山东省白榆种源选择研究报告

白榆是我国分布广、栽培历史悠久的优良乡土树种。但过去对白榆种源未开展系统研究,自1980年开始,由中国林科院林研所主持,组织了全国白榆种源选择科技协作,本试验属全国协作的组成部分,在省内组织了白榆种源选择研究协作组,从该年开始,进行国内全分布区的地理种源试验、产地加家系子代测定试验和省内产地试验。其目的主要是探索白榆全分布区种源及省内不同种源的变异规律,为提高白榆选种和生产水平提供科学依据。经1980～1985年多点苗期和造林试验,初步     

15年生火炬松种源试验研究初报

１９８１年在我国３个气候带７个试验 开展火炬松全分布区种源试验。试验目的是找出火炬松种源地理变异规律,综合评选出适合不同气候的优良种源,达到“适地、适树、适原”。试验采取９株小区、６次重复、种源与树种对比同时进行,即有产自美国１０个州的种源各１个及福建南屿林场次生种源,用湿地松（Ｓ－８）及当地马尾松作对照;采用５￣８个月苗龄容器育苗造林。试验结果表明,火炬松种源差异显著;种源高生长与原产地最低温度     

杉木地理变异及优良种源选择

本文对两次杉木全分布区种源试验各点试验林的生长、发育、适应性等进行分析,评定种源优劣与环境互作。研究表明:杉木种源间存在极显著差异,第一次试验各试点20个参试种源11年生材积前三名平均生产量为后三名的152%—183%;第二次试验各点造林64个种源8年生材积前十名平均生长量为后十名的191%—223%。材积最大种源为最小种源的2—4倍。本省种源也优劣悬殊,我省不同地区种源选择增产效果为0—59%。根据生长量、开花结实状况、稳定性,树皮厚度、侧枝粗度、bi 值等指标综合评定,为我省不同地区选择了一批优良种源并提出了种、条调拨意见。     

白榆种源试验研究报告

前言本项试验是1980年参加由中国林科院林研所主持的全国白榆种源研究协作课题,1983年列入区内白榆种源试验研究。区内在呼市、乌盟、伊盟三处组织了二级白榆区域协作试验。六年来已看出不同种源苗期到幼林     

乐昌杉种在杉木地理种源试验中的表现

在生产实践中可发现到,不同种源营造的杉木林分,生长差别悬殊;一些小规模的杉木种源试验结果也显示出进行杉木种源选择的增产潜力。我县在1973年冬便开始进行了杉木地理种源试验,初步确定了几个适于本县生长的优良杉木种源,乐昌杉种是其中之一。1976年以来,我县杉种又作为试验种之一,参加了全国杉木地理种源试验,该试验经过几年较系统的试验比较,已于1985年底初步综合评选出了一批我国南岭山地的杉木优良种源,其中我县的杉种也是有较明显增产效益的优良种源之一。一、九省杉木种源在乐昌的生长评定(一)试验情况1973年冬,搜集了湖南江华、会同,广东乐昌(大源茅坪),贵州天柱,浙江丽水,广西融水,福建莱州,江苏宜兴、江西赣州,四川德昌等九省十个产地的杉木种子,在乐昌县大源区进行了地理种源试验。试验点位于北纬25°,东经113°,海拔高700m,最低气温-2—5℃,最高气温30—     

不同林龄马尾松的种源选择效果

利用1984年营造的马尾松全分布区种源试验林在5,10,15,20和25年生时测定材料,分析种源主要生长性状在不同测定年龄的遗传变异和早期优良种源选择效果.结果表明:胸径、树高和材积等马尾松主要经济性状在种源间存在差异,这种差异有随试验林年龄增长而不断加大的趋势,25年生时各性状最大种源比最小种源分别大94.85%,47.66%和355.68%.虽然材积等主要生长性状在不同年龄间生长与秩次相关均极显著,但由于不同种源的早晚生长习性不尽相同,过早开展种源选择可能会误选或漏选部分优良种源,如把正确入选率控制在90%以上,则马尾松种源试验优良种源早期选择的合理年龄应在10～15年生,其相应的选择强度为材积遗传增益>20%或种源入选率在30%～40%.     

马尾松造林区优良种源选择*

利用１９７６年开始的全国马尾松种源试验１３省（区）６批种源试验林（含局部、全分布区种源试验及中试）材料，对幼林高径、材积生长，干形，结实，抗性，保存率等作性状间遗传、表型相关和年度间相关分析，结果表明对马尾松种源作早期选择是可行的。据两次全分布区试验多点材积资料分析，种源与造林区，种源与试验点间均存在明显的交互作用，种源材积在地点间相关密切；用Ｗｒｉｇｈｔ模型衡量两次试验各参试种源稳定性并划分类型     

第一次杉木种源试验幼林阶段初报

为探讨杉木不同地理种源遗传变异规律,合理地区划种源,使调拔种子有一定的科学依据,做到适地适树适种源,以提高林分生产力,并提供育种原始材料,由中国林科院林研所统一组织,于一九七七年春开展全国第一次杉木种源试验。现将4年生幼林试验结果报导如下:     

种源试验、种源—子代测定和子代测定—实生种子园

种源试验、种源—子代测定、子代测定—实生种子园是林木良种选育工作中常用的方法。本文试图简要地介绍有关概念、方法及提出一些建议,供大家参考。一、种源试验种源(provenance)通常泛指种子和苗木的原产地或原始起源地(origin area),因而人们也常把种源试验(provenance trial)称为产地试验。到目前为止,对于种源的确切含意仍有不同理解,有人认为种源相当于产地,产地指某个地区,而这个地区内有若干个林分;但也有人把一个或几个相邻的林分作为一个种源。例如1911年德国在北部伦茨堡林区进行的欧洲赤松(Pinus sylvestris)种源试验中,5个种源分别来自萨     

全国杉木第二次地理种源试验实施方案

全国杉木良种选育科技协作组,于1976—1978年组织了有全国十四省(区)参加的全国杉木第一次地理种源试验。在中国林业科学研究院领导和各省(区)有关部门、生产单位的大力支持下,经参加试验各协作单位的共同努力,已按原试验方案完成了育苗对比试验及造林工作,进入造林后观测阶段,达到了预期目标。由于杉木的授粉、结实和环境条件的变化大,一次种源的试验结果,难于作出科学的判断,加上第一次种源试验缺乏经验,在组织和试验实施上都还存在一定问题。因此,有必要总结经验,继续开展全国杉木第二次地理种源试验。现根据二年来的实践,有关协作单位的意见,对全国杉木第一次地理种源试验实施方案(讨论稿)进行修改、补充,提出全国杉木第二次地理种源试验实施方案如下:     

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.