大型底栖动物入侵种:它们是否对德国水生动物群落构成威胁?

在水体中发现大型底栖动物入侵种是一种世界范围普遍的现象。人类移动的同时将物品从一个大陆带到另一个大陆,这使许多水生动物物种能够突破自然的防线侵入到其他的区域和大陆。藉由人类现代的旅行方式,在不同区域间移动的物种数量显著增加,成功入侵种的数量也随之增多。成功入侵种需要具备一些特征,如可动性,小体型,适应性强和繁殖率高等,这些均有利于物种跨区域的入侵。当然,新生活环境也必须满足可适应的标准。对一个受人类活动破坏而丧失其原有物种的水环境来说,它对新物种入侵的抵抗力会很弱甚至缺乏。德国水体受人类活动的胁迫非常严重,许多自然水体受到的破坏已无法挽回,有些甚至已经完全成为了人工环境。这些水体由相互连接着的溪流河川网络组成,这很容易使新物种的入侵范围扩大。在外来物种的入侵面前,受人类活动胁迫和直接破坏的水体,比尚保持着天然环境状况的水体更加脆弱。     

大型底栖动物入侵种:它们是否对德国水生动物群落构成威胁?

在水体中发现大型底栖动物入侵种是一种世界范围普遍的现象。人类移动的同时将物品从一个大陆带到另一个大陆,这使许多水生动物物种能够突破自然的防线侵入到其他的区域和大陆。藉由人类现代的旅行方式,在不同区域间移动的物种数量显著增加,成功入侵种的数量也随之增多。成功入侵种需要具备一些特征,如可动性,小体型,适应性强和繁殖率高等,这些均有利于物种跨区域的入侵。当然,新生活环境也必须满足可适应的标准。对一个受人类活动破坏而丧失其原有物种的水环境来说,它对新物种入侵的抵抗力会很弱甚至缺乏。德国水体受人类活动的胁迫非常严重,许多自然水体受到的破坏已无法挽回,有些甚至已经完全成为了人工环境。这些水体由相互连接着的溪流河川网络组成,这很容易使新物种的入侵范围扩大。在外来物种的入侵面前,受人类活动胁迫和直接破坏的水体,比尚保持着天然环境状况的水体更加脆弱。     

Climatic niche shifts are rare among terrestrial plant invaders

The assumption that climatic niche requirements of invasive species are conserved between their native and invaded ranges is key to predicting the risk of invasion. However, this assumption has been challenged recently by evidence of niche shifts in some species. Here, we report the first large-scale test of niche conservatism for 50 terrestrial plant invaders between Eurasia, North America, and Australia. We show that when analog climates are compared between regions, fewer than 15% of species have more than 10% of their invaded distribution outside their native climatic niche. These findings reveal that substantial niche shifts are rare in terrestrial plant invaders, providing support for an appropriate use of ecological niche models for the prediction of both biological invasions and responses to climate change.     

Invasion biology of the cotton mealybug,Phenacoccus solenopsis Tinsley: Current knowledge and future directions

The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), which is native to North America, emerged as a major invasive insect pest of multiple crops in Asia at the beginning of the 21st century. Considering the economic significance of this insect and its rapid worldwide spread, we examined the possible factors driving its invasions. In this paper, we summarize the life history traits of P. solenopsis conceivably related to population development in invaded regions; these traits include its use of diverse host plants, reproductive capacity and mode, adaptation to temperature, response to food shortage, and insecticidal resistance. Then, focusing on the multiple trophic interactions that may promote or hinder invasion, we review the mutualistic relationship of this mealybug with ants and predation and parasitism by natural enemies. Finally, we suggest topics for future research and provide our perspective on the biological invasions of this mealybug. We speculate that specific biological factors associated with this mealybug, particularly its wide host range, high reproductive potential, evolved changes in life history traits, and mutualism with ants have played important roles in its invasions, allowing this pest to become established and rapidly increase its population upon its introduction into new regions.     

安徽省外来植物研究

介绍了安徽省自然环境条件、外来植物、外来入侵植物,并分析了外来入侵植物区系及迁入方式。     

Invasion genetics of alien insect pests in China: Research progress and future prospects

An unwelcome side effect of the globalization of the world's economy and dramatic increase in human mobility and trade has been a marked increase in species invasions that have posed severe threats to the ecological, economic, and/or social stability of the introduced regions. In this review, we analyzed the application of molecular markers in invasion genetics of invasive alien insect pests (IAIPs) in China based on a bibliometric survey. Our report discusses the considerable progress that has been made during the past two decades in understanding the invasion genetics of IAIPs in China. We reviewed the major findings in the main topics including the effects of origin and routes of invasion on genetic structure, spatial and temporal genetic changes, factors contributing to the genetic changes of IAIPs, and genetic mechanisms involved in IAIPs' invasions. On the other hand, some of these research areas remain relatively unexplored in China, especially those pertaining to spatial and temporal genetic changes of IAIPs and genetic mechanisms of IAIPs' invasions. Finally, the future research prospects of IAIPs in China are discussed. We hope this review will stimulate an interest in and provide an increased understanding of the field of invasion genetics of IAIPs in China, and provide a basis for future research in this area.     

Rapid spread of a bacterial symbiont in an invasive whitefly is driven by fitness benefits and female bias

Maternally inherited bacterial symbionts of arthropods are common, yet symbiont invasions of host populations have rarely been observed. Here, we show that Rickettsia sp. nr. bellii swept into a population of an invasive agricultural pest, the sweet potato whitefly, Bemisia tabaci, in just 6 years. Compared with uninfected whiteflies, Rickettsia-infected whiteflies produced more offspring, had higher survival to adulthood, developed faster, and produced a higher proportion of daughters. The symbiont thus functions as both mutualist and reproductive manipulator. The observed increased performance and sex-ratio bias of infected whiteflies are sufficient to explain the spread of Rickettsia across the southwestern United States. Symbiont invasions such as this represent a sudden evolutionary shift for the host, with potentially large impacts on its ecology and invasiveness.     

Translocation as a species conservation tool: status and strategy

Surveys of recent (1973 to 1986) intentional releases of native birds and mammals to the wild in Australia, Canada, Hawaii, New Zealand, and the United States were conducted to document current activities, identify factors associated with success, and suggest guidelines for enhancing future work. Nearly 700 translocations were conducted each year. Native game species constituted 90 percent of translocations and were more successful (86 percent) than were translocations of threatened, endangered, or sensitive species (46 percent). Knowledge of habitat quality, location of release area within the species range, number of animals released, program length, and reproductive traits allowed correct classification of 81 percent of observed translocations as successful or not.     

雌雄异株植物簇毛槭繁殖代价延迟效应研究

目的植物将大部分资源用于繁殖活动时必将导致其对生长发育等其他功能的资源投入下降，生活史理论把这种现象称为繁殖代价。植物繁殖代价主要体现为当年繁殖资源投入与当年营养生长资源投入之间的权衡，以及当年繁殖资源投入与未来生长发育资源投入之间的权衡，这意味着植物的繁殖代价可能存在着一定的延迟效应。本文利用雌雄异株植物雌雄功能分离的属性，验证吉林蛟河针阔混交林中簇毛槭是否存在繁殖代价的延迟效应。方法2012年选取簇毛槭雌雄各90株，将不同性别植株分成3个处理组（A为对照组，B为摘除花朵即开花不结实组，C为摘除花蕾组）进行试验操作。2013年和2017年跟踪调查不同处理组中簇毛槭繁殖及生长状况。利用双因素方差分析检验不同处理方式下雌雄植株的1年生枝条长度和叶片生物量的差异显著性。结果2013年花期，在1年生枝条水平和2级侧枝水平上1年生枝条长度顺序为C组 > B组 > A组。其中雌株的B组和C组显著大于A组，雄株的处理组间差异显著。2013年花期，在1年生枝条水平和2级侧枝水平上雌株的叶片生物量顺序为C组 > B组 > A组；其中B组和C组显著大于A组。2017年花期，在1年生枝条水平雄株的叶片生物量顺序为C组 > B组 > A组，其中C组显著大于A组。结论构件水平影响着繁殖代价延迟效应的检测结果；雌雄异株树种簇毛槭的繁殖代价的延迟效应在营养器官上的表现具有性别和养分分配差异；繁殖代价延迟效应持续表现时间也具有性别差异。      

南方拟(韰)生活史类型的研究

[目的]判定南方拟的生活史类型。[方法]以15种已知生活史类型的鱼类的生态学参数作为参照,选择渐近体长(L∞)、渐近体重(W∞)、生长系数(k)、自然死亡系数(M)、初次性成熟年龄(Tm)、最大年龄(Tmax)和种群繁殖力系数(PF)等7个生态学参数,分别采用主成分分析法、聚类分析法和Beverton-Holt动态综合模型对南方拟生活史类型进行判定。[结果]在16种鱼的第1、2及1、3主成分散点图中,南方拟均与r-选择鱼类聚成一簇。在聚类分析中,K-选择鱼类聚成一支,南方拟和已知的r-选择鱼类聚成一支;而Beverton-Holt动态综合模型也表明,南方拟的产量曲线为典型的r-选择鱼类产量曲线。[结论]南方拟为r-选择鱼类。     

城市商业银行发展对农村商业银行的启示

通过将农村商业银行与城市商业银行进行对比分析,发现二者在发展中既存在共同点也存在差异。以城市商业银行发展的成功经验研究为例,提出了农村商业银行在未来的发展中应进一步完善公司治理结构,明确市场定位,做好风险管理等建议。     

恒温和温室波动温度下异色瓢虫种群生命表

【目的】异色瓢虫（Harmonia axyridis Pallas）是一种重要的捕食性天敌昆虫,广泛应用于害虫生物防治。生命表是研究外界环境因子对昆虫发育、繁殖、存活及种群动态影响的工具。室内恒温下异色瓢虫生命表研究已有报道,但是在田间释放时经历的是昼夜波动温度。与恒温相比,波动温度能显著改变昆虫的生物学特性。论文通过构建室内恒温和温室波动温度下异色瓢虫种群生命表,比较分析异色瓢虫在两种条件下的生活史和生命表参数,为规模化生产、释放提供技术支撑,充分发挥其在生物防治中的作用。【方法】利用年龄-龄期两性生命表分析室内恒温和温室波动温度下异色瓢虫发育历期、存活率和繁殖率数据,并利用统计软件SPSS17.0 t-test比较两种温度下生活史数据间的差异;应用Bootstrap方法计算种群参数的平均数和标准误,并利用TWOSEX-MSChart 的t-test比较两种温度下种群参数间的差异。【结果】温室波动温度下异色瓢虫发育历期延长、成虫寿命缩短,繁殖力降低。由年龄-阶段特定存活率（s_xj）和年龄-特定存活率（l_x）可知温室波动温度下异色瓢虫各发育阶段存活率明显降低。由繁殖力曲线（f_x、m_x）可以看出室内恒温下异色瓢虫产卵时间长,产卵量高。两种条件下异色瓢虫期望寿命（e_xy）均随年龄增加而缩短,且温室条件下其期望寿命更短。生殖价值（v_xj）是个体对未来种群的贡献,随着异色瓢虫雌虫的羽化生殖价值增加,当雌虫产卵生殖价值达到最大,温室波动温度下异色瓢虫的生殖价值要明显低于室内恒温下的。室内恒温和温室波动温度下异色瓢虫内禀增长率（r）分别为0.1395和0.0613 d^-1,周限增长率（λ）分别为1.150和1.062 d^-1,净增殖率（R₀）为257.3和13.3后代/个体,种群平均世代周期（T）为39.7和42.7 d。【结论】室内恒温和温室波动温度下异色瓢虫生活史特性和种群参数存在显著差异,恒温可能过高或过低的估计许多生命表参数,依据恒温下得到的生命表数据进行田间释放应用存在一定误差,从而影响其防控效果。     

雌雄异株植物鼠李生殖分配与生殖耗费补偿机制

目的检验鼠李个体大小对其生殖分配的影响,比较相同径级雌雄鼠李生殖分配的差异,探讨鼠李可能存在的生殖耗费补偿机制, 对今后雌雄异株植物生理生态学方面的研究提供论据支撑。方法在鼠李的花期和果期选择当年进行繁殖活动且生长状况与立地条件类似的植株作为调查样本,对每株鼠李的性别、叶生物量、花生物量（花期）、果生物量（果期雌株）进行了调查,通过Li-6400 便携式光合作用测定仪比较不同性别鼠李叶片的光合能力。结果（1） 大径级鼠李的生殖生物量与营养生物量均显著大于小径级鼠李（P < 0.05）。（2） 相同径级鼠李雌株的生殖生物量均显著高于雄株（P < 0.05）,雌雄鼠李的营养生物量没有显著差异（P > 0.05）。（3） 当光强处于500 ~2 000 μmol/（m2?s）时,鼠李雌株单位叶面积的光合速率大于雄株。结论研究区域内鼠李的个体大小对其生殖分配有显著影响,这是不同个体可利用资源总量不同造成的。鼠李雌株相较于雄株,并没有因较高的生殖耗费而缩减对营养生长的投入。鼠李雌株通过光合作用获得了更多的可利用资源来满足其生殖和营养生长过程需要,这种较强的光合能力是雌株在较高繁殖压力下进化出的一种生殖耗费补偿机制。      

发达国家都市农业的成功经验对我国的借鉴与启示

结合我国目前都市农业发展的现状,比较分析了美国、日本、德国、荷兰、法国和新加坡等发达国家在发展都市农业方面的成功经验,以及各国不同的发展特征、组织形式、生产特点、营销与物流、功能作用和扶植政策的典例,这些成功经验可以为我国都市农业发展提供借鉴和启示。     

生物入侵对农业生态系统稳定性的影响及防治对策

全球化不仅带来了世界政治和经济格局的变化,而且也改变了生物分布的空间格局——导致生物种群的重新分布,由此而产生的生物入侵已成为各国政府、国际社会和学术界所共同关心的全球变化问题。生物入侵、全球变化和生境丧失是21世纪的最棘手的三大环境问题。本文简述了生物入侵的概况、定义、入侵途径和过程,特别是其对农业生态系统的稳定性的影响,在此基础上提出了一些防止生物入侵的治理方法和策略。     

Relationship Between Behavioral Frequency and Reproductive Potential of Female Alpine Musk Deer in Captivity

Between June 2005 and February 2006, focal sampling and all occurrence behavior recording were used to quantify the behavioral patterns of captive female alpine musk deer （Moschus sifanicus） at Xinglongshan Musk Deer Farm, Gansu Province, China. Copulation success was used to differentiate individuals into two groups （successful and unsuccessful） and to provide a basis for behavioral comparisons, throughout both mating （rut） and non mating seasons. The results indicated significant differences between the behavior patterns of successful and unsuccessful females; however, the reproductive season played an important environmental factor. Pooling results across reproductive seasons, successfully copulating females showed significantly higher frequencies of vigilance and lower frequency of feeding behavior as compared with unsuccessfully copulating females. In the non-mating season, unsuccessfully copulating females had higher frequency of self-directed behavior, environment sniffing, and were less aggressive than successful copulating females. Furthermore, females who were successful at copulating also demonstrated tail-pasting behavior; however, this only occurred during the rut season. The results of this study can improve management practices for musk deer farms through increasing mating success and reducing maintenance costs. Furthermore, variation in behavior may also be used as a predictor of copulation success and reproductive potential, whereby females can be grouped and separated according to their reproductive history and past reproduction success.     

The illusion of invariant quantities in life histories

Life-history theory attempts to provide evolutionary explanations for variations in the ways in which animal species live their lives. Recent analyses have suggested that the dimensionless ratios of several key life-history parameters are the same for different species, even across distant taxa. However, we show here that previous analyses may have given a false picture and created an illusion of invariants, which do not necessarily exist; essentially, this is because life-history variables have been regressed against themselves. The following question arises from our analysis: How do we identify an invariant?     

When biotas meet: understanding biotic interchange

When the barrier between biotas with long separate histories breaks down, species invade from one biota to the other. Studies of episodes of marine and terrestrial biotic interchange that have occurred during the last 20 million years show that large-scale extinction of species before the onset of interchange renders biotas especially prone to invasion. As environments and species are being exploited and eliminated on an ever increasing scale in the human-dominated biosphere, the geographical expansion of species from biotas in which evolution of high competitive, defensive, and reproductive abilities has proceeded the furthest will become more frequent. Historical events and interactions are essential ingredients for understanding the current and future structure and composition of the world's biota.     

不同区域间棉花期货价格发现功能对比分析——以新疆为例

通过对比分析,研究棉花期货价格与不同区域棉花现货价格的关系,以便在新形势下不同区域制定出相应的策略。运用Eviews5.0统计软件中的ADF单位根检验、E-G两步法协整检验和Granger因果检验等研究方法实证检验了棉花期货价格与全国棉花现货价格、新疆棉花现货价格之间的关系,结果表明,棉花期货价格与全国棉花现货价格、新疆现货价格均具有长期均衡关系;棉花期货价格对全国棉花现货价格、新疆棉花现货价格具有单向引导作用;棉花期货价格发现功能在我国棉花市场中的发挥的作用要优于在新疆棉花市场中发挥的作用。     

Phenotypic basis of reproductive success in a social insect: genetic and social determinants

Social insects live in societies that include both reproductive and nonreproductive adults. Understanding the factors that determine which individuals become successful reproductives is necessary to explain the evolution of these societies. The phenotypic effects of the gene Pgm-3 (or a closely linked gene) that may cause workers of the fire ant Solenopsis invicta to selectively execute all queens of a specific genotype were investigated. These effects, which involve differences in queen reproductive development, are expressed only in colonies exhibiting a particular type of social organization (multiple-queen colonies), and it is only in such colonies that selective execution on the basis of genotype occurs. This is an unusual example of genotype-environment interaction in gene expression in which the environmental component is the social environment. The queens executed are, surprisingly, those with the greatest reproductive development. Thus, there is a counterintuitive relation between the potential and realized reproductive success of queens in multiple-queen societies of this ant.