四翅滨藜育苗技术

四翅滨藜是饲料型灌木树种，1994年从美国引进。本文就该树种在山西省栽培范围、树种特性、育苗技术要点进行了介绍，为该树种规模繁殖和推广提供了帮助依据。     

山西省森林物种多样性分析

为了科学规划发展人工林,促进植被恢复,提高山西省森林物种多样性,笔者利用2015年山西省第九次森林资源清查数据,对山西省主要造林乔木树种、灌木树种的多样性进行了研究。结果表明,2015年山西省乔木树种香农-威纳指数值达到4.426,灌木树种香农-威纳指数值达到3.754,表明山西省森林植物多样性丰富,分布较为均匀,造林规划科学合理。     

山西省秋千沟林场林种和树种结构的研究

选用分析系统递阶层次结构的层次分析法作为数学工具。对山西省秋千沟林场的林种、树种结构进行了研究。结果表明，该法对于“目标结构比较复杂，缺乏必要数据的结构优化问题”比较适用，可按兼顾生态效益、社会效益、经济效益，又有所侧重的原则，将各林种、树种的面积比例落实到合理的水平上。     

千沟林场林种、树种结构的研究

本文对山西省秋千沟林场的林种、树种结构进行了研究。在结构优化过程中，考虑到森林结构的层次性，选用了分析系统递阶层次结构的层次分析法作为数学工具，结果表明：该法对于“目标结构比较复杂，缺乏必要数据的结构优化问题”比较适用，可按兼顾生态效益、社会效益、经济效益，又有所侧重的原则，将各林种、树种的面积比例落实到合理的水平上。     

山西省林业科学研究院

正山西省生物防火林带构建技术研究完成单位:山西省林业科学研究院内容简介:提出了山西省生物防火林带建设中防火树种选择、防火林带宽度和结构、山西省生物防火林带营造模式的关键技术。对山西省30个主要造林树种的理化性质指标和生物学、生态学特性指标数据,采用层次分析法进行综合评判排序,数量化划分了各树种的防火能力。通过     

山西省主要树种立木材积表管理系统研究

以《山西省主要树种立木一元材积表》和《山西省主要树种二元材积表》为基础资料,实现了山西省主要树种一元材积表和二元材积表的数字化、可视化、计算机化管理。同时,根据山西省林业调查工作的需要拓展了相应功能,满足在森林资源调查工作中对材积的查询、大径界材积计算、样地调查因子计算等需要。系统由材积查询模块、基础信息模块、蓄积调查计算模块、数据导入导出模块等组成,镶嵌有山西省主要树种二元材积计算公式、轮尺围尺转换公式。具有查询快捷、使用方便、界面友好、可即时更新等特点。     

山西省林业科学研究院

正珍贵用材树种黄菠萝引种及人工林培育技术完成单位:山西省林业科学研究院内容简介:项目针对山西省珍贵阔叶用材树种稀缺的现状,将原产于我国东北地区的珍贵用材树种黄菠萝引种到霍州、安泽等地,经过40余年的试验和观测研究,引种成功;根据黄菠萝的生物学、生态学特性,进行了树种适应性评价,提出了黄菠萝在山西的适宜栽培区域;同时进行了黄菠萝播种育苗、造林、大苗移植等试验研究,总结出黄菠萝人工林培育系列技术,对山西省珍贵用材树种培育具有重要意义。     

山西省文冠果种质资源调查分析

文冠果是我国珍贵的生物质能源树种,也是优良的水土保持树种、园林绿化树种和蜜源植物树种。笔者通过查阅资料、电话咨询和实地调查等方式,初步了解了山西省野生文冠果种质资源的分布概况和生境特征,以期为山西省文冠果种质资源的开发利用提供科学依据。     

珍稀乡土树种大果榉在国土绿化中的应用

系统介绍了大果榉（Zelkovasinica Schneid．）的分类位置、地理分布、生态习性和用途；通过综述大果榉及其近缘树种的研究进展，表明大果榉是山西省珍稀乡土树种，在国土绿化中有很大的发展潜力；同时，对大果榉繁育技术进行研究，筛选出适用于不同造林绿化目的的大果榉苗木，对于丰富我省的造林绿化树种、培育珍稀用材树种以及振兴乡土树种具有重要的经济意义和生态价值。     

晋北地区文冠果育苗及造林技术探讨

文冠果是晋北地区常见的乡土经济树种，在荒山绿化和产业发展中具有重要的生态价值和经济价值，是山西省特色经济林造林树种之一。介绍了晋北地区文冠果育苗与造林技术。     

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.