The Structure of the Two Ecological Paradigms

Ecological theory is built upon assumptions about the fundamental nature of organism-environment interactions. We argue that two mutually exclusive sets of such assumptions are available and that they have given rise to alternative approaches to studying ecology. The fundamentally different premises of these approaches render them irreconcilable with one another. In this paper, we present the first logical formalisation of these two paradigms.The more widely-accepted approach - which we label the demographic paradigm - includes both population ecology and community ecology (synecology). Demographic ecology assumes that the environment is relatively stable and that biotic processes, governed predominantly by resource availability, are the most important of ecological and evolutionary influences. Moreover, ecological processes are assumed to translate into directional selection pressures that drive significant evolutionary change on a local scale through the process of optimisation.Serious deficiencies in aspects of the demographic approach have been identified over the past few decades by various ecologists, including Gleason, Andrewartha and Birch, White, Den Boer, Strong, Simberloff, and others. Short-term evolutionary optimisation has also been seriously questioned.The development of the alternative approach (autecology) has been subverted by the prominence of demographic ecology. Moreover, it has not been recognised that autecology is underpinned by robust principles and that they are independent of the underlying demographic principles. Components of the autecological approach have been developed to some extent, but they have not been integrated with ancillary fields of study. We therefore articulate the assumptions from which autecology is derived, and use this as a basis for integrating the various spheres of autecological research.We add to the ongoing development of autecology by linking autecological understanding, in so far as it is developed, with the evolutionary justification for species' characteristics being stable in an environment that is continuously dynamic in space and time. The ecology of organisms is essentially an ongoing matching of their species-specific characteristics to the prevailing environmental factors and dynamics. We thus provide a consistent logic through the following subject areas; climate and climate change, spatial and temporal environmental heterogeneity and dynamic theory, physiology, behaviour, migration, and evolution. We demonstrate why adaptation cannot be an ongoing process, but takes place only when organisms are prevented, by incidental influences, from matching the overall dynamics of the environment.     

Rethinking the fast-slow continuum of individual differences

The idea that individual differences in behavior and physiology can be partly understood by linking them to a fast-slow continuum of life history strategies has become popular in the evolutionary behavioral sciences. I refer to this approach as the “fast-slow paradigm” of individual differences. The paradigm has generated a substantial amount of research, but has also come increasingly under scrutiny for theoretical, empirical, and methodological reasons. I start by reviewing the basic empirical facts about the fast-slow continuum across species and the main theoretical accounts of its existence. I then discuss the move from the level of species and populations to that of individuals, and the theoretical and empirical complications that follow. I argue that the fast-slow continuum can be a productive heuristic for individual differences; however, the field needs to update its theoretical assumptions, rethink some methodological practices, and explore new approaches and ideas in light of the specific features of the human ecology.     

Tools for assessing European streams with macroinvertebrates: major results and conclusions from the STAR project

This short paper summarises the information developed in the EU funded research project STAR on autecology databases, metrics, multimetrics and community approaches. For Europe the WFD implementation gave an important stimulus for the development of ecology based assessment techniques. Along with the development of metrics and multimetrics indices taxalists and autecological information were strongly improved. Recommendations are given to further develop ecological assessment in European streams and rivers.     

Reducing redundancy in invasion ecology by integrating hypotheses into a single theoretical framework

Aim Invasion ecology includes many hypotheses. Empirical evidence suggests that most of these can explain the success of some invaders to some degree in some circumstances. If they all are correct, what does this tell us about invasion? We illustrate the major themes in invasion ecology, and provide an overarching framework that helps organize research and foster links among subfields of invasion ecology and ecology more generally. Location Global. Methods We review and synthesize 29 leading hypotheses in plant invasion ecology. Structured around propagule pressure (P), abiotic characteristics (A) and biotic characteristics (B), with the additional influence of humans (H) on P, A and B (hereon PAB), we show how these hypotheses fit into one paradigm. P is based on the size and frequency of introductions, A incorporates ecosystem invasibility based on physical conditions, and B includes the characteristics of invading species (invasiveness), the recipient community and their interactions. Having justified the PAB framework, we propose a way in which invasion research could progress. Results By highlighting the common ground among hypotheses, we show that invasion ecology is encumbered by theoretical redundancy that can be removed through integration. Using both holistic and incremental approaches, we show how the PAB framework can guide research and quantify the relative importance of different invasion mechanisms. Main conclusions If the prime aim is to identify the main cause of invasion success, we contend that a top‐down approach that focuses on PAB maximizes research efficiency. This approach identifies the most influential factors first, and subsequently narrows the number of potential causal mechanisms. By viewing invasion as a multifaceted process that can be partitioned into major drivers and broken down into a series of sequential steps, invasion theory can be rigorously tested, understanding improved and effective weed management techniques identified.     

Parent-offspring conflict and co-adaptation: behavioural ecology meets quantitative genetics

The evolution of the complex and dynamic behavioural interactions between caring parents and their dependent offspring is a major area of research in behavioural ecology and quantitative genetics. While behavioural ecologists examine the evolution of interactions between parents and offspring in the light of parent-offspring conflict and its resolution, quantitative geneticists explore the evolution of such interactions in the light of parent-offspring co-adaptation due to combined effects of parental and offspring behaviours on fitness. To date, there is little interaction or integration between these two fields. Here, we first review the merits and limitations of each of these two approaches and show that they provide important complementary insights into the evolution of strategies for offspring begging and parental resource provisioning. We then outline how central ideas from behavioural ecology and quantitative genetics can be combined within a framework based on the concept of behavioural reaction norms, which provides a common basis for behavioural ecologists and quantitative geneticists to study the evolution of parent-offspring interactions. Finally, we discuss how the behavioural reaction norm approach can be used to advance our understanding of parent-offspring conflict by combining information about the genetic basis of traits from quantitative genetics with key insights regarding the adaptive function and dynamic nature of parental and offspring behaviours from behavioural ecology.     

How to understand species’ niches and range dynamics: a demographic research agenda for biogeography

Range dynamics causes mismatches between a species’ geographical distribution and the set of suitable environments in which population growth is positive (the Hutchinsonian niche). This is because source–sink population dynamics cause species to occupy unsuitable environments, and because environmental change creates non‐equilibrium situations in which species may be absent from suitable environments (due to migration limitation) or present in unsuitable environments that were previously suitable (due to time‐delayed extinction). Because correlative species distribution models do not account for these processes, they are likely to produce biased niche estimates and biased forecasts of future range dynamics. Recently developed dynamic range models (DRMs) overcome this problem: they statistically estimate both range dynamics and the underlying environmental response of demographic rates from species distribution data. This process‐based statistical approach qualitatively advances biogeographical analyses. Yet, the application of DRMs to a broad range of species and study systems requires substantial research efforts in statistical modelling, empirical data collection and ecological theory. Here we review current and potential contributions of these fields to a demographic understanding of niches and range dynamics. Our review serves to formulate a demographic research agenda that entails: (1) advances in incorporating process‐based models of demographic responses and range dynamics into a statistical framework, (2) systematic collection of data on temporal changes in distribution and abundance and on the response of demographic rates to environmental variation, and (3) improved theoretical understanding of the scaling of demographic rates and the dynamics of spatially coupled populations. This demographic research agenda is challenging but necessary for improved comprehension and quantification of niches and range dynamics. It also forms the basis for understanding how niches and range dynamics are shaped by evolutionary dynamics and biotic interactions. Ultimately, the demographic research agenda should lead to deeper integration of biogeography with empirical and theoretical ecology.     

The scope of mission-orientation in Dutch fresh-water ecology

In response to growing concern about environmental problems ecologists have engaged in a variety of mission-oriented efforts in which they claim to have taken into account the objective of helping to solve environmental problems in their research strategies or research programmes. The significance of these efforts is evaluated here in terms of both the theoretical development of the field of ecology and its orientation towards social objectives.Three examples of mission-orientation are analyzed on the basis of a case-study of Dutch fresh-water ecology; (1) ecosystems research within the framework of the International Biological Programme; (2) landscape ecology, and (3) ecological research on the management of fresh-water resources. These examples demonstrate that in principle the scope of missionorientation in ecology can be broad. In Dutch fresh-water ecology, however, two specific approaches have become particularly institutionalized. The ecologists tended to opt either for theory-centered approaches close to the type of research carried out by ecologists developing the field regardless of any societal mission or for problem-centered approaches without much emphasis on theory development. Types of mission-orientation which can be placed between these extremes have been established only to a limited extent in Dutch fresh-water ecology.     

动物移动网络研究对景观生态学的贡献

景观生态学在其发展之初的20世纪80年代, 提出了关于景观网络研究(包括景观网络概念、网络结构指数和景观连接度)的基本构想, 这些构想需要在景观过程的研究中逐渐被落实和发展。动物移动过程因动物在斑块或廊道上有着独特丰富的属性特征、与周围资源环境之间存在复杂反馈而区别于无机物运移的景观过程, 则动物移动网络研究在实现关于景观网络研究的基本构想、推动景观生态学发展中贡献独特。因此, 总结动物移动网络研究的来源脉络及其对景观生态学的理论贡献对于景观网络领域和景观生态学学科的发展都具有重要意义。本文抓住景观生态学发展之初提出的关于景观网络研究的基本构想, 寻找和剖析其中所蕴含的景观生态学思想, 追踪这些思想如何被落实、发展、并形成目前的三个热点方向: 动物移动网络模拟、重要值评价和景观连接度分析; 总结这三个方向的研究进展, 指出整合动物的空间行为特征是必然发展趋势; 揭示出动物移动网络研究始终都以发掘斑块或廊道的动物有机体的属性特征(如种群数量)、以及描述这种属性在不同斑块或廊道之间的差异和联系为方向, 正是这种属性的发掘有效地落实、发展和丰富了关于景观网络研究的最初构想, 对景观生态学的贡献比其他过程更为独特。文章还总结了我国动物移动网络研究与国际研究相比较为滞后的现状, 指出其暂时尚未显示出对我国景观生态学的独特贡献; 强调发展源于跟踪定位数据的动物空间行为生态学研究是减小差距的重要、必要前提。期望本文能引发关于景观网络乃至景观生态学理论发展的方向性思考, 为研究者提供参考。     

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.     

Biogeography and ecology: towards the integration of two disciplines

Although ecology and biogeography had common origins in the natural history of the nineteenth century, they diverged substantially during the early twentieth century as ecology became increasingly hypothesis-driven and experimental. This mechanistic focus narrowed ecology''s purview to local scales of time and space, and mostly excluded large-scale phenomena and historical explanations. In parallel, biogeography became more analytical with the acceptance of plate tectonics and the development of phylogenetic systematics, and began to pay more attention to ecological factors that influence large-scale distributions. This trend towards unification exposed problems with terms such as ‘community’ and ‘niche,’ in part because ecologists began to view ecological communities as open systems within the contexts of history and geography. The papers in this issue represent biogeographic and ecological perspectives and address the general themes of (i) the niche, (ii) comparative ecology and macroecology, (iii) community assembly, and (iv) diversity. The integration of ecology and biogeography clearly is a natural undertaking that is based on evolutionary biology, has developed its own momentum, and which promises novel, synthetic approaches to investigating ecological systems and their variation over the surface of the Earth. We offer suggestions on future research directions at the intersection of biogeography and ecology.     

奥德姆的生态思想是整体论吗?

奥德姆的生态思想是妥协的整体论,有还原论的一面。把生态系统看作是功能性整体、承认生态系统各层次的涌现属性属于整体论,把生态关系简化为能量关系、把生态系统看作是物理系统的分析方法则是还原论的。这种矛盾的生态思想决定了其方法论的先天不足:生态模型的内在逻辑关系没有理顺;较少考虑生态系统的进化;生态研究方法的排它性等。但是,它并不妨碍奥德姆的生态思想在夯实生态学的本体论基础、促进理论生态学和生态工程学的形成、协调生态整体论与还原论分歧、奠定生态系统服务功能研究基础等方面发挥重要作用。要超越生态整体论与还原论,繁荣发展生态复杂性理论也许是最好的选择。     

微生物生态学理论框架

微生物是生态系统的重要组成部分,直接或间接地参与所有的生态过程。微生物生态学是基于微生物群体的科学,利用微生物群体DNA/RNA等标志物,重点研究微生物群落构建、组成演变、多样性及其与环境的关系,在生态学理论的指导和反复模型拟合下由统计分析得出具有普遍意义的结论。其研究范围从基因尺度到全球尺度。分子生物学技术的发展,使人们可以直接从基因水平上考查其多样性,从而使得对微生物空间分布格局及其成因的深入研究成为可能。进而可以从方法学探讨微生物生物多样性、分布格局、影响机制及其对全球变化的响应等。在微生物生态学研究中,群落构建与演化、分布特征(含植物-微生物相互关系)、执行群体功能的机理(生物地球化学循环等)、对环境变化的响应与反馈机理是今后需要关注的重点领域。概述了微生物生态学的概念,并初步提出其理论框架,在对比宏观生态学基础理论和模型的基础上,分析微生物多样性的研究内容、研究方法和群落构建的理论机制,展望了今后研究的重点领域。     

History and heroes: the thermal niche of fishes and long-term lake ice dynamics

These perspectives on climate change come largely from two views, i.e. that of a fish and fisheries ecologist with an autecological interest and that of a limnologist interested in long-term dynamics and change. Ideas about the thermal niche evolved from the late F. E. J. Fry's (University of Toronto) paradigm of fish response to environmental factors and the late G. Evelyn Hutchinson's (Yale University) formalization of the niche concept. In contrast, ideas about climatic change and variability have been shaped by long-term observation records from lakes around the northern hemisphere. The history of each set of ideas, i.e. the thermal niche of fishes and learning from nature's long-term dynamics, is briefly reviewed in the context of climatic change.     

Emergentism as a default: Cancer as a problem of tissue organization

During the last fifty years the dominant stance in experimental biology has been reductionism. For the most part, research programs were based on the notion that genes were in ’the driver’s seat’ controlling the developmental program and determining normalcy and disease (genetic reductionism and genetic determinism). Philosophers were the first to realize that the belief that the Mendelian genes were reduced to DNA molecules was questionable. Soon after these pronouncements, experimental data confirmed their misgivings. The optimism of molecular biologists, fueled by early success in tackling relatively simple problems, has now been tempered by the difficulties found when attempting to understand complex biological problems. Here, we analyse experimental data that illustrate the shortcomings of this sort of reductionism. We also examine the prevailing paradigm in cancer research, the somatic mutation theory (SMT), the premises of which are: (i) cancer is derived from a single somatic cell that has accumulated multiple DNA mutations; (ii) the default state of cell proliferation in metazoa is quiescence; and (iii) cancer is a disease of cell proliferation caused by mutations in genes that control proliferation and the cell cycle. We challenge the notion that cancer is a cellular problem caused by mutated genes by assessing data gathered both from within the reductionist paradigm and from an alternative view that regards carcinogenesis as a developmental process gone awry. This alternative view, explored under the name of the tissue organization field theory (TOFT), is based on premises that place cancer in a different hierarchical level of complexity from that proposed by the SMT, namely: (i) carcinogenesis represents a problem of tissue organization comparable to organogenesis, and (ii) proliferation is the default state of all cells. We propose that the organicist view, in which the TOFT is based, is a good starting point from which to explore emergent phenomena. However, new theoretical concepts are needed in order to grapple with the apparent circular causality of complex biological phenomena in development and carcinogenesis.     

Developmental plasticity in plants: implications of non-cognitive behavior

There has been a surge of interest in phenotypic plasticity in the last two decades. Most studies, however, are being carried out within relatively narrow disciplinary frameworks. Consequently, researchers differ not only in their scientific agenda; they often use different terminologies and conceptual frameworks even when studying the very same phenomena. The diversity of approaches has often generated parallel bodies of theory on subjects that can be best understood in broader interdisciplinary terms. This special issue points out the differences between the concepts and questions that are characteristic of various approaches. Bridging all gulfs may be impossible and not necessarily desirable, yet, awareness of the varied approaches should be instrumental in promoting interdisciplinary advances. It is the contribution to such awareness that is the major purpose of this special issue, and for this reason it deals with molecular, physiological, ecological and evolutionary approaches to the study of developmental plasticity. So as to focus the discussion, six topics have been selected, ranging from the fundamental essence of developmental plasticity to its implications to ecology and evolution. These topics were considered by scholars who were chosen for the diversity of their research, not only their expertise. Rather than a comprehensive body of theory, the current issue thus seeks the diversity of opinions on the discussed topics. It is hoped that the confrontation, in its original Latin sense, which includes bringing together and discussion, of scholars who are studying these phenomena at very different levels and from different points of view will generate new insights and promote future interdisciplinary research.     

Reconciling classical and individual-based approaches in theoretical population ecology: a protocol for extracting population parameters from individual-based models

The two main approaches in theoretical population ecology-the classical approach using differential equations and the approach using individual-based modeling-seem to be incompatible. Linked to these two approaches are two different timescales: population dynamics and behavior or physiology. Thus, the question of the relationship between classical and individual-based approaches is related to the question of the mutual relationship between processes on the population and the behavioral timescales. We present a simple protocol that allows the two different approaches to be reconciled by making explicit use of the fact that processes operating on two different timescales can be treated separately. Using an individual-based model of nomadic birds as an example, we extract the population growth rate by deactivating all demographic processes-in other words, the individuals behave but do not age, die, or reproduce. The growth rate closely matches the logistic growth rate for a wide range of parameters. The implications of this result and the conditions for applying the protocol to other individual-based models are discussed. Since in physics the technique of separating timescales is linked to some concepts of self-organization, we believe that the protocol will also help to develop concepts of self-organization in ecology.     

Parasites as predators: unifying natural enemy ecology

Parasitism and predation have long been considered analogous interactions. Yet by and large, ecologists continue to study parasite-host and predator-prey ecology separately. Here we discuss strengths and shortcomings of the parasite-as-predator analogy and its potential to provide new insights into both fields. Developments in predator-prey ecology, such as temporal risk allocation and associational resistance, can drive new hypotheses for parasite-host systems. Concepts developed in parasite-host ecology, such as threshold host densities and phylodynamics, might provide new ideas for predator-prey ecology. Topics such as trait-mediated indirect effects and enemy-mediated facilitation provide opportunities for the two fields to work together. We suggest that greater unification of predator-prey and parasite-host ecology would foster advances in both fields.     

Mechanistic Approaches to Community Ecology: A New Reductionism

Mechanistic approaches to community ecology are those whichemploy individual— ecological concepts—those ofbehavioral ecology, physiological ecology, and ecomorphology—as theoretical bases for understanding community patterns. Suchapproaches, which began explicitly about a decade ago, are justnow coming into prominence. They stand in contrast to more traditionalapproaches, such as MacArthur and Levins (1967),which interpretcommunity ecology almost strictly in terms of "megaparameters.". Mechanistic approaches can be divided into those which use populationdynamics as a major component of the theory and those whichdo not; examples of the two are about equally common. The firstapproach sacrifices a highly detailed representation of individual—ecological processes; the second sacrifices an explicit representationof the abundance and persistence of populations. Three subdisciplines of ecology—individual, populationand community ecology—form a "perfect" hierarchy in Beckner's(1974) sense. Two other subdisciplines—ecosystem ecologyand evolutionary ecology—lie somewhat laterally to thishierarchy. The modelling of community phenomena using sets ofpopulation-dynamical equations is argued as an attempt at explanationvia the reduction of community to population ecology. Much ofthe debate involving Florida State ecologists is over whetheror not such a relationship is additive (or conjunctive), a verystrong form of reduction. I argue that reduction of communityto individual ecology is plausible via a reduction of populationecology to individual ecology. Approaches that derive the population-dynamicalequations used in population and community ecology from individual-ecologicalconsiderations, and which provide a decomposition of megaparametersinto behavioral and physiological parameters, are cited as illustratinghow the reduction might be done. I argue that "sufficient parameters"generally will not enhance theoretical understanding in communityecology. A major advantage of the mechanistic approach is that variationin population and community patterns can be understood as variationin individual-ecological conditions. In addition to enrichingthe theory, this allows the best functional form to be chosenfor modeling higher-level phenomena, where "best" is definedas biologically most appropriate rather than mathematicallymost convenient. Disadvantages of the mechanistic approach arethat it may portend an overly complex, massive and special theory,and that it naturally tends to avoid many-species phenomenasuch as indirect effects. The paper ends with a scenario fora mechanistic-ecological utopia.