赤峰市阿鲁科尔沁旗桑褶翅尺蛾的发生与防治

赤峰市阿鲁科尔沁旗山杏Armeniaca sibirica林遭受桑褶翅尺蛾Zamacra excavata幼虫的严重危害。该虫大发生时,以植物源农药3.6%烟碱·苦参碱进行化学防治时,使用原药375 ml/hm~2飞机超低量喷雾,防治效果达90.0%,以1000倍液采用背负式喷雾喷粉机防治,防治效果达79.5%,以1000倍液采用车载式低容量风送喷雾机防治,防治效果达86.8%。     

洒金东瀛珊瑚菌核性根腐病初步研究

对洒金东瀛珊瑚菌核性根腐病症状、发生原因及发病规律进行了研究，并进行了五种杀菌剂的室内抑菌试验、田间药剂防治试验，结果表明：多霉威可湿性粉剂1000倍液防治效果最好、其次为咪鲜氨乳油1000倍液和三唑酮乳油1000倍液。     

药剂防茶黑胶粉虱幼虫试验初报

茶黑胶粉虱是近几年来在薛城区茶树主栽区发生较重的一种重要害虫。采用2种高效，低毒，强渗透，强内吸新型农药对茶黑胶粉虱幼虫进行药剂喷雾防治试验。结果显示，1．8％爱福丁2000倍液喷雾防治初孵幼虫，效果显著，防治效果达100％，1．8％爱福丁1000倍液喷雾防治2龄幼虫，防治效果达93．3％。     

苹果园山楂叶螨田间药剂防治试验

山楂叶螨的发生与高温干旱气候有关，叶螨繁殖盛期在7月上句。选用5种药剂进行叶螨防治试验，20％螨死净乳油2500倍液、40％水胺硫磷乳油1000倍液、灭扫利3000倍液防治效果较好；40％氧化乐果1000倍液和20％三氯杀螨醇乳油800倍液防治效果较差。     

嘉兴地区重阳木锦斑蛾的发生情况调查与防治技术研究

重阳木锦斑蛾是重阳木的一种重要虫害。该虫在桐乡市苗圃地、通道绿化林带及片林中经常爆发成灾，6～9月叶片被取食殆尽，严重影响了苗木出圃率和林木的正常生长，影响绿化林带的形象，降低了生态功能。在对全市重阳木锦斑蛾发生情况调查的基础上，进行了防治技术的研究。结果表明，灭多威喷雾防治重阳木锦斑蛾效果显著，尤以500倍液喷雾防治2龄幼虫效果最佳；对3龄以上重阳木锦斑蛾的防治以400倍液喷雾防治效果最好。同时筛选出防治效果好的药剂，分别为灭多威、0．18％森乐1：1000倍液、1．5％抑虫琳1：500倍液和1％甲维盐1：2000倍液，以上药剂适期用药后防治效果都在95％以上。     

农药加酒精可防治果树害虫抗药性

果树害虫对农药产生抗性，使防治效果降低，是生产中普遍存在的问题，科技人员对已产生抗药性的苹果黄蚜、棉蚜和红蜘蛛进行酒精加农药防治试验，取得较好成效。害虫初发时分别喷洒40％氧化乐果800倍、1000倍、1200倍和40％水胺硫磷800倍、1000倍、1200倍液，喷前在药中往0．1％、0．2％、03％的浓度加入95％酒精。结果表明，加酒精后对两种蚜虫防治效果均达到95％以上，较不加酒精防治增效33．4％，对红蜘蛛加O．2％酒精防治效果达到93％，较不加酒精增效32．8％。农药加酒精可防治果树害虫抗药性…     

菊花霜霉病的形态特征及其防治技术

菊花霜霉病多发生在平均温度16．4℃-19．0℃、年降雨量1500min左右、春季低温多雨的山区，是菊花的主要病害之一。选用抗病品种、用50％福美双可湿性粉剂拌种、加强肥水管理、防止田间积水及湿气滞留对菊花霜霉病具有很好的预防效果。发病初期用72％克露可湿性粉剂600倍液喷雾，防治效果达70％；用60％灭克可湿性粉剂800—1000倍液和65％代森锌可湿性粉剂500倍液喷雾，防治效果分别达到85％和90％；用69％安克·锰锌可湿性粉剂800倍液喷雾，每隔10d1次，防治效果达80％。     

几种杀虫剂防治云杉树叶象试验

应用6种杀虫剂对云杉树叶象成虫进行室内杀虫药效测定和田间防治试验,筛选出了3种杀虫药效较好的杀虫剂对14.6 hm2的云杉苗木进行大面积的防治试验,结果表明:1 000倍液的50%辛硫磷、1000倍液的40%甲基异柳磷、800倍液的80%敌敌畏对云杉树叶象成虫均有较好的防治效果,平均防治效果达92.8%。     

几种无公害农药防治柽柳条叶甲试验

用6种无公害农药对柽柳条叶甲进行防治试验，结果表明，2％阿维菌素5000倍液、5％阿维@除虫脲5000倍液等防治效果可达96％以上，且经济有效。防治时间为每年6～8月第1、2代2龄幼虫始盛期至3龄幼虫期。     

喜树溃疡病的防治试验

采取化学药剂结合人工抚育措施进行喜树溃疡病防治试验，结果表明：多菌灵500倍液和甲基托布津800倍液交替使用，用药量2250kg／hm^2，当年防治效果最好，达97．1％；用药量3000kg／hm^2，当年防治效果次之，达88．9％；用药量1500kg／hm^2，当年防治效果相对较低，仅为66．3％；后2a再按第1a的方法进行防治，防治效果均达100％。人工抚育措施可为保留木提供良好的生长空间，促进立木健康生长，对喜树溃疡病的发生具有一定的防治效果，但疏伐经济损失较大。     

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.