杨树抗蝉害性的调查

本文通过对两片杨树林的20个杨树无性系的蝉害调查,初步确认其中3个杨树无性系具较强的抗蝉害性。即Ⅰ—69杨×美洲黑杨(Populus deltoides cv‘Lux’×P.deltoides)的两个无性系52号和66号,Ⅰ—69杨(P.deltoides cv‘Lux’)。     

转PeTLP基因‘南林895’杨对土壤微生物的影响及外源基因分子检测

转基因技术是当今林木分子育种的手段之一,但其生物安全性问题广受关注。本研究选择进入田间试验的转PeTLP(类甜蛋白)基因‘南林895’杨Populus deltoides×P. euramericana cv.‘Nanlin 895’为材料,开展转基因杨树对土壤微生物影响及外源基因分子检测等分析。结果显示,转基因杨树在进入田间试验一年后,外源基因仍稳定存在于转基因植株基因组中;转基因与非转基因植株根系周围可培养土壤微生物菌落数量无显著差异,表明外源基因对土壤微生物无显著影响;对土壤微生物总DNA进行分子检测也显示外源基因未有向周围土壤微生物扩散现象;叶片化感作用试验显示转基因植株叶片未对生菜Lactuca sativa L. var. ramose Hort.种子的生长造成显著影响。初步分析结果表明,转PeTLP基因‘南林895’杨在进入田间试验后未出现外源基因水平转移,也未对周围生态环境造成显著影响。     

落叶松—杨栅锈菌无性繁殖后代反应型及接种研究

通过叶盘法对落叶松—杨栅锈菌Melampsora larici-populina Kleb.混合菌系Hj的4个无性系菌株Hj1,Hj2,Hj3,Hj4进行反应型测定,结果证明4个菌株致病力一致,属于1个生理小种。4菌株夏孢子不同接种浓度和杨树互作结果表明,随着夏孢子接种浓度的增加,感病杨树品种健杨Populus×euramericana cv.‘Robusta’、杂交杨P.deltiodes×P.trichocarpa、波兰15号杨P.×euramericana cv.‘Polska 15A’、川杨P.×szechuanica和卜氏杨P.purdomii产生的夏孢子堆数量增加;免疫品种美洲黑杨P.deltiodes不感病。     

四个意大利杨树新品种区域试验小结

<正> 1972年我国出席七届世界林业会议代表团从意大利带回两个美洲黑杨(69,63),两个欧美杨新无性系(72,45),由原中国农林科学院引种组分别在本院和南京林产工业学院繁殖,其中南京林产工业学院在江苏泗阳县试种初步成功。为了确定这四个新无性系在我国推广范围,1978年我们采用江苏省泗阳县林苗圃繁殖的种条,在40个试验点进行统一测试。1980年秋林业部造林司在湖北、河南、安徽等省的50个县扩大区域造林试验。一、试验材料来源及遗传性状分析 1.鲁克斯杨(Populus deltoides Bartr.CL.‘LUX’I-69/55)是意大利杨树研究所1952年由美国伊里诺斯州的马萨克引入的美洲黑杨种子中选育出来的。 2.圣·马丁诺杨[P.×euramericana(Dode)Guinier.CL.‘SAN MARTINO’I-72/58]是意大利杨树研究所从成年杂种欧美杨自然授粉种子中选出。 3.哈佛杨(P. deltoides Bartr. CL.‘HA-     

NL-95等3个杨树无性系秋栽试验初报

对NL-95(P.×euram ericanaCL‘NL-95’)、NL-895(P.×euram ericanaCL‘NL-895’)、35杨等杨树无性系秋栽及春栽进行试验,结果表明;秋栽成活率高于春栽:其当年长势也是秋栽比翌年春栽好。因此,从气温、地温、湿度、苗木含水量等因素分析,认为杨树秋栽在苏北是可以推广的一项技术。     

美洲黑杨杂种无性系的抗寒性研究

本文用电导法测定美洲黑杨杂种无性系休眠的1年生苗经不同低温处理后的电解质渗出率,又将同样低温处理过的插惠进行水培,观察其生根、发芽情况。结果,各无性系抗寒能力的次序是:(Populus deltoides cv.Lux’×P.deltoides)—52>(P.deltoides cv,‘Lux’×P.cat-hayana)—1062>(P.deltoides cv.‘Lux’×P.deltoides)—66>(P.deltoides cv.‘Lux’×P.deltoides)—65>P.euramericana cv.‘Luisa Avanzo’>P.deltoides cv.‘Lux’>(P.delto-ides ev‘Lux’×P.cathayana)—1145>P.deltoides cv.‘Harvard’。     

阿万佐杨和西玛杨的引种试验

<正> 杨树引种是我国杨树遗传改良的重要途径之一。为了改良我国现有杨树乡土树种,很需要创造一批早期速生且材质好、抗性强的优良无性系。为此,1981年中国林业科学研究院林研所从国外引进阿万佐杨(Populus×euramericana‘Luisa Avanzo’)和西玛杨(P.×euramericana     

欧美杨107号引种试验初报

2a的引种育苗试验表明,欧美杨107号(Populus euramericana clone‘74／76’)在陕西关中具有良好的引种前景。1a生107号杨苗木地径生长量显著大于本地优良品种陕林3号杨(P.deltoides cl.‘SL-3’),抗病虫能力与陕林3号相当。与中林46号相比,107号具有较高的高生长量和明显的抗病性。     

对四个速生树种的木材物理力学性质的初步试验

<正> 我省选育的“予林一号”泡桐和选筛的72杨(PopuJus X euramericana CV、‘San’Martino(1-72/58J)、69杨(P、detcides CV、‘Lux’[I-69/55])、63杨(P、deltoides CV、‘Harvard’[I-63/51])三个优良无性系,生长快、抗性强、成材早。但对其材质的优劣和经济价值如何,人们尤为关心。为了推广上述树种和为木材利用提供科学依据,特进行本试殓。     

69杨×青杨杂种一代的性状研究

美洲黑杨(Populus deltoides Marsh.)是北美的一个重要杨树种,69杨(P.deltoid-es CV.‘I-69/55’或者 P.deltoides CV.‘L-ux’是意大利从美洲黑杨中选育出的一个优良无性系。各国杨树育种工作者用美洲黑杨与欧洲黑杨杂交培育出许多欧美杨品种,也用美洲黑杨与青杨派树种杂交培育出不少品种。近年来,一些国家对美洲黑杨与青杨派树种的杂交尤为重视,如比利时、新西兰等国用美洲黑杨与毛果杨(P.tricoca-pa)、滇杨(P.yunnanensis)等杂交,选出了一些较好的无性系。我国青杨派树种的种类多,分布广。育种工作者曾用小叶杨(P.simonii)、青杨(P.cathayana)等与欧洲黑杨(P.nigra)     

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。     

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.     

Key Habitats in the Norwegian Production Forest: A Case Study

This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes.