闽楠无性系扦插繁殖试验

对闽楠无性系采穗圃嫩枝进行扦插繁殖生根试验,结果表明:闽楠无性系嫩枝扦插生根兼有愈伤组织生根和皮部生根两种生根类型,参试的20个无性系中有15个无性系以皮部生根类型为主,占参试无性系的75%,有5个无性系同时包含有两种生根类型;闽楠无性系嫩枝生根能力(根系效果指数REI)与生根率之间成显著的正相关关系;在遮荫降温、农膜保湿及自然温度条件下,以6月、9月和10月上旬闽楠嫩枝扦插生根率最高。     

大叶桂樱无性系扦插繁殖

对大叶桂樱(Laurocerasus zippeliana)无性系采穗圃嫩枝进行扦插繁殖生根试验,结果表明:大叶桂樱无性系嫩枝扦插生根兼有皮部生根和愈伤组织生根,参试的10个无性系中有2个无性系同时含有2种生根类型,有8个无性系以皮部生根类型为主,占参试无性系的80%。大叶桂樱无性系嫩枝生根能力既根系效果指数REI与生根率之间成显著的正相关关系;在遮荫降温、农膜保湿及自然温度条件下,以6月、9月和10月上旬大叶桂樱嫩枝扦插生根率最高。     

大叶桂樱无性系扦插繁殖

对大叶桂樱（Laurocerasus zippeliana）无性系采穗圃嫩枝进行扦插繁殖生根试验,结果表明：大叶桂樱无性系嫩枝扦插生根兼有皮部生根和愈伤组织生根,参试的10个无性系中有2个无性系同时含有2种生根类型,有8个无性系以皮部生根类型为主,占参试无性系的80%。大叶桂樱无性系嫩枝生根能力既根系效果指数REI与生根率之间成显著的正相关关系;在遮荫降温、农膜保湿及自然温度条件下,以6月、9月和10月上旬大叶桂樱嫩枝扦插生根率最高。     

杂交松无性系嫩枝扦插繁殖效应分析

研究表明,杂交松无性系间嫩枝扦插繁殖生根率有显著差异,参试无性系穗条扦插生根率变幅为81.1%~28.9%。本试验筛选出了扦插生根率高的无性系1个即杂P02;生根剂不同浓度处理对参试的5个无性系嫩枝扦插生根率无显著影响;不同基质对嫩枝扦插生根率有显著影响,以纯黄心土作为扦插基质效果最佳。     

台湾桤木无性系扦插繁殖试验

以台湾桤木52个无性系为材料进行扦插试验,试验结果表明:台湾桤木无性系扦插生根兼有皮部生根和愈伤组织生根两种生根类型,大多数无性系为皮部生根类型,少数无性系同时包含两种生根类型;台湾桤木无性系生根能力(根系效果指数REI)与生根率成正相关关系;台湾桤木不同无性系之间扦插生根率差异显著,52个无性系中具有优良生根性能的无性系15个,包括湘桤F01、湘桤F02、湘桤F03、湘桤F04、湘桤F05、湘桤F06、湘桤F07、湘桤F08、湘桤F09、湘桤F10、湘桤F11、湘桤F12、湘桤F13、湘桤F14、湘桤F15,其扦插生根率达80%以上;在遮荫保湿条件下,以9月上旬扦插成活率最高;扦插基质以无菌黄心土或泥炭加珍珠岩为佳;穗条带1~2片叶可显著提高生根率;GGR生根剂浓度以300 mg/kg最好。     

川黔紫薇嫩枝扦插繁殖效应研究

以川黔紫薇嫩枝为试验材料,采用15个川黔紫薇无性系扦插繁殖试验筛选出的扦插生根率高的无性系5个,即湘紫L01、湘紫L02、湘紫L06、湘紫L07、湘紫L11进行川黔紫薇嫩枝扦插繁殖效应研究。结果表明:参试无性系穗条扦插生根率变幅为42.2%~89.8%;带2~4个半片叶的穗条可显著提高穗条的生根率;多菌灵不同浓度处理对穗条生根率有显著影响;GGR生根剂不同浓度处理对穗条生根率没有显著影响;不同扦插基质对穗条扦插生根率有显著影响,考虑成本因素,纯黄心土是最经济有效的扦插基质。     

红椿无性系嫩枝扦插繁殖试验

为解决优质家具材树种红椿苗木快繁的问题,开展了红椿无性系嫩枝扦插繁殖试验.结果表明:10个无性系穗条扦插生根率变幅为47.4％ ～91.5％,TC01、TC04和TC08这3个无性系扦插生根率最高,无性系间的生根率有极显著差异;穗条带2片叶可显著提高穗条的生根率;不同浓度GGR对穗条生根率有显著影响.     

板栗扦插繁殖的系统研究

本文系统研究了板栗扦插繁殖技术,插穗生根特性,嫩枝扦插不定根形成的细胞组织学基础和嫩枝扦插生根过程中营养物质的消长规律。结果表明,板栗嫩枝扦插,经HL—43生根剂(自制)处理,在全光照喷雾条件下,生根率可达80％以上,插条生根率与母树年龄、枝条木质化程度呈负相关;扦插时间以5月中旬～7月下旬最适宜,8月后生根率下降;插条部位以中部条生根率最高,基部条次之,梢部条最差;不定根主要发生于韧皮部和维管形成层,从皮部伸出,为皮部生根树种,愈伤组织生根极少,插条大量生根时间,碳水化合物和氮素含量明显下降,表明板栗扦插生根过程需要大量碳水化合物。     

平欧杂种榛子扦插育苗试验研究

经过2 a多对平欧杂种榛子扦插试验研究的结果表明:(1)400 mg·L-1GGR1号生根粉水溶液浸泡的插穗生根率最高,达65.1%,清水处理的穗条效果最差,生根率为6.7%;(2)一年中插穗在6月、9月扦插效果最好,成活率分别可达58.86%、67.48%;(3)插穗摘除1/3叶片扦插效果最好,生根率达66.7%;(4)母树上部穗条扦插效果最佳,成活率可达66.8%;(5)平欧杂种榛子插穗以皮部生根为主,属于皮部和愈伤组织混合生根型,夏季扦插60 d后成活穗条皮部生根的占84.46%。     

全光照自动喷雾条件下毛红椿嫩枝扦插正交试验分析

在全光照自动喷雾条件下通过正交实验L9（34）,2013年4~6月研究插穗粗度、插穗长度、激素处理时间和基质4个因素对1年生毛红椿嫩枝扦插的影响。结果表明,毛红椿嫩枝扦插生根均属皮部生根型,不同处理对嫩枝扦插生根、苗木生长均有显著影响,各因素对发根数量影响大小依次为插穗粗度〉插穗长度〉激素处理时间〉基质,对最长根长度、生根率、根系效果指数的主次效应均是基质〉插穗粗度〉插穗长度〉激素处理时间,插穗粗度是扦插发根数量的决定因素,基质对扦插生根起重要的主导作用。本次扦插最佳组合为：插穗粗度0.31~0.4 cm、长度4.1~6 cm、300倍根太阳生根剂浸泡5 s、膨化蛭石＋泥炭土3∶1基质,扦插生根成活率高达95.1%,将有利于毛红椿嫩技扦插的规模化设施育苗。     

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.