枣树归圃育苗技术研究

枣树是我国普遍种植的干果经济植物,为探索归圃育苗在大量繁殖枣树苗木过程中促进生根的技术关键进行了归圃育苗试验。结果表明:枣树归圃后至萌芽前保持土壤微湿润状态,可使枣苗成活率提高8%,且苗木萌芽早;用300 mg/kg的NAA、IBA、矿质磷肥混合液蘸根后效果最好,可使地径、高生长量分别提高44.8%、20.2%。     

枣树苗木快速繁殖及脱毒技术

枣树为鼠李科枣属,是我国特有的经济树种之一。优质枣树苗木繁殖速度慢和“枣疯病”是目前影响我国枣树发展的重要障碍。 “枣树苗木快速繁殖及脱毒技术”是经北京林业大学科技人员多年的研究取得的重要成果。1992年由林业部组织的专家鉴定认为:“该项研究成果在枣树组织培养配套技术方面及脱毒苗培养技术和枣疯病类菌原体检测方面达到国际先进水平”,并在1995年获林业部科技进步二等奖,1996年获国家科技进步三等奖。1993年被国家科委批准列为“国家级科技成果重点推广项目”,现已在全国十     

枣树嫩枝扦插育苗技术试验与推广前景展望

1　枣树育苗技术现状生产上枣树多采用根蘖苗、归圃育苗和嫁接育苗等方式进行繁殖。利用枣树根系分蘖能力强 ,根部不定芽萌发长出的小苗与母树断根分离后定植建园或者大田归圃培养为成品苗 ;嫁接育苗是用酸枣实生苗作砧木 ,或用根蘖归圃苗作砧木嫁接培育良种苗木。它的缺点是育苗周期长 ,成本较高 ,品种混杂 ,苗木大小参差不齐。用组织培养育苗方式 ,经北京林业大学、中国农业大学等科研院所多年的试验 ,已培育出良种组培苗。但由于枣树品种不同 ,遣传特性各异 ,需配制不同的培养基 :组培设备投资大 ,成本高 ,目前 ,组培育苗还不能用于良种…     

枣树机械铺膜播种育苗技术

<正>枣树(Ziziphus jujuba Mill)为鼠李科枣属,1998年枣树在北疆引种成功,打破了在北纬43°、冬季最低气温不得低于-23℃种植枣树的界限,在北疆地区掀起了种枣高潮, 2000年至今,苗木供不应求,外地大量苗木涌人新疆,品种混杂,且经长途运输,苗木适应性差,成活率低。新疆农垦科学院从1998年开始育苗,选用适应性广、萌蘖力强、在各类土壤均能生长的酸枣做砧木,当     

良种枣树组培及拱棚弥雾扦插育苗技术

在北京林业大学田砚亭教授的指导下,与其多名学生合作,对苹果枣、赞皇大枣等枣树进行了组培快繁,并成功地应用于生产。对枣树的接种外植体、启动培养、继代培养、生根、炼苗、扦插繁殖、苗木移栽、丰产栽培等技术进行了研究,介绍如下。     

全国最大的枣树组培脱毒工厂化育苗基地

全国最大的枣树组培脱毒工厂化育苗基地山东省平度市积极实施“科技兴林”战略，与北京林业大学合作完成的“枣树快速繁殖及脱毒技术”，达到国际先进水平，到目前已生产枣树脱毒苗木６０万株，成为全国最大的枣树组培脱毒工厂化育苗基地。地处胶东半岛西部的平度市，为加...     

红叶山樱花苗木繁殖技术规程

对红叶山樱(Prunus serrulata Lindl.Royal Burgundy)苗木的播种繁殖、扦插繁殖、嫁接繁殖和组培快繁等繁殖技术进行了总结,以期为提升其苗木质量、加快苗木生产和推广应用提供技术参考。     

辽西地区枣树绿苗高效栽培技术实践

针对目前辽西半干旱地区枣树传统栽植成活率偏低问题,发展和推广枣树的高效、高产栽培技术体系,成为发展枣树产业和改善辽西林业生态环境的主要内容之一。枣树绿苗高效栽培通过苗木处理、大棚催苗及栽植等技术措施能较好地改善枣苗形态,从而较大幅度地提高枣树苗木的成活率,是半干旱地区枣树高效栽培的有效技术方案,具有积极的学术价值和现实意义。     

枣树硬枝扦插育苗

<正> 枣树对气候、土壤适应性较强,抗干瘠、耐涝碱,是干旱瘠薄山地及盐碱地营造经济林的主要树种之一,也是华北平原著名的林粮间作树种。近几年,随着枣树优良新品种的不断推出,栽培面积迅速增加,苗木需求量越来越大,为加快优良品种的繁殖,我们结合枣树冬季修剪,利用剪下的枝条,进行了硬枝扦插育苗试验,取得了扦插成活率85％以上,667 m2产苗1.8万余株的效果,并且提前1年出圃。     

不同修剪措施对平欧杂交榛苗木繁殖的影响

试验以章古台地区沙地栽培的3个品(系)平欧杂交榛(Corylus heterophylla×C.avellana)为试材,研究了重剪、轻剪、自然生长3种修剪措施对平欧杂交榛植株繁殖苗木的数量、基径、高度的影响。结果表明:不同修剪处理都可以提高平欧杂交榛的苗木繁殖数量;重剪处理虽然可以显著提高植株的繁苗数量,但繁殖的苗木基径明显小于轻剪处理,繁殖的苗木高度也显著低于自然生长的植株;不同品(系)的平欧杂交榛植株繁育情况也有差异,82-11繁育数量明显高于84-226和84-254。     

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.