生态学课件_生态学

1、 要 点有机体的生态位（niche）是它在它的环境中所处的位置，包括它发现的各种条件、所利用的资源和在那里的时间。有机体的栖息地（habitat，或译生境）是它所处的物理环境，例如，温带阔叶林。每一个栖息地提供许多生态位。定义有机体生态位的每一个条件和资源，对于有机体能出现的空间提供一个维度。一起考虑所有维度，全面确定的有机体的生态位，是多维生态位空间，或“n-维超体积”。生 态 位栖 息 地多维生态位空间The ecological niche of an organism is the position it fills in its environment, comprising the

2、 conditions under which it is found, the resources it utilizes and the time it occurs there.Key NotesKey Notes The habitat of an organism is the physical environment it is found in, for example, a temperate broad-leaved woodland. Each habitat provides.Each condition or resource which defines the nic

3、he of an organism contributes one dimension to the space in which the organisms niche, and is the multidimensional niche space, orn-dimensional hypervolume.NicheHabitatMultidimensionalniche space基础生态位在没竞争和捕食条件下，有机体的生态位空间叫做基础生态位（fundamental niche）。相关主题竞争的性质（见I1） 资源分配（见I3）种内竞争（见I2）实际生态位当有竞争和捕食出现时，有机体所

4、占有的生态位空间是实际生态位（realized niche），实际生态位始终是基础生态位的一个子集。The niche space an organism can fill in the absence of competition or predation is known as the fundamental niche.The niche space occupied by an organism when competition and predation occur is the realized niche, which is always a subset of the fund

5、amental niche.The nature of competition (11) Resource partitioning(13)Intraspecific competition (12) Fundamental nicheRealized nicheRelated topics 要 点营养物资源群落以形形色色的方式获得和损失营养物。机械风化、化学腐蚀，特别是碳酸化作用，都是重要的过程。矿物质在水中的简单溶解也使营养物从岩石和土壤中获得成为可能。在水流中水可能携带着营养物，给下流地区提供一个重要的资源。大气也提供营养物，特别是二氧化碳和氮。大气中其他营养物可能以湿降落（雨，雪和雾）

6、和干降落（干燥期间的颗粒沉淀物）的方式回到群落。Nutrients are gained and lost by communities in a variety of ways. Mechanical weathering, chemical weathering, particularly carbonation, are important processes. Simple dissolution of minerals in water also makes nutrients available from rock and soil. Water may carry nutrien

7、ts in watercourses providing an important source in downstream areas. Atmospheric gases provide nutrient sources too, particularly carbon dioxide and nitrogen. Other nutrients from the atmosphere become available to communities as wetfall (rain, snow and fog) and dryfall (settling of particles durin

8、g dry periods).Key NotesNutrient sources陆地群落营养物预算有机体吸收的特定营养物微粒可连续地循环，直到营养物最终损失，这是通过许多过程中的任一个过程把营养物从系统中除去。营养物释放可直接到达空气或通过细菌作用（如甲烷）。对于许多元素来说，最重要的是丢失途径是在水流中。营养物损失的其他途径包括火灾、庄稼的收获和森林砍伐。A particular nutrient atom taken up by an organism may cycle continuously until eventually the nutrient will be lost thr

9、ough any one of a number of processes that remove nutrients from the system. Release may be direct to the atmosphere or via bacterial action (as in the case of methane). For many elements, the most substantial pathway of loss is in streamflow. Other pathways of nutrient loss include fire, the harves

10、ting of crops and deforestation.Nutrient budgets in terrestrial communities水生群落营养物预算水生系统从水流中得到它们所需的大量营养物。在具有流出口的溪流、河流和湖泊中，水流出是个重要因素。通常，无机营养物置换阶段与营养物固定在生物量中的时期是交替进行的。浮游生物在湖泊中的营养物循环中起关键作用。海洋含有温暖的表层水，生活着大多数的植物，还有冷的深层水（占总水容量的90%）。表层水的营养物来源于两种方面：（i）深层水的上涌流（组成物预算的95%以上），（ii）河流的输入。Aquatic systems obtain th

11、e bulk of their supply of nutrients from streamflow. In streams, rivers and lakes with a stream outflow, export in outgoing stream water is a major factor. Commonly, phases of fast inorganic nutrient displacement alternate with periods when the nutrient is locked in biomass. In lakes, plankton play

12、a key role in nutrient cycling. Oceans contain warm suface waters, where most plant life is found and cold deep waters (which make up 90% of the total water volume). Nutrients in the suraface waters come from two sources: (i) upwelling from deep water (which comprise over 95% of the nutrient budget)

13、,and (ii) river input.Nutrient budgets in aquatic communities地球化学地球上的化学元素库存在于各种圈层（compartments）中：在岩石（岩圈）和土壤水、溪流、湖泊或海洋（可组合构成水圈）中。在上述情况下，化学元素以无机形式存在。同时，生命有机体和已死亡及腐烂的有机物质是在含有有机元素的圈层里。研究在这些区域内发生的化学过程和圈层间元素的流动（通过生物过程产生了功能性的改变和影响），称为生物地球化学。The pools of chemical elements on earth exist in various compartme

14、nts: in rocks (the lithosphere), and soil water, streams, lakes or oceans (whish, combined, constitute the hydrosphere). In all these cases, the chemical elements exist in the inorganic form. In contrast, living organisms and dead and decaying organic matter are compartments which contain elements i

15、n the organic form. Studies of the chemical processes occurring within these compartments and the flux of elements between them (which are fundamentally altered and affected by biotic processes) is termed biogeochemistry.Geochemistry全球生物地化循环陆地植物利用空气中CO2作为光合作用的碳源，而水生植物使用溶解的碳酸化合物（水圈的碳）。呼吸作用把固定在光合产物中的碳

16、，再释放到气圈和水圈的碳圈层中。在全球氮循环中，气相是占优势的，其中，氮的固定和微生物的脱氮作用特别重要。磷主要储存在土壤水、河流、湖泊、岩石和海洋沉淀物中，而硫储存在大气和岩石的组分中。相关主题植物与消费者（G2） 土壤形成、特性和分类（G3节）初级和次级生产力（P2）Terrestrial plants utilize atmospheric CO2 as their carbon source for photosynthesis, whereas aquatic plants use dissolved carbonates (hydrosphere carbon). Respirat

17、ion releases the carbon locked in photosynthetic products back to the atmospheric and hydrospheric carbon compartments. The atmospheric phase is predominant in the global nitrogen cycle, in which nitrogen fixation and denitrification by miocroorganisms are of particular importance. The main stocks o

18、f phosphorus occur in soil water, atmospheric and lithospheric components.GeochemistryRelated topicsPlants and consumers (G2) Primary and secondary productionSoil formation, properties and (P2) classification(G3) 要 点土壤形成在陆地生态系统的底部是土壤：一薄层由生物和气候改造的地球外壳。土壤提供了栖息地，具有营养物传递系统、再循环系统和废物处理系统。土壤的研究称为土壤学。土壤中的有机

19、体参与了栖息地的形成，是土壤形成中构成五个相互作用的因素之一；其他四个是气候、地形、母质和时间。土壤母质的开始居住者通常是蓝细菌，它能进行光合作用和固定氮。高等植物形成后，土壤变化过程的多样性产生了活的和死的细胞，和土壤有机物质（SOM）的动态混合物。Underlying terrestrial ecosystems is the soil; a thin layer of the Earths crust that has been remade by life and weather, Soil provides habitats with a nutrient delivery syst

20、em, a recycling system and a waste-disposal system. The study of soils is called pedology, Soil organisms participate in the formation of the habitat and constitute one of the five interactive factors in soil formation; the other four are climate, topography, parent material and time. The initial co

21、lonizers of soil parent material are usually the cyanobcteria, capable of photosynthesis and nitrogen fixation. After higher vegetation has become established, a variety of soil processes produces the dynamic mixture of living and dead cells, soil organic matter (SOM).Key NotesSoil formation土壤剖面土壤表面

22、是死亡腐烂植物部分的枯枝落叶层，下面由完全不同的物质组成的一层或多层。这些层可叫做“层”土层的形成是由于腐烂植物与矿物质土壤的上层相混合。下面的亚土壤是土壤起始形成的地方，称为母质。这种分层的外貌叫做土壤剖面。土壤科学家认为母质以上的土层有三类：A、B和C层。这三层之下是不变的母质。这些以R层著称。土壤剖面是重要生态系统过程中一个即时指标。At the surface of soil is a litter of dead or rotting plant parts, with one or more distinctly different layers underneath. These

23、 layers have come to be called horizons. Soil horizons form as rotting plant parts mix with the upper layers of the mineral soil. The subsoil underneath is the earth from which the soil was made and is called the parent material. This layered appearance is called the soil profile. Soil scientists re

24、cognize three kinds of soil horizon above the parent material; the A, B and C horizons. Under these three groups of horizons is the unaltered parent material. These are known as R horizons. The soil profile is an instant indicator of important ecosystem processes. The soil profile 主要分类： 大土壤群在全球范围上，大

25、土壤群在土壤分类中是最容易制图划分的。土壤剖面的颜色和条带用来区分大土壤群。全球土壤图表示了一个粗略的大土壤群图，与气候和植被图很相似。土壤勘测员是以农田或郡县部分为尺度来绘制土壤图。通常只有大土壤群之一会存在。所使用的单位“土系”，是指从相同类型的母质，通过相同类型的结合过程而发展起来的一类土壤，它们的土层在它们的排列和一般特性上是完全相似的。相关主题演替（R1） 生态系统格局（S1）Related topicsSuccession (R1) Ecosystem patterns (S1)On a world scale, the great soil groups are the most

26、 easily mapped of any class in a soil classification. Color and banding of the soil profile distinguish the great soil groups. World soil maps represent a rough plot of the great soil groups and are very similar to maps of climate or vegetation. Soil surveyors map soils on the scale of farm fields o

27、r parts of counties. Usually only one of the great soil groups will be present. The units used, soil series, are a group of soils developed from the same kind of parent material, by the same generic combination of processes, and whose horizons are quite similar in their arrangement and general chara

28、cteristics.Primary classification: the great soil groups 要 点相互作用的分类个体或物种间的相互作用可以相互作用的机制和影响为基础来分类。关键的种间相互作用是竞争、捕食、寄生和互利共生，而主要的种内相互作用是竞争、自相残杀和利他主义。Interactions between individuals and species can be classified on the basis of the effects and the mechanism of the interaction. The key interspecific inte

29、ractions are competition, predation, parasitism and mutualism, whilst the main intraspecific interactions are competition, cannibalism and altruism.Key NotesClassifying interactions竞 争竞争是共同利用有限资源的个体间的相互作用，会降低竞争个体间的适合度。竞争即可在利用共同资源的物种间发生（种间竞争），也可在同种个体间发生（种内竞争）。个体或物种的生态位（它所处的环境，利用的资源和它发生的时间）是决定该个体或物种与其

30、他个体或物种竞争程度的关键。大范围的生态位重叠一般导致激烈竞争。Competition is an interaction among individuals utilizing a limited resource, resulting in reduced fitness in the competing individuals. Competition occurs both between species utilizing a shared resource (interspecific competition) and among members of a species (int

31、raspecific competition). The niche of an individual or species (the conditions under which it is found, the resources it utilizes and the time it occurs there) is critical in determining the degree of competition with other species or individuals. Large niche overlap generally results in intense com

32、petition.Competition种内竞争当个体对资源的需要非常相似时，竞争会特别强烈。种内竞争是生态学的一种主要影响力，是扩散和领域现象的原因，并且是种群通过密度制约过程进行调节的主要原因。种间竞争种间竞争发生在利用同样有限资源的两物种之间。极少种能够逃脱其他种与之竞争共同资源的影响。Interspecific competition occurs between two species using the same limited resource. Very few species can escape from the effects of other species compe

33、ting for the same resource.Interspecific CompetitionAs individuals are quite similar in their resource requirements, such competition may be particularly intense. Intraspecific competition is a major force in ecology and is responsible for phenomena such as dispersal and territoriality, as well as b

34、eing the primary cause of population regulation via density-dependent processes.Interspecific Competition利用性竞争竞争有两种作用方式。在资源利用性竞争方式下，个体不直接相互作用，而是耗尽资源使供应不足。由于可利用资源不足而造成适合度下降。干扰性竞争在干扰性竞争方式下，个体直接相互作用，在一些动物种类中，最明显的通过打斗，也通过产生毒物（如植物异株克生）进行竞争。在这种相互作用中“败者”适合度下降，可能由于干扰（如受伤或死亡），也或许由于缺乏可用资源。In interference comp

35、etition, individuals interact directly, most obviously, in the case of some animal species, by fighting, but also by producing toxins (e.g. plant allelopathy). Fitness reduction in the loser in such interactions may be due to the interference (e.e. injuries or death) as well as the lack of resource

36、access.Interfernce CompetitionThere are two ways in which competition can operate. In exploitation competition, individuals only interact indirectly, by depleting the resource in short supply. Reduced fitness occurs due to a shortfall in resource availability.Exploitation Competition相关主题生态位（B3） 资源分配

37、（I3）种内竞争（I2）竞争结果的不对称竞争通常不均等的影响竞争者，一个体的竞争代价远高于另一个体。竞争杀死失败者是很普遍的，或通过掠夺资源或通过干扰。Competition often unevenly affects competitors, such that the cost for one individual is far greater than for another. It is common for competition to kill the losers, either via exploitation or interference.Asymmetry in the

38、 effects of CompetitionRelated topicsThe niche (B3) Resource partitioning (I3)Intraspecific competition (I2) 要 点密度制约密度制约描述适合度与种群大小之间的关系。种群调节的一个关键因子是负的密度制约，当种群密度增加时，由于种内竞争，使适合度下降。Density dependence describes the relationship between fitness and population size. A key population regulatory factor is n

39、egative density dependence, where declining fitness occurs as population density increases within a species due to intraspecific competition.Key NotesDensity dependence扩 散生物可通过扩散离开种群密度高的地区，来对高水平的种内竞争做出反应。即使在生活周期内大部分时间营固着生活的种类，也有一个可运动的扩散期。扩散通常由种群内较年轻的个体进行，而在许多哺乳动物中雄性比雌性扩散更多。领 域 性许多动物种（包括昆虫、鸟类和哺乳动物）的个

40、体或群体为争夺空间而竞争。保持领域边界的个体间有积极的相互干扰行为。领域使其所有者受益，为对抗入侵者，保护领域所付出的代价，被增加的食物供应、提高的交配成功率和降低的被捕食的危险所带来的价值超过。Organisms can respond to high levels of intraspecific competition by dispersing away from the area of high population.density. Even in species that are sessile for most of the lifecycle, there is a mobi

41、le dispersal stage. Dispersal is often undertaken by the younger members of a population, whilst in many mammal species males disperse more than females to DispersalIn many animal species (including insects, birds and mammals) individuals or groups compete for areas of space. There is active interfe

42、rence between individuals to maintain the territory boundaries. Territoriality gives a benefit to the territory-holder, such that the costs of defending the territory against intruders are outweighed by advantages such as in creased food supplies, increased mating success and reduced predation risk.

43、Territoriality自 疏固着生长的生物，包括植物，不能通过运动逃避竞争，因此竞争中的失败者死去在同样年龄大小的植物群中，这种竞争结果使较少量的较大个体存活下来。这一过程叫做“自疏”。自疏导致密度与植物个体大小之间的关系，这在双对数作图时呈现典型的-3/2斜率。这种关系叫做Yoda-3/2自疏法则。相关主题生态位（B3） 竞争的性质（I1）密度和密度制约（H3） 资源分配（I3）Related topicsThe niche (B3) The mature of competition (I1)Density and density dependence (H3) Resource p

44、artitioning (I3) Sessile organisms, including plants, cannot escape competition by movement, and therefore the losers in the competitive battle die. In a group of plants of the same age, this results in fewer individuals of larger size surviving. This process is described as self-thinning. Self-thin

45、ning results in a relationship between density and individual plant mass, which typically has a slope of 3/2on a log-log plot. This relationship is known as Yodas 3/2 law.Self-thinning 要 点猎物收益率面对两种类型猎物的选择时，捕食者要获得最佳捕获努力，就应该选择收益最大的猎物。真蟹和白脊 令 的证据表明捕食者优先选择能使其在单位时间内获得最大能量的一定大小的猎物，而不是比该体积更大或更小的猎物。鸟鸟Given

46、a choice between two potential prey types, a predator which is optimizing its effort should choose the most profitable prey. Evidence from common shore crabs and pied wagtails demonstrates that prey of a size which return the greatest energy reward per unit time are preferred over smaller and larger

47、 individuals.Key NotesProfitability of prey猎物转换依据猎物种数量的多少，捕食者有时会转换其选择而捕食某一特定的猎物种。这时捕食者主要捕食优势种猎物而大大忽略其他猎物。猎物密度影响功能反应一般认为在高猎物密度下，捕食者的摄食率会增加，然后随猎物饱和达到最大速度。这种关系称为功能反应，可能采用多种模式，传统上分为三种类型：功能反应I、II和III。Predators may alter or switch their preference for a particular prey species depending on the abundance o

48、f that species, When this occurs, common prey are consumed super proportionately whilst less common prey are largely ignored.Switching between prey typesIt is generally expected that at high densities of prey, a predators consumption rate will increase and then flatten out as prey saturation occurs,

49、 this relationship is termed the functional response and may adopt different patterns, which can be stereotyped into three classes: functional responses I, II and III.The effect of prey density functional responses搜寻和处理为得到食物，捕食者必须首先搜寻猎物，然后处理（抓住、加工和吃掉猎物）。可以认为捕食者食谱的宽度是由泛化种对策与特化种对策之间的权衡决定的。泛化种对策捕食者寻找多种

50、猎物（相对容易），特化种对策捕食者寻找一类猎物，非常有效的处理它。最佳觅食理论假定进化会最优化动物行为以使其获得的能量效率最大，从而做出捕食者如何权衡搜寻与处理的预测。To obtain food, a predator must first search for its prey and then handle (catch, process and eat) it. Diet width can be regarded as being determined by a balance between a generalist strategy of searching for a wide

51、 variey of prey (relatively easy) and a specialist strategy of searching for one type of prey and handling that very efficiently. Optimal foraging theory assumes that evolution will have optimized predator behavior to maximize the rate of energy gain and makes predictions about how we should expect

52、predators to balance searching and handling.Searching and handling异质性和猎物隐蔽处实验室捕食者猎物实验表明在一个单纯环境中，或（i）捕食者吃掉所有猎物个体，或（ii）捕食者种群消亡而猎物存活。然而，如果环境更为复杂，则一些猎物个体可能在猎物避难所中摆脱捕食，从而出现捕食者猎物的共存。由于生境斑块在维持竞争种间共存中所起的作用（见I1）推论，环境异质性很可能在允许捕食与猎物共存中具有关键的重要意义。Predator-prey experiments in the laboratory indicate that in simpl

53、e environment, either (i) predators are able to consume all prey individuals, or (ii) the predator population becomes extinct and the prey survives. If, however, the habitat is more complex some prey refuges and coexistence between predators and prey may occur. In corollary with the role of habitat

54、patchiness in maintaining coexistence between competing species (see topic I1), environmental heterogeneity is likely to be of critical importance in allowing predators and prey to coexist.Heterogeneity and prey refuges理想自由分布捕食者并不单独对猎物的分布与密度做出反应它们对与之竞争的捕食者的分布也会反应。捕食者趋向于聚集在最有利可图的斑块中，但捕食者之间的拥挤会降低斑块的有利

55、度，直到移到另一块不太拥挤的斑块中去会更好。理想自由分布理论认为捕食者会在各分布区间移动，直到各区有利度相等。Predators do not solely respond to the distribution and density of prey they may also respond to the distribution of competing predators. Predators will tend to aggregate in the most profitable patches, but predator crowding will reduce the patc

56、h profitability until it is better to move to another less crowded patch. The ideal free distribution theory suggests that predators should move among sites until profitability is equal.The ideal free distribution植物防御植物以两种主要方式来保护自己免遭捕食：（i）毒性与差的味道，和（ii）防御结构。在植物王国已发现大量的多种化学武器来保卫植物免遭捕食和寄生者的进攻。这些次生性化合物或

57、直接有毒，或可降低植物的食物价值，如降低动物肠道对植物叶组织蛋白的吸收。防御结构在各种水平上都存在，从叶表面可陷住昆虫及其他无脊椎动物的微小绒毛，到可阻止哺乳类草食动物的大型针刺。经历过落叶的植物，其次生化合物水平及防御结构大小都会提高或“被诱导”。相关主题竞争的性质（I1） 捕食的性质（J1）Related topicsThe mature of competition (I1) The nature of predation J1)Plants defend themselves from predation in two main ways: (i) toxicity and unpal

58、atablity, and (ii) defensive structures. There is a vast variety of chemical ammunition found in the plant kingdom used to defend plants against attacks from predators and parasites. These secondary compounds may either be directly toxic or they may reduce the food value of the plant, for example, b

59、y reducing the availablity of the leaf tissue protein to the animal gut. Defensive structures exist on a variety of scales, from small hairs on the leaf surface which may trap insects and other invertebrates, to large spines which deter mammalian herbivores. Both the levels of secondary compounds an

60、d the size of defensive structures may be elevated or induced in plants that have suffered defoliation.Plant defense 要 点演替经典模型生态演替是指在一个自然群落中，物种的组成连续地、单方向地、有顺序地变化。这一顺序被称为是一个演替序列，最后达到的阶段称为顶级。早期的演替阶段，具有先锋物种、低生物量和低营养水平的特征。随着演替的进行，群落的复杂性增加，通常在演替的中期阶段，复杂性达到最大。一个中期的演替群落具有高生物量、高有机营养水平和高的物种多样性。Ecological suc