Chap.16 Population Regulation

Chap.16 Population RegulationChap.16 Population Regulation

Ecology 2000Ecology 2000

chap.16 population regulationchap.16 population regulation 22

目錄目錄

16.1 The logistic equation describes the growth 16.1 The logistic equation describes the growth of a regulated population.of a regulated population.

16.2 A qualitative model of continuous populat16.2 A qualitative model of continuous population growth reveals the relationship between poion growth reveals the relationship between population density and growth rate.pulation density and growth rate.

16.3 Populations may be regulated by the effec16.3 Populations may be regulated by the effects of density-dependent factors.ts of density-dependent factors.


目錄目錄

16.4 Andrewartha and Birch Challenged de16.4 Andrewartha and Birch Challenged density-dependent regulation of population siznsity-dependent regulation of population size.e.

16.5 The theory of density independence cr16.5 The theory of density independence created a major controversy among ecologists.eated a major controversy among ecologists.


16.1 The logistic equation describes the growth of a regulated population.16.1 The logistic equation describes the growth of a regulated population.

dN / dt = rNdN / dt = rN dN / dt = rdN / dt = r00 N( 1- N/K) N( 1- N/K) K is the carrying capacityK is the carrying capacity


Fig. 16-1 Fig. 16-1 美國於美國於 1790-19101790-1910 年間的族群成長情況。垂直線代表年間的族群成長情況。垂直線代表每每 1010 年的年的 exponential rateexponential rate 。。


Fig. 16-2 Fig. 16-2 美國人口的成美國人口的成長之長之 exponential rateexponential rate 。。


Fig. 16-3 Fig. 16-3 族群族群 sizesize 於於 K/2K/2 時，增加速率最快。於時，增加速率最快。於 KK時，增加率等於時，增加率等於 00 。。


Fig. 16-4 a S-shaped curve Fig. 16-4 a S-shaped curve

dN / dt = r0 N( 1- N/K)


Fig. 16-5 A logistic curve fitted to the population of the Fig. 16-5 A logistic curve fitted to the population of the United States between 1790-1910.United States between 1790-1910.


16.2 A qualitative model of continuous population growth reveals the relationship between population density and growth rate.

16.2 A qualitative model of continuous population growth reveals the relationship between population density and growth rate.

dN / dt = rN = f (N) = b(N) - d(N)dN / dt = rN = f (N) = b(N) - d(N) 當當 b(N) = d(N) b(N) = d(N) ，達到平衡。，達到平衡。當當 dN / dt > 0dN / dt > 0 ，族群增加。，族群增加。當當 dN / dt < 0dN / dt < 0 ，族群減少。，族群減少。


Fig. 16-6 Fig. 16-6

(a) per capita growth rat(a) per capita growth ratee

(b) dN/dt(b) dN/dt

Break pointBreak point


16.3 Populations may be regulated by the effects of density-dependent factors.16.3 Populations may be regulated by the effects of density-dependent factors.

Density-dependent factors effects increase Density-dependent factors effects increase with crowding can bring a population under with crowding can bring a population under control.control.

Density-independent factors may influence Density-independent factors may influence the exponential growth rate , but they do not the exponential growth rate , but they do not regulate the size that the population will regulate the size that the population will attain in the environment.attain in the environment.


Fig. 16-7 density-dependent population regulation in laboratory popFig. 16-7 density-dependent population regulation in laboratory populations of the fruit fly ulations of the fruit fly Drosophila melanogasterDrosophila melanogaster. .

密度密度

生育力生育力

壽命壽命


Fig. 16-8 effects of Fig. 16-8 effects of density (number of density (number of larvae per grain) on larvae per grain) on migration and migration and mortality in the mortality in the grain beetle.grain beetle.穀物虫穀物虫

LarvaeLarvae 的密度愈高的密度愈高，遷移開的，或是，遷移開的，或是死亡的數量愈高。死亡的數量愈高。


Fig. 16-9 Fecundity in laboratory populations of Fig. 16-9 Fecundity in laboratory populations of Daphnia Daphnia pulexpulex as a function of age at different densities. as a function of age at different densities.

高密度高密度


Fig. 16-9 survival probality in laboratory populations of Fig. 16-9 survival probality in laboratory populations of DDaphnia pulexaphnia pulex as a function of age at different densities. as a function of age at different densities.

8 ind. Per cm38 ind. Per cm3

16 ind.16 ind.

32 ind.32 ind.4 ind.4 ind.

1 ind.1 ind.

2 ind.2 ind.


Fig. 16-10 Values of Fig. 16-10 Values of , calculated from the life table of , calculated from the life table of DaDaphnia pulexphnia pulex. The population growth rate decreases as a fun. The population growth rate decreases as a function of density.ction of density.

跳蚤密度跳蚤密度

A stable A stable population sizepopulation size


Fig. 16-11 Density dependence in the Fig. 16-11 Density dependence in the Mandarte Island song sparrow populatMandarte Island song sparrow population.ion.

FloatersFloaters 增加。增加。 FloatersFloaters 指的是沒指的是沒有能建地盤的雄性。有能建地盤的雄性。

平均每個雌鳥的平均每個雌鳥的 young fledgedyoung fledged

Proportion of juveniles survivingProportion of juveniles surviving


白尾鹿白尾鹿

五個不同地區五個不同地區

最好最好

最差的環境最差的環境

環境的好壞，決定生育力。環境的好壞，決定生育力。


獵捕減少族群數量，刺激族群生長。獵捕減少族群數量，刺激族群生長。

獵捕之前獵捕之前

獵捕之後獵捕之後


Density dependence in plantsDensity dependence in plants

Like animals, plants experience increased mortLike animals, plants experience increased mortality and reduced fecundity at high densities. ality and reduced fecundity at high densities.

Fig.16-12Fig.16-12 ：密度愈高，個體的平均體重愈：密度愈高，個體的平均體重愈輕。輕。

Fig. 16-13Fig. 16-13 ：幼苗成長，許多死亡，密度持：幼苗成長，許多死亡，密度持續下降。續下降。

Fig. 16-14Fig. 16-14 ：： self-thinning curve (self-thinning curve ( 自我疏伐自我疏伐曲線曲線 )) ，通常關係是，通常關係是 - 3/2 power law. - 3/2 power law.


Fig. 16-12 distribution of dry weights of individuals in populations of flaFig. 16-12 distribution of dry weights of individuals in populations of flax plants in a low density (a) and at two high densities ( b x plants in a low density (a) and at two high densities ( b 和和 c ).c ).

絕大部份絕大部份的個體都的個體都很小很小

平均個體平均個體可以有近可以有近1.0g 1.0g 乾乾重重


Fig. 16-13 horseweed (a) Fig. 16-13 horseweed (a) 存活數量持續下降，植物體重量持續上升存活數量持續下降，植物體重量持續上升。。 (b) (b) 平均植物體乾重持續上升，存活數量的密度持續下降。平均植物體乾重持續上升，存活數量的密度持續下降。


Fig. 16-14 Fig. 16-14 兩種不同的植栽。密度與平均體重的兩種不同的植栽。密度與平均體重的關係。斜率都是關係。斜率都是 - 3/2 - 3/2 。。


16.4 Andrewartha and Birch Challenged density-dependent regulation of population size.16.4 Andrewartha and Birch Challenged density-dependent regulation of population size.

1954 Lack1954 Lack 的看法：的看法： the regulation of poputhe regulation of population size by density-dependent factors, prilation size by density-dependent factors, principally food, predators, and disease.ncipally food, predators, and disease.

Andrewartha Andrewartha 和和 Birch (Birch ( 昆虫學者昆虫學者 )) ：族：族群成長受到三項因素限制：群成長受到三項因素限制： (a) (a) 資源有資源有限、限、 (b) (b) 獲取資源的困難、獲取資源的困難、 (c) (c) 時間有時間有限限其中以最後一個最為重要；第一個卻是最不其中以最後一個最為重要；第一個卻是最不

重要。重要。


Fig. 16-15 Thrips Fig. 16-15 Thrips 小虫，寄生於花朵。澳洲小虫，寄生於花朵。澳洲 (1933)(1933) 。。

點點是每天的數量，曲線是每點點是每天的數量，曲線是每 1515 天的平均。天的平均。


Thrips 數量與食物量無關Thrips 數量與食物量無關

甚至在甚至在 thripsthrips 量最大的時候，整體的密度量最大的時候，整體的密度並未呈現過度的現像並未呈現過度的現像 ( ( 除了一些局部地點除了一些局部地點和暫時的時段和暫時的時段 )) 。。

ThripsThrips 快速繁殖，但花朵的增加更加快速。快速繁殖，但花朵的增加更加快速。當當 ThripsThrips 數量開始下降，密度下降，花朵數量開始下降，密度下降，花朵

的量仍很多。的量仍很多。 Thrips populations Thrips populations 和氣候的關係。和氣候的關係。


Thrips 數量與氣候的關係Thrips 數量與氣候的關係

Dependent variable Dependent variable ，， YY ：平均每朵花上的：平均每朵花上的 thrips thrips 數量。數量。

Independent variables Independent variables ，， XX11 ：： the effective degree-days from the first rains othe effective degree-days from the first rains o

f the winter season to August 31.f the winter season to August 31. XX22 ：： the rainfall during Sept. and Oct.the rainfall during Sept. and Oct.

XX33 ：： the effective degree-days during Sept. and Oct. the effective degree-days during Sept. and Oct.

XX44 ：： the same as Xthe same as X11, but for the previous year., but for the previous year.


Fig. 16-16 Observed peak numbers of thrips per rose between 1932 Fig. 16-16 Observed peak numbers of thrips per rose between 1932 and 1945(green vertical lines) compared with the predictions of a reand 1945(green vertical lines) compared with the predictions of a regression equation based upon four climate variables (black line). gression equation based upon four climate variables (black line).


16.5 The theory of density independence created a major controversy among ecologists.

16.5 The theory of density independence created a major controversy among ecologists.

Smith (1961) argued that Davidson and AnSmith (1961) argued that Davidson and Andrewartha(1948) had analyzed their data in drewartha(1948) had analyzed their data in such a way that they could not have detectesuch a way that they could not have detected density dependence. d density dependence.

Smith Smith 運用同樣的運用同樣的 datadata ，作不同的分析，作不同的分析處理。處理。 (Fig. 16-17)(Fig. 16-17)

dN dN 與與 log N log N ，呈現負相關。，呈現負相關。


Fig. 16-17 Increase in thFig. 16-17 Increase in the size of the thrips popule size of the thrips population between October aation between October and November as a functind November as a function of the size of the popon of the size of the population in October.ulation in October.


Fig. 16-18 (a) monthly mean numbers of thrips per rose recorded over neFig. 16-18 (a) monthly mean numbers of thrips per rose recorded over nearly 7 years (b) The mean and variance for each month of the year.arly 7 years (b) The mean and variance for each month of the year.

若是若是 d N d N 與與 N N 間無關，間無關， variance variance 應該會隨著應該會隨著 log(N)log(N) 升降。但結升降。但結果於果於 October October 和和 NovemberNovember 間，間， variancevariance 有明顯的下降，但有明顯的下降，但 log(N)log(N)仍是在上升。仍是在上升。


The contemporary view of density dependenceThe contemporary view of density dependence

demographic stochasticitydemographic stochasticity variation in the birth and death ratesvariation in the birth and death rates

environmental stochasticity environmental stochasticity variation in the environmentvariation in the environment

density vaguenessdensity vagueness random fluctuations or noise, compared with random fluctuations or noise, compared with

density-dependent responsesdensity-dependent responses


鳥類族群的 regulation鳥類族群的 regulation

雖然鳥類一般被認為是主要受到雖然鳥類一般被認為是主要受到 density-density-dependentdependent 的影響，但是資料顯示並不是的影響，但是資料顯示並不是如此。如此。 Greenwood and Baillie (1991) analyzed populatGreenwood and Baillie (1991) analyzed populat

ion trends for 39 species of British passerine birion trends for 39 species of British passerine birds, ords, or

Murdoch (1994) looked at time series density dMurdoch (1994) looked at time series density data for 59 species of birdsata for 59 species of birds

這兩份報告顯示只有少部份呈現出是受這兩份報告顯示只有少部份呈現出是受 densdensity-dependent ity-dependent 的影響。的影響。


Density-dependence 的證據Density-dependence 的證據

Woiwod Woiwod 和和 Haski (1992) looked for evideHaski (1992) looked for evidence of density dependence in 5,715 time sernce of density dependence in 5,715 time series of 447 species of moths and aphids and fies of 447 species of moths and aphids and found strong evidence of its presence.ound strong evidence of its presence.


Equilibrium vs. non-equilibriumEquilibrium vs. non-equilibrium

Equilibrium dynamics vs. non-equilibrium Equilibrium dynamics vs. non-equilibrium dynamicsdynamics

The notion of equilibrium is central to regulThe notion of equilibrium is central to regulation.ation.

Non-equilibrium dynamics, in which metapNon-equilibrium dynamics, in which metapopulations are keyopulations are key

metapopulation theory (Chap.17)metapopulation theory (Chap.17)


Fig. 16-19 Possible interactions between density-dependent and density-Fig. 16-19 Possible interactions between density-dependent and density-independent mortality factors.independent mortality factors.

(a) A population with a constant rate of reproduction, R, and a density-(a) A population with a constant rate of reproduction, R, and a density-dependent mortality rate, dm, showing an equilibrium point at K1dependent mortality rate, dm, showing an equilibrium point at K1

(b) A population having both a density-dependent mortality rate and a (b) A population having both a density-dependent mortality rate and a density-independent mortality factor, m. The presence of the density-density-independent mortality factor, m. The presence of the density-independent factor lowers the population equilibrium density to Kindependent factor lowers the population equilibrium density to K22

(c) A population in which the density-independent mortality factor (c) A population in which the density-independent mortality factor fluctuates (within the green shaded area) in response to environmental fluctuates (within the green shaded area) in response to environmental stochasticity, creating a situation in which the equilibrium density stochasticity, creating a situation in which the equilibrium density fluctuates between K2 and K3. fluctuates between K2 and K3.


Suggested readingsSuggested readings

Clutton-Brock, T. H., M. Major, and F. E. Guinness (1985) Clutton-Brock, T. H., M. Major, and F. E. Guinness (1985) Population regulation in male and female red deer. Journal Population regulation in male and female red deer. Journal of Animal Ecology 54:831-846.of Animal Ecology 54:831-846.

Murdoch, W. W. (1994) Population regulation in theory aMurdoch, W. W. (1994) Population regulation in theory and practice. Ecology 75:271-287.nd practice. Ecology 75:271-287.

Myers, R. A., N. J. Barrowman, J. A. Hutchings, and A. A. Myers, R. A., N. J. Barrowman, J. A. Hutchings, and A. A. Rosenberg (1995) Population dynamics of exploited fish stRosenberg (1995) Population dynamics of exploited fish stocks at low populations levels. Science 269:1106-1108.ocks at low populations levels. Science 269:1106-1108.

Weller, D. E. (1987) A reevaluation of the -3/2 power rule Weller, D. E. (1987) A reevaluation of the -3/2 power rule of plant self-thinning. Ecological Monographs 57:23-43.of plant self-thinning. Ecological Monographs 57:23-43.


問題與討論問題與討論

請提出請提出問題問題！！

Chap.16 Population Regulation

Documents