云杉球果锈病流行规律的研究

通过定点系统观察，云杉球果锈病病原菌Ｔｈｅｋｏｐｓｏｒａ ａｒｅｏｌａｔａ Ｍａｇｎｕｓ．担孢子５月中旬开始飞散，侵入期为５月下旬，病害初期下状出现在６月下旬，锈隐子在７月下旬前后形成，８月中旬锈子器成熟。病情变化与气象有一定相关性，其回归预测模型为Ｙ＝－２４２．６８－５．７３Ｘ１－１．０３Ｘ２＋４．０２Ｘ３－１．９３Ｘ４－２．５７Ｘ５＋５４２．８４Ｘ６＋２６８．６２Ｘ７＋０．９２Ｘ８复相关系数Ｒ     

对马尾松毛虫敏感的苏云金杆菌菌株筛选试验研究

用对鳞翅目比较敏感的４种苏云金杆菌菌液浸渍马尾松针叶，喂食３—４龄马尾松毛虫幼虫，５天后感染浓度与死亡机率值回归方程为Ｙ１＝１．０６３５＋０．４５１５ｘ，Ｙ２＝－１．４４７０＋０．８１３０ｘ，Ｙ３＝０．２０５９＋０．６１５ｘ，Ｙ４＝３．００２６＋０．１１７９ｘ；半致死中浓度ＬＣ５０值分别为５．２３６８ｘ１０８、８．５１７１ｘ１０７、６．２３７４ｘ１０７和８．７６４８ｘ１０１５ｃｅｌｌ／ｍｌ。以３ｘ１０８ｃｅｌｌ／ｍｌ浓度感染４龄幼虫，其致死中时间ＬＴ５０值分别为５．７４７３、３．５５７２、４．８１７７、１６．０８６２天。结果表明：Ｂｔ（２）菌株对马尾松毛虫毒力次于Ｂｔ（３），但致死中时间最短，可供生产上应用于林间防治。     

青杨叶锈病流行规律及防治技术

落叶松－－场锈病菌的冬孢子５月中下旬萌发，锈孢子５月下旬到６月上旬出现；夏孢子６月中旬出现，７月底或８月初冬孢子形成并越冬。该病７月中旬发平凡经最高，应采取春防早、防小，夏防了以及冬季清除枯落物的防治措施，并做到连续防，集中防，防治药物以粉锈宁为佳。     

马尾松产脂力与生长力性状的典范相关分析

应用典范分析方法可简化马尾松的产脂力和生产力之间错综复杂的关系，根据生长力指标分析选择产脂力的典范综合指数为：Ｉ＝０．００９６ｘ１＋０．００１９ｘ２－０．０２５４ｘ３－０．０２４４ｘ４－０．０９７３ｘ５＋０．０３１３ｘ６，典范分析可将５５株候选优树划分为４个类型。     

四季海棠的组织培养

１植物名称：四季海棠（Begoniafibrous）。２材料类别：刚展平的嫩叶。３培养条件培养基：（单位：mg／L）（１）MS＋BA３＋２．４－D１，（２）MS＋BA２＋NAA０．２，（３）MS＋BA１＋NAA０．５，（４）MS＋BA１＋NAA０．１，（５）MS＋BA１＋２．４－D０．０５，（６）MS＋BA２＋２．４－D０．０５，（７）MS＋BA０．４＋NAA０．１，（８）１／２MS＋NAA０．５，（９）１／２MS＋BA０．０１。其中蔗糖浓度除培养（８）为２％，其余均为３％，琼脂为０．８％～１．０％，pH值为５．７～５．８，培养温度为２０±４…     

角蜡蚧产卵量与卵期预测预报的研究

角蜡蚧是雪松等园林树木的重要害虫之一,产卵多、繁殖强、危害重,准确测报其发生量与若虫孵化期,是防治成败的关键。通过１９９７年５月对产卵末期雌虫体质量、体长及产卵量的测定与室内变温、恒温饲养研究,其平均虫体质量ｘ１＝０．１１０３±０．０８４９ｇ,体长ｘ２＝７．０２７±０．２０２ｍｍ,产卵量（ｙ）＝４８８０．５±４４４０．５３粒;产卵量与虫体质量、体长相关方程式分别为：ｙ１＝－５７１．２５＋５００７８．３ｘ１,ｒ１＝０．９７１９＞ｒ０．０１＝０．４９６;ｙ２＝－１０３５６．４６＋１９８３．３９ｘ２,ｒ２＝０．８４３６＞ｒ０．０１＝０．４９６。卵发育起点温度：Ｃ＝１０．２５±１．５３℃或Ｃ＝９．９４±０．１９℃;有效积温Ｋ＝１６５．１５±６．９６ＤＤ或Ｋ＝１４１．５１±２．１５ＤＤ。经应用及检验与实际符合。     

广华枝的取食量及其防治研究

本文研究了广华枝ＳｉｎｏｐｈａｓｍａｌａｒｇｕｍＣｈｅｎｅｔＣｈｅｎ的食叶量。其一生食叶量为２０．８０２ｇ，其中１～４龄低龄若虫期的食量占其一生食量的３．１３％，５～６（７）龄老龄若虫期的食量占２１．９５％，成虫期的食量占７４．９２％，老龄若虫期和成虫期是主要的危害期，占其一生食量的９６．８７％；并建立了个体食叶量模型、个体日均食量模型及其活动量指数增长模型，分别为Ｘ１＝０．０３９４ｅ０．５９７９Ｘ０，校正Ｒ２＊＊＝０．８９３１；Ｘ２＝２６．５１７６ｅ０．２２３３Ｘ０，校正Ｒ２＊＊＝０．７６７３；Ｘ３＝１．３０９３ｅ０．５００１Ｘ０，校正Ｒ２＊＊０．９４４０，复相关系数平方显著或极显著；胸径为８～１２ｃｍ的寄主，其防治指标为９３．１头，并提出了防治意见。     

落叶松落叶病的生态控制技术研究

根据吉林省近千块长白落叶松人工林林分病情与１０个林分因子关系的标准地调查分析，推导出长白落叶松落叶病病情指数与其相关的林分生态因子──林分类型、密度、林龄、枝下高、土壤、地形的数学模型：ｙ＝１５＋２１Ｃ１１＋６Ｃ１２＋９Ｃ１３－２３Ｃ２１－１５Ｃ２２－Ｃ２３＋３Ｃ３１＋１９Ｃ３２＋１９Ｃ４１＋９Ｃ４２＋８Ｃ５１－１０Ｃ６１（磐石模型）；ｙ＝２１．０＋１６．５Ｃ１１＋２．９Ｃ１２＋４．９Ｃ１３－２２．６Ｃ２１－１５．０Ｃ２２－１．７Ｃ２３＋０．４Ｃ３１＋１５．８Ｃ３２＋１６．９Ｃ４１＋７．４Ｃ４２＋７．９Ｃ５１－９．５Ｃ６１（吉林模型）；其偏相关系数分别为：磐石模型：０．６０５、０．７２３、０．６３４、０．６２７、０．３２３、０．４２６，复相关系数０．９１９；吉林模型：０．６５７、０．７５、０．６９、０．６４、０．４２、０．４９，复相关系数０．９３１。用此两公式对应判对。对磐五县１９８７～１９９１年１４１块标准地判对率为７２．３％，对１９８７～１９９２年全省８２３块标准地的应用判对率为６７．４％。提出该病林分病情生态预测预报技术和造林营林措施为主的生态控制技术。     

樟树溃疡病病原菌的生物学特性

樟树溃疡病菌的菌丝生长、分地孢子形成与萌发和子囊孢子萌发的最适温度分别为２５－３５℃、２５－２６℃、２０－３５℃和２０－３０℃；最适湿度分别为６０％以上、９８％以上、９８％和水滴中；最适ｐＨ值分别为７．０－８．０、６．０－８．０、４．０－９．０和５．０－９．０。菌丝生长，培养基以大麦、燕麦和ＰＳＡ＋１‰酵母；碳源以蔗糖、葡萄糖；氮源；氮源以ＤＬ－甲硫氨酸、脯氨酸、苯丙氨酸和胱氨酸为最佳。分生孢子形     

拐棍竹生物学特性及其生物量的研究

１９８７－１９９１年，对拐棍竹生物学特性及其生物量进行了研究，研究表明：拐棍竹于４月１０日开始发笋，当年６月中旬高生长基本结束，高生长指数期是５月２０日－６月１０日之间高生长节律呈逻辑斯蒂（ＬＯＧＩＳＴＩＣ）曲线，其方程式为：Ｙ＝３７８．２４６／１＋１５１．３５ｅ＾－０．４７４３２ｘ，６月底后，竹笋－幼林开始了枝，叶生长，当年发枝轮数为１７轮，一轮中约发８枚小枝，一小枝当年发叶４－５枚，建立了单株     

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.