Population Ecology Flashcards
(80 cards)
1
Q
for ecologists, it is a group of individuals of single species inhabiting specific area
A
Population
2
Q
Physical environmental conditions that allow individuals of species to survive AND reproduce
A
Habitat
3
Q
Ability of environmental conditions to support reproduction and survival
A
Habitat quality
4
Q
3 abilities of environmental conditions to support reproduction and survival
A
– Habitat area/volume
– Resource concentration
– Time
5
Q
High habitat quality = organisms acquire many resources; high survival + reproduction =
A
large population
6
Q
Characteristics of a population
A
- Distribution
- Density
- Abundance
7
Q
a group of similar species living in a certain place at the same time.
A
Population
8
Q
Physical environment limits geographic distribution of species
– Organisms can only compensate so much for environmental variation
Environment limits the geographic distribution of species
A
Distribution Limits
9
Q
Arrangement of the individuals of a population within a particular space
A
Distribution
10
Q
3 types of Distribution
A
- Random Distribution
- Uniform distribution
- Clumped distribution
11
Q
organisms are spread throughout the area without an over-all pattern.
A
Random Distribution
12
Q
– organisms are distributed over an area.
A
Uniform distribution
13
Q
organisms are concentrated in an area.
A
Clumped distribution
14
Q
3 reasons for clumped distribution
A
- Patchy distribution of physical and chemical condition suitable for growth;
- Some part of the habitat offer more protections to prey organism; and
- Dispersal of seeds, larvae and other representative forms of each generation is often limited.
15
Q
_______ is brought by severe competition and positive antagonism among individuals.
A
Uniform distribution
16
Q
Number of individuals in a population.
A
Size
17
Q
Format of Sizing of species
A
Kind (what species) – time (what date/month/year) - Place – location – how many
18
Q
Factors affecting the size of a population
A
- Natality
- Mortality
- Immigration
- Emigration
19
Q
the number of species that are born
A
Natality
20
Q
2 types of Natality
A
- maximum natality
- Ecological natality
21
Q
absolute or theoritical production of new individual under ideal condition.
A
maximum natality
22
Q
population increase under actual or environmental condition
A
Ecological Natality
23
Q
the number of species that die
A
Mortality
24
Q
2 types of mortality
A
- Minimum mortality
- Ecological mortality
25
– loss of individual under ideal condition
minimum mortality
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loss of individual under given environmental condition
ecological mortality
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the number of species that entered the land
Immigration
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– the number of species that leave the land
emigration
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Number of individuals of a species living in a particular area of that population.
density
30
Factors affecting density of a population
1. resources
2. diseases and parasites
3. competition
4. predation
31
Physical Factors Affecting Pop. Density
1. Relief (shape and height of land)
2. Resources
3. Climate
32
Relief in High Density
Low land which is flat e.g. Ganges Valley in India
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Relief in Low Density
High land that is mountainous e.g. Himalayas
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Resources in High Density
Areas rich in resources (e.g. coal, oil, wood, fishing etc.) tend to densely populated e.g. Western Europe
35
Resources in Low Density
Areas with few resources tend to be sparsely populated e.g. The Sahel
36
Climate in High Density
Areas with temperate climates tend to be densely populated as there is enough rain and heat to grow crops e.g. UK
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Climate in Low Density
Areas with extreme climates of hot and cold tend to be sparsely populated e.g. the Sahara Desert
38
Human Factors Affecting Population Density
1. Political
2. Social
3. Economic
39
Political Factors in High Density
Countries with stable governments tend to have a high population density e.g. Singapore
40
Political Factors in Low Density
Unstable countries tend to have lower population densities as people migrate e.g. Afghanistan.
41
Social Factors in High Density
Groups of people want to live close to each other for security e.g. USA
42
Social Factors in Low Density
Other groups of people prefer to be isolated e.g. Scandinavians
43
Economic Factors in High Density
Good job opportunities encourage high population densities, particularly in large cities in MEDCs and LEDCs around the world.
44
Economic Factors in Low Density
Limited job opportunities cause some areas to be sparsely populated e.g. Amazon Rainforest
45
The number of offsprings that could theoretically exist if all offsprings survived and produced young.
Biotic potential
46
Biotic potential depends on:
– Number of offspring produced at a given time
– Frequency of reproduction
– Reproductive life cycle of the organism
47
collection of environmental factors that reduces the growth rate of a population
Environmental Resistance
48
Number of individuals in a particular population that the environment can support over an indefinite period of time in terms of food, space, and shelter.
Carrying Capacity
49
Environmental Resistance + Biotic Potential + Carrying Capacity
Size of Population
50
Factors influencing population growth
o Density dependent limiting factor
o Density independent limiting factor
51
directly associated with living things factor that depends on the size of population
Density dependent limiting factors
52
influences the population regardless of the density
Density Independent Factors
53
Density Independent Factors examples
- changes in weather
- temperature
- daily and seasonal variations of sunlight
- Amount of available air
- Water and soil condition
- Slope of the environment
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Types of Population Growth
1. Logistic Growth
2. Exponential Growth
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– have a period of rapid population growth, goes through a number of phases and eventually stops or slows down.
Logistic Growth
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– population growth is extremely rapid and at a constant rate.
Exponential Growth
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Slow increase in population growth due to increase density of population and increase in competition among members of population. Mortality increases, birth rate decreases.
Logistic Growth
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Population Growth rate of Logistic Growth
Maximum net reproduction per individual x Number of individuals x Portion of unexploited resources
m = r massN (K-N/K)
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Logistic Growth Curve
Sigmoid or S-shaped curve
60
the maximum growth rate of population achieving biotic potential
Exponential Growth
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Population growth rate of Exponential Growth
Net Reproduction individual x No. of individuals
G=rN
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Exponential Growth Curve
J-shaped curve
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dN/dt = rN x (K – N)/K
d = instantaneous change in n
N = number of individuals already in a population
t = unit of time
r = realized intrinsic rate of population growth
K = carrying capacity
64
Life Cycle
1. Prereproductive Period (juvenile period)
2. Reproductive Period
3. Postreproductive period
65
Over-all population growth rate under unlimited environmental conditions depend on the age composition and the specific growth rates due to ....
the reproduction of component age group
66
a chart showing the age and sex distribution Age interval of the population in a given time.
Age Pyramid
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Types of Age Pyramid
1. Pyramid with broad base
2. Bell Shaped polygon
3. Urn shaped
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Pyramid with large percentage of young individual
Pyramid with broad base
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Pyramid with moderate proportion of young to old
Bell Shaped polygon
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Pyramid with low percentage of young individual. Senile or declining population
Urn shaped
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Types of population pyramid1
1. Stable pyramid
2. Stationary pyramid
3. Expansive pyramid
4. Constrictive pyramid
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- A population pyramid showing an unchanging pattern of fertility and mortality.
Stable pyramid
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A population pyramid typical of countries with low fertility and low mortality, very similar to a constrictive pyramid.
Stationary pyramid
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- A population pyramid showing a broad base, indicating a high proportion of children, a rapid rate of population growth, and a low proportion of older people.
Expansive pyramid
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A population pyramid showing lower numbers or percentages of younger people. The country will have a greying population which means that people are generally older, as the country has long life expectancy, a low death rate, but also a low birth rate.
Constrictive pyramid
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recording of the births and deaths among individuals of different ages.
Life Table
77
3 general types of survivorship curves
1. Type 1 populations
2. Type 2 populations
3. Type 3 populations
78
high survivorship until some age, then high mortality. ex. humans in developed countries and animals in zoos.
Type 1 populations
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fairly constant death rate at all ages ex. rodents, adult birds, and certain turtle species
Type 2 populations
80
low survivorship early in life ex. fishes, seeds, and marine larvae
Type 3 populations
