梨喀木虱与异喀木虱混合发生区防治药剂选择

用3类（生物剂、低毒、有机磷）8种药剂试验，结果表明：异喀木虱比梨喀木虱对药物的敏感性稍高，这也是田间异喀木虱种群小于梨喀木虱的一个原因。1.0%爱诺虫清3000倍液、20％梨虱霸乳油2000倍液、5％蚜虱净乳油1500倍液防治效果都在95％以上，1.0%爱诺虫清作为生物药剂，更适宜推广应用。     

异喀木虱生物学特性与防治技术初步研究

异喀木虱1年发生3代，以第3代4龄若虫在枝干粗皮、枝杈、芽隙越冬；天敌有瓢虫、猎蝽、盲蝽、花蝽、胡蜂、草蛉、食蚜蝇等昆虫及蜘蛛12种；防治时间为6、7、8月上旬，1．0％爱诺虫清(Avermectins)3000倍液、20％梨虱霸(Lishiba)乳油2000倍液、5％蚜虱净乳油(Imidacloprid)1500倍液防治效果都在95％以上，1．0％爱诺虫清作为生物药剂，更宜推广应用。     

四种杀虫剂对梨上瘿螨的田间药效试验

应用4种药剂进行了梨上瘿螨的田间药剂防治，结果表明：施药14d后，0．2％爱诺虫清EC2000倍液、10％哒四螨悬浮液、15％哒螨灵EC和20％灭扫利EC2000、3000倍液可取得良好的防治效果，其防效均达99．1％以上。     

中国梨喀木虱预测预报及综合防治技术

中国梨喀木虱(Cacopsylla chinensis Yang&Li)是栽培的各种梨的主要害虫。本文运用有效积温法、各虫态历期法、物候征兆法、有效基数预测法,预测预报下一虫态的发生期和虫口数量,提出了以营林措施为基础、利用生物药剂防治、物理防治及保护和利用梨园中捕食性天敌的自然控制作用相结合的多种防治措施,为更好的开展中国梨喀木虱防治工作提供了重要依据。     

黄刺蛾的生活习性及防治技术

黄刺蛾在通化地区1a1代，以幼虫在为害树的枝叉处结茧越冬，是园林植物的主要食叶害虫之一。可采用秋冬季节人工摘除虫茧或敲碎树干上的虫茧，用黑光灯诱杀成虫，幼虫期喷施每克含孢子100亿以上的青虫菌600倍，喷施80％敌敌畏乳油1000—1200倍液或50％杀螟松、50％辛硫磷乳油1000—1500倍液、50％马拉硫磷乳油1000倍液、25％亚胺硫磷乳油1300倍液、5％来福灵乳油3000倍液、2．5％氯氰菊酯乳油2000，3000倍液等方法进行防治。     

枣树日本龟蜡蚧防治技术研究

采取化学防治与生物防治措施对枣树日本龟蜡蚧进行防治试验，结果表明：在蚧卵孵化率达４０％～５０％时，使用２５％广克威乳油１０倍液树干涂环防治效果达９０％以上；在蚧卵孵化率达７０％～８０％时，使用２５％广克威乳油５０００倍液或４０％氧化乐果乳油１０００倍液或２４％万灵水剂２０００倍液喷雾防治，效果分别达９６．６８％，９３．３８％和９５．２３％；该蚧天敌种类较多，保护与利用这些天敌可在一定程度上控制日本龟蜡蚧的为害。     

松阿扁叶蜂发生规律及防治技术研究

在研究松阿扁叶蜂的发生危害、生活史、主要习性及发生规律的基础上，从7种不同药剂中筛选出了5种防治该虫的有效药剂和最佳使用浓度：用8％绿色威雷300倍液防治出蛰成虫，防效达93．58％；用40％氧化乐果乳油、25％灭幼脲Ⅲ号胶悬剂1500倍液防治3龄前幼虫，防效分别达91．35％和95．34％；利用2．5％敌杀死乳油4000倍液防治3龄后大幼虫，防效为96．62％；在郁闭度0．7以上的林分，用22．5kg／hm^2林丹烟剂防治树上幼虫，防效达97．96％。     

敌木虱防治中国梨木虱药效试验

采用山东省农药研究所研制的复配制剂敌木虱１号和敌木虱２号与４０％水胺硫磷乳油、１０％氯氰菊酯乳油和３０％灭蛾净乳油进行防治梨木虱若虫药效对比试验,结果表明：敌木虱１号药效明显优于其它农药品种,其２０００倍液是经济有效的使用浓度,其室内与田间２４小时药效均达９３％以上     

山地橄榄星室木虱防治初报

应用不同药剂、浓度对橄榄星室木虱(Pseudophacopteron canariumYang et Li)进行室内毒力测定和林间防治试验,结果表明:2.5%功夫菊酯乳油对橄榄星室木虱的毒力最高,其相对毒力是苦.烟乳油的1.7倍;复合药剂的防效明显高于单一药剂,最佳组合以功夫乳油5 500倍液+木虱净乳油6 000倍液+苦.烟乳油5 000倍液林间喷雾效果最佳,药后3 d、7 d、14 d、21 d的防效分别为73.63%、90.54%、93.51%、95.43%;连续施用复合药剂7 d的防效达100%,不仅防治效果好,而且持效长,可有效地控制星室木虱的危害。     

三种杀虫剂对橄榄星室木虱的控制作用

应用生命表方法分析吡虫啉、木虱净、稻虱净3种化学农药对橄榄星室木虱的控制效果。结果表明：吡虫啉、木虱净、稻虱净和对照的种群趋势指数分别为0．4148，0．8328，4．9908，6．3925。说明吡虫啉和木虱净处理区的橄榄星室木虱种群数量呈下降趋势，稻虱净和对照区的橄榄星室木虱种群数量以4．9908和6．3925倍的速度增长；吡虫啉、木虱净和稻虱净的干扰作用控制指数分别为0．0649，0．1303和0．7807。表明吡虫啉和木虱净施用区种群数量相当于对照区的6．49％和13．03％，取得了很好的防治效果；稻虱净施用区种群数量是对照的78．07％，不是防治橄榄星室木虱的理想药剂。     

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.