(枝条梢段、中段、基段)的扦插效果比较试验,结果表明:红叶石楠树冠上部及树冠中部插穗的生根及抽梢效果最好,树冠上部的扦插生根率达96.3%,≥2cmⅠ级侧根数达3.3条,抽梢率达97.3%;树冠中部的扦插生根率达95.0%,≥2cmⅠ级侧根数达3.2条,抽梢率达96.0%。红叶石楠枝条梢段及枝条中段插穗的生根及抽梢效果最好,枝条梢段的扦插生根率达96.7%,≥2cmⅠ级侧根数达3.3条,抽梢率达98.7%;枝条中段的扦插生根率达96.3%,≥2cmⅠ级侧根数达3.1条,抽梢率达98.0%。     

红叶石楠大苗培育技术

红叶石楠扦插育苗简单,成活率高,又能保持红叶石楠的优良特性,红叶石楠在扦插过程中主要注意扦插的时间,母树的选择、穗条的选择、穗条的处理与保湿、扦插的方法等。要保证扦插的成活率还必须注意扦插质量、保温、保湿、控制光照等。大苗培育主要是多次移栽等。     

红叶石楠扦插繁育技术

红叶石楠是蔷薇科石楠属的杂交品种和选育栽培品种群,常绿小乔木,因其红色新梢嫩叶而得名,在欧美、日本和韩国非常流行,近几年传入中国。总结了浙江森禾公司的工厂化繁育技术,建立采穗圃、剪取穗条、扦插繁育,自行研制基质配方、采用穴盘苗、现代化设施、自行配制“森生一号”生根剂、小拱棚、防病和炼苗等,该技术5 a来已累计扩繁扦插苗5 000余万株,在10多个省(区)(北京以南、西安以东)的园林工程应用。     

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.