§ 4.2 Composition of species

1. Chapter 4Community ecology §4.2 Composition of species 江西师范大学 邵明勤

2. 第二节 Composition of species 1 Minimum area 2 Composition of species 3 种类组成的数量特征(Quantitative attribute) 4 Species diversity 5 Species association

3. 教学目标： 1.了解生物群落的定义、性质、基本特 点以及种类组成和数量特征 2.掌握优势种、建群种的定义 3.运用生物群落的数量特征解决问题 4.物种多样性的定义

4. 教学重难点： 1.根据各个种在群落中的作用正确划分群落成员型 2.对种类组成进行数量分析 3.优势度，重要值的计算（I.V.） 4.辛普森多样性指数，香浓威佛指数

5. 生态学词汇：

6. 1 Minimum area Definition：基本上能够表现出某群落类型生物种类的最小面积。 In general, the minimum area should be larger when the species is rich. • Tropical rain forest，50×50㎡ • Summer green broad-leaved • forest，20×20㎡ • Coniferous and deciduous • forest针叶林及落叶林，10×10㎡ • Shrubland， 5×5 或 10×10㎡ • Grassland， 1×1 或 2×2㎡ 6

7. 2 Composition of species Composition of species is the most important factor that determine the community property(群落性质). It can also be regarded as basic features to distinguish different communities. 群落学研究一般都从分析种类组成开始。 对群落的种类组成进行逐一登记后，得到一份所研究群落的生物种类名录(species list)，一个区域内所有植物种类的组合叫做植物区系(flora)，群落的种类组成情况在一定程度上反映出群落的性质。然后，根据各个种在群落中的作用而划分群落成员型。下面是植物群落研究中常用的群落成员型分类。

8. 鸟类种类名录

9. (1)Dominant species: the species that can control the structure and environment of community.它们通常是那些个体数量多、投影盖度大、生物量高、体积较大、生活能力较强，即优势度较大的种。群落的不同层次可以有各自的优势种dominant species，比如森林群落中，乔木层，灌木层，草本层和地被层分别存在各自的优势种，其中森林乔木层的优势种，即优势层的优势种常称为建群种 (2)Constructive species: dominant species in the dominant layer . 单建群种群落和共建群种群落概念、

10. Keystone species(关键种)：species that, despite low biomass, exert strong effects on the structure of the communities they inhabit.（对维持生物群落的组成composition和多样性diversity具决定性意义，但一般数量较少，这与优势种是不同的）

11. (3)Subdominant species: Number and role are smaller than that of dominant species, however they can play a certain role in controlling community quality and environment.在复层群落中，它通常居于下层，如大针茅草原中的小半灌木冷蒿就是亚优势种。 (4)Companion species: The common species. These species do not play main role on community structure and present together with dominant species in the community . 为群落的常见种类，它与优势种相伴存在，但不起主要作用。

12. (5)Rare species: The species with low frequency. 有些偶见种具有生态指示意义(ecological indicator)。 同一个植物种群在不同的群落中可表现为不同的群落成员型。

13. 3 Quantitative attribute of species composition (1)Number of individuals ①Abundance多度:the total number of individuals, or biomass, of a species present in a specified area. 是对物种个体数目多少的一种估测指标，多用于群落野外调查。 Methods to measure abundance A Direct count直接计算法：we can get density of this species from this method B 目测估计法：sociales多、copiosae很多等

14. Relative abundance：the ratio of the number of individuals for each species to the total number of individuals in the community.因此每个群落物种相对多度的总和为1。 Species1 Species2 Species3 Species4 5 2 8 3 The relative abundance of species 1 is 5/18；species 4 is 3/18。

15. ②Density: The number of individuals in a population per unit area.一般对乔木，灌木和丛生草本以植株或株丛计数，根茎植物以地上枝条计数。 • Relative density: the ratio of the number of individuals for a specific species to the total number of individuals for all species. • Density ratio: the ratio of the density for a specific species to the highest density in the community.

16. ③Cover degree，或Coverage: 是指植物的地上部分垂直投影面积占样地面积的百分比,即投影盖度。对森林群落，则以树木胸高(1.3m处)断面积计算。分盖度或层盖度之和大于总盖度。群落中某一物种的分盖度占所有分盖度之和的百分比，即相对盖度Relative coverage。

17. ④Frequency: The occurrence frequency of a specific species in the study area.即某个物种在调查范围内出现的频率。常按包含该种个体的样方数占全部样方数的百分比采计算，即： 频度=某物种出现的样方数／样方总数×100％ Most species are moderately abundant; few are very abundant or extremely rare.

18. Raunkiaer: Law of frequency：A>B>C≥D<E If you thoroughly sample groups of organisms, you will find a few abundant species and a few that are very rare. Most species will be moderately abundant.

19. How to count frequency?（ 5 plots per time） 1，2 1 • Frequency of species1 4/5；2（2/5）；3（2/5）； • 4（1/5）；5（2/5） 4，5 1，3 1，2，3，5

20. （2）综合数量指标 ①优势度(dominance) 优势度用以表示一个种在群落中的地位与作用，但其具体定义和计算指标各家意见不同。 ②重要值(important value) 也是用来表示某个种在群落中的地位和作用的综合数量指标，因为它简单、明确，所以在近些年来得到普遍采用。重要值是美国的Curtis和R．P．McIntosh(1951)首先使用的，计算的公式如下:

21. IV = relative density + relative frequency + relative dominance （relative base coverage） • 上式用于草原群落时，相对优势度可用相对盖度代替： • IV = relative density + relative frequency + relative base coverage • significance： • a summed index to reflect population size, abundance and distribution； • reflect the status and role of a population in the community; • determine the dominant species and demonstrate the property of community; • estimate the environmental features of community； • used to community classification;

22. 4 Species diversity 生物多样性Biodiversity可定义为“生物中的多样化和变异性及物种生境的生态复杂性”。它包括plant、动物animal和微生物microorganism的所有种及其组成的群落community和生态系统ecosystem。 Biodiversity has three levels: Genetic diversity，指地球上生物个体中所包含的遗传信息之总和； Species diversity，that is the diversity of organisms in the globe, include species richness and species evenness, is the measure of diversity that increases with species evenness and species richness. ； Ecosystem diversity，涉及的是生物圈(biosphere)中生物群落(community)、生境(habitat)与生态过程(ecological process)的多样化。 本节从群落特征角度，讨论物种的多样性(species diversity)。

23. (1)Definition of species diversity We first need to know how to identify species of plants and animals, and then how to measure biodiversity.物种多样性具有下面二种涵义： ①Species richness: The number of species in a community or collection. This is simplest measure of biodiversity. ②Species evenness or equitability: The relative abundance of species in a community or collection.它反映的是各物种个体数目分配的均匀程度。For example, 100 individuals in community A，90 individuals belong to species 1, 10 individuals belong to 2; 100 in community B,50 belong to species 1, 50 species.群落A的均匀度就比群落B低得多。 总之，物种数目越多，越均匀，物种多样性就越高。越均匀表明异质性越高。

24. Species evenness and diversity

25. （2）Quantitative index of diversity 测定多样性的公式很多，我们这里仅选取其中几种有代表性的作一说明。 ①Richness index由于群落中物种的总数与样本含量有关，所以这类指数应限定为可比较的。生态学上用过的丰富度指数很多，现举几例。 Gleason(1922)index： 式A: per area，S: Number of species in a community

26. ②Species diversity index: (A)the number of species in the community, which ecologists usually call species richness, and (B) the relative abundance of species, or species evenness. a. Simpson‘s diversity index D=1-ΣPi2 D: the value of Simpson‘s diversity index Pi: the proportion of the ith species 多样性指数是丰富度和均匀性的综合指标，有人称为异质性指数(heterogeneity index)或种的不齐性(species heterogenity)。

27. ②Species diversity index b、Shannon-Weiner index: a commonly applied measure of species diversity. H: the value of the Shannon-Weiner index Pi: the proportion of the ith species S: the number of species in the community H= — 公式中对数的底可取2，e，10

28. ②Species diversity index 多样性指数计算 • Simpson index：D=1-ΣPi2 • DA=0 • DB=1-[(50/100)2+(50/100)2]=0.5000 • Dc=1-ΣPi2=1-Σ(Ni/N)2=1-[(99/100)2+(1/100)2]=0.0198 • Shannon-Wiener index： H= —ΣPilog2Pi • Hmax=--S(1/S*ln1/S)=lnS • HA=0 • HB=-(0.50×ln0.50+0.50×ln0.50)=0.69 • HC=-ΣNi/N ln Ni/N= -(0.99×ln0.99+0.01×ln0.01)=0.056 • Pielou Evenness index： • Hmax=lnS=ln2=0.69 • EA= H/Hmax=-[(1.0×ln1.0)+0]/0.69=0 • EB=-0.50×ln0.50+0.50×ln0.50)/0.69=0.69/0.69=1 • EC=0.056/0.69=0.081

29. 案例分析：啮齿类群落调查的方法和多样性计算案例分析：啮齿类群落调查的方法和多样性计算

30. 物种多样性 5Diversity gradient 1. Species diversity 的变化规律： （1） Latitude； （2） Altitude； （3）Water depth. 2. Latitude梯度上species diversity 七个学说）： （1）Evolutionary time theory； （2）Ecological time theory； （3）Competition theory； （4）Predation theory ； （5）Spatial heterogeneity theory； （6）Climatic stability theory； （7）Productivity theory.

31. 物种多样性 生态学词汇

32. 中国及江西最新鸟类物种数 中国鸟类物种数1315种（张正旺，2004） 江西鸟类物种数481种（邵明勤，2010） A：鸢 Milvus sp.；B：信天翁 Diomedea sp.；C：天鹅 Cygnus sp.；D：丹顶鹤 Grus sp.；E：翠鸟 Alcedo sp.；F：环颈雉 Phasianus sp.；G：王企鹅 Aptenodytes sp.；H：鸮 Asio sp.；I：黑鹳 Ciconia nigra；J：雨燕 Apus sp.；K：鹫 Aegypius sp.；

33. 物种多样性 Species Diversity in the desert Which habitat do you prefer to? 做好宣传教育工作，不能因为眼前利益过度砍伐和捕猎等，否则就不能保持现有的物种多样性。 Species Diversity in the tropic forest

34. 物种多样性 （1）Latitude 观点1：从热带到两极随纬度的增加,species diversity will decrease gradually. We can see this fact in trees、 ants、 lizards、 birds and mammals.即无论在陆地、海洋和淡水环境,都有类似的趋势. 观点2：当然也有例外，如企鹅和海豹在极地种类最多而针叶林和姬蜂类在温带物种最丰富。 Some mammal groups such as pocket gophers（地鼠） shrews（鼩鼱）and ungulates（有蹄类）are more diverse in the temperate zone and become less diverse toward the tropics. (Wilson 1974)

35. 物种多样性 Species richness of mammals in North and South America in relation to latitude. The number of mammals species declines from equator to poles at the same rate in both continents, even though the mammals of these two continents have different evolutionary histories (Kaufman and Willig 1998)

36. 物种多样性 Tropical to polar gradient in species diversity for the calanoid copepods（桡足类） of the upper 50 meters of a transect from the tropical Pacific Ocean (太平洋) to Arctic Ocean北冰洋 （Fischer 1960）

37. 物种多样性 （2）Altitude 观点：Species diversity decreases with the altitude increasing（注:低海拔人为影响强烈） 如果在赤道区登山，随海拔的增高，能见到热带、温带、寒带的环境。 （3）Water depth 观点：Species diversity will reduce with the increasing of water depth of marine or freshwater. 显然，在大型湖泊中，温度低、含氧少、黑暗的深水层，其水生生物种类明显低于浅水区；同样，海洋中植物分布也仅限于光线能透入的光亮区，一般很少超过30米。

38. 物种多样性

39. 物种多样性 （1）Evolutionary time theory (abiotic factor) 观点: Tropical forest has long evolutionary time and is an ancient community. All communities diversify over time, and older communities consequently have more species than younger ones. In other words, as evolution time goes by, the number of species in all communities, will become larger.

40. 物种多样性

41. 物种多样性 • First,organisms in the warm, humid tropics are likely to evolve and diversify more rapidly than those in the temperate and polar regions because of a constant , favorable environment and a relative freedom from climatic disasters like glaciation. • Second,species diversity is a product of evolution and therefore is dependent on the length of time through which the organisms has developed in anuninterrupted fashion.

42. 物种多样性 （2）Ecological time theory (abiotic factor) 观点：Considering short-term time scale, species dispersal needs some time. 例如左图 牛背鹭（Bubulcus ibis）就是从非洲经南美而扩展到北美的. 例如右图 白头鹎（Pycnonotus sinensis ).

43. 物种多样性 （3）Competition theory(种间) 观点:Competition results in niche separation and produces more specialists (特化种) . Tropical species are more highly evolved and possess finer adaptations than do temperate species. Consequently , more species can occupy a given habitat in the tropics . Niche separation：The situation that because of difference in food type、feeding time and location or occurrence time different species of insects living in the same ecosystem form their own niche.

44. 物种多样性 Anolis cybotes coexists共存with five other Anolis species on Jara- bacoa and has a narrow niche. Anolis marmoratus is the only species on Marie Galante (Roughgarden 1974)

45. 物种多样性 Many naturalists argued that natural selection in the temperate and polar zones is controlled mai-nly by physical factors of the environment, whereas biological competition becomes a more important part of evolution in the tropics. Animals may also have more restricted diets in each habitat of tropics. Competition is keener(激烈) in the tropics and niches are smaller. (Dobzhansky 1950)

46. 物种多样性 （4）Predation theory（种间） 观点：Paine(1966) argued that predators and parasitesare more abundant in the tropics than elsewhere and they hold their prey population to such low levels , which competition among prey organisms is reduced . This reduced competition allows the addition of more prey species,which in turn support new predators . More prey species support more predator species.

47. 物种多样性 • Paine removed Pisaster (海星)and observed a decrease in diversity from a 15-species to an 8-species system. A Myt - ilus (贻贝) tended to dominate the area , crowding out other species.The species that disappeared were not eaten by Pisaster but, were affected by the increase in Mytilus. By continual predation, the Pisaster prevent the barnacles (藤壶) and Mytilusfrommonopolizingspace. Paine called the Pisaster a keystone species in this community.

48. Effect of removing a top predator from two interidal food web

49. 物种多样性 （5）Spatial heterogeneity theory 观点:From high latitude (寒带) to low latitude (热带) the environmental complexity increases , the more heteroge-neous and complex the physical environments , the more complex the plant and animal communities and the higher the species diversity.如植物垂直结构越复杂动物多样性越高。 Simpson(1964)has shown that the highest diversities of mammals in United States occur in mountainous areas. The explanation for this seems quite simple: Areas of high topographic relief contain many different habitats and hence more species.如山区物种多样性明显高于平原；群落中小生境丰富多样,物种多样性越高。

50. 物种多样性 （6）Climatic stability theory (abiotic factor) 观点: The species of animals and plants are rich when the climate is stable. The more stable the climatic parameters and the more favorable the climate , the more species will be present. According to this idea, regions with stable climates allow the evolution of finer speciali- zation and adaptations than do areas with erratic climates, resulting in smaller niches and more species occupying a unit space of habitat.