茉莉的繁殖方法

1．扦插繁殖：于4～10月,选成熟的1年生枝条,剪成长10cm ,去除下部叶片,顶端带一对完整叶片,插入泥、沙等量的插床,覆盖塑料薄膜,保持较高的空气湿度,插后20d左右愈合,随后嫩根生出,插穗顶端和节间腋芽萌发,50d左右,扦插苗进入正常生长。扦插以夏季生根最快,成活率也高,当年可以开花。用0．05％吲哚丁酸溶液将插条基部浸蘸3～5s ,处理的插条一般15～20d生根,成活率在90％以上,25d左右开始抽梢放叶。长成新植株后,进入正常管理。     

红锥扦插生根过程中内源激素的变化

以红锥嫩枝插穗为材料,用清水处理,研究红锥插穗扦插生根过程中插穗基部韧皮部的4种内源激素含量的变化。结果表明:在插穗生根过程中,插穗基部韧皮部的IAA含量在扦插过程中呈现出先升高、后降低、再升高的变化趋势;ABA、ZR、GA3等激素含量在扦插过程中基本呈现出先降低、后升高、再降低的变化趋势。判别生根难易的IAA/ABA比值呈现出先上升、后下降、再上升的变化趋势,ZR/IAA则呈现先下降、后上升、再下降的变化趋势。外部形态学观察结果,红锥插穗扦插后第21d开始生根,第60天生根基本结束,生根率达92.5%,说明插穗自身的激素含量影响生根性状,红锥插穗自身的激素含量有利于生根,故红锥插穗生根能力较强。     

观光木高龄植株扦插繁殖技术的初步研究

对影响观光木高龄植株扦插成活率的插穗基部处理方式、生长促进剂、ABT生根粉处理效果、扦插基质等因素作初步探讨。结果表明 :①插穗基部以环剥、单削、双削、平口 4种处理方式中 ,双削处理的成活率高 ;②双氧水、高锰酸钾、吲哚乙酸、细胞分裂素处理插穗 ,均有利于促进观光木的生根成活 ,其中 1%H2 O2 处理效果最好 ;③ 4种ABT的 8种处理插穗基部 ,ABT1# 效果较好 ,15 0× 10 -6ABT1# 效果最好 ;④利用河沙和蛭石 2种插壤 ,沙壤的扦插成活率明显高于蛭石     

红叶石楠扦插繁殖试验

本试验研究了不同生长素种类与浓度及处理方法对红叶石楠扦插繁殖的影响。结果表明:对木质化程度较大的上段插穗(留1片叶),以NAA 1 000 mg/L液浸泡插穗基部5 s较好;对半木质化的中段插穗(留2片叶)和较幼嫩的下段插穗(留3片叶),以NAA 100 mg/L液浸泡插穗基部2 h的处理效果最佳,能较好地促进插穗生根,萌芽情况良好。     

沉水樟高龄植株扦插繁殖的初步研究

对沉水樟高龄植株 (16年生 )的插穗基部处理方式、生根促进剂、ABT生根粉处理效果、扦插基质等方面作初步探讨。结果表明 :沉水樟的插穗基部以双削处理的成活率高 ;1%H2 O2 、0 0 5 %KMnO4 、5 0× 10 -6IAA、5 0× 10 -6NAA处理插穗 ,均有利于促进沉水樟的生根成活 ,其中 1%H2 O2 处理效果最好 ;4种ABT的 8种处理沉水樟插穗 ,以 15 0× 10 -6ABT1#效果最好 ;利用河沙和蛭石两种插壤 ,河沙的扦插成活率明显高于蛭石     

希蒙得木嫩枝扦插正交试验

正交试验表明:希蒙得木嫩枝扦插生根率高的理论组合是A1B3C1D3(基部、三节、1000g/kg、30min)。综合分析认为,希蒙得木嫩枝扦插从当年生半木质化枝条的基部、中部截制插穗,穗长2～3节,用IBA1000g/kg或2000g/kg浸穗条基部30min,插穗的生根率最高。     

邮购《林业苗圃化学除草指南》

1 硬枝扦插 春季于枝条萌动前，在兴安盟地区于4月上、中旬，选用采穗圃里生长健壮、粗0．4～0．6cm的枝条，也可采用生产园中优良植株上的徒长枝，剪成12-15cm长作插穗，每段应有3～5个腋芽，基部斜剪，顶部切口剪平，其中以枝条中段截取的插穗最易发根。扦插前用15％的萘乙酸浸泡1d，以利于插穗生根，浸泡部位应在插穗下部3cm。扦插前先挖15cm深的插床，床面铺10cm厚的细沙，将准备好的插穗按10cm×10cm株行距插入沙中，深度6～7cm。根据各地气候不同，随时采条，及时扦插。扦插后浇透水，为保墒和提高地温，促进生根发芽，在插后搭小拱棚覆盖薄膜保湿。白天（晴天）加盖遮阳网，床内温度保持在20-25℃、地温26℃、土壤湿度20％左右，经15-20d，插穗基部和中部即能生出不定根。此法操作简便，生产上已普遍采用。     

黄杞容器扦插繁殖技术试验研究

通过正交试验设计L9（34）深入研究了使用不同种类生根促进剂（H ）来处理母株不同采插穗部位的插穗（F ）和插穗不同基部下切口型（E ）对黄杞扦插生根率、生根数及生根长的影响差异。试验结果表明：采用生根促进剂ABT －1＃（H1）＋母株下部采的插穗（F3）＋基部下切口型为双削面（E2）,即 H1 F3 E2组合试验效果最好,其平均生根率高达86．8％、平均生根数8．8条、平均生根长达18．6cm。     

白玉兰容器扦插快繁技术试验

采用L8(2^7)正交试验设计研究2种不同生根促进剂(U)、2种不同生根促进剂浓度(G)、2种不同木质化插穗(N)及2种不同长度的插穗(M)对白玉兰插穗生根率的影响,用双因子方法比较了3种不同配比的扦插基质(S)及3种不同插穗基部下切口型(W)对白玉兰扦插生根率的影响。结果表明:采用浓度750mg kg^-1(G2)ABT-1^#(U1)生根促进剂来处理长度为12cm(M1)的白玉兰硬枝(N1)插穗时生根率最高,平均生根率达83.7%;3种不同插穗基部下切口型和3种不同配方的基质扦插试验中,以插穗双边各成45°斜切(W3)扦插到各50%红壤和珍珠岩(S3)中时生根效果最佳,平均生根率达85.3%,平均生根数达15.6条。     

金叶银杏硬枝扦插繁殖生根过程及其生根机制研究

【目的】研究不同生长调节剂处理对金叶银杏硬枝扦插生根率和成活率的影响,探讨金叶银杏的生根机制,为金叶银杏苗木扦插快繁技术体系的建立提供技术支持和理论指导。【方法】通过NAA和IBA处理金叶银杏硬枝插穗,检测它们对插穗的生根状态、生根指标及IBA对扦插过程中插穗皮部可溶性糖、抗氧化酶、激素含量的影响,探究金叶银杏硬枝扦插繁殖技术和生根机理。【结果】1)金叶银杏插穗愈伤组织诱导期和形成期、不定根发生期和形成期分别在插后的20~26、26~42、42~53、53~79 d。2)800 mg·L^-1 IBA和400 mg·L^-1 NAA+400 mg·L^-1IBA(混合)处理的插穗愈伤组织和不定根出现期及生根率与根数都较其他相应处理的效果好,其中生根率分别达64.4%和51.1%;不定根数分别达8.6条和9.3条。3)插穗生根过程中(500 mg·L^-1 IBA处理)基部韧皮部的SOD、PPO活性在插后40、60 d达到高峰,均比对照提前20 d达到峰值;插穗的POD活性出现上升-下降-升高的趋势,插穗可溶性糖也出现升高-下降-升高的趋势,但时间点不一致;而淀粉的含量出现下降-上升的趋势。4)生根期间插穗基部韧皮部的IAA含量出现了2个峰值和一个谷值;而ZR含量在第40天达到峰值后下降;GA含量先下降后上升;ABA含量在插后的前期高后期低,且值都低于同期对照。IAA/ABA比值在插后的第40天(愈伤组织形成期)达到谷底,后又上升(不定根形成期)。IAA/GA在插后的40~60 d内快速上升,80 d后又开始大幅下降;IAA/ZR值在扦插愈伤组织形成期(40 d)呈下降趋势,到60 d时(不定根发生期)又急剧上升到峰值。【结论】高活性的SOD和POD有利于插穗初期愈伤组织的形成(40 d),高活性的POD与PPO有利于不定根的形成(60 d)。较高的IAA含量是保证愈伤组织形成(20~40 d)的必要条件,不定根形成期(60 d)需要较高的IAA/ZR、IAA/ABA、IAA/GA比值。本研究为金叶银杏扦插繁殖技术和生根机理的研究及金叶银杏苗木的快速繁殖生产提供技术支持。     

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.