噻虫啉林间防治松褐天牛药效试验

应用噻虫啉不同剂型对松褐天牛成虫进行了林间防治试验。结果表明,1%噻虫啉微胶囊粉剂7.5kg/hm2,1%噻虫啉粉剂7.5 kg/hm2,2%噻虫啉微胶囊悬浮剂200倍液,48%噻虫啉水悬浮剂2 000倍液的杀虫效果均超过90%,持效期可达28 d。1%噻虫啉微胶囊粉剂试验区,松褐天牛成虫诱捕量减少69.2%;松褐天牛成虫刻槽密度降低92.6%,松树死亡率下降60%。     

噻虫啉防治马尾松毛虫和蜀柏毒蛾的林间试验

开展了静电喷雾与非静电喷雾48%噻虫啉悬浮剂和2%噻虫啉微胶囊悬浮剂防治马尾松毛虫Dendrolimus punctatus(Walker)和蜀柏毒蛾Parocneria orienta Chao林间试验。试验结果表明:使用相同浓度药液,静电喷雾的防治效果明显优于非静电喷雾的防治效果,药液浓度越低,增效幅度越大;静电喷雾低浓度药液与非静电喷雾高浓度药液能获得同样防治效果,可节省农药30%以上;48%噻虫啉悬浮剂4 000倍液和2%噻虫啉微胶囊悬浮剂2 000倍液可作为静电喷雾防治马尾松毛虫3～4龄幼虫和蜀柏毒蛾4～5龄幼虫的适宜药液浓度。     

高效氯氰菊酯微胶囊水悬浮剂对几种害虫的防治试验

文章详细介绍了高效氯氰菊酯微胶囊水悬浮剂防治几种害虫的实验过程和结果,证明了该药对青杨虎天牛、落叶松毛虫、草地螟有较好的防治效果,药剂持效期长达20d以上,可直接减少施药次数,降低施药费用,减少用药量,降低环境影响。根据不同害虫生活习性,可采用大面积喷雾、喷毒环、喷隔离带等不同施药方法防治。     

利用地面喷雾封闭技术防治松阿扁叶蜂

采用3%高效氯氰菊酯微胶囊水悬浮剂在松阿扁叶蜂Acantholyda posticalis Matsumura羽化前进行地面喷雾防治,使药剂在地表面形成封闭层,在成虫破土而出时即被触杀。同时,运用敌敌畏杀虫烟剂和苦参·烟碱杀虫烟剂等防治幼虫,形成效果对比。结果表明,地面喷雾3%高效氯氰菊酯微胶囊水悬浮剂500倍液,防治效果在95%以上,好于烟剂。     

用绿色威雷杀虫剂防治落叶松毛虫

绿色威雷是一种触破式微胶囊杀虫剂。于2001年4月在讷河市保安林场对该杀虫剂防治落叶松毛虫(Dendrolimus superans T.)进行了药效试验。在越冬幼虫上树之前,分别用150,250,350,和450倍药液喷洒落叶松树干,喷洒长度(高度)为1.0, 2.5, 5.5 m。防治结果表明,喷洒150,250,350倍药液取得较为理想的防治效果(幼虫死亡率达97%),450倍液的防治效果为70%幼虫死亡率。绿色威雷杀虫剂可以用作春季防治落叶松毛虫越冬幼虫的一种有效的杀虫剂。推荐使用350倍液和1m的喷洒长度。表1参5。     

2%噻虫啉微胶囊悬浮剂防治黄斑星天牛林间试验

应用2%噻虫啉微胶囊悬浮剂对黄斑星天牛Anoplophora nobilis Ganglbauer成虫进行了林间防治试验,结果表明,2%噻虫啉微胶囊悬浮剂2 000倍液持效期可达60 d,产卵刻槽减退率91.2%,孕卵成虫死亡率90.9%。     

20%毒死蜱微胶囊悬浮剂防治松墨天牛成虫药效试验

以8%氯氰菊酯(绿色威雷)微胶囊悬浮剂为对照药剂,测定了20%毒死蜱微胶囊悬浮剂对松墨天牛成虫的防治效果。野外罩笼试验结果表明,药后1 d,毒死蜱500,400,300倍和8%氯氰菊酯300倍处理的松墨天牛成虫校正死亡率分别为60.13%,60.78%,73.63%和60.73%;药后第3天,各处理校正死亡率达83.92%~89.68%,处理之间差异不显著。罩笼试验的持效期可达15 d以上。野外原木材垛上的药效试验结果显示,药后第7天,毒死蜱600,300倍和8%氯氰菊酯300倍处理的防治效果依次为64.68%,63.12%和72.92%,处理间无明显差异。研究结果表明,20%毒死蜱微胶囊悬浮剂对松墨天牛成虫的防治效果与8%氯氰菊酯微胶囊悬浮剂接近,可以作为替代药剂交替使用,以延缓靶标害虫抗药性的产生。     

噻虫胺·高效氯氟氰菊酯微囊悬浮剂防治落叶松毛虫高龄幼虫的试验效果

落叶松毛虫(Dendrolimus superans)在春季大发生时多为3~6龄,可造成严重危害。通过使用噻虫胺·高效氯氟氰菊酯微囊悬浮剂对春季高龄幼虫进行防治试验,结果表明:使用该药剂稀释1000倍液防治3~6龄幼虫见效快、效果好;虫口密度不高时可采用1800倍液喷雾施药;防治3龄以下幼虫,可稀释2500倍液喷雾防治。     

四种药剂对桃红颈天牛初孵幼虫药效试验

桃红颈天牛Aromia bungii Faldermann是蔷薇科果树和园林树木的主要蛀干害虫，近些年在河北省的桃园和樱桃园暴发成灾。为有效控制桃红颈天牛危害，比较4种供试药剂在不同稀释倍数下对桃红颈天牛初孵幼虫的防治效果。结果表明：施药24 h后，4种药剂在不同稀释倍数下均对桃红颈天牛初孵幼虫有一定的防治效果；随着稀释倍数增加，4种药剂对桃红颈天牛初孵幼虫的致死率逐渐降低；4种药剂在最低稀释倍数下，只有25%杀虫双水剂（AS）200倍液的校正死亡率与12%噻虫·高氯氟悬浮剂（SC） 300倍液加96%聚硅氧烷类化合物60倍液的具有显著差异（P<0.05），其余各药剂间的校正死亡率差异不显著（P>0.05）。考虑防治成本等因素，建议在每年8月下旬至10月中旬，采用10%吡虫啉可湿性粉剂（WP） 250倍液或25%杀虫双AS 200倍液常规树干喷雾防治，桃红颈天牛初孵幼虫在施药24 h后的校正死亡率可以达到70%左右。     

静电喷雾与非静电喷雾防治森林害虫对比试验

采用静电喷雾机进行了静电喷雾和非静电喷雾2%噻虫啉微胶囊悬浮剂和3%高渗苯氧威乳油防治马尾松毛虫Dendrolimus punctatus(Walker)、杨小舟蛾Micromelalopha troglodyta Graeser及杨扇舟蛾Clostera anachoreta(Fabricius)幼虫对比试验。结果表明:在同一药剂浓度下,林间防效静电喷雾明显优于常规喷雾;2%噻虫啉微胶囊悬浮剂4 000倍液和3%高渗苯氧威乳油3 000倍液可作为静电喷雾防治马尾松毛虫2～3龄幼虫和杨小舟蛾及杨扇舟蛾2～4龄幼虫的推荐使用浓度。     

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.