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1.
黄脊竹蝗又名黄脊雷蓖蝗,属昆虫纲、直翅目、蝗总科、网翅蝗科、竹蝗亚科、雷蓖蝗属,主要分布于中国秦岭——淮河以南及其邻近国家。黄脊竹蝗是竹蝗属昆虫中分布最为广泛、危害最为严重的林业害虫之一,广泛分布于我国南方各省,以江苏、浙江、湖南、安徽、四川、重庆、广东、广西等省市为害最为严重。据统计,黄脊竹蝗每年造成林农直接经济损失上千万元,近年来其危害性呈加重趋势,是我国危害面积第二大林业有害生物。  相似文献   

2.
天目山北部余脉竹类植物区系分析   总被引:1,自引:1,他引:1  
对天目山脉北部余脉地区进行为期5年的竹类植物调查,并进行分析研究,认为该地区竹类植物区系具有以下几个特征;(1)本区竹类植物区系在“属”级和“种”级上均 热带性质;(2)种类比较丰富,共有竹类7属40种5变各上8变型,是安徽竹类植物最丰富的地区;(3)以散生竹种为主,全生竹类很少,是刚竹属和短穗竹属的重要分化变异中心;(4)地理成分复杂,东西或南北起源的一些竹种相互渗透交汇,具一定的过渡性特征;(  相似文献   

3.
福建省等翅目昆虫(白蚁)初步名录的考查   总被引:3,自引:0,他引:3  
根据在福建省林木白蚁种类研究过程中收集的大量文献资料和实地调查的结果,列出了福建省等翅目昆虫名录,计4科19属75种。名录中附有等翅目昆虫在福建省的分布地点、寄主植物,文献出处。是迄今为止福建省等翅目昆虫最系统详细的报道。  相似文献   

4.
管启良  俞仲辂 《林业科学》1993,29(5):389-392
香榧是我国特有的经济树种,雌雄异株。根尖细胞染色体分析表明:雌株有一对异形性染色体,异配性别,属ZW型;雄株是同配性别,属ZZ型。雌株的核型为2n=2x=22=22m(2SAT+ZW),雄株的核型为2n-2x=22=22m(2SAT+ZZ)。雌株的体细胞中只有一条最短的Z染色体,间期核的两个染色中心的差明显。雄株有一对最短的Z的染色体,间期核的两个染色中心的大小相同。根据这些特征,植株的性别可...  相似文献   

5.
甘肃南部地区,地形地貌复杂,属大陆性中亚热带季风湿润气候,昆虫资源十分丰富,首次报道了这一地区襀翅目的种类和分布。结果表明共有襀翅目昆虫16科12属19种,其中包括甘肃省新纪录10种。  相似文献   

6.
5种昆虫生长调节剂防治黄脊竹蝗(Ceracriskiangsu)1~2龄跳蝻的室内药效试验结果表明:灭幼脲3号、卡死克和抑太保对跳蝻的致死作用较大;灭幼脲3号增效粉剂有明显的速效作用  相似文献   

7.
黄脊竹蝗Ceracris kiangsu隶属直翅目Orthop-tera蝗总科Acridodea 竹蝗亚科Ceracrinae,别名竹蝗,属东洋区特有种,主要分布于我国秦岭—淮河以南及临近国家和地区[1-2].在我国,该害虫主要分布在江苏、浙江、安徽、福建、江西、湖北、湖南、广东、广西、四川、贵州、云南等多个南方竹子种...  相似文献   

8.
毛白杨透翅蛾幼虫主要危害毛白杨苗干部。设10块标准地,经多次适合性检查,其结果表明,毛白杨透翅蛾幼虫的空间分布状态全部呈现负二项分布,用多种聚集度指标测定,则均属聚集分布。由此建立了不同密度下的理论抽样曲线图和序贯抽样检索表,确定了序贯抽样公式:To(n)=0.3n±1.2n。  相似文献   

9.
柴长宏 《甘肃林业科技》2006,31(3):14-16,29
对麦积山风景区蝗虫多样性进行了初步研究,研究结果表明,麦积山风景区的蝗虫共有47种,分别隶属于7科32属。各科中属数最多的是丝角蝗科,占总数的43.75%,其次是斑翅蝗科,占总属数的21.88%;各科中种数最多的是丝角蝗科,占总数的42.55%,其次是网翅蝗科,占总数的17.02%,种数最少的是锥头蝗科,仅为1属1种,分别占总数的3.13%和2.13%。不同生境蝗虫种类存在一定的差异性,在阔叶杂木林、农田和草地3种生境中阔叶杂木林中蝗虫种类最多,占总种数的76.6%。从蝗虫区系多样性来看,景区蝗虫区系以古北界为主,占总种数的55.32%,其次东洋界的种类占到38.3%。  相似文献   

10.
【目的】基于黄脊竹蝗若虫不同龄、成虫不同性别及不同组织筛选稳定表达的内参基因,为黄脊竹蝗后续转录调控研究提供参考。【方法】依据黄脊竹蝗转录组测序结果,以TUB、RPS27A、RPL10、AK、GAPDH、EF1A、RPS3、Actin和18S rRNA常用的9种昆虫内参基因作为候选,本地Blast后获得碱基序列并设计引物。利用GeNorm、NormFinder和BestKeeper软件分析这9种内参基因的稳定性,筛选出在若虫不同龄、成虫不同性别与不同组织(触角、头、唇须、肌肉组织、精/卵巢)中表达量最为稳定的内参基因。【结果】9种候选内参基因在黄脊竹蝗体内均为首次验证并报道,且与其他昆虫相应基因同源性高(高于70%),差异值小;9种候选内参基因的引物均具有良好的扩增效率(均在90%~120%);在所有样品中,18S rRNA表达水平最高(Ct=10.78±2.58,P<0.05),Actin表达水平差异值最大(Ct=23.55±3.84,P<0.05)。黄脊竹蝗不同龄若虫的内参基因稳定性分析时,3个软件排在前2位的内参基因均为RP...  相似文献   

11.

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   

12.

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   

13.

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   

14.

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   

15.
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   

16.

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   

17.
18.

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   

19.
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   

20.
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   

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