Conservation Genetics of Potentially Endangered Mutualisms: Reduced Levels of Genetic Variation in Specialist versus Generalist Bees

Abstract:  Oligolectic bees collect pollen from one or a few closely related species of plants, whereas polylectic bees visit a variety of flowers for pollen. Because of their more restricted range of host plants, it maybe expected that specialists exist in smaller, more isolated populations, with lower effective population sizes than generalists. Consequently, we hypothesized that oligolectic bees have reduced levels of genetic variation relative to related polylectic species. To test this hypothesis, we used five phylogenetically independent pairs of species in which one member was oligolectic and the other was polylectic. We assayed genetic variation in our species pairs at an average of 32 allozyme loci. Within each species pair, the oligolectic member had fewer polymorphic loci, lower average allelic richness, and lower average expected heterozygosity than its polylectic relative. Averaged over all species pairs, this corresponds to a 21% reduction in allelic richness, a 72% reduction in the proportion of polymorphic loci, and an 83% reduction in expected heterozygosity in specialists compared with generalists. Our data support the hypothesis of reduced effective population size in oligolectic bees and suggest that they may be more prone to extinction as a result. We suggest that in instances in which bee specialists are involved in mutually codependent relationships with their floral hosts, these mutualisms may be endangered for genetic and ecological reasons.     

提高耕地综合生产能力保证粮食安全

粮食是保障国家经济安全的重要战略物资，我国政府一直高度重视粮食安全问题。关注粮食安全问题，不能只重视粮食流通体制的改革，应更多地重视粮食生产领域，即粮食综合生产能力。而粮食综合生产能力又与耕地综合生产能力密切相关。只有稳定提高耕地的综合生产能力，才能提高粮食综合生产能力，保证粮食安全。实行最严格的耕地保护制度，大力实施“沃土工程”，培肥地力，进一步加强农田水利基本建设，改造中低产田，提高耕地综合生产能力，是保证粮食安全的有效措施。     

环境司法专门化视阈下环境法庭之检视与完善

随着环境问题日益凸显,我国积极推进环境司法专门化进程,从最高人民法院到基层人民法院初步形成了具有中国特色的环境法庭体系。这一体系由环境保护审判庭、环境保护合议庭、环境保护巡回法庭以及为数不多的基层环境保护派出法庭构成。目前的环境法庭主要采用"三加一"模式、"三合一"模式、"二合一"模式以及单一模式等四种审理方式,在缓解环境案件审判压力、公正审理环境案件、推进环境公益诉讼、提高环境司法水平等方面发挥了一定的作用。但同时亦应注意到,现有的环境法庭存在诸多问题:基层人民法院缺少法定权限,中级以上人民法院缺少设立环境法庭的程序性依据,致使法律依据不足;缺乏合理的机构建制,级别管辖和地域管辖制度不甚科学;受案范围有限和受害者起诉意愿不足,致使案源不足;特别程序缺失,监测评估机构缺乏中立性,审判人员专业性不强,致使支持保障机制不健全。为此,应从如下几个方面完善我国的环境法庭:首先,为环境法庭建设提供明确的法律依据,规范环境法庭的设立、职责定位及基本权限等事项,将环境法庭建设全面纳入法制轨道;其次,健全环境法庭体系,着重健全环境法庭审级设置,同时完善地域管辖;再次,改进审判模式,健全"多审合一"程序;再次,拓宽案件来源,合理确定环境公益诉讼的起诉主体,扩大受案范围,完善鼓励起诉机制;最后,完善支持保障机制,针对一审程序设立专业陪审员,针对二审程序设立专家委员会。     

Analysis of rodent populations in technogenically transformed areas (with reference to <Emphasis Type="Italic">Apodemus</Emphasis> (<Emphasis Type="Italic">S.</Emphasis>) <Emphasis Type="Italic">uralensis</Emphasis> from the EURT zone)

It is shown that the response of rodent populations to acute and chronic irradiation depends on its functional structure, i.e., on specific features of animals with two alternative types of ontogenetic development. Upon acute irradiation, sexually immature young of the year (animals with the second type of ontogeny) are most radioresistant. Exposure to chronic irradiation, as in the zone of the Eastern Ural Radioactive Trace (EURT), leads to an increase in the proportion of mature young of the year (animals with the first type of ontogeny), which are the most radiosensitive part of the population. The abundance and fecundity of mice in the impact zone are consistently higher than in the background zone, which improves the adaptive potential of the population. The role of species ecological specialization and configuration of the contaminated zone in the formation of migrant rodent population is emphasized. It is concluded that a high migration activity allows the pigmy wood mouse (a radiosensitive species) to avoid long-term radiation exposure.     

企业班组安全生产管理新模式研究

为提高企业班组安全管理效率和水平,本文在对电力、矿山、化工、钢铁冶炼等行业企业的班组安全管理现状进行调研的基础上,提出我国代表性班组安全管理模型存在的问题;基于实践和研究,从核心思想、工作理念、工作原则、安全生产目标指标与责任制系统建设、基础保障5大方面阐释班组安全管理新模式,并应用于实践。研究表明:班组安全生产管理的新模式可以全方位、全层次有效提升班组安全管理的水平,更具有系统性和有效性。     

农业生产性服务对农户耕地质量保护行为的影响——来自江汉平原水稻主产区的证据

利用江汉平原水稻种植农户调查数据,建立Ordered Probit模型,讨论农业生产性服务对农户耕地质量保护行为的影响,揭示服务规模经营促进农户耕地质量保护行为的理论机制和现实逻辑。研究表明：（1）目前农户对修整农田水渠、施用农家肥、测土配方施肥、秸秆还田四类典型耕地质量保护措施的采纳比例分别为17.79%、17.31%、7.89%和90.69%;（2）控制其他条件不变,农业生产性服务能显著促进农户耕地质量保护行为,经检验后该结论依然稳健;（3）排除秸秆还田这一强制性措施后,生活型农户偏向采纳资本投入型技术,生产型农户则更偏好劳动投入型技术;（4）较之于生产型农户,农业生产性服务对生活型农户采纳耕地质量保护措施的促进作用更强。     

加速开发宁夏南部山区农业资源

本文分析了宁南山区农业生产条件和存在的问题,认为宁南山区农业资源十分丰富,只要合理开发利用,宁南山区必将成为我区油料、大豆、畜产品的生产基地,并相应地提出了加速开发宁南山区农业资源的措施。     

基于生态足迹的东北地区可持续发展分析

以区域生产量取代消费量,并用生产性生态足迹作为区域可持续发展的评价指标,对东北地区1995,2000～2003年的生产性生态足迹进行了计算分析。结果表明,东北地区上述年份的生物生产模式处于一种不可持续的状态,并提出了消除生态赤字的途径和方法,旨在为东北地区振兴提供了一定的指导性意见。     

Use of Basic Biological Information for Rapid Prediction of the Response of Species to Habitat Loss

Abstract:  Much research has focused on identifying traits that can act as useful indicators of how habitat loss affects the extinction risk of species, and the results are mixed. We developed 2 simple, rapid-assessment models of the susceptibility of species to habitat loss. We based both on an index of range size, but one also incorporated an index of body mass and the other an index combining habitat and dietary specialization. We applied the models to samples of birds (Accipitridae and Bucerotidae) and to the lemurs of Madagascar and compared the models' classifications of risk with the IUCN's global threat status of each species. The model derived from ecological attributes was much more robust than the one derived from body mass. Ecological attributes identified threatened birds and lemurs with an average of 80% accuracy and endangered and critically endangered species with 100% accuracy and identified some species not currently listed as threatened that almost certainly warrant conservation consideration. Appropriate analysis of even fairly crude biological information can help raise early-warning flags to the relative susceptibilities of species to habitat loss and thus provide a useful and rapid technique for highlighting potential species-level conservation issues. Advantages of this approach to classifying risk include flexibility in the specialization parameters used as well as its applicability at a range of spatial scales.