水杉小爪螨生物学特性及防治研究

水杉小爪螨（ＯｌｉｇｏｎｙｃｈｕｓｍｅｔａｓｅｑｕｏｉａｅＫｕａｎｇ）是在陕西汉中发现的新种，为该区水杉的主要害螨。通过对２１４ｋｍ行道树随机抽样调查，水杉受害率１００％，危害程度平均２．８级。该螨一年发生１２代，以卵越冬，为害盛期６～８月，发育历期随环境温度增高而缩短。雄成螨具第二若螨期。在自然条件下，深点食螨瓢虫等天敌是其限制因予，暴雨是害瞒急剧下降的主要因素。三氯杀螨醇和螨死净混合使用防效最佳。     

水杉小爪螨生物学特性及防治研究

水杉小爪螨是在陕西汉中发现的新种，为该区水杉的主要害螨。通过对２１４ｋｍ行道树随机抽样调查，水杉受害率１００％，危害程度平均２．８级。该螨一年发生１２代，以卵越冬，为害盛期６－８月，发育历期随环境温度增高而缩短。雄成螨具第二若螨期。在自然条件下，深点食螨瓢虫等天敌是其限制因素。三氯杀螨醇和螨死净混合使用防效最佳。     

曲阜孔林地区土壤甲螨区系及群落结构的初步研究

通过在曲阜孔林地区选择四种典型生境作为采集样点,定时定量采集土样,共分离获得标本8934号,经鉴定发现所采集标本隶属21科33属45种,其中含有16种中国新记录种。对鉴定出的45种甲螨进行区系分析表明,该地区土壤甲螨在世界动物地理区划中的分布,可以划分为8个区系型。在中国动物地理区划中可划分11种区系型。其群落分析表明:No-thrus asiaticus Aoki et ohnishi、Erembelba foliata Foliata hummer、Zygoribatula hailongensis、Ceratozetes japonicus Aoki、Scheloribates latipes为该地区的优势类群。多样性分析表明C样地多样性指数最高。     

芬兰钝绥螨对针叶小爪螨的捕食作用研究

芬兰钝绥螨的雌成螨对针叶小爪螨幼螨、若螨和成螨的捕食功能反应均属ＨｏｌｌｉｎｇⅡ型。针叶小爪螨的螨态、芬兰钝绥螨的饥饿程度、生境大小等因素均可引起功能反应参数的变化。芬兰钝绥螨的雌成螨喜食针叶小爪螨的幼螨和若螨，而对雌成螨的良能力较弱。     

二斑叶螨的防治试验

二斑叶螨的防治试验＊⒇王铁章高鸿燕赵艳雪王春青葛更地（饶阳县林业局０５２７００）二斑叶螨属世界性害螨,近年在北方许多地区发现并迅速蔓延,并逐渐成为一种主要害螨。该螨在我国北方地区每年发生８～９代,以橙黄色越冬滞育型雌成螨越冬,春季先在阔叶杂草和果树根...     

针叶小爪螨板栗和杉木种群的形态差异

针叶小爪螨(Oligonychus ununguis)俗称板栗红蜘蛛、杉木红蜘蛛,属叶螨科(Tetranychidae),小爪螨属(Oligonychus),广泛分布在亚洲、欧洲、澳洲、美洲的众多国家.     

柑桔红叶螨生物学特性的观察

<正> 柑桔红叶螨 Panonychus Citri Mcgregor 属蛛形纲,蜱螨目,叶螨科。又名柑桔红蜘蛛,柑桔瘤皮红蜘蛛,柑桔全爪螨。该虫常和柑桔始叶螨 Eotetranychus Kankitus Ehara、柑桔锈壁虱 Phyllocoptruta Oleivora Ashmead 等混同发生危害,在我国广大桔区均有发生。近几年来,由于一些桔区使用农药不当,桔园生态系统受到破坏,柑桔红叶螨已上升为头等重要的害虫。云梦县肖李柑桔园,总面积50亩,受害率达100%。为了控制其危害,1988年以来,我们在肖李柑桔园对柑桔红叶螨生物学特性进行了观察,并开展了综合防治试验,现将结果整理如下。     

长宁竹区竹裂爪螨生物学及楠竹害螨消长动态研究

在21℃、24℃、27℃、30℃、33℃5种不同温度条件下,用新鲜的离体楠竹叶片在室内饲养竹裂爪螨,得出该螨实验种群的主要生物学参数,应用直接最优法计算该螨的世代发育起点温度和有效积温分别为12.53℃、150.25日度,根据气象资料预测竹裂爪螨在长宁竹区年发生13－14代;每年3月下旬－4月上旬出蜇,11月份开始以雌成螨越冬。林间实际调查表明,楠竹害螨在竹区的发生与危害存在明显的春季高峰并与楠竹林的敏感生长期相吻合;降雨与高温严重影响楠竹害螨的生长发育,表现为7、8月份高温多雨季节林间害螨种群数量呈现出急剧下降。     

辽宁三种林业害螨生物学特性研究初报

本文报道了三种林业害螨，即棒毛小爪螨，柏小爪螨，云杉小爪螨的生物学特性。上述三种害螨均属蜱螨目叶螨科，是为害针叶树人工林的主要害螨之一。近年来在辽宁很多地区的油松、赤松、樟子松、落叶松人工林中大量发生，城市绿化的柏树也受到为害，造成针叶枯黄脱落，影响林木生长。三种害螨每年发生７￣９代不等，均以卵在树皮缝，芽鳞，果鳞等处越冬，适时采用４０％氧化乐果，５０％二溴磷乳剂或８０％敌敌畏喷洒，均可收到较好的     

应用智利小植绥螨防治叶螨情况简介

本文参考了国内外有关资料,介绍了国内外利用智利小植绥螨防治叶螨的研究及应用情况,供有关方面参考。 智利小植绥螨Phyloseiulus persimlisAthiashenriot广泛分布于智利及地中海沿岸的阿尔及利亚、摩洛哥、突尼斯、叙利亚、黎巴嫩,土耳其等国。1957年法国人Athias—Henriot最早发现于阿尔及利亚的蔷薇、土豆、梨树上;1962年Gonzalez等在智利的苹果树上也采到了该螨。经研究证实有很高的生殖和控制害     

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.