Plant conservation ecology for management and restoration of riparian habitats of lowland Japan

Conservation ecology is a new paradigm of ecology that aims at scientific contributions to maintaining earth's biodiversity and is committed to ecosystem management indispensable to intergenerational long-term sustainability. Population ecology plays a central role in conservation ecology. Persistence of the metapopulation rather than that of each local population should be pursued in species conservation management. Biological interactions essential to reproduction and soil seed bank components of the population should be investigated and applied to planning for the conservation of a plant population. Gravelly floodplains and moist tall grasslands are among typical riparian habitats containing many threatened plants in Japan. These riparian habitats are now subjected not only to heavy fragmentation but also to intensive invasion of highly competitive alien (nonnative) plants. Extreme habitat isolation may result in reproductive failure or fertility selection in a plant population without pollinators, as exemplified by a nature reserve population of Primula sieboldii. Biological invasions, which are facilitated by extensive changes in the river environment including decreased seasonal flooding, abandonment of traditional vegetation management, eutrophication, and extensive clearing of the land for recreational use, threaten endemic riparian species. To preserve safe sites and growing conditions for threatened plants such as Aster kantoensis, active management to suppress the dominance of alien invader plants is necessary. Population management and habitat restoration should be based on sound information on the population ecology of both threatened and alien invader plants, designed as an ecological experiment to clarify effective ways for management. Received: September 18, 1998 / Revised: October 22, 2001 / Accepted: October 23, 2001     

Dependence of Intake Fraction on Release Location in a Multimedia Framework

A defining feature of industrial ecology is the design of processes to minimize any disruption of the functioning of the natural ecosystem that supports life, including human beings. The extent of human exposure to anthropogenic contaminants in the environment is a complex function of the amount of chemical emitted, its physicochemical properties and reactivity, the nature of the environment, and the characteristics of the pathways for human exposure, such as inhalation, dermal contacts, and intake of food and water. For some chemicals, the location of emissions relative to areas of high population density or intense food production may also be an important factor. We explore the relative importance of these variables using the regionally segmented Berkeleyf-Trent (BETR) North America contaminant fate model and data for food production patterns and population density for North America. The model is applied to fourfff contaminants emitted to air: benzene, carbon tetrachloride, benzo-a-pyrene, and 2,3,7,8 tetrachlorodibenzo-pff-dioxin. The total continental intake fraction (iF), relating exposure quantity to emission quantity, is employed as a metric for assessing population exposure to these contaminants. Results show that the use of continentally averaged parameters for population density and food production provides an accurate estimate of the median of iF calculated for emissions in individual regions; however, iF can range from this median by up to 3 orders of magnitude, especially for chemicals transferred to humans through foods. The locations of population and food production relative to sources of chemicals are important variables that should be considered when assessing the possible human health impacts of chemical emissions as in life-cycle assessment.     

Human embryonic stem cell lines derived from the Chinese population

Six human embryonic stem cell lines were established from surplus blastocysts. The cell lines expressed alkaline phosphatase and molecules typical of primate embryonic stem cells, including Oct-4, Nanog, TDGF1, Sox2, EBAF, Thy-1, FGF4, Rex-1, SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81. Five of the six lines formed embryoid bodies that expressed markers of a variety of cell types; four of them formed teratomas with tissue types representative of all three embryonic germ layers. These human embryonic stem cells are capable of producing clones of undifferentiated morphology, and one of them was propagated to become a subline. Human embryonic stem cell lines from the Chinese population should facilitate stem cell research and may be valuable in studies of population genetics and ecology.     

The long and winding road of evolutionary demography: preface

Fitness can be calculated using demographic parameters such as survival and fecundity, which are normally used to examine population dynamics in ecology. This concept is at the heart of Darwin's thinking on natural selection. Natural selection optimizes survival and fertility schedules through differential fitness, and these optimal schedules drive changes in population dynamics. Therefore, there must exist an interaction between ecology and evolution. One of the disciplines that focus on the interaction is "Evolutionary demography". It uses age- or stage-specific demographic parameters throughout the whole life history to explore the evolution of life histories. Data throughout the life history of a species is indispensable to study evolutionary demography. To this end, two large-scale databases of plant and animal life history are now available online, the COMPADRE Plant Matrix Database and the COMADRE Animal Matrix Database. We are now in a revolutionary era in the demographic research of plant and animal populations (including human populations). Many skills and approaches are needed to answer questions on evolutionary demography including bodies of theory and analytical toolkits. This special issue covers a wide array of subjects: (1) Demographic analysis of populations (including human populations) from the point of view of evolutionary ecology, (2) Meta-analysis using big databases of populations, (3) Eco-evolutionary studies at the population and/or community level and (4) Theoretical studies and the development of mathematical models of life history evolution. 14 collected papers are published to answer a variety of questions using original ideas, new tools, and big data.     

Human Ecology for Introductory Biology Courses: An Overview

Human ecology, specifically the population—resource—environmentdilemma, should be given thorough coverage in every introductorybiology course. To aid educators in integrating it into thecourse, the subject is outlined here and suggestions are givenon what topics should be emphasized and how they might be introducedto students. Special attention is given to the fundamental roleof population growth in the dilemma, and to the complex interactionsamong population growth, depletion of resources, and environmentaldeterioration. Today's human population size appears to be abovethe long-term carrying capacity of Earth, and is only maintained(albeit often badly) by the exploitation of a "one-time bonanza"of fertile soils, fossil fuels, concentrated ores, ground water,and other species of organisms. If current trends continue,the depletion of these resources will progressively degradethe human environment, destroying the capacity ofnatural ecosystemsto supply civilization with indispensible services. The resultswill be in increasing frequency and severity of disasters, especiallyfamines, that will at first most seriously affect the poor.But the rich will increasingly be impoverished, and be engulfedalso. The basic solution to the dilemma is reduction of thesize of the human population to one well below the long-termcarrying capacity (one living on resource "income" rather than"capital") and establishing an equitable society with a sustainableeconomic system.     

Biology and taxonomy of Bacillus cereus, Bacillus anthracis, and Bacillus thuringiensis

Three species of the Bacillus cereus group (Bacillus cereus, Bacillus anthracis, and Bacillus thuringiensis) have a marked impact on human activity. Bacillus cereus and B. anthracis are important pathogens of mammals, including humans, and B. thuringiensis is extensively used in the biological control of insects. The microbiological, biochemical, and genetic characteristics of these three species are reviewed, together with a discussion of several genomic studies conducted on strains of B. cereus group. Using bacterial systematic concepts, we speculate that to understand the taxonomic relationship within this group of bacteria, special attention should be devoted also to the ecology and the population genetics of these species.     

布氏田鼠种群生态及行为生态学研究进展

布氏田鼠种群生态及行为生态学研究进展尹峰房继明（北京师范大学生物学系,１００８７５）ＲｅｓｅａｒｃｈＡｄｖａｎｃｅｓｉｎＰｏｐｕｌａｔｉｏｎＥｃｏｌｏｇｙａｎｄＢｅｈａｖｉｏｒａｌＥｃｏｌｏｇｙｏｆＢｒａｎｄｔ’ｓＶｏｌｅｓ（Ｍｉｃｒｏｔｕｓｂｒａｎ...     

Pools versus Queues: The Variable Dynamics of Stochastic “Steady States”

Mathematical models in ecology and epidemiology often consider populations “at equilibrium”, where in-flows, such as births, equal out-flows, such as death. For stochastic models, what is meant by equilibrium is less clear – should the population size be fixed or growing and shrinking with equal probability? Two different mechanisms to implement a stochastic steady state are considered. Under these mechanisms, both a predator-prey model and an epidemic model have vastly different outcomes, including the median population values for both predators and prey and the median levels of infection within a hospital (P < 0.001 for all comparisons). These results suggest that the question of how a stochastic steady state is modeled, and what it implies for the dynamics of the system, should be carefully considered.     

Positive and negative feedbacks in human population dynamics: future equilibrium or collapse?

The future number of people inhabiting the planet will influence the impact over natural ecosystems. In consequence, the growth of the human population represents one of the most important challenges for the near future. In this paper we used population dynamic theory to analyze human population growth. The results suggest that human population growth exhibited important fluctuations during the last 2000 years. In particular two different phases during the last 400 years can be distinguished, a positive relationship with population size implying positive feedback processes, followed by a negative relationship with population size – suggesting that negative feedback processes have been operating during the last 45 years. Our results support the view that ecological concepts derived from population ecology can be useful for understanding human dynamics. While cooperation at low densities in animal populations reminds us the Boserupian view that population growth induces economic development and higher standards of living, competition at high densities reconciles ecological theory with the original Malthusian view. We conclude that the present reduction in human per capita growth rates appears to be consequence of different limiting factors operating in combination around the globe in a similar manner, except in Africa where the factors operating appears to be very different. Humans may achieve a stable equilibrium population in the next century but the possibility of a population collapse caused by second‐order oscillations should be considered.     

Ecological engineering: A rationale for standardized curriculum and professional certification in the United States

The demand for engineering solutions to ecosystem–level problems has increased as the impact of human activities has expanded to global proportions. While the science of restoration ecology has been developed to address many critical ecosystem management issues, the high degree of complexity and uncertainty associated with these issues demands a more quantitative approach. Ecological engineering uses science-based quantification of ecological processes to develop and apply engineering-based design criteria for sustainable systems. We suggest that in the United States ecological engineering curricula should be offered at the graduate level and should require rigorous Accreditation Board of Engineering and Technology-accredited (or equivalent) undergraduate preparation in engineering fundamentals. In addition to strengthening students’ mastery of engineering theory and application, the graduate curriculum should provide core courses in ecosystem theory including quantitative ecology, systems ecology, restoration ecology, ecological engineering, ecological modeling, and ecological engineering economics. Advanced courses in limnology, environmental plant physiology, ecological economics, and specific ecosystem design should be provided to address students’ specific professional objectives. Finally, professional engineering certification must be developed to insure the credibility of this new engineering specialization.     

穿山甲生态学研究概况

综述了全球现存7种穿山甲生态学研究概况,目前的研究主要是通过访问法对中国穿山甲(Manis pentadactyla)的栖息地、活动习性、食性、繁殖习性、打洞习性进行一般性的描述。开普穿山甲(M．temminckii)主要集中在家域、活动和运动、食谱和觅食行为生态上,繁殖生态学、种群生态学及栖息地的研究没有涉及。树穿山甲(M．tricuspts)仅见其家域研究的报道。其它4种穿山甲生态学研究未见任何报道。7种穿山甲的习性相似。今后应当强调从生命的各个层次对其生态学进行比较研究,以揭示其存在的生态差异。重点应是洞穴生态、觅食生态、行为生态(如家域与活动)、繁殖生态和种群生态。     

The evolution of insecticide resistance: Have the insects won?

While insecticides have greatly improved human health and agricultural production worldwide, their utility has been limited by the evolution of resistance in many major pests, including some that became pests only as a result of insecticide use. Insecticide resistance is both an interesting example of the adaptability of insect pests, and, in the design of resistance management programmes, a useful application of evolutionary biology. Pest susceptibility is a valuable natural resource that has been squandered; at the same time, it is becoming increasingly expensive to develop new insecticides. Pest control tactics should therefore take account of the possibility of resistance evolution. One of the best ways to retard resistance evolution is to use insecticides only when control by natural enemies fails to limit economic damage. This review summarizes the recent literature on insecticide resistance as an example of adaptation, and demonstrates how population genetics and ecology can be used to manage the resistance problem.     

Recent novel approaches for population genomics data analysis

Next‐generation sequencing (NGS) technology is revolutionizing the fields of population genetics, molecular ecology and conservation biology. But it can be challenging for researchers to learn the new and rapidly evolving techniques required to use NGS data. A recent workshop entitled ‘Population Genomic Data Analysis’ was held to provide training in conceptual and practical aspects of data production and analysis for population genomics, with an emphasis on NGS data analysis. This workshop brought together 16 instructors who were experts in the field of population genomics and 31 student participants. Instructors provided helpful and often entertaining advice regarding how to choose and use a NGS method for a given research question, and regarding critical aspects of NGS data production and analysis such as library preparation, filtering to remove sequencing errors and outlier loci, and genotype calling. In addition, instructors provided general advice about how to approach population genomics data analysis and how to build a career in science. The overarching messages of the workshop were that NGS data analysis should be approached with a keen understanding of the theoretical models underlying the analyses, and with analyses tailored to each research question and project. When analysed carefully, NGS data provide extremely powerful tools for answering crucial questions in disciplines ranging from evolution and ecology to conservation and agriculture, including questions that could not be answered prior to the development of NGS technology.     

云南野生珍稀油料树种琴叶风吹楠资源调查

采用走访和实地调查相结合的方法对云南野生琴叶风吹楠进行资源调查.结果表明:琴叶风吹楠在云南分布于热带雨林内水热条件较好地段,由于生境破坏,种群数量锐减,仅在分布区边缘的沟谷和低洼地呈斑块状分布,种群数量小;琴叶风吹楠现存植株开花结实和种子萌发正常,而且苗木生长良好.生境破坏是导致种群数量锐减的主要原因之一.建议加强原境...     

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.     

From Biodiversity to Ecodiversity: A Landscape-Ecology Approach to Conservation and Restoration

An environmental revolution is urgently needed that will lead to a post-industrial symbiosis between man and nature. This can be realized only if the present unrestrained biological impoverishment and neotechnological landscape degradation are replaced by the creation of healthy and attractive landscapes. Restorationists can fulfill a vital role in this process. They must broaden their scales from biodiversity restoration in small, protected nature islands to the large-scale restoration of natural and cultural landscapes. To achieve this they must restore not only the patterns of vegetation but also the processes that create these patterns, including human land uses. Their goal should be to restore the total biological, ecological, and cultural landscape diversity, or “ecodiversity,” and its intrinsic and instrumental values of highly valuable, endangered seminatural, agricultural and rural landscapes. For this purpose it is essential to maintain and restore the dynamic flow equilibrium between biodiversity, ecological, and cultural landscape heterogeneity, as influenced by human land uses, which occur at different spatial and temporal scales and intensities. Recent advances in landscape ecology should be utilized for broader assessment of ecodiversity, including proposed indices of ecodiversity, new techniques such as Intelligent Geographical Information Systems (IGIS), and Green Books for the holistic conservation and restoration of valuable endangered landscapes. Restoration ecology can make an important contribution to an urgently needed environmental revolution. This revolution should lead to a new symbiosis between man and nature by broadening the goal of vegetation restoration to ecological and cultural landscape restoration, and thereby to total landscape ecodiversity.     

The Moore's Law of microbiology - towards bacterial culture miniaturization with the micro-Petri chip

A recent publication has reported the fabrication of a new microbial culture device containing an array of unprecedented density - a million growth chambers. This micro-Petri chip should impact on various fields, including biotechnology, ecology, food microbiology and drug development, by enabling high-throughput screens and therefore the detection of rare phenotypes within a large population of microorganisms.     

旧石器时代考古与栖居及生计形态分析

由于打制石器本身所含的人类行为信息比较有限,我国旧石器时代考古研究应该引入文化生态学的理论方法,从宏观的生态位、中观的遗址域和微观的居住面分析来充分提炼古人类觅食方式和资源利用的信息。本文介绍了栖居(聚落)形态和遗址域概念的方法论及意义,并用墨西哥瓦哈卡河谷圭拉那魁兹的研究案例来说明这些概念在人地关系研究和农业起源研究中的重要性。文章呼吁旧石器时代考古研究要从低端的分类描述转向人类环境和行为的重建,以期令我们的研究水准跻身世界先进水平。     

ABC as a flexible framework to estimate demography over space and time: some cons,many pros

The analysis of genetic variation to estimate demographic and historical parameters and to quantitatively compare alternative scenarios recently gained a powerful and flexible approach: the Approximate Bayesian Computation (ABC). The likelihood functions does not need to be theoretically specified, but posterior distributions can be approximated by simulation even assuming very complex population models including both natural and human‐induced processes. Prior information can be easily incorporated and the quality of the results can be analysed with rather limited additional effort. ABC is not a statistical analysis per se, but rather a statistical framework and any specific application is a sort of hybrid between a simulation and a data‐analysis study. Complete software packages performing the necessary steps under a set of models and for specific genetic markers are already available, but the flexibility of the method is better exploited combining different programs. Many questions relevant in ecology can be addressed using ABC, but adequate amount of time should be dedicated to decide among alternative options and to evaluate the results. In this paper we will describe and critically comment on the different steps of an ABC analysis, analyse some of the published applications of ABC and provide user guidelines.     

Glu496Ala polymorphism of human P2X7 receptor does not affect its electrophysiological phenotype

A glutamateto alanine exchange at amino acid position 496 of the humanP2X₇ receptor was recently shown to be associated with aloss of function in human B lymphocytes in terms of ATP-induced ethidium⁺ uptake, Ba²⁺ influx, and induction ofapoptosis (Gu BJ, Zhang WY, Worthington RA, Sluyter R, Dao-UngP, Petrou S, Barden JA, and Wiley JS. J Biol Chem 276:11135-11142, 2001). Here we analyzed the effect of theGlu⁴⁹⁶ to Ala exchange on the channel properties of thehuman P2X₇ receptor expressed in Xenopus oocyteswith the two-microelectrode voltage-clamp technique. The amplitudes ofATP-induced whole cell currents characteristic of functionalexpression, kinetic properties including ATP concentration dependence,and permeation behavior were not altered by this amino acid exchange.Also in HEK293 cells, the Ala⁴⁹⁶ mutant mediated typicalP2X₇ receptor-dependent currents like the parentGlu⁴⁹⁶ hP2X₇ receptor. Because the function ofthe P2X₇ receptor as an ATP-gated channel for small cationsincluding Ba²⁺ remained unaffected by this mutation, weconclude that Glu⁴⁹⁶ plays a critical role in poreformation but does not determine the ion channel properties of thehuman P2X₇ receptor.