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中国寄生于竹瘿广肩小蜂的金小蜂一新种：（膜翅目：小蜂总科,金小蜂科） 总被引：2，自引：0，他引：2
记述了我国金小蜂科角金小蜂属一新种－－竹瘿长角金小蜂Ｎｏｒｂａｎｕｓ ａｉｏｌｏｍｏｒｐｈｉ ｓｐ．ｎｏｖ．。新种寄生在我国南方为害毛竹的竹瘿广肩小蜂Ａｉｏｌｏｍｏ－ｒｐｈｕｓ ｐｈｏｐａｌｏｉｄｅｓ Ｗａｌｋｅｒ的幼虫及蛹上，寄生率达３６．６％，在控制这种害虫上具有重要意义。新种的模式标本保存在西北林学院天敌昆虫室及中南林学院昆虫标本室。 相似文献
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刚竹瘿蚊 Procystiphora sp:在天津1a 发生1代,以蛹在竹小枝内越冬.成虫出现在4月上旬,产卵于早园竹 Phyllostachys propinqua McClure的新芽中,幼虫孵化后钻蛀取食虫瘿内物质,于10月上旬化蛹.刚竹瘿蚊有1种内寄生天敌:瘿蚊柄腹姬小蜂Pediobius sp.;2种外寄生天敌:刺胫广肩小蜂Eurytoma setigera Mayr和栗瘿旋小蜂 Eupelmus urozonus Dalman.另有3种伴生昆虫:竹瘿广肩小蜂 Aiolomorphus rhopaloides Walker、纹黄枝瘿金小蜂 Homoporus japonicus Ashmead和秆蝇金小蜂Gastrancistrus sp.. 相似文献
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栗瘿蜂生活习性观察与防治经验曹芳琴（商洛地区森防站，陕西商洛７２６０００）栗瘿蜂（ＤｒｙｏｃｏｓｍｕｓｋｕｒｉｐｈｉｌｕｓＴａｓｕｍａｔｓｕ）属膜翅目瘿蜂科。栗瘿蜂是我区板栗的主要害虫之一。栗树的枝芽被害后，该部位可形成瘤状虫瘿，严重影响抽生新梢和开... 相似文献
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竹长尾小蜂Ｄｉｏｍｏｒｕｓａｉｏｌｏｍｏｒｐｈｉ，１年１代、４月下旬日均气温达２０℃时羽化，雌虫产卵于竹广肩小蜂Ａｉｏｌｏｍｏｒｐｈｕｓｒｈｏｐａｌｏｉｄｅｓ产过卵的嫩梢内，卵平均历期１５ｄ，以幼虫取食竹瘿内组织危害。经打孔注药防治试验，久效磷、氧化乐果药效优于其它药剂，用药时间以５月下旬～６月５日为好。 相似文献
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本文研究了雅竹（Ｐｈｙｌｌｏｓｔａｃｈｙｓｖｉｖａｘ）、斑苦竹（ｐｌｅｉｏｂｌａｓｔｕｓｍａｃｕｌａｔｕｓ）、满山爆竹（Ｓｉｎｏｂａｍｂｓａｌａｅｔａ）、孝顺竹（Ｂａｍｂｕｓａｍｕｌｔｉｐｌｅｘ）、大节竹（Ｉｎｄｏｓａｓａｃｒａｓｓｉｆｌｏｒａ）和茶秆竹（Ａｒｒｎｄｉｎａｒｉａａｍａｂｉｌｉｓ）６个竹种的节长变化规律，发现其共有两种节长变化类型．可用不同的模型去拟合，拟合效果良好．同时，应用数学分析的方法，对这两类节长模型的特性作了探讨． 相似文献
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十三种散生竹同生酶分析 总被引：1，自引：0，他引：1
本文对大节竹属Ｉｎｄｏｓａｓａ、唐竹属Ｓｉｎｏｂａｍｂｕｓａ、酸竹属Ａｃｉｄｏｓａｓａ三属１３种散生竹作了过氧化物酶（简称ＰＥＲ）同工酶和酯酶（简称ＥＳＴ）同工酶的垂直板聚丙烯酰胺凝胶电泳的研究。结果表明：ＰＥＲ和ＥＳＴ同工酶谱在一些外形相近的种与种之间有明显差异，可以作为鉴别这些种的参考依据；大节竹属和唐属工酶谱不支持将两属合并的观点；摆竹和倭形竹，据其同工酶谱上的差异，建议摆 竹仍恢复其发表时 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
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. 相似文献
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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。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):131-138
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):472-479
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. 相似文献
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Srisuda Thippayarugs Banyong Toomsan Patma Vityakon Viriya Limpinuntana Aran Patanothai Georg Cadisch 《Agroforestry Systems》2008,72(2):137-148
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. 相似文献
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A. Rigueiro-Rodríguez M. R. Mosquera-Losada E. Gatica-Trabanini 《Agroforestry Systems》2000,48(3):245-256
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. 相似文献