从文献看种群、种群生态及种群行为研究

通过维普中文期刊网和英文ScienceDirect数据库有关种群、种群生态和种群行为文献的查询,发现文献的发表量很不平衡,种群研究文献的年增长率远大于种群生态和种群行为。英文文献中关于种群行为研究的文献增长率高于种群生态,而中文文献正好相反。     

Predicting extinctions: interspecific competition,predation and population variability in experimental Daphnia populations

We examine how interspecific competition and two types of size-selective predation affect population density, variability and persistence in laboratory cultures of two species of Daphnia, D. magna and D. longispina. When both species were analysed together, and for D. longispina alone, there were weak negative relationships between mean population density and population variability. Interspecific competition resulted in lower population densities and higher population variability. Extinct populations had lower densities and were also more variable than persisting ones. There was still an effect of population variability on extinction probability after the effect of density on population variability had been accounted for. Hence, the effects of population density and variability on population persistence were partly independent of each other. The effects of size-selective predation on population persistence were more species-specific and not directly related to density or variability. Since the effects of species interactions on persistence were large, we suggest that it is likely that population vulnerability analyses not incorporating effects of interspecific interactions are often misleading.     

印楝素乳油对小菜蛾种群的控制作用模拟

应用害虫种群系统控制控制的状态空间方程和作用因子添加分析法,模拟1％印楝素乳油对小菜蛾种群的控制作用,结果表明,印楝素浮油对小菜蛾种群的控制机理,主要是对小菜蛾成虫的显忌避作用,尤其是在种群发展的初期,由于其显的忌避作用,降低田间卵量,使其种群数量明显降低下来,有效控制其为害。     

Towards a population approach for evaluating grassland restoration—a systematic review

Persistence of restored populations depends on growth, reproduction, dispersal, local adaptation, and a suitable landscape pattern to foster metapopulation dynamics. Although the negative effects of habitat fragmentation on plant population dynamics are well understood, particularly in grasslands, the population traits that control grassland restoration are less known. We reviewed the use of population traits for evaluating grassland restoration success based on 141 publications (1986–2015). The results demonstrated that population demography was relatively well‐assessed but detailed studies providing information on key stages of the life cycle were lacking despite their importance in determining population viability. Vegetative and generative performances have been thoroughly investigated, notably the components of plant fitness, such as reproductive output, while genetic and spatial population structures were largely ignored. More work on the population effects of ecological restoration would be welcomed, particularly with a focus on population genetics. Targeted species were principally common and dominant natives, or invasive plants while rare or threatened species were poorly considered. Evaluation of ecological restoration should be conducted at different scales of ecological complexity, but so far, communities and ecosystems are over represented, and more focus should be directed towards a population approach as population traits are essential indicators of restoration success.     

我国特有树种长叶榧树的生物学特性与保护问题研究

在持续１０余年对我国特有珍贵树种长叶榧树的分布区、生长环境、生物学特性调查研究基础上,全面系统地提出了该树种保护措施与开发利用意见。     

Population growth rate and its determinants: an overview

We argue that population growth rate is the key unifying variable linking the various facets of population ecology. The importance of population growth rate lies partly in its central role in forecasting future population trends; indeed if the form of density dependence were constant and known, then the future population dynamics could to some degree be predicted. We argue that population growth rate is also central to our understanding of environmental stress: environmental stressors should be defined as factors which when first applied to a population reduce population growth rate. The joint action of such stressors determines an organism's ecological niche, which should be defined as the set of environmental conditions where population growth rate is greater than zero (where population growth rate = r = log(e)(N(t+1)/N(t))). While environmental stressors have negative effects on population growth rate, the same is true of population density, the case of negative linear effects corresponding to the well-known logistic equation. Following Sinclair, we recognize population regulation as occurring when population growth rate is negatively density dependent. Surprisingly, given its fundamental importance in population ecology, only 25 studies were discovered in the literature in which population growth rate has been plotted against population density. In 12 of these the effects of density were linear; in all but two of the remainder the relationship was concave viewed from above. Alternative approaches to establishing the determinants of population growth rate are reviewed, paying special attention to the demographic and mechanistic approaches. The effects of population density on population growth rate may act through their effects on food availability and associated effects on somatic growth, fecundity and survival, according to a 'numerical response', the evidence for which is briefly reviewed. Alternatively, there may be effects on population growth rate of population density in addition to those that arise through the partitioning of food between competitors; this is 'interference competition'. The distinction is illustrated using a replicated laboratory experiment on a marine copepod, Tisbe battagliae. Application of these approaches in conservation biology, ecotoxicology and human demography is briefly considered. We conclude that population regulation, density dependence, resource and interference competition, the effects of environmental stress and the form of the ecological niche, are all best defined and analysed in terms of population growth rate.     

Estimation of the number of individuals founding colonized populations

A method for estimating the number of founding chromosomes in an isolated population is introduced. The method assumes that n/2 diploid individuals are sampled from a population and that alleles are identified at L unlinked loci. The population is assumed to have been founded T generations in the past by individuals carrying c chromosomes drawn randomly from a known source population, which has also been sampled. If c is small and the population grew rapidly after it was founded, accurate estimates of c can be obtained and those estimates are not sensitive to details of the history of population sizes. If c is larger or the population remained small after it was founded, then estimates of c depend on the history of population sizes. We test the performance of our method on simulated data and demonstrate its use on data from a rainbow trout (Oncorhynchus mykiss) population.     

海南山蛭种群数量动态与气象因素关系研究

在海南岛橡胶林内,每月观测海南山蛭Ｈａｅｍａｄｉｐｓａ ｈａｉｎａｎａ种群数量Ｂａ,用逐步回归分析方法研究了１０个气象因子对海南山６种数量的影响,结果表明,１）每年海南山蛭种群数量不同,６ａ间影响海南山蛭种群数量的主要气候因素是Ｘ１（月雨量）、Ｘ３（月雨日）和Ｘ５（月有露日数）;２）海南岛５～１０月份为雨季,海南山蛭这种群数量明显增大,影响山蛭种群数量的主要气候因素是Ｘ５和Ｘ１６（月最大风速和）和     

Decomposing variation in population growth into contributions from environment and phenotypes in an age-structured population

Evaluating the relative importance of ecological drivers responsible for natural population fluctuations in size is challenging. Longitudinal studies where most individuals are monitored from birth to death and where environmental conditions are known provide a valuable resource to characterize complex ecological interactions. We used a recently developed approach to decompose the observed fluctuation in population growth of the red deer population on the Isle of Rum into contributions from climate, density and their interaction and to quantify their relative importance. We also quantified the contribution of individual covariates, including phenotypic and life-history traits, to population growth. Fluctuations in composition in age and sex classes ((st)age structure) of the population contributed substantially to the population dynamics. Density, climate, birth weight and reproductive status contributed less and approximately equally to the population growth. Our results support the contention that fluctuations in the population's (st)age structure have important consequences for population dynamics and underline the importance of including information on population composition to understand the effect of human-driven changes on population performance of long-lived species.     

秦岭大熊猫种群扩散格局及研究方法

种群扩散格局是研究种群扩散规律和机制的关键信息,也是制定物种保护对策的重要基础。大型动物种群扩散格局研究方法为扩散生态学研究的薄弱领域,并制约扩散生态学的发展。以秦岭大熊猫为研究对象,根据2000年以来的种群调查数据,基于大熊猫领域的特性,利用GIS的扩展区分析功能和景观分析方法研究了大熊猫种群分布区及动态;基于聚集的特性,利用GIS的核密度分析功能对大熊猫种群多度和聚集状况及空间变化进行了分析。发现2012年的秦岭大熊猫种群分布区较2000年增加5.5%(即15307.8hm~2),高密度种群聚集区从2处变成1处,种群聚集程度进一步增加、聚集格局的完整性大大提升,尤以中密度聚集区增长最显著,种群格局呈明显的分布区扩张、聚集度增加的态势。表明基于物种的生物学特性,立足于种群分布和多度格局变化,通过长期调查和监测可以有效掌握物种的种群扩散格局;大型动物可根据其生物学特性探索可行的方法与量化种群扩散的参数来研究其扩散格局,从而促进大型动物种群扩散研究的开展。     

IS THE POPULATION SIZE OF A SPECIES RELEVANT TO ITS EVOLUTION?

Abstract This paper examines aspects of genetic draft, the stochastic force induced by substitutions at one locus on the dynamics of a closely linked locus. Of particular interest is the role of population size on genetic draft. Remarkably, the rate of substitution of weakly selected advantageous mutations decreases with increasing population size, whereas that for deleterious mutations increases with population size. This dependency on population size is the opposite of that for genetic drift. Moreover, these rates are only weakly dependent on population size, again contrary to the strong dependency of drift‐based dynamics. Four models of the strongly selected loci responsible for genetic draft are examined. Three of these exhibit a very weak dependency on population size, which implies that their induced effects will also be weakly dependent on population size. Together, these results suggest that population size and binomial sampling may not be relevant to a species' evolution. If this is the case, then a number of evolutionary conundrums are resolved.     

Effect of unsampled populations on the estimation of population sizes and migration rates between sampled populations

Current estimators of gene flow come in two methods; those that estimate parameters assuming that the populations investigated are a small random sample of a large number of populations and those that assume that all populations were sampled. Maximum likelihood or Bayesian approaches that estimate the migration rates and population sizes directly using coalescent theory can easily accommodate datasets that contain a population that has no data, a so-called 'ghost' population. This manipulation allows us to explore the effects of missing populations on the estimation of population sizes and migration rates between two specific populations. The biases of the inferred population parameters depend on the magnitude of the migration rate from the unknown populations. The effects on the population sizes are larger than the effects on the migration rates. The more immigrants from the unknown populations that are arriving in the sample populations the larger the estimated population sizes. Taking into account a ghost population improves or at least does not harm the estimation of population sizes. Estimates of the scaled migration rate M (migration rate per generation divided by the mutation rate per generation) are fairly robust as long as migration rates from the unknown populations are not huge. The inclusion of a ghost population does not improve the estimation of the migration rate M; when the migration rates are estimated as the number of immigrants Nm then a ghost population improves the estimates because of its effect on population size estimation. It seems that for 'real world' analyses one should carefully choose which populations to sample, but there is no need to sample every population in the neighbourhood of a population of interest.     

Genetic Effects of a Persistent Bottleneck on a Natural Population of Ornate Box Turtles (Terrapene ornata)

Human activities in the past few hundred years have caused enormous impacts on many ecosystems, greatly accelerating the rate of population decline and extinction. In addition to habitat alteration and destruction, the loss of genetic diversity due to reduced population size has become a major conservation issue for many imperiled species. However, the genetic effects of persistent population bottlenecks can be very different for long-lived and short-lived species when considering the time scale of centuries. To investigate the genetic effects of persistent population bottlenecks on long-lived species, we use microsatellite markers to assess the level of genetic diversity of a small ornate box turtle population that has experienced a persistent bottleneck in the past century, and compare it to a large relatively undisturbed population. The genetic signature of a recent bottleneck is detected by examining the deviation from mutation-drift equilibrium in the small population, but the bottleneck had little effect on its level of genetic diversity. Computer simulations combined with information on population structure suggest that an effective population size of 300, which results in a census population size of 700, would be required for the small population to maintain 90% of the average number of alleles per locus in the next 200 years. The life history of long-lived species could mask the accelerated rate of genetic drift, making population recovery a relatively slow process. Statistical analysis of genetic data and empirical-based computer simulations can be important tools to facilitate conservation planning.     

How does temporal variability affect predictions of weed population numbers?

1. Population models that are used to predict weed population dynamics or the impact of control measures on weed abundance typically ignore temporal variability in life-history parameters and control measures, and utilize mean arithmetic population growth rates to predict population abundance.
2. We demonstrate that the persistence of weeds in a stochastically varying environment depends on the geometric mean population growth rate being greater than zero, rather than the arithmetic mean population growth rate being greater than zero.
3. In a stochastically varying environment we show that temporal variability in fecundity, germination and survivorship will tend to decrease population size, relative to predictions based on arithmetic means. Conversely, variability in competitive effects and weed control will tend to increase population size, relative to predictions based on arithmetic mean values. The distinction between these two sets of parameters is that increases in the former will increase population growth rate, whereas increases in the latter will decrease it.
4. We argue that population models based on arithmetic mean population growth rates will tend to over-estimate population size. Numerical simulations indicate that this bias may be considerable.
5. Since short-term studies cannot, in general, estimate the geometric mean growth rate of a population we suggest several approaches for estimating the degree of bias in the predictions of models owing to the effects of variability. Accounting for such variability is necessary since current models for the dynamics of weed populations are based on arithmetic mean measures of population growth and hence likely to be biased.     

Genetic impoverishment of the last black grouse (Tetrao tetrix) population in the Netherlands: detectable only with a reference from the past

We have studied a small isolated population of black grouse (Tetrao tetrix) in the Netherlands to examine the impact of isolation and reduction in numbers on genetic diversity. We compared the genetic diversity in the last extant Dutch population with Dutch museum samples and three other black grouse populations (from England, Austria and Norway, respectively) representing isolated and continuous populations. We found significantly lower allelic richness, observed and expected heterozygosities in the present Dutch population compared to the continuous populations (Austria and Norway) and also to the historical Dutch population. However, using a bottleneck test on each population, signs of heterozygosity excess were only found in the likewise isolated English population despite that strong genetic drift was evident in the present Dutch population in comparison to the reference populations, as assessed both in pairwise F(ST)and STRUCTURE analyses. Simulating the effect of a population reduction on the Dutch population from 1948 onwards, using census data and with the Dutch museum samples as a model for the genetic diversity in the initial population, revealed that the loss in number of alleles and observed heterozygosity was according to genetic drift expectations and within the standard error range of the present Dutch population. Thus, the effect of the strong decline in the number of grouse on genetic diversity was only detectable when using a reference from the past. The lack of evidence for a population reduction in the present Dutch population by using the program bottleneck was attributed to a rapidly found new equilibrium as a consequence of a very small effective population size.     

小菜蛾颗粒体病毒对小菜蛾防治作用的评价

用以作用因子组配的生命表,种群趋势指数和控制指数评价小菜蛾颗粒体病毒对小菜蛾种群动态的作用。结果表明,施用该病毒对小菜蛾种群动态有明显的控制作用,种群趋势指数为０．９７,干扰作用控制指数为０．１９,即施用病毒后,其种群趋势指数相当于对照的０．１９,施用化学杀虫剂的种群趋势指数为７．２０,干扰作用控制指数为１．４３,即种群趋势指数将增长为对照的１．４３倍。     

Persistence,extinction, and critical patch number for island populations

Sufficient conditions are derived for persistence and extinction of a population inhabiting several islands. Discrete reaction-diffusion population models are analyzed which describe growth and diffusion of a population on a group of islands or a patch environment. A critical patch number is defined as the number of islands below which the population goes extinct on that group of islands. It is shown that population persistence on one island leads to population persistence for the entire archipelago. Both single-species and multi-species models are discussed.     

沙地云杉种群稳定性研究

沙地云杉种群稳定性研究郑元润徐文铎（中国科学院植物研究所,北京１０００９３）（中国科学院沈阳应用生态研究所,１１００１５）ＳｔｕｄｙｏｎＰｏｐｕｌａｔｉｏｎＳｔａｂｉｌｉｔｙｏｆＰｉｃｅａｍｏｎｇｏｌｉｃａｏｎＳａｎｄｙＬａｎｄ．ＺｈｅｎｇＹｕａｎ...     

The Effect of Chemical Information on the Spatial Distribution of Fruit Flies: I Model Results

Animal aggregation is a general phenomenon in ecological systems. Aggregations are generally considered as an evolutionary advantageous state in which members derive the benefits of protection and mate choice, balanced by the costs of limiting resources and competition. In insects, chemical information conveyance plays an important role in finding conspecifics and forming aggregations. In this study, we describe a spatio-temporal simulation model designed to explore and quantify the effects of these infochemicals, i.e., food odors and an aggregation pheromone, on the spatial distribution of a fruit fly (Drosophila melanogaster) population, where the lower and upper limit of local population size are controlled by an Allee effect and competition. We found that during the spatial expansion and strong growth of the population, the use of infochemicals had a positive effect on population size. The positive effects of reduced mortality at low population numbers outweighed the negative effects of increased mortality due to competition. At low resource densities, attraction toward infochemicals also had a positive effect on population size during recolonization of an area after a local population crash, by decreasing the mortality due to the Allee effect. However, when the whole area was colonized and the population was large, the negative effects of competition on population size were larger than the positive effects of the reduction in mortality due to the Allee effect. The use of infochemicals thus has mainly positive effects on population size and population persistence when the population is small and during the colonization of an area. Electronic Supplementary Material  The online version of this article () contains supplementary material, which is available to authorized users.     

Consequences of the Allee Effect and Intraspecific Competition on Population Persistence under Adverse Environmental Conditions

The impact of intraspecific interactions on ecological stability and population persistence in terms of steady state(s) existence is considered theoretically based on a general competition model. We compare persistence of a structured population consisting of a few interacting (competitive) subpopulations, or groups, to persistence of the corresponding unstructured population. For a general case, we show that if the intra-group competition is stronger than the inter-group competition, then the structured population is less prone to extinction, i.e. it can persist in a parameter range where the unstructured population goes extinct. For a more specific case of a population with hierarchical competition, we show that relative viability of structured and unstructured populations depend on the type of density dependence in the population growth. Namely, while in the case of logistic growth, structured and unstructured populations exhibit equivalent persistence; in the case of Allee dynamics, the persistence of a hierarchically structured population is shown to be higher. We then apply these results to the case of behaviourally structured populations and demonstrate that an extreme form of individual aggression can be beneficial at the population level and enhance population persistence.