htt/www.cucdecom.cn中国高校课件下载中心 、 WHAT IS ECOLOGY? A definition of ecology Ecology is the study of the interactions between organisms and their environment environment is a combination of the physical environment( temperature, water availability and any influences on an organism exerted by other organisms-the biotic environment 生态学的定义 生态学是硏究有机体与其环境相互作用的科学。“环境”是物理环境(温度、可利用水等)和 生物环境(对有机体的、来自其他有机体的任何影响)的结合体。 生态学的定义:研究生物与其环境相互关系的科学 内涵:1)环境对生物的决定和塑造作用 2)生物对环境的适应 3)适应环境的生物对环境的改善作用 为什么要开展生态学研究 人类面监的四大危机: (1)环境危机 (2)人口危机 (3)资源危机 (4)能源危机 Individuals, populations, communities and ecosystems There are four identifiable subdivisions of scale which ecologists investigate (i) considering the response of individuals to their environments (ii) Examining the response of populations of a single species to the environment and considering processes such as abundance and fluctuations (iii)The composition and structure of communities( the populations occurring in a defined area) (iv ) the processes occurring within ecosystems(the combination of a community and the abiotic nponents of the environment), such as energy flow, food webs and the cycling of nutrients 个休、种群、群落和生态系统 生态学所研究的有4个可辨别尺度的亚部分: (i)探讨个体对其环境的反应; (i)研究单个物种的种群对于环境的反应,和探讨诸如多度( abundance)及其波动等的过程(i) 群落(出现在确定面积中的种群集合)的组成和结构;(ⅳ)生态系统(群落与环境的非生物 成分的结合)内的各种过程,例如能流、食物网和营养物的循环等 生态学的交叉学科 在生物学内的交叉:生理生态学,生态遗传学,行为生态学, 与自然科学的交叉:数学生态学,化学生态学,… 与人文、经济和社会科学的交叉:经济生态学,社会生态学,政治生态学,人类生态学,民 族生态学,哲学生态学, 生态学的研究方法 14.3生态学研究问题的步骤 TEN RULES IN ECOLOGY? hors experience of teaching ecology has given them experience of some common pitfalls which ecology students often make. This list, designed to counter these pitfalls is neither comprehensive nor mutually exclusive, but we hope will nevertheless serve as a useful guide to
http://www.cucdc.com.cn 中国高校课件下载中心 一、WHAT IS ECOLOGY? A definition of ecology Ecology is the study of the interactions between organisms and their environment. The ‘environment’ is a combination of the physical environment (temperature, water availability, etc.) and any influences on an organism exerted by other organisms-the biotic environment. 生态学的定义 生态学是研究有机体与其环境相互作用的科学。“环境”是物理环境（温度、可利用水等）和 生物环境（对有机体的、来自其他有机体的任何影响）的结合体。 生态学的定义: 研究生物与其环境相互关系的科学 内涵：1）环境对生物的决定和塑造作用 2）生物对环境的适应 3）适应环境的生物对环境的改善作用 为什么要开展生态学研究 人类面监的四大危机： （1）环境危机 （2）人口危机 （3）资源危机 （4）能源危机 Individuals,populations,communities and ecosystems There are four identifiable subdivisions of scale which ecologists investigate; (i) considering the response of individuals to their environments; (ii) Examining the response of populations of a single species to the environment,and considering processes such as abundance and fluctuations; (iii) The composition and structure of communities (the populations occurring in a defined area); (iv)the processes occurring within ecosystems (the combination of a community and the abiotic components of the environment), such as energy flow, food webs and the cycling of nutrients. 个休、种群、群落和生态系统 生态学所研究的有 4 个可辨别尺度的亚部分： (i)探讨个体对其环境的反应； (ii)研究单个物种的种群对于环境的反应，和探讨诸如多度(abundance)及其波动等的过程（iii） 群落（出现在确定面积中的种群集合）的组成和结构；(iv)生态系统（群落与环境的非生物 成分的结合）内的各种过程，例如能流、食物网和营养物的循环等。 生态学的交叉学科 在生物学内的交叉：生理生态学，生态遗传学，行为生态学，… 与自然科学的交叉：数学生态学，化学生态学，… … 与人文、经济和社会科学的交叉：经济生态学，社会生态学，政治生态学，人类生态学，民 族生态学，哲学生态学，… … 生态学的研究方法 1.4.3 生态学研究问题的步骤 TEN RULES IN ECOLOGY? What are these rules? The authors’ experience of teaching ecology has given them experience of some common pitfalls which ecology students often make. This list, designed to counter these pitfalls, is neither comprehensive nor mutually exclusive, but we hope will nevertheless serve as a useful guide to
htt/www.cucdecom.cn中国高校课件下载中心 这些规律是什么? 生态学的授课实践使得本书作者能够觉察到大学生学习生态学时常常陷入的某些一般性错 误。本目录是为克服这些错误而设计的,既不全面,也不互相排斥,但是我们希望它将作为 有用的指南 Rule 1 ecology is a science Ecology is a purely scientific discipline which aims to understand the relationships between organisms and their wider environment. It is important to segregate political and social impacts of ecological understanding from the scientific viewpoint 规律1:生态学是科学 生态学是一门纯科学学科,目标是了解有机体与其广阔环境的相互关系。分清楚科学观点与 生态学知识的政治和社会影响这一件事是十分重要的。 Rule 2 Ecology is only understandable in the light of evolution The huge diversity of organisms, and the wealth of variety in their morphologies, physiologies and behavior are all the result of many millions of years of evolution. Those evolutionary history has left an indelible impression on each and every individual. It is only possible to make sense of the patterns we find today in the light of this evolutionary legacy 规律2:生态学只有按照进化论才可理解 有机体巨大的多样性,以及其形态学、生理学和行为的变异的丰富性,全都是亿万年进化的 结果。这个进化历史对于每一个个体都留下了不能去除的影响。我们今天发现的种种模式, 只有按照进化论的观点才可能有意义。 Rule 3 Nothing happens' for the good of the species A very common misconception is the idea that patterns of behavior in organisms which appear to be costly to an individual occur'for the good of the species. This is absolutely and completely wrong. Natural selection will favor those genes which are passed on to the most offspring, even if these genes may cause a reduction in the species'population size 规律3:“对动物种有利”现象并不存在 对于那些看起来对个体是花费的有机体行为模式,认为其出现是由于“对物种有利”的这种想 法是一个非常普遍的误解。这是绝对和完全错误的。自然选择将会有利于那些传给大多数后 裔的基因,即使这些基因有可能导致物种种群大小的下降 Rule 4 genes and environment are both important The environment an organism finds itself in plays an important role in determining the options open to that individual. The genes which define an organism's makeup are also of fundamental importance. To understand ecology it is important to appreciate the fundamental nature of both of these factors and the fact that they interact 规律4:基因和环境都很重要 有机体自己所处的环境,对于它在开放的各种选择中决定取舍上,具有重要的作用。决定有 权体构造的基因,同样具有根本的重要性。这两方面因素的基本性质及其相互作用,对于理 解生态学都是很重要的 Rule 5 Understanding complexity requires models Ecology is a complex subject, with huge variation at almost every scale-millions of species, each with considerable genetic variation, varying numbers and ever-changing behaviors in a complex and dynamic environment To understand it it is necessary to clearly identify specific questions and then formulate hypotheses which can be tested. It is often very useful to frame the hypothesis
http://www.cucdc.com.cn 中国高校课件下载中心 protocol. 这些规律是什么？ 生态学的授课实践使得本书作者能够觉察到大学生学习生态学时常常陷入的某些一般性错 误。本目录是为克服这些错误而设计的，既不全面，也不互相排斥，但是我们希望它将作为 有用的指南。 Rule 1 Ecology is a science. Ecology is a purely scientific discipline which aims to understand the relationships between organisms and their wider environment. It is important to segregate political and social impacts of ecological understanding from the scientific viewpoint. 规律 1：生态学是科学 生态学是一门纯科学学科，目标是了解有机体与其广阔环境的相互关系。分清楚科学观点与 生态学知识的政治和社会影响这一件事是十分重要的。 Rule 2 Ecology is only understandable in the light of evolution. The huge diversity of organisms, and the wealth of variety in their morphologies, physiologies and behavior are all the result of many millions of years of evolution. Those evolutionary history has left an indelible impression on each and every individual. It is only possible to make sense of the patterns we find today in the light of this evolutionary legacy. 规律 2：生态学只有按照进化论才可理解 有机体巨大的多样性，以及其形态学、生理学和行为的变异的丰富性，全都是亿万年进化的 结果。这个进化历史对于每一个个体都留下了不能去除的影响。我们今天发现的种种模式， 只有按照进化论的观点才可能有意义。 Rule 3 Nothing happens’ for the good of the species’. A very common misconception is the idea that patterns of behavior in organisms which appear to be costly to an individual occur’ for the good of the species’. This is absolutely and completely wrong. Natural selection will favor those genes which are passed on to the most offspring, even if these genes may cause a reduction in the species’population size. 规律 3：“对动物种有利”现象并不存在 对于那些看起来对个体是花费的有机体行为模式，认为其出现是由于“对物种有利”的这种想 法是一个非常普遍的误解。这是绝对和完全错误的。自然选择将会有利于那些传给大多数后 裔的基因，即使这些基因有可能导致物种种群大小的下降。 Rule 4 Genes and environment are both important. The environment an organism finds itself in plays an important role in determining the options open to that individual. The genes which define an organism’s makeup are also of fundamental importance. To understand ecology it is important to appreciate the fundamental nature of both of these factors and the fact that they interact. 规律 4：基因和环境都很重要 有机体自己所处的环境，对于它在开放的各种选择中决定取舍上，具有重要的作用。决定有 权体构造的基因，同样具有根本的重要性。这两方面因素的基本性质及其相互作用，对于理 解生态学都是很重要的。 Rule 5 Understanding complexity requires models. Ecology is a complex subject, with huge variation at almost every scale-millions of species, each with considerable genetic variation, varying numbers and ever-changing behaviors in a complex and dynamic environment. To understand it,it is necessary to clearly identify specific questions and then formulate hypotheses which can be tested. It is often very useful to frame the hypothesis
htt/www.cucdecom.cn中国高校课件下载中心 in mathematical terms to avoid ambiguity and confusion which are often inevitable in a verbal model. Mathematical models are widely used in ecology 规律5:理解复杂性要求模型 生态学是一复杂的对象,几乎每一个尺度都有大量变异——亿万个种,每种有大量基因变异 在复杂和动态的环境中有变化着的数量和随时间而改变的行为。为了理解它,必需清楚的认 明特异问题,然后形成可以检验的假设。以数学的思想方法构造假说常常是很有用的,可以 躲开在语言模型中不能避免的含糊不清和混淆。数学模型在生态学里被广泛的应用 Rule 6 Story-telling is dangerous In attempting to explain ecological patterns or relationships, it is easy to slip into a make-believe world where every observation is readily explained by some ad hoc assertion-'story-telling. The temptation to advance hypotheses as facts should be avoided at all costs 规律6:“讲故事”是危险的 在打算解释生态学种种模式或相互关系的时候,人们很容易滑到虚假世界之中,每一个观察 都很容易的被某特设的断言(所谓的“讲故事”)所解释了。无论如何,总想去推进假设实际 上是应该避免的 Rule 7 There are hierarchies of explanations For any observation there is often an immediate cause that can be diagnosed. Often this causal explanation is insufficiently informative and we need to probe deeper to reach a fuller grasp of the situation. Even if a phenomenon is 'explained there may well be further and deeper explanations which allow us to see the fuller picture 规律7:要有分层次的解释 对于任何观察,常常可以识别出一个直接的原因,但这种因果解释往往是资料不足的,我们 需要进一步探索,以达到更完全的抓住情况。即使是现象已经被“解释”了,更进一步和更深 入的解释也是很好的,它允许我们看见更完全的情景。 Rule 8 There are multiple constraints on organisms Whilst the total diversity of form, function and environmental resilience exhibited by organisms is awe-inspiring, each individual(and, to a slightly lesser extent, each species) operates within a elatively narrow range of constraints. Constraints fundamentally take two forms, (i) physical and (ii) evolutionary. Evolution cab never reach 'perfection because of these constraints and organisms are essentially hotchpotches of numerous compromises 规律8:有机体具有很多限制 有机体表现出来的形态、功能和环境适应力的总多样性是令人惊叹的,每个个体(和每一个 种,但较少程度)则在相对较小的约束范围中运转。约束基本上有两类:(i)物理的,(ⅱ) 进化的。由于这些约束,进化从来就没有达到“完善”过,有机体基本上是许多妥协的杂烩。 Rule 9 Chance is important Chance events play a critical role in ecology. The opening of a gap in a forest canopy or the breaching of a sand dunce after a storm will have a major impact on the ecology of the local fauna and flora, but both are unpredictable in either time or location. The importance of chance events in ecology does not mean ecological patterns are wholly unpredictable, but it necessarily 规律9:机会是重要的 随机事件在生态学中起关键性的作用。林冠中出现林窗或沙丘在风暴后裂口,对于当地动植 物区系将有重要的影响,但是,林窗和裂口出现的时间和地点都是不可预测的。机会的作用 也与有机体过去进化综合在一起。生态学中机会事件的重要性并不意味着生态学中的模式是
http://www.cucdc.com.cn 中国高校课件下载中心 in mathematical terms to avoid ambiguity and confusion which are often inevitable in a verbal model. Mathematical models are widely used in ecology. 规律 5：理解复杂性要求模型 生态学是一复杂的对象，几乎每一个尺度都有大量变异——亿万个种，每种有大量基因变异， 在复杂和动态的环境中有变化着的数量和随时间而改变的行为。为了理解它，必需清楚的认 明特异问题，然后形成可以检验的假设。以数学的思想方法构造假说常常是很有用的，可以 躲开在语言模型中不能避免的含糊不清和混淆。数学模型在生态学里被广泛的应用。 Rule 6 ‘Story-telling’ is dangerous. In attempting to explain ecological patterns or relationships, it is easy to slip into a make-believe world where every observation is readily explained by some ad hoc assertion – ‘story-telling’. The temptation to advance hypotheses as facts should be avoided at all costs. 规律 6：“讲故事”是危险的 在打算解释生态学种种模式或相互关系的时候，人们很容易滑到虚假世界之中，每一个观察 都很容易的被某特设的断言（所谓的“讲故事”）所解释了。无论如何，总想去推进假设实际 上是应该避免的。 Rule 7 There are hierarchies of explanations. For any observation there is often an immediate cause that can be diagnosed. Often this causal explanation is insufficiently informative and we need to probe deeper to reach a fuller grasp of the situation. Even if a phenomenon is ‘explained’ there may well be further and deeper explanations which allow us to see the fuller picture. 规律 7：要有分层次的解释 对于任何观察，常常可以识别出一个直接的原因，但这种因果解释往往是资料不足的，我们 需要进一步探索，以达到更完全的抓住情况。即使是现象已经被“解释”了，更进一步和更深 入的解释也是很好的，它允许我们看见更完全的情景。 Rule 8 There are multiple constraints on organisms. Whilst the total diversity of form, function and environmental resilience exhibited by organisms is awe-inspiring, each individual (and, to a slightly lesser extent, each species) operates within a relatively narrow range of constraints. Constraints fundamentally take two forms, (i) physical and (ii) evolutionary. Evolution cab never reach ‘perfection’ because of these constraints and organisms are essentially hotchpotches of numerous compromises. 规律 8：有机体具有很多限制 有机体表现出来的形态、功能和环境适应力的总多样性是令人惊叹的，每个个体（和每一个 种，但较少程度）则在相对较小的约束范围中运转。约束基本上有两类：（i）物理的，（ii） 进化的。由于这些约束，进化从来就没有达到“完善”过，有机体基本上是许多妥协的杂烩。 Rule 9 Chance is important. Chance events play a critical role in ecology. The opening of a gap in a forest canopy or the breaching of a sand dunce after a storm will have a major impact on the ecology of the local fauna and flora, but both are unpredictable in either time or location. The importance of chance events in ecology does not mean ecological patterns are wholly unpredictable, but it necessarily places boundaries on the potential level of predictive detail. 规律 9：机会是重要的 随机事件在生态学中起关键性的作用。林冠中出现林窗或沙丘在风暴后裂口，对于当地动植 物区系将有重要的影响，但是，林窗和裂口出现的时间和地点都是不可预测的。机会的作用 也与有机体过去进化综合在一起。生态学中机会事件的重要性并不意味着生态学中的模式是
htt/www.cucdecom.cn中国高校课件下载中心 完全不可预测的,但是它必然是位于预言细节的潜在水平之边缘。 Rule 10 There boundaries of ecology are in the mind of the ecologist Ecology is a broad science, covering both organisms and physical environments and hence potentially relevant. Mathematics, chemistry and physics are tools essential to the understanding of ecology 规律10:在生态学家心目中的生态学边界 生态学是一门广泛的科学,覆盖着生物和物理环境,从而作为潜在相关的,很少有被排除在 外的了。数学、化学和物理学都是理解生态学的基本工具。 二、 ADAPTATION Fitness is measure of the ability of an individual to produce viable offspring and contribute to future generations. Individuals vary in their relative fitness, and this variation is due partly to genetic differences among individuals and partly to environmental influences 适合度 适合度是个体生产能存活后代、并能对未来世代有贡献的能力的指标。个体的相对适合度是 有变化的,这种变化部分决定于个体的遗传区别,部分决定于环境的影响。 Any heritable trait possessed by an organism which aids survival or reproduction is an adaptation Such traits may be physiological, morphological or behavioral. Adaptation is the result of natural 适应 有机体所具有的有助于生存和生殖的任何可遗传特征都是适应。适应性特征可以是生理的 形态的或行为的。适应是自然选择的结果 Natural selection The individuals in a species which have the highest fitness will contribute disproportionately to the subsequent generations. If fitness differences have a genetic component, then the genetic ake-up of the subsequent generations will be altered. This process is known as natural selection or 'survival of the fittest 自然选择 种中具有最高适合度的个体将会对未来世代作出特别高的贡献。如果适合度的差别含有遗传 的成分,则后代的遗传组成会有改变。这个过程称为自然选择或“最适者生存”。 Genotype and phenotype The genotype is the genetic composition of an individual. The phenotype is the individual organism,a product of the interaction between its genotype environmental influences on its genotype is known as phenotypic plasticity(e.g. human suntan, wind-shaped plants locust morph ( solitary or migratory)) 基因型和表型 基因型是个体的遗传组成。表型是各个有机体,它是基因型与环境的相互作用的产物。由于 环境对基因型的影响,表型发生变化的能力叫做表型可塑性(如人的晒黑、风造形的植物 蝗虫的单生或群居型)。 COPING WITH ENVIRONMENTAL VARIATION Variable environmental factors which organisms respond to are conditions. Examples include temperature, acidity and salinity. Conditions are not depletable-they are not used up or consumed
http://www.cucdc.com.cn 中国高校课件下载中心 完全不可预测的，但是它必然是位于预言细节的潜在水平之边缘。 Rule 10 There boundaries of ecology are in the mind of the ecologist. Ecology is a broad science, covering both organisms and physical environments and hence excludes little as potentially relevant. Mathematics, chemistry and physics are tools essential to the understanding of ecology. 规律 10：在生态学家心目中的生态学边界 生态学是一门广泛的科学，覆盖着生物和物理环境，从而作为潜在相关的，很少有被排除在 外的了。数学、化学和物理学都是理解生态学的基本工具。 二、ADAPTATION Fitness Fitness is measure of the ability of an individual to produce viable offspring and contribute to future generations. Individuals vary in their relative fitness, and this variation is due partly to genetic differences among individuals and partly to environmental influences. 适合度 适合度是个体生产能存活后代、并能对未来世代有贡献的能力的指标。个体的相对适合度是 有变化的，这种变化部分决定于个体的遗传区别，部分决定于环境的影响。 Adaptation Any heritable trait possessed by an organism which aids survival or reproduction is an adaptation. Such traits may be physiological, morphological or behavioral. Adaptation is the result of natural selection. 适应 有机体所具有的有助于生存和生殖的任何可遗传特征都是适应。适应性特征可以是生理的、 形态的或行为的。适应是自然选择的结果。 Natural selection The individuals in a species which have the highest fitness will contribute disproportionately to the subsequent generations. If fitness differences have a genetic component, then the genetic make-up of the subsequent generations will be altered. This process is known as natural selection or ‘survival of the fittest’. 自然选择 种中具有最高适合度的个体将会对未来世代作出特别高的贡献。如果适合度的差别含有遗传 的成分，则后代的遗传组成会有改变。这个过程称为自然选择或“最适者生存”。 Genotype and phenotype The genotype is the genetic composition of an individual. The phenotype is the individual organism, a product of the interaction between its genotype environmental influences on its genotype is known as phenotypic plasticity (e.g. human suntan, wind-shaped plants locust morph (solitary or migratory)). 基因型和表型 基因型是个体的遗传组成。表型是各个有机体，它是基因型与环境的相互作用的产物。由于 环境对基因型的影响，表型发生变化的能力叫做表型可塑性（如人的晒黑、风造形的植物、 蝗虫的单生或群居型）。 三、COPING WITH ENVIRONMENTAL VARIATION Conditions Variable environmental factors which organisms respond to are conditions. Examples include temperature, acidity and salinity. Conditions are not depletable – they are not used up or consumed
htt/www.cucdecom.cn中国高校课件下载中心 by 条件 引起有机体对其反应的、可变的环境因子是条件( conditions),例如温度、酸度和盐度。条 件是不可能被减少的——它不能被有机体用掉或消耗掉 Resources Anything which the organism uses up or depletes is a resource for that organism. Thus, nectar is a resource for honey bees, and light is a resource for all green plants 资源 有机体消耗的任何东西,对该有机体而言,就是资源。例如,蜜是蜜蜂的资源,光是一切绿 色植物的资源 生态因子的相关概念 生态因子:环境要素中对生物起作用的因子 生存条件:生态因子中生物生存不能缺少的生态因子的总称 生态环境:一定区域所有生态因子的总和 生境( habitat):特定生物个体或群体的栖息地的生态环境 生态因子的分类 根据性质划分为: 气候因子:如温度、水分、光照、风、气压和雷电等 土壤因子:如土壤结构、土壤成分的理化性质及土壤生物等 地形因子:如陆地、海洋、海拔高度、山脉的走向与坡度等 生物因子:包括动物、植物和微生物之间的各种相互作用 人为因子:人类活动对自然的破坏及对环境的污染 生态因子的分类 有无生命特征:生物因子和非生物因子 对生物种群数量变动的作用 密度制约因子:食物、天敌等生物因子 非密度制约因子:温度、降水等气候因子 稳定性及其作用特点 稳定因子:终年恒定的因子,决定生物的分布,如地心引力、地磁等 变动因子: 周期性变动因子:一年四季变化和潮汐涨落 非周期性变动因子:如风、降雨、捕食等 生态因子的作用特征 综合作用:生态因子间相互联系、相互影响、相互制约 主导因子作用:生态因子的非等价 作用的阶段性:生物发育的不同阶段,需要不同 不可替代性和补偿性:生态因子间不可替代,但在一定程度上可以补偿 直接作用和间接作用: 直接因子:直接对生物发生影响的生态因子 间接因子:通过影响直接因子而对生物发生影响生态因子 限制因子和限制因子定律 限制因子( limiting factor 限制因子是对生物的生存、生长、繁殖或扩散等起限制作用的因子 当生态因子接近或超过生物的耐受性极限而影响其生存、生长、繁殖或扩散时,这个因子
http://www.cucdc.com.cn 中国高校课件下载中心 by an organism. 条件 引起有机体对其反应的 、可变的环境因子是条件(conditions)，例如温度、酸度和盐度。条 件是不可能被减少的——它不能被有机体用掉或消耗掉。 Resources Anything which the organism uses up or depletes is a resource for that organism. Thus, nectar is a resource for honey bees, and light is a resource for all green plants. 资源 有机体消耗的任何东西，对该有机体而言，就是资源。例如，蜜是蜜蜂的资源，光是一切绿 色植物的资源。 生态因子的相关概念 生态因子：环境要素中对生物起作用的因子。 生存条件：生态因子中生物生存不能缺少的生态因子的总称。 生态环境：一定区域所有生态因子的总和。 生境（habitat）：特定生物个体或群体的栖息地的生态环境。 生态因子的分类 根据性质划分为： 气候因子：如温度、水分、光照、风、气压和雷电等 土壤因子：如土壤结构、土壤成分的理化性质及土壤生物等 地形因子：如陆地、海洋、海拔高度、山脉的走向与坡度等 生物因子：包括动物、植物和微生物之间的各种相互作用 人为因子：人类活动对自然的破坏及对环境的污染 生态因子的分类 有无生命特征：生物因子和非生物因子 对生物种群数量变动的作用 密度制约因子：食物、天敌等生物因子 非密度制约因子：温度、降水等气候因子 稳定性及其作用特点 稳定因子：终年恒定的因子，决定生物的分布，如地心引力、地磁等 变动因子： 周期性变动因子：一年四季变化和潮汐涨落 非周期性变动因子：如风、降雨、捕食等 生态因子的作用特征 综合作用： 生态因子间相互联系、相互影响、相互制约 主导因子作用：生态因子的非等价 作用的阶段性： 生物发育的不同阶段，需要不同 不可替代性和补偿性：生态因子间不可替代，但在一定程度上可以补偿 直接作用和间接作用： 直接因子：直接对生物发生影响的生态因子 间接因子：通过影响直接因子而对生物发生影响生态因子 限制因子和限制因子定律 限制因子 (limiting factor) -限制因子是对生物的生存、生长、繁殖或扩散等起限制作用的因子 -当生态因子接近或超过生物的耐受性极限而影响其生存、生长、繁殖或扩散时，这个因子