思茅松毛虫质型多角体病毒的应用

应用思茅毛虫质型角体病毒ＤｅｎｄｒｏｌｉｍｕｓｋｉｋｕｃｈｉｉＣｙｔｏｐｌａｓｍｉｃＰｏｌｙｅｄｒｏｓｉｓＶｉｒｕｓ（ＤｋＣＰＶ）防治思茅松毛虫Ｄｅｎｄｒｏｌｉｍｕｓｋｉｋｕｃｈｉｉ和文山松毛虫Ｄ．ｐｕｎｃｔａｔｕｓｗｅｎｓｈａｎｅｎｓｉｓ的实验证明用ＤｋＣＰＶ粉剂防治３－５龄幼虫效果达９７％，且具有显著的扩散流行和持续控制效果。     

德昌松毛虫质型多角体病毒防治大柏毛虫应用研究

应用德昌松毛虫质型多角体病毒Ｄｅｎｄｒｏｌｉｍｕｓ ｐｕｎｃｔａｕｓ ｔｅｃｈａｎｇｅｎｓｉｓ Ｃｙｔｏｐｌａｓｍｉｃ ＰｏｌｙｈｅｄｒｏｓｉｓＶｉｒｕｓ防治四川内地柏木林区大柏毛虫Ｄ．ｈｏｕｉＬａｊｏｎｑｕｉｅｒｅ的试验表明,以７．５×１０＾９ＰＩＢ／６６６．６ｍ＾２以上剂量防治３龄幼虫,其综合防效达８５％以上,且具有显著的扩散流行和持续防治效果     

黄褐天幕毛虫幼虫食叶量观测及防治指标的测定

该文探讨了荒漠地区黄褐天幕毛虫ＭａｌａｃｏｓｏｍａｎｅｕｓｔｒｉａｔｅｓｔａｃｅａＭｏｔｓｃｈｕｌ－ｓｋｙ幼虫的食叶量。人工模拟不同摘叶强度对胡杨高、径生长量的方差分析及多重比较，Ｆ＞Ｆ０．０１，Ｄ＞Ｄ＊，摘叶３０％、５０％与摘叶１００％之间高、径生长量差异极显著。掌握了胡杨１００ｃｍ标准枝承受的害虫幼虫数及允许受害密度，建立了胡杨幼树单株材积生长量的一元回归方程：Ｙ＝２７．６８１８１＋２５１４２．３５９５７Ｘ。提出天幕毛虫幼虫防治指标：３．４头／１００ｃｍ标准枝，投入防治费用等于挽回经济损失的危害比例为３３．４％，即害虫幼虫危害大于摘叶３３．４％以上，则应立即防治。     

德昌松毛虫质型多角体病毒防治德昌松毛虫的持续效果观察

在Ｄｐｔ ＣＰＶ防治后的德昌松毛虫林区内，通过林间调查及室内镜检连续观测松毛虫的带毒率及感病死亡率。结果 Ｄｐｔ ＣＰＶ的持续效果明显，Ｄｐｔ ＣＰＶ能通过带毒成虫产卵传给子代，并引起幼虫大量感病死亡，蛹重，羽化率，产卵量明显下降；与化防区相比天敌昆虫明显增加，能控制松毛虫５年以上有虫不成灾，郁闭度大的林分已长达１２年；     

人工招引鸟类防治柏毛虫

人工招引鸟类防治柏毛虫＊崔传顺１杜克国２郭恒芳１王廷光１刘广玺３黑峪林场是历城区的第２大国营林场，林分主要为侧柏纯林，其主要害虫为柏毛虫Ｄｅｎｄｒｏｌｉｍｕｓｓｕｆｆｕｓｌｕｓ。该场柏毛虫１９７１年开始发生危害，１９７３～１９７５年暴发成灾，１９７６...     

思茅松毛虫的初步研究

思茅松毛虫Ｄｅｎｄｒｏｌｉｍｕｓ ｋｉｋｕｃｈｉｉ Ｍａｔｓｕｍｕｒａ于１９８６年在首次发现，经３年调查研究，我市１年仅发生１代，幼虫有７龄，４龄越冬，多发生在海拔５００ｍ以上短叶松林中，并已基本摸清该虫在本市的分布及各虫态，虫龄的发生期与历期。     

AcNPV病毒试验初报

用 Ａｃ Ｎ Ｐ Ｖ 病毒对德昌松毛虫 Ｄｅｎｄｒｏｌｉｍ ｕｓ ｐ ｕｎｃｔａｔｕｓ ｔｅｈｃｈａｎｇｅｎｓｉｓ Ｔｓａｉｅｔ Ｌｉｕ 进行初感和回感试验,采用浓度为 １×１０５ Ｐ Ｉ Ｂ／ｍ ｌ,第 １６ 天的死亡率达到 ９８％ ,用同一浓度回感试验,第１４ 天的死亡率达到 １００％ ,效果较明显。     

黄褐天幕毛虫幼虫食叶量观测及防治指标的测定

该文探讨了荒漠地区黄褐天幕毛虫Ｍａｌａｃｏｓｏｍａ ｎｅｕｓｔｒｉａ ｔｅｓｔａｃｅａ Ｍｏｔｓｃｈｕｌｓｋｙ幼虫的食叶量。人工模拟不同摘叶强度对胡杨高、径生长量的方差分析及多重比较,Ｆ〉Ｆ０．０１,Ｄ〉Ｄ。摘叶３０％、５０％与摘叶１００％之间高,径生长量差异极显著。掌握了胡杨１００ｃｍ标准枝承受的害虫幼虫数及允许受害密度,建立了胡杨对单株材积生长量的一元回归方程：Ｙ＝２７．６８１８１＋２５１４２     

新型蜡质毒笔防治柿毛虫的研究

介绍了蜡质毒笔的生产工艺及使用方法。防治试验结果表明蜡质毒笔涂环防治柿毛虫（ｌｙｍａｎｔｒｉａｄｉｓｐａｒ）杀虫率高，蜡毒环经雨水冲刷以后不影响药效，在密封的环境中蜡毒笔保存１年防治柿毛虫的校正死亡率仍达９４．５％。     

栎毛虫核型多角体病毒毒力的生物测定

为害水杉和银杏的标毛虫ｐａｒａｌｅｂｅｄａｐｌａｇｉｆｅｒａｗａｌｋｅｒ幼虫经人工感染核型多角体病毒（ＰｐＮＰＶ）后，第４天便开始出现死亡，２５天内最高死亡率可达９０％。病毒的致死中浓度（ＬＣ５０）为１．４９×１０４±３×１０２ＰＩＢ／ｍｌ（Ｐ＝０．５）．害虫死亡率与感染浓度呈正相关，试验表明ＰｐＮＰＶ对栎毛虫有较强的毒力。     

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。     

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.     

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.     

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.