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灭幼脲Ⅲ号对马尾松林昆虫群落多样性的影响研究   总被引:12,自引:0,他引:12  
1995年7月至1996年6月在湘中丘陵区马尾松林内用灭幼脲Ⅲ号作的喷药试验结果表明,灭幼脲Ⅲ号不仅直接影响鳞翅目昆虫的物种组成主多样性水平,而且对膜翅目昆虫(主要是蚂蚁)和蜘蛛的物种组成及多样性水平有间接影响。在时间过程中,施药区鳞翅目和直翅目昆虫的多样性水平有一定程度的下降,但下降程度不如对照区大,膜翅目和蜘蛛的多样性水平则有较大程度的上升,因此林内昆虫群落趋于相对稳定。由于药剂对蚜虫种群无影  相似文献   

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Land snail faunas from maquis and phrygana sites on the islandsof Naxos and Crete, and from the eastern Peloponnese were sampledto determine the relationships between local (site) and regionaldiversities. Mean site diversities are similar in each region.In both the Peloponnese and Crete, however, these representa much lower proportion of total diversity than is the casefor forest faunas from more northerly parts of Europe. The smallisland of Naxos has more uniform faunas. Some of this between-sitediversity is a product of habitat heterogeneity, but most isa product of small-scale biogeographical differentiation. Despitethe short (c. 250km) distances between regions, the faunas ofeach region differ far more than do faunas from forests in northernEurope spread over much greater distances. Nearly 80% of speciesrecorded were found in only one region. These results are comparedwith those from elsewhere, and discussed in the context of thehigh diversity of snail faunas in the mediterranean area generally. (Received 5 May 1999; accepted 1 July 1999)  相似文献   

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采用典型样地捕网调查方法,对整个山地主要放牧地区昆虫物种和群落进行分析,结果表明:鞘翅目(Coleoptera)、直翅目(Orthoptera AxeDgb)、鳞翅目(Lepidoptera)、膜翅目(Hymmenoptera)是构成宁夏香山荒漠草原区的主要昆虫类群;该地区的天敌昆虫数量较少,环境十分适合蝗虫类(Acrididae)和拟步甲类(Tenebrionidae)生存.而蝗虫类和拟步甲类对植被的取食,造成植被破坏,使得环境进一步恶化.  相似文献   

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Variability of marine faunas in Middle Pennsylvanian rocks in central Colorado, as generally of modern marine faunas, increases with increasing depth and distance from shore in shallow water. Less than 3 genera of brachiopods lived nearshore, whereas 10 were present in water computed to have been 22 meters deep, about 5 kilometers offshore. Foraminifers increase from 1 or 2 irregularly formed types nearshore, to 6–8 types in offshore areas, and foraminiferal density increases sharply 3l/2 kilometers offshore at a depth of about 15 meters. Several genera of brachiopods, 3 types of foraminifers, and phylloid algae show a distribution closely related to depth of water and distance from shore. On the basis of significant changes in genera of brachiopods, types of foraminifers, general faunal diversity, and foraminiferal density, three distinct biotopes can be recognized. These biotopes were occupied by the euphemitid, dictyoclostid- Composita , and fusulinid fossil communities.  相似文献   

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前乐平统海洋动物灾变事件   总被引:10,自引:0,他引:10  
张进  尚庆华 《古生物学报》1995,34(4):410-427
作为古生代最后阶段的乐平统可划分为2个阶和4个亚阶,暂以逼近自然界线的Clarkina postbitteri带之底为下界;在二叠纪形成了栖霞期之前和吴家坪期之前两个超序界面,乐平世海侵居于二叠一三叠纪超序的低水位体系,乐平世末的海泛淹没了古特提斯区的残留陆棚;二叠纪末的生物大绝灭形成规模和性质不同的两幕;茅口期末全球性海退使栖居地丧失而导致地方性类群和远洋浮游生物灭亡的前乐平统海泮动物灾变事件,  相似文献   

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昆虫的变态类型与分类体系   总被引:3,自引:0,他引:3  
变态类型作为昆虫分类的一种根据,可说由来已久。远在林奈以前,著名自然学者史璜默邓(Swammerdam)和雷约翰(John Ray)即已根据变态现象,制订“昆虫”的分类体系;当然,那时所指的“昆虫”,几乎包括所有的节足动物和环节动物在内。林奈以后,李区(Leach,1815)、勃马斯德(Burmeister,1829,1832)和西波尔特(von Siebold,1848)都以同  相似文献   

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Abstract  In field control of insects with insecticides, insects could develop different degrees of resistance. When resistance data were reviewed more extensively, it was found that detoxication alone cannot explain very high resistance of house flies to OC1 (organochlorine) insecticides. As a group, flies can develop much higher resistance to OC1 than to OP (organophosphorus) insecticides. although OPs are generally less stable in insects. With the consideration of the dynamics of insect toxicology. one can readily realize the importance of penetration. Based on the rates of penetration and detoxication. slow penetration is a limiting factor for detoxication. To further explain the observed results on the control of S (susceptible) 'and R (resistant) insects, several correlation curves were plotted. on the relationship between physical and biological factors. These relationships not only indicate approximate degrees of resistance of flies to OPs and OCls, but also help select new toxicants. For example, fast speed of action index of insecticides can produce lower resistance, and the analysis of the joint action of insecticides helps evaluate the types (same or different) of mode of action for controlling resistant insects.  相似文献   

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昆虫抗药性和昆虫毒理动力学(英文)   总被引:1,自引:0,他引:1  
不断地使用一种杀虫药剂防治昆虫,会导致昆虫产生抗药性。对昆虫抗药性资料进行广泛综述时,发现了仅单独的解毒作用不能被解释为家蝇对有机氯杀虫药剂产生高抗性原因。作为一个基因。家蝇可以对有机氯产生比对有机磷杀虫剂更高的抗药性,尽管有机磷杀虫剂一般在虫体内是不太稳定的。考虑到昆虫毒理的动力学,杀虫药剂的穿透作用更显示出其实际的重要性。根据穿透和解毒的速率,慢的穿透作用是解毒作用的一个限制因子。防治敏感和抗性昆虫的观察结果,可以划出物理和生物因子之间关系的几种相关曲线图解。这些相关性不仅能说明家蝇对有机磷和有机氯杀虫剂的抗性程度,而且也助于选择出新的杀虫毒剂。  相似文献   

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钦俊德 《昆虫学报》1979,(3):249-256
化学防治是解决害虫问题最为有效的手段之一,三十年来曾对杀虫药剂和毒理学做了不少的科学研究。据统计,《昆虫学报》发表的有关论文在第一个十年中占总篇数的9%,反映我国对害虫的化学防治在早期已有一定的基础。然而,最早试验用昆虫病原防治害虫开始于五十年代中期,对于昆虫病毒的研究开始于六十年代,所以昆虫病理学在我国的开展较晚。这两门能密切结合生产实践的昆虫学分支学科的内容和在我国发展的过程不同,宜加以分述。  相似文献   

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陕西蓝田地区第四纪哺乳动物群的划分   总被引:5,自引:0,他引:5  
<正> 陕西蓝田地区的新生代地层保存得非常完好,各个时代的地层,几乎都有其代表,并发现了丰富的哺乳动物化石。在第四纪地层中,特别具有意义的是公王岭及陈家窝分别发现了蓝田人头盖骨及下颌骨,一些地区还发现了旧石器,更进一步证实这一地区在第四  相似文献   

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柴达木盆地石炭纪的Ting类,珊瑚和腕足动物的代表属与中国其它代表地区-塔里木盆地,准噶尔盆地,陕甘宁地区,华北地区,华南地区,西藏北部地区可以进行对比,在计算大Zong相似系数的基础上,进行Q型聚类分析,得出古生物地理分区结果,则解决柴达木盆地石炭纪古生物地理归属问题,研究结果表明,早石炭世可划分为:柴达木-华南-陕甘宁生物区;塔里木-藏北生物区和准噶尔生物区,柴达木属于柴达木-华南生物亚区,晚  相似文献   

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景观多样性测度:格局多样性的亲和度分析   总被引:18,自引:5,他引:18  
介绍景观格局多样性亲和度分析的原理和方法,指出亲和度分析能够测定景观各亚单元的相对位置及镶嵌多样性。镶嵌多样性是综合了亲和度分析信息的一个指标,是对格局多样性的有效测度。镶嵌多样性低意味着景观结构简单,镶嵌多样性高意味着景观结构复杂,亲和度分析可以比较不同景观的多样性和复杂性,可以判断群落与景观整体的关系的远近,还可以判断两个群落的相似性和亲和度差异的显著程度。因而亲和度分析将景观层次的多样性与物  相似文献   

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