桤叶唐棣组培苗瓶外扦插生根试验

采用不同类型基质、不同种类激素及浓度对桤叶唐棣组培苗进行了瓶外扦插生根试验,结果表明:最适宜的生长激素为NAA+IBA(1 ∶ 1),最佳浓度为800 mg·L-1;最适宜的扦插基质为珍珠岩+熟表土+草炭土(1 ∶ 3∶1),生根率可达67％.     

支撑物对试管内蓝莓组培苗生根的影响

以蓝莓品种‘蓝丰’组培苗为材料,采用正交试验设计,研究了不同类型的支撑物(珍珠岩、草炭和琼脂)、不同液体培养基(WPM、1/2WPM和1/4WPM)、不同激素(IBA、NAA、IBA+NAA)及其不同添加浓度(0.5 mg·L-1、1 mg·L-1、2 mg·L-1)对试管内蓝莓组培苗生根的影响。结果显示:以珍珠岩为支撑物的各处理有效生根率分别为82.5%、77.5%和79.31%,明显高于其他处理,且根系发达,分支多。基础液体培养基以WPM的R值最大,为44.44;激素类型以0.5 mg·L-1 IBA+0.5 mg·L-1 NAA组合的R值最大,为42.22;激素浓度以1 mg·L-1的R值最大,为43.33。蓝莓组培苗的最佳生根组合方式为以珍珠岩为支撑物,添加0.5 mg·L-1 IBA和0.5 mg·L-1 NAA的WPM液体培养基。     

中国特有濒危植物崖柏扦插繁殖研究

在重庆市城口县咸宜乡苗圃和中国林科院温室开展崖柏扦插繁殖试验,研究采穗母树年龄、不同激素种类及其组合、激素浓度、扦插基质、物理促根等不同处理方式下崖柏扦插生根效应.结果表明:(1)在咸宜乡苗圃,采用自动喷雾设施,以蛭石-泥炭土-珍珠岩(1∶1∶1)为扦插基质,用3种激素和清水处理崖柏幼树1年生枝条,扦插后160d的生根率为74.76％～96.70％,不同处理组合生根效应具有显著差异,2000 mg· L-1 IBA＞清水对照(CK)＞1 000mg·L-1 IBA＞1 000 mg·L-1IBA+ 500 mg· L-1NAA;(2)在林科院温室用2种激素和清水处理崖柏幼树1年生枝条,扦插于蛭石-泥炭土-珍珠岩(1∶1∶1)的基质,搭塑料拱棚,扦插后120 d的生根率远低于咸宜乡苗圃,为25.93％～45.37％,激素处理后的枝条与对照差异显著,1 000 mg·L-1 IBA+ 50 mg·L-1 NAA=2 000 mg·L-1 IBA＞清水对照(CK);(3)在咸宜乡苗圃用不同激素和物理促生根方法组成的27种组合处理的成年崖柏枝条,最高生根率仅为20.83％.生根率超过10％的处理组合是:清水处理,泥炭土∶蛭石∶珍珠岩(1∶1∶1);1 000 mg·L-1IBA+500 mg·L-NAA,泥炭土∶珍珠岩(2∶1);1 000 mg·L-1IBA,泥炭土∶蛭石∶珍珠岩(1∶1∶1),流水冲洗.     

美国红枫硬枝扦插育苗试验研究

对不同基质、不同生根液浓度与不同处理方法、不同扦插时间对美国红机枫硬枝插生根的影响进行了研究。结果表明,以2∶1的珍珠岩与黄泥土混合为最佳扦插基质,生根时间为35 d,生根率达到81.5%;植物激素采用50%吲丁.萘合剂附加谷氨酸、肌醇,使用浓度分别为150 mg·L-1和1 000 mg·L-1,用浸泡2 h和蘸泥浆两种方法处理插条,其中浓度为1 000 mg·L-1插条蘸泥浆,生根时间30 d,生根率达到82.7%;浓度为150 mg·L-1浸泡插条2 h,生根时间32 d,生根率61.3%;扦插时间以2月上、中旬为最佳,生根时间为28 d,生根率达到85.1%;3月上旬扦插的反而生根时间长,40 d以后才发现有新根长出。     

辣木组织培养与植物激素培养基筛选试验

以辣木种子为外植体组织培养并在各培养阶段添加不同浓度植物激素培养基的试验结果表明:外植体消毒以脱壳种子→84消毒液预处理→Hg Cl2消毒效果最佳,污染率10%;最好的发芽诱导培养基为Mc+6-BA 0.4 mg·L-1,发芽率达82%;继代增殖培养基为Mc+6-BA 0.5 mg·L-1+KT 0.1 mg·L-1,增殖倍数达5.8倍;生根培养基为1/2Mc+IBA 0.5 mg·L-1+NAA 0.2 mg·L-1+AC 1.0 g·L-1,生根率达80%。炼苗20 d移栽于河沙∶珍珠岩∶刨花(1∶1∶1)混合基质的成活率最高。     

基质和激素处理对树头菜扦插生根的影响

研究不同基质、不同浓度激素处理对树头菜扦插生根的影响,结果表明:混合基质比其他单一基质扦插生根率高,可达86%;不同浓度激素处理中,以NAA-150mg/L为最佳激素浓度,生根率达93%。促进树头菜扦插生根的最佳处理组合为混合基质(珍珠岩:河沙:草炭=1:1:1)、激素NAA最适浓度为150mg/L。     

福建山樱花组织培养试验

以半木质化枝条为外植体,探讨外植体消毒时间、植物生长调节剂对福建山樱花组培各阶段的影响,结果表明:外植体先用75%酒精消毒30 s,再使用0.1%HgCl溶液消毒5 min的消毒效果较好。较适宜的诱导培养基为:MS+6-BA 1.5mg·L-1+NAA 0.1 mg·L-1;较适宜的继代培养基为:3/2 MS+6-BA 1.0 mg·L-1+NAA 0.2 mg·L-1;较适宜的生根培养基为:1/3 MS+IBA 1.0 mg·L-1+NAA 0.2 mg·L-1,生根率达97.4%。生根苗移栽到泥炭土∶珍珠岩∶黄心土(6∶3∶1)的基质中成活率可达90%以上。     

基质与激素对茵芋扦插苗萌芽效应研究

由于茵芋野生种质十分稀缺,生产上采取快繁技术培育苗木时,扦插繁植受限于穗条紧缺,组培繁植受限于以芽为主的外植体材料紧缺。为解决茵芋繁植材料问题,本课题采用16种基质类型、5种激素类型及7种浓度水平进行分组试验。探明了珍珠岩+泥炭+河沙(3:4:3)配制的混合基质对萌芽促进效果最优、萌芽率达到65.69%,其他依次为珍珠岩+泥炭(6:4)、珍珠岩+泥炭+红心土(3:4:3)、珍珠岩+泥炭(4:6)、珍珠岩+河沙(4:6)、泥炭等。摸清5种植物生长素对茵芋扦插苗萌芽促进作用的强弱程度为IAA+NAAIBAIBA+NAANAAIAA清水对照,而且萌芽率与成活率二者之间呈反规律现象,即萌芽促进作用若强、生根成活作用就弱;发现IAA对茵芋萌芽没有浓度效应,且它与清水对照一样对萌芽促进作用较弱;发现混合激素明显优于单项激素,而且IAA+NAA(1:1)在(400+400)mg·L-1浓度水平下对茵芋萌芽促进效应最突出;IBA在1200mg·L-1的浓度水平下对茵芋萌芽促进效应最突出。提出3个促进茵芋萌芽方案:最优方案为珍珠岩+泥炭+河沙(3:4:3)的混合基质,配合使用浓度为(400+400)mg·L-1的IAA+NAA(1:1)混合激素;次优方案为珍珠岩+泥炭+河沙(3:4:3)混合基质,配合实施浓度为1200mg·L-1的IBA激素;方案三为珍珠岩+泥炭(6:4)混合基质,浓度为(1200+1200)mg·L-1的IBA+NAA(1:1)混合激素。     

耐寒月季‘高山朝霞’嫩枝扦插繁殖技术研究

以耐寒月季‘高山朝霞’嫩枝为材料,研究不同扦插基质、不同生长调节剂种类(IBA、NAA、IAA)和质量浓度(400 mg·L^-1、800 mg·L^-1、1 200 mg·L^-1)对其扦插生根的影响。结果表明：最适合的基质为河沙+蛭石+珍珠岩(体积比3∶1∶1),生根率达到93.33%。经不同生长调节剂处理后,生根率较对照有显著提高,1 200 mg·L^-1 IBA处理后的根系生长和根系构型最佳。     

假叶树组织培养植物激素应用筛选试验

采用假叶树的幼嫩茎段为外植体组织培养,对加入适合的植物激素作筛选试验,结果表明:MS+ZT 2.0 mg·L-1+IBA 0.5 mg·L-1培养基愈伤组织的诱导率最高;MS+ZT 1.5 mg·L-1+IBA 0.2 mg·L-1培养基分化不定芽效果最佳,并且在MS+ZT 1.0 mg·L-1-1.5 mg·L-1+IBA 0.2 mg·L-1培养基上继代增殖培养增殖系数可达4⁵倍;不定芽在1/2MS+NAA 1.0+1.5 g·L-1活性炭的培养基上,生根率达100%;生根小苗移栽珍珠岩与泥炭土(1∶1)基质上,成活率达95%以上。     

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.