草履蚧可持续控制策略与技术

对草履蚧Drosicha corpulenta kuwana及其主要天敌－－红环瓢虫Rodlia Iimbata Motschulsky的生物学特性，发生规律，预测预报，防治指标，防治技术等方面进行了系统的研究基础上，总结出的以阻隔防治和保护利用红环瓢虫进行生物防治为主的草履蚧可持续控制技术，1999－2001年应用该技术在西安市的周至、户县等8县区防治草履蚧1．37万hm^2,3年内防治全部实现了可持续控制目标，经济，生态和社会效益十分显著。     

杨树害虫草履蚧的阻隔防治新技术

指出了2007~2015年,有关部门组织科技人员开展了草履蚧阻隔防治技术研究,探索出了在树干上涂敷黄泥层,然后在树干套铁皮套筒,及在铁皮套筒外表涂层杀虫药膏,从而阻隔草履蚧若虫上树的危害,及时把草履蚧若虫阻隔在树干下喷药杀灭。通过反复试验,总结出了使用寿命长、阻隔阻杀效果好、防效率效果显著的防治新技术。     

草履蚧的生物学特性及防治

草履蚧是杨树、法桐、核桃的主要害虫,在河北省邢台地区1年发生1代,以卵在寄主附近的土中越冬.翌年2月上旬至3月上旬,越冬卵孵化.4月下旬,雄虫羽化,和雌虫交配后死亡.雌虫5月下旬由树干爬到树根附近疏松的泥土中产卵,越冬卵至翌年2月～3月孵化.根据草履蚧发生规律,在防治上主要抓住若虫期,分别采用人工、阻隔及药物防治,     

草履蚧虫的危害及防治

草履蚧虫的危害及防治赵庚钧草履蚧虫是介壳虫类中的一种，分布于我国大部分地区，危害珊瑚树、杨树、悬铃木等树木，严重时可造成树木生长不良，早期落叶，甚至死亡。对草履蚧虫的防治不可忽视。一、草履蚧虫的形态识别草履蚧虫成虫有雌雄之分，雌虫无翅，扁平，椭圆形，...     

草履蚧壳虫阻隔效果的观察

草履蚧壳虫（Drosicha corpulenta kuwana），简称草履蚧，属同翅目蚧壳虫科，雌、雄异形，雌虫无翅，以卵越冬。原为果树花卉害虫，随着杨树面积的扩大，已成为杨树的主要害虫。一年发生一代，以若虫或雌成虫吸食林木枝条树液而生活，从而造成枝条干枯、林木生长不良，严重时整株死亡。由于若虫在温度适宜时每天24小时不间断地从土中上树，在时间上给喷药防治带来了困难。同时若虫上到树梢后，一般手压喷雾器无法喷洒到位，担架式高压喷雾器因受到多因素（如沟坝、农田、风向）的影响，防治效果也很不理想。2002—2003年我们在蒙城县小涧镇用透明胶带等不同材料对草履蚧进行阻隔试验，并对阻隔效果进行了观察。     

草履蚧防治技术研究

在观察了草履蚧的虫态、生活史的基础上，采用人工绑扎塑料薄膜阻隔若虫上树，油泥粘胶，喷洒氯氰菊脂、溴氰菊脂毒杀，夏季扫除虫卵和黑光灯诱杀雄虫防治试验。结果认为，以人工绑扎塑料薄膜阻隔若虫上树防治效果最佳     

草履蚧防治试验

草履蚧在连云港地区1 a发生1代,以卵在卵囊内于土中越冬,危害杨树等寄主26种.草履蚧的天敌有大红瓢虫和黑红缘瓢虫2种,以幼虫取食草履蚧若虫.防治试验结果表明,在2月上中旬若虫上树前在树干上缠胶带阻隔若虫上树,阻隔率98%以上;6月上中旬,于树干基部周围培松土诱集成虫产卵,防治率90%以上;用20%吡虫啉20倍液注射防治,杀虫效果在90%以上;在小树树干上用20%吡虫啉原液直接涂刷毒环,杀虫率在98%以上;分别用50%辛硫磷、50%敌敌畏、25%扑虱灵可湿性粉剂等各1 000 倍液及果树宝200倍液进行喷雾防治,施药后48 h(扑虱灵7 d),校正防效均在95%以上.     

红环瓢虫生物学特性观测及保护利用

红环瓢虫是草履蚧的重要天敌,整个世代经过卵、幼虫、蛹、成虫4个阶段,共4龄,以成虫越夏越冬,翌年2月下旬至3月上中旬开始出蛰,出蛰不整齐,3月上中旬至5月上旬为卵期,3月中下旬至5月下旬为幼虫期,5月中旬开始化蛹,5月下旬至翌年4月下旬为成虫期。红环瓢虫具有互相残杀的习性,对草履蚧有很强的抑制能力,能取食草履蚧的若虫、蛹和成虫,可利用红环瓢虫对草履蚧进行生物防治。     

草履蚧的发生与综合防治——以颐和园为例

草履蚧在我国分布广泛,是重要的林业有害生物,在颐和园内危害柳树、杨树、榆树、槲树、紫薇等园林植物,因园内柳树基数大,造成草履蚧对柳树的危害尤为突出。草履蚧常群集危害,若虫和雌成虫吸食树汁,树木受害后不能正常萌芽或萌芽后失水萎蔫,影响园林景观。为了保护皇家园林植物资源、提高颐和园植物景观与游览舒适度,草履蚧的防治工作迫在眉睫。经过多年观察草履蚧的生物学特性和在颐和园的危害规律,实践包括物理防治、化学防治和释放天敌昆虫等不同防控手段,总结出一套具有颐和园特色的草履蚧综合防治措施。在核心游览区、新东堤及六桥区域、团城湖水源保护地周边使用泥环法,既能有效阻隔害虫上树,又能保证外观统一整洁、副作用小。万寿山区域采用粘虫胶,达到防治效果的同时节省人力物力资源。当出现个别地点害虫爆发严重影响园林景观,采用化学药剂进行紧急救治。坚持在团城湖周围释放小蜂、瓢虫等天敌昆虫,并种植蜜源植物,促进群落稳定生存并发展,将草履蚧数量控制在可接受范围内。     

北方城市草履蚧暴发成因及综合防治技术

该文介绍了草履蚧的生物学特性,分析了草履蚧在城市园林绿化区域易大发生的成因,介绍了草履蚧的提前预防措施、物理防治措施、生物防治措施、化学防治措施等技术,对于防治草履蚧的蔓延和发展有积极的指导意义,有利于城市园林环境的改善和提高。     

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.