广东省杉木无性系选育程序与策略

对广东省的杉木无性系选育程序与策略提出了建议，即把近阶段的优良种源、优良家系混系繁殖利用迅速提高到优良杂交个体的无性系利用方面来；全省需要制订１个综合育种体系，包括有性选育系统与无性选育系统，在应用时做到有性与无性交互使用，多层次多途径地利用各方面的遗传效益，以充分发挥遗传改良效果。对今后育种群体建设，提议采用单群体多功能实生种子园方案。并对早期测定，群体遗传结构的改变和基因型与环境交互效应问题进行了探讨。     

云南松优良无性系早期选育关键问题的探讨

多年来,对云南松的遗传改良一直沿着有性方式的方向进行,虽然积累了丰富的有性改良材料,却忽视了无性改良的优越性.针对这一问题,在回顾有性改良工作的基础上,对无性改良的可行性汗丶侍饨辛颂教?如育种群体的建立、早期选择年龄的确定、如何提高无性繁殖系数等.针对缩短育种周期、提高单位时间遗传增益和选择可靠性的目标,提出了无性系早期选择的程序.     

高世代杉木种子园营建技术

国家科技攻关项目“高世代杉木种子园建立技术研究”，根据轮回选择、多世代遗传改良原理，经过10年的努力．选出初级化树52株、2代化树46株；建立来穗困4公顷；评选出优良全同胞家系31个，半同胞家系120个，双系种子园亲本8组；改建1．5代种子园118．5公顷，新建1．5代种子园100公顷，双系种子园10．67公顷，2代种子园13．33公顷。该项成果已在湖南及周边省份推广应用，其前景十分广阔。专家鉴定认为：按20年为一个周期，1．5代种子园后代材积增益20％，双系种子园后代材积增益30％．种子利润每千克20元，木材每立方500元，折现率12％计算…     

云南松遗传改良研究进展及育种策略

本文在综述云南松地理变异与种源试验、优良林分选择与母树林建立、优树选择与种子园建立等遗传改良研究现状的基础上,针对存在的问题提出了今后的育种策略,尤其要重视遗传资源的收集、开展遗传变异和遗传多样性研究、营建高世代种子园、提高种子园的经营管理,以及加强无性系早期选择等研究.     

樟子松优树后代测定方法的研究

在建立种子园的同时，对各产地的优树进行了后代测定，笔者就有性与无性测定 方式等提出了建议，并对今后建立高世代种子园提供了借鉴。     

关于山东省林木遗传育种研究的思考与建议

根据国内林木遗传育种发展的现状与趋势，结合山东省的林木改良情况，讨论了育种策略、育种群体、有性与无性结合、育种区划和区域试验、早期选择、多性状指数选择等问题，并提出一些建议。     

杉木幼林选优及无性利用的初步研究

优树的利用有两种途径:一是有性利用,即建立种子园,控制授粉,经半同胞和全同胞子代测定后,生产出遗传品质优良的种子用于生产;二是进行大量的无性繁殖,用于生产。从理论上来看,后者获得的遗传增益大,而且缩短了育种程序和周期。但是,目前杉木老枝扦插成活率很低,用嫁接的方法成本很高,难于大面积推广。能否在实生幼林中选优,并用扦插育苗的方法加以繁殖、测定,评选出优良的无性系,获得比家系更大的遗传增益?本文将用杉木幼林优树与其无性后代生长量的相关关系及后代测定结果来论证此一问题。     

关于山东林木遗传育种研究的思考与建议

根据国内林木遗传育种发展的现状与趋势，结合山东少年省的林木改良情况，讨论了育种策略、育种群体、有性与无性结合、育种区和区域试验、早期选择、多性状指数选择等问题，并提出一些建议。     

杉木不同世代不同类型种子园遗传改良增益研究

以浙江省17个无性系种子园为研究对象,连续2年采种育苗造林,进行2次4地点5区组的种子园子代测定试验,测定树高、胸径、材积、冠幅、侧枝等8个性状.结果表明:从未经遗传改良普通林分种子到1代、1.5代、2代种子园,子代生长增益是逐代增长的,但世代之间增幅明显下降.优良双系种子园子代生长增益最大,优良种源种子园次之.1代、1.5代和2代种子园,种源种子园,双系种子园的子代生长,在6年生时,树高生长现实增益分别为4.35%、6.04%、7.88%、12.02%和12.02%,遗传增益依次为3.90%、5.41%、7.06%、10.77%和10.77%;胸径现实增益为7.60%、9.68%、12.08%、15.05%和19.70%,遗传增益为7.07%、9.00%、11.23%、14.00%和18.32%;材积现实增益为20.65%、27.47%、32.14%、39.93%和46.14%,遗传增益为16.97%、22.58%、26.42%、32.82%和37.93%.为持续获得高增长的遗传改良效果,在高世代种子园建设中,应充分发掘和优先利用优良种源的优质种质资源;在提升育种群体遗传水平,保持遗传基础多样性的同时,建立双系种子园,实现工业原料林用种的品种化,应是今后的一个重要发展方向.     

苏南杉木当地单株选优与种源选择的效果比较

杉木的遗传改良应以种源选择为主。先选择适宜的优良种源组成育种原始群体，再从优良种源群体中选出优良单株，建立嫁接种源种子园。然后，根据后代表现挑选最优亲本建立第一代生产性种子园，或直接引进优良种源经鉴定的优良单株无性系，建立一代性种子园．这样优树子代才能有效地提高选种的效益，而从当地种源杉木中选优，建立种子园意义不大，优树子代多表现不良。     

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.