长白落叶松全光喷雾嫩枝扦插育苗技术的研究

在全光喷雾条件下,采用长白落叶松嫩枝进行扦插试验。结果表明,长白落叶松嫩枝扦插应在2a生幼树上采用地径(距切口3cm处)2 0～2 6mm、穗长10cm的嫩枝做插穗,从生根率、平均根数、平均根长等因素综合比较,用GGR6号50mg·kg-1、GGR7号150mg·kg-1溶液处理,插穗生根效果好,生根率稳定在85%～90%以上。     

植物生长素对东北红豆杉嫩枝扦插生根的影响

以ABT-1#、2.4—D、IAA、IBA、NAA5种植物生长素处理东北红豆杉当年生半木质化嫩枝,进行扦插生根试验,结果表明:嫩枝插穗扦插40~60 d后在形态下端形成愈合瘤,并逐渐长出不定根,属于愈合组织生根型;在激素配比均为100×10-6的条件下,经2.4-D处理的插穗生根率达到68%以上,经ABT-1#和IBA处理的达到52%以上;采自幼龄植株的嫩枝插穗生根率高于老龄植株。     

植物生长素对东北红豆杉嫩枝扦插生根的响

以ABT-1^#、2．4-D、IAA、IBA、NAA5种植物生长素处理东北红豆杉当年生半木质化嫩枝，进行扦插生根试验，结果表明：嫩枝插穗扦插40-60d后在形态下端形成愈合瘤，并逐渐长出不定根，属于愈合组织生根型；在激素配比均为100×10^-6的条件下，经2．4-D处理的插穗生根率达到68％以上，经ABT—1^#和IBA处理的达到52％以上；采自幼龄植株的嫩枝插穗生根率高于老龄植株。     

银杏扦插育苗试验研究

通过对银杏不同插穗枝条、插穗愈合生根条件、插穗剪口形状、树龄、生根粉浓度进行对比试验,结果表明:插穗剪口为斜剪口,室内相对湿度85%~95%,温度22~28℃,基质含水率35%~55%的环境是保障银杏插穗正常愈合生根的最佳条件;银杏各类枝条插穗在生根粉溶液中浸泡的时间长短对插穗愈合生根无明显影响;生根粉的浓度为100 mg.L-1时插穗生根率最高。     

枣树扦插育苗研究

于生长旺季，分别采取铃铃枣、板枣、骏枣、木枣与油枣绿枝插穗，经吲哚丁酸（IBA）0．3％与0．5％浓度处理后，扦插于塑料大棚内，保持空气相对湿度90％，气温不超过30℃，1个月后板枣与骏枣插穗生根率达90％，其它3个品种插穗生根率达70％以上。生根插穗移植苗圃成活率为80％左右。试验表明，7月中旬至8月上旬进行扦插，效果最好。     

沙棘不同节数插穗嫩枝扦插生根率比较

利用不同节数(芽数)嫩枝插穗进行扦插试验,结果表明不同节数嫩枝插穗扦插皆可生根,但生根率差异较大;1～2节(1～2芽)插穗生根率低,3节(3芽)以上生根率较高,生根率随节数(芽数)的增加而提高.     

南京椴嫩枝扦插技术研究

以南京椴嫩枝为研究材料,通过设置不同IBA粉剂处理浓度、穗条制备保留叶片数量、制备穗条的枝条粗度等,研究穗条制备及处理对南京椴嫩枝扦插生根的影响。研究结果表明:使用IBA粉剂处理有助于插穗生根,处理浓度以1 000~1 500 mg·L~(-1)为宜,可兼顾扦插生根率与生根质量;嫩枝插穗适度保留叶片有助于生根,保留一片完整叶片效果最佳,生根率可达80%,且所生根系质量较优,除腐烂插穗外其余插穗全部生根;插穗粗度对插穗生根效果存在影响,幼嫩细枝扦插生根率较低且所生根系质量不高,插穗粗度应不低于0.55 cm;南京椴扦插生根不属于愈伤组织生根型,其多由插穗下切口处及切口上部皮部生根;水分控制对于南京椴嫩枝扦插至关重要,选用透水效果较好的珍珠岩、及时拣除掉落叶片、增加自动喷雾频次、降低喷雾时间等措施将有利于插穗生根。南京椴嫩枝扦插以选用粗度0.55 cm以上半木质化枝条制备插穗为宜,插穗长10~15cm,上切口平截,下切口单面斜切,保留一片叶片,扦插前插穗基部蘸取1 000~1 500 mg·L~(-1) IBA粉剂进行促根。     

柳桉组织培养与工厂化育苗技术研究

以柳桉带腋芽的幼嫩茎段为外植体进行组培快繁，其启动培养、增殖培养、生根培养的最佳培养基依次为MS＋6-BA2＋NAA1、改良MS＋6-BA0．2＋NAA0．2＋IBA0．8、改良MS＋NAA0．2＋IBA0．8，繁殖系数可达3以上，生根率可达85％以上；试管苗移栽前需炼苗10—15d，移栽时间选在3、4、10、11月份移栽成活率最高，可达90％以上；柳桉萌发力强，试管苗移栽成活后长到一定高度经过采穗可促使腋芽不断；蒡发，生产上可利用此原理建立田间采穗圃，1株试管苗6个月内可供采穗10—12根；试管苗移栽前必须经过一个炼苗阶段，炼苟时间为10—15d，移栽成活率可达90％以上；气温与柳桉扦稳的愈合、生根关系十分密切，在气温18—25℃时扦插，有利于插穗愈合生根；使用50mg／LGGR溶液处理插穗，可使插穗生根提早5d左右，同时可使生根率提高10％。     

丘陵山地银杏扦插繁殖试验初报

在丹东地区丘陵山地开展了银杏扦插繁殖试验,对插穗截取部位、萘乙酸生根剂不同浓度和插穗长度对扦插成活率和生根率的影响进行了分析。结果显示:银杏1年生枝条中部生根率较高,生根率可达84.4%;NAA的浓度影响生根率,其中400μg·kg~(-1)成活率最高;8~12cm长的插穗,生根率均达到90.83%以上。     

迷迭香扦插繁殖技术研究

以经种植筛选的迷迭香组培苗3-5 cm的嫩芽及7-10 cm的嫩梢作为插穗,研究了不同基质、季节和生根促进剂等因子对生根率的影响。结果表明:以珍珠岩:河沙(1:2)作基质,激素以IBA 50 mg/L 处理插穗30 min,于春季扦插有利于生根和移栽成活率的提高,插穗生根率达98％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.