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关键词： threatened species   predation   Australia   feral cats   body size   demography   diet   prey  

摘要： Globally, wildlife managers often control predator populations to protect biodiversity, livestock or other valued resources. Most assume that the predation impact of each individual predator is the same and that removing any individual predator produces a benefit to the target species. However, research suggests predation efficacy can vary within a predator species according to phenotypic characteristics. Understanding these individual differences may be critical for managing predation impacts on particular categories of prey including small populations where predation effects are amplified. We used dietary data from 1748 feral cats euthanized over 30 years during a control programme in arid Australia to determine whether any predator attributes could predict their effect on different prey weight classes. Feral cats in our study ate a wide range of prey including reptiles, mammals, birds and invertebrates. Demography (body mass) was a highly significant predictor of diet. Cats weighing 3 kg fed predominantly on prey 500 g when cats attained a body mass of 6 kg. Of more significance was that diet varied between demographic groups but also within a single demographic group (adult males) based on body mass, with results having significant implications for threatened prey. Modelling indicated that for a fixed predator population size, the predation rate on prey in a >500 g weight class increased by 28% when the ratio of large (>4.2 kg) to small adult males varied according to its natural range (12%-80% over the 30-year study). Results suggest that variations in predator demography can significantly impact predation rates on prey species and should be included in predator-prey models for small prey populations. On average, large male cats comprised 23% of the population and our findings suggest that targeting this 'lethal demographic' and manipulating predator demography should be prioritized along with lowering predator density to reduce predation impacts on prey weighi

关键词： Complexity of regulation   Volume of regulation   Fragmentation of regulation   Business demography  

摘要： The volume and fragmentation of the regulatory framework matter for the study of business demography. They may imply that the market is divided, reducing the ability of companies to take advantage of economies of scale and may reduce firm size. This article has two objectives: it analyzes the results of a new database on regulation in Spain and explores the impacts of the complexity of the regulatory framework on business demography. The volume of new norms adopted in Spain has increased by four-fold since the end of the 70s, reaching 11,737 regulations in 2018. The results of our analysis indicate that the complexity of the regulatory framework, broken down at the local level, is negatively related to the total number of firms in Spain. The negative association is clearer in the case of limited liability companies (which are larger firms) than in individuals with business activity (which have a smaller size). The analysis in this article is relevant to the study of productivity in Spain.

关键词： coralline turf algae   demography   ecosystem engineer   fucoid   Hormosira banksii   intertidal   macroalgae  

摘要： Canopy-forming macroalgae form the basis of diverse coastal ecosystems globally. The fucoid Hormosira banksii is often the dominant canopy-forming macroalga in the temperate intertidal of southern Australia and New Zealand, where it is commonly associated with an understory of coralline turf. Hormosira banksii is susceptible to both natural and anthropogenic disturbance and despite its abundance, few studies have examined the demography of this important species. This study determined the demographic response of H. banksii to different gradients of disturbance to both its canopy and to the understory coralline turf. We established plots in which the density of H. banksii and/or understory coralline turf was manipulated in a pulse perturbation to simulate a disturbance event. The manipulated plots contained eight treatments ranging from 100% removal of H. banksii to 100% removal of the understory coralline turf. We then measured recruitment and followed individual recruits for up to 18 months to determine growth and survivorship. We found that H. banksii recruitment was seasonally variable throughout the experiment and highest over summer, survivorship of recruits was generally high, and the species was slow-growing and long-lived. Moreover, the level of disturbance did not seem to affect recruitment, growth, or survivorship and post-recruitment mortality was independent of H. banksii density. In this system, it appears that H. banksii is a relatively long-lived perennial species whose demography is density-independent which appears to allow recovery from disturbance.

关键词： Banksia ornata   chronosequence   fire regime   population dynamics   primary juvenile period   pyrodemography  

摘要： Predicting changes in the abundance of species over time is a central goal of conservation ecology. Typically, demographic data are used to parameterise models which describe population dynamics. Vital rates of plants vary across a species' distribution, yet most demographic estimates are spatially constrained. Banksia ornata (Proteaceae), a widespread serotinous obligate-seeding shrub in southern Australia, has previously had a fire management model developed based on demographic data derived from a chronosequence in one part of the species' range. We asked: are demographic data collected from a limited geographic range robust for developing population dynamic models that are applied across the broader species' range? How much variation exists in the demography of species across their range and does this matter for estimating fire return intervals necessary for species persistence? We examine site-to-site variation in the pyrodemography of six populations of B. ornata encompassing its geographic range. We documented changes in population density, time to first reproduction and canopy seed bank accumulation in stands varying in age from 0.5 to 55 years. We model year of maximum seed production on demographic parameters such as population starting density and survival rate. Density, primary juvenile period, rates of mortality and seed bank accumulation varied across populations. Primary juvenile period varied across populations (from 6 to <20 years), while time to maximum seed production was estimated to take 34-39 years after fire. Hence, the fire intervals that correspond to minimising extinction risk (due to variation in primary juvenile periods) diverge moreso among populations than the fire intervals that produce (on average) the highest maximum seed production with respect to time since fire. Demographic data collected at different locations in a species' range are likely valuable for building realistic species response models to disturbance, providing underlyi

关键词： 高职   统计学基础   课程思政   教学改革   分析研究  

摘要： 在发展社会主义事业中,提升人才具有战略意义。在教育探索与改革的大背景下,教育的发展方向是追求传统职业教育的专业技术与思想政治综合训练相结合。在培养理论、专业技能和知识的基础上,同时注重对学生思想和职业道德的培养。因此,教育部门致力于在课程中将理论技能与不同学科的思想道德素质统一起来。以高职院校基础统计学课程为例,说明如何改革思想政治课教学,以支持统计学课程的思想政治定位。

关键词： 统计学   经济社会发展   作用   意义  

摘要： 随着社会经济的不断发展,在国民经济运行收支方面的计算工作越来越重要,统计学是进行国民经济预测工作最常使用的方法。统计学是在社会经济运行过程中进行资料的搜集、数据加工、数据处理、资料分析,然后得出论证的一种重要的方法体系,能够具体的分析出我国国民经济的运转状况和趋势,能够帮助财政收支进行合理科学的预测,制定严谨的经济决策。本文将从统计学的含义及原理着手,再分析统计学对经济社会发展的作用,最后从三个方面分析统计学对经济社会发展的意义。

关键词： 大数据   经管类专业   统计学   课程改革   路径   实现  

摘要： 统计学是经管类专业至关重要的一门核心课程,此课程主要是借助定量分析法来进一步强化是学生的数据整理能力以及分析能力。最近几年,信息技术得到了蓬勃发展,人类已经进入大数据时代,在数据分析与处理方面的要求越来越高,所以统计学人才培养至关重要。对与此同时,新时代环境下的数据具备多样性、海量性的显著特征,造成数据处理统计分析的难度较高,而专业性人才培养工作也比较困哪。随着企业对数据分析能力的要求逐步提升,传统统计学教学模式已经无法切实满足社会发展要求,新时代环境下,统计学模式必须要进行改革发展,强化学生的实践能力,而该项工作也是现阶段统计学教学工作发展过程中亟待解决的一个难题。

关键词： 课程思政   统计学   教学改革   思政目标  

摘要： 《统计学》是一门重要的专业基础课,受众面比较广,因此,利用《统计学》进行思政教育有着非常重要的作用和意义。《统计学》蕴含着较为丰富的思政教育资源,能够激发学生的爱国情怀、强化学生的社会责任感等,这与高校思政目标完全吻合。该文探索了以《统计学》专业知识为载体对大学生进行思政教育的相关路径,具体包括:提高教师自身思政意识、挖掘《统计学》中的思政资源等。