抚顺地区油松人工林病虫害调查

油松林是抚顺地区两大人工针叶林之一,在森林生态系统中占有重要的生态位。大面积的油松人工纯林为以油松为取食对象的病虫害提供了丰富的食源。为了培育健康的油松林,避免危害发生,该文对抚顺地区的油松林病虫害进行了长期的调查与监测,以掌握其发生趋势,尽早发布预警预报,为实施调控提供依据。     

油松花粉采集技术

油松是我国北方地区的一个主要造林树种，其花粉资源十分丰富。承德市范围内就有人工油松林22万hm^2，且多为中幼龄林，花粉总储量近2000t，易于人工采集。油松花粉广泛应用于保健品行列，现市场价格在每吨3万元左右，市场前景广阔。     

千家坪林区油松赤枯病调查及对策

本文调查了陕西省平利县千家坪林区油松赤枯病的发生和危害情况，在调查的818．4hm^2油松人工林中，发病611hm^2，占74．4％。同时对赤枯病的发生特点进行了调查，结果表明该病的发生与树龄、海拔、坡向有一定的关系。在高海拔地区应该采取更新树种，低海拔地区进行疏伐和化学防治的策略。     

3种生物制剂喷烟防治油松毛虫试验

油松毛虫(Dendrolimus Tabulaeformis)是我国北方森林危害最严重的食叶害虫，分布范围广，发生面积大，危害造成的损失严重，在我国主要分布在西北、华北、东北部分地区和四川省。甘肃省主要分布在陇南地区成县和西和县，发生面积3000hm^2。油松毛虫大发生时，大面积油松针叶被吃光，影响油松生长，连年危害造成油松成片枯死。     

辽宁省栗山天牛综合防治对策

栗山天牛(Massicus raddei)是一种钻蛀性害虫，主要危害栎属、栗属、桑属、玄参科、泡桐属等，在辽宁省主要危害蒙古栎、辽东栎。栗山天牛于1992年在辽宁省首次发现，目前发生面积已达12万hm^2，发生区主要分布在抚顺、丹东、本溪、锦州、阜新、葫芦岛等地区。为有效地控制栗山天牛的危害，辽宁省经过多年的防治实践，探索出适合辽宁地区的综合防治技术，并有效地控制了栗山天牛的危害。     

辽西地区水土保持林主要林分类型及结构特征分析

对辽西地区现有几种主要的水土保持林分类型进行了结构特征分析，结果表明，混交类型的水土保持林，其林分层次结构、生长情况均好于油松纯林，物种我样性指数高于纯林；林分生物量以油松－刺槐形成的乔木混交林最高，达96．550t/hm^2，比油松纯林提高57．658t/hm^2；各类型混交林林地土壤理化性质有了很大的改善，混交类型林地土壤容重比纯林减小0．05－0．2g/cm^3、孔隙度提高0．76％－3．45％、有机质提高0．03％－0．73％、全氮含量提高0．004％－0．036％，说明油松阔叶混交林在改善土壤理化性质方面起了重要作用；林分枯枝落叶量及持水量也明显高于油松纯林，油松－刺槐形成的乔木混交林是辽西地区林分结构较为理想的混交类型。     

皋落林场

中条山国有林管理局皋落林场位于中条山区的垣曲县境内,始建于1950年。经营总面积1．59万hm^2，其中有林地面积10133万hm^2，活立木总蓄积33万m^3，有林地中乔木树种主要有栓皮栎（占林分面积60％）、油松、辽东栎，辖区森林覆盖率达到4120％。国家天然林保护工程实施以来，共完成天然林保护工程飞播造林872hm^2，封山育林1050hm^2，全部达到合格以上工程。     

油松松针锈病病原菌的研究

油松(Pinus tabulaeformis)分布在辽宁、河北、山东、内蒙古等地,因为生长迅速,木材纹理致密通直,所以是经济建设大地园林化的重要树种。但在近30年来,随着大面积人工林栽植与成林,油松松针锈病亦相继普遍发生。即如1958年本溪达贝沟、草河口、凤城通远堡、清原及新宾一带油松、赤松发生不同程度松针锈病的危害。至1965年凤城通远堡12年生油松林发生较严重的松针锈病发病率为40％;同年章古台地区8—9年生,数十亩油松林发生严重的松针锈病,发病率为100％,病情指数为58—91。1979年清原辽宁省林校数百亩油松、赤松林发病率为40—     

抚顺地区松树外生菌根菌调查

为了更有效地保护和利用抚顺地区珍贵的外生菌根菌资源,该文对抚顺地区松树外生菌根菌的种类、资源分布、林相特征等进行了调查分析。文中以与油松形成外生菌根的血红铆钉菇为例,分析了血红铆钉菇资源减少、产量下降的原因,建议重视发展赤松林和油松林,积极研究和探索油松林及赤松林的更新换代,为发展血红铆钉菇等外生菌根菌创造条件。     

北京西山油松人工林结构特征研究

以西山试验林场近自然经营试点区建立的11块中龄油松人工林样地为依据,对油松林分的结构特点、表达模型和树种多样性格局进行了分析。结果表明：油松人工林林分平均密度为1069株／hm^2,平均胸径为13．7cm,平均高为8．6m,蓄积量为86．36m3／hm^2。应用正态分布、Weibull分布、对数正态分布、Gamma分布和Beta分布拟合直径和树高结构,发现正态分布拟合直径分布和树高分布效果最好,也符合人工林的林分结构规律;油松人工林层次结构简单,物种多样性较低,乔木层、灌木层和草本层的Shannon—wiener指数、均匀度指数分别为0．355、0．726、0．160和0．372、0．651、0．266;幼苗更新各高度级均以构树和栾树为主,他们分别占总体更新树种的72．2％和10．2％。     

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.