桂花嫩枝扦插繁殖技术试验

2013年6月在福建邵武市苗圃对桂花进行了当年生半木质化嫩枝扦插繁殖试验。采用不同生根促进剂、不同浓度,以及不同扦插基质处理。6个月后结果表明:桂花的嫩枝扦插生根率有显著差异,生根数量及根长等生根性状未达显著差异水平;桂花嫩枝扦插较佳的处理组合是:ABT3号生根剂,质量浓度为250 mg·L-1,生根率达90.0%;桂花在不同扦插基质条件下,生根率以2号基质(黄心土70%+河沙30%(体积比))较好。     

铅笔柏全光自动喷雾扦插育苗试验初报

通过对铅笔柏当年生嫩枝采用不同基质和激素浓度的扦插效果对比试验,结果表明:采用轻基质网袋容器基质(泥炭土∶炭化稻壳=1∶1)要明显优于其它基质;采用不同种类、不同浓度激素处理对铅笔柏插穗的成活率影响较大,用浓度300 mg/L的NAA处理,有利于提高扦插成活率,其愈伤组织形成率、腐烂率、生根率分别为17%、9%、54%。     

五叶地锦不同年龄插穗扦插生根试验

以五叶地锦不同年龄的硬枝和当年生嫩枝为材料进行扦插生根试验,结果表明:在相同立地和外源激素条件下,1 a生和2 a生硬枝插穗扦插生根状况最佳,生根率平均为96.6%和94.5%,每穗生根数平均为14.6条和12.8条,根系平均长为2.2 cm和2.4 cm;3 a生硬枝和当年生嫩枝生根状况较差,与1a生和2 a生硬枝相比较差异极显著。     

曼地亚红豆杉扦插繁殖研究初探

连续3 a在福建闽清进行曼地亚红豆杉扦插繁殖试验,结果表明:用100 mg.L-1的NAA浸泡插穗6 h,生根率最高,可达92%;不同基质间生根率差异显著,混合基质(蛭石∶珍珠岩∶河沙=2∶2∶3)效果最佳,生根率达95%;不同年龄插穗扦插生根率差异显著,1年生穗条生根率最高,生长势最旺;最佳扦插时间是秋季(9月)。     

蚯蚓粪、插穗部位与扦插时间对美国白蜡嫩枝扦插生根的影响

为解决美国白蜡嫩枝扦插苗生根率低、根系不发达等技术瓶颈问题,以1年生美国白蜡嫩枝为材料,采用单因素随机区组试验设计,研究蚯蚓粪、插穗部位和扦插时间对美国白蜡扦插繁育的影响。结果表明,不同蚯蚓粪配比、插穗部位和扦插时间对美国嫩枝扦插苗生根率、生根数量、最大根长和平均根长的影响差异达到显著水平。以基质3（蚯蚓粪∶蛭石=2∶1）为扦插基质插穗生根率最高,为90.24%;中部位置插穗生根率最优,为89.23%;8月份扦插的效果最好,生根率为91.56%。综上,以基质3为扦插基质,采用美国白蜡1年生枝条的中部位置为插穗,扦插时间为8月份上旬,扦插生根效果最佳,当年苗高达到95 cm左右。     

卷斗青冈扦插繁育技术研究

通过试验研究了卷斗青冈母树树龄(A)、NAA使用浓度(B)及插穗长度(C)对卷斗青冈扦插生根率的影响;比较了不同插穗下切口型(D)对卷斗青冈扦插生根率的影响;研究了不同基质配方网袋容器(E)对卷斗青冈扦插苗移栽成活率的影响。结果表明:母树树龄、NAA使用浓度及插穗长度这3个因素对卷斗青冈扦插生根率影响的主次关系是ABC,母树树龄5a(A1)+NAA使用浓度为800mg·L-1(B2)+插穗长度13cm(C2)组合最好,其生根率最高;不同插穗下切口型的扦插试验中,以平切面(D1)的生根率最高;将已诱导生根的卷斗青冈扦插苗移栽至6种配方的轻基质网袋容器中,以泥炭∶椰粉∶珍珠岩=3∶2∶1(E6)的配方的生长情况最优。     

互叶白千层扦插育苗技术初探

以互叶白千层当年生的嫩枝为试验材料,采用L9(34)正交试验方案,研究不同生根促进剂、不同浓度以及不同基质对互叶白千层扦插生根的影响,筛选各因素水平的最佳组合。试验结果表明:生根促进剂的种类及其浓度对扦插生根影响显著;ABT/NAA混合促进剂,浓度为1 000 mg.kg-1,基质采用珍珠岩和泥土1∶2组合,是互叶白千层扦插最佳的因素水平组合。其生根率可达78%,生根数可达4.02条,最长生根长度为3.48 cm。     

栓翅卫矛嫩枝扦插育苗技术

在节能二代温室内用穴盘进行栓翅卫矛的嫩枝扦插育苗试验。结果表明,在7年生优良母树上,采集母树中上部1年生嫩枝,在6月底7月初用1 000 mg/L的IBA+NAA生根剂溶液速蘸10~15 s后,按蛭石∶珍珠岩=1.5∶1的比例作基质进行扦插,其生根时间早,成活率最高,生根率达到90%以上。     

紫椴嫩枝扦插繁殖技术研究

为了筛选能提高紫椴生根率的扦插繁殖技术,文中研究了植物生长调节剂的不同种类(ABT1、IBA、NAA)、浓度(50、100、200 mg L-1)、浸泡时间(1、4、8 h)、基质类型(河沙、蛭石、体积比为3∶1的泥炭与珍珠岩)、母株年龄(1、2 a)对紫椴嫩枝扦插生根质量的影响情况。结果表明:植物生长调节剂的处理效果以IBA为最好,其对紫椴嫩枝的生根率、生根数量和平均根长的影响显著;嫩枝扦插,以100 mg L-1的IBA浸泡时间8 h的处理为最优组合,其生根率为63.07%;3种不同类型扦插基质的生根效果明显不同,河沙的生根效果最好,生根率最高达到37.16%,蛭石次之,泥炭土+珍珠岩(体积比为3∶1)最差。不同母株年龄对紫椴嫩枝扦插生根的影响也不同,1年生紫椴嫩枝的生根质量比2年生嫩枝好,其生根率、生根量和平均根长均明显优于后者。     

榉树的扦插繁殖技术

为了寻找适合榉树新品种的繁殖技术,就采穗母树的树龄、扦插基质、激素种类和浓度对榉树扦插生根的影响进行了扦插繁殖试验。结果表明:随着采穗母树树龄的增加,榉树扦插生根率呈显著下降趋势,用以扦插的采穗母树以幼龄树比较合适;扦插基质以珍珠岩∶泥炭土等于3∶1的为好;榉树扦插用的激素以NAA与IBA混合使用的效果为好,其中以3.0 g.L-1的IBA和3.0 g.L-1的NAA混合的效果为最好,其生根率为58.7%。     

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.