#16 Population Ecology

Question 1

Ecology

Answer 1

The scientific study of interactions among organisms and between organisms and their environment

Question 2

Biotic

Answer 2

Organisms

Question 3

Abiotic

Answer 3

Non-living physical characteristics (temp, pressure, light, water, etc.)

Question 4

Physiological and behavioral ecology

Answer 4

Interactions between individual organisms and environment

Question 5

Population ecology

Answer 5

Changes in population size over time (growth, decline, reproduction, etc.)

Question 6

Community ecology

Answer 6

Interactions between population and species (predator/prey, competition, etc.)

Question 7

Ecosystem ecology

Answer 7

Interactions between communities and their abiotic environment (nutrients, water, etc.)

Question 8

Population

Answer 8

Group of individuals of a single species that occupy the same general area

• rely on same resources
• influenced by same environmental factors
• likely to interact and breed with one another

Increase- birth and immigration
Decrease- death and emigration

Question 9

Population ecology

Answer 9

Concerned with

• changes in population sie
• factors that regulator populations over time

Question 10

Population density

Answer 10

Number of individuals for a species per unit area or volume

-calculated by sampling

Question 11

Population dispersion

Answer 11

Way that individuals in a population are spaced
-reflects environmental conditions

Clumped- uneven resources
Uniform- evenly spaced
Random- multiple factors

Question 12

Life tables

Answer 12

Track survivorship, the chance of an individual in a given population of surviving to various ages

Question 13

Survivorship curves

Answer 13

Type I: high survival until old age (k selected)
-raise fewer offspring
-maintain relatively stable populations
Type II: constant survival rate
Type III: low survival at young age, high after (r selected)
-produce more offspring
-grow rapidly in unpredictable environments

Question 14

Population growth model

Answer 14

Change in # of individuals = births - deaths + immigrants - emigrants

Question 15

Exponential growth

Answer 15

The rate of population increase under IDEAL conditions

Question 16

Exponential growth model

Answer 16

G=rN

G- growth rate of population
r- population size
N- per capita rate of increase (avg. contribution of each individual to population growth)

Question 17

Limiting factors

Answer 17

Restrict population growth

Question 18

Exponential growth

Answer 18

births + immigrants > deaths + emigrants

Question 19

Logistic growth model

Answer 19

Idealized population growth that is slowed by limiting factors as the population size increases

Predicts that population growth will slow and eventually stop as population density increases (bell curve)

Question 20

Carrying capacity

Answer 20

The maximum population size a particular environment can sustain
birth + immigrants = death + emigrants

Question 21

Density-dependent

Answer 21

At increasing population density, rates result in

• declining births
• increase in deaths

Effect on population directly from size

Question 22

Intraspecific competition

Answer 22

Competition between individuals of the same species for limited resources
A density-dependent factor that limits growth in natural populations (e.g. food, nesting sites, etc.)

Question 23

Density-independent factors

Answer 23

Unrelated to population density (e.g. fire, storm, etc.)

Question 24

Boom-and-bust cycle

Answer 24

Fluctuate in density with regularity

May be due to food shortages, predator-prey interactions, etc.

Question 25

Life history

Answer 25

Made up by traits that affect an organism’s schedule of reproduction and death

Key traits include

• age of first reproduction
• frequency of reproduction
• number of offspring
• amount of parental care

Trade-offs, cannot all be at maximum

Question 26

Sustainable resource management

Answer 26

Seeks to set limits on harvests to limit damaging the resources

Question 27

Maximum sustainability yield

Answer 27

Produce consistent yield without causing population to decline

Question 28

Invasive species

Answer 28

Organisms introduced to new environments grow uncontrollably (no natural predators) and cause economical and environmental damage

Question 29

Demographic transition of human population

Answer 29

In developed countries, shift from
high birth and death rates to
low birth and death rates and
has lowered the rate of growth

In developing countries:
death rates dropped
birth rates still high
growing rapidly
(Population momentum)

Question 30

Age structure of population

Answer 30

Proportion of individuals in different age groups

Affects the future growth of the population

Question 31

Population momentum

Answer 31

Continued growth that occurs

• despite reduced fertility
• girls in childbearing years on previously expanding population

Question 32

Growing population

Answer 32

More young individuals

Question 33

Stable population

Answer 33

More even distribution of ages

Question 34

Declining population

Answer 34

Fewer young individuals

Question 35

Ecological footpring

Answer 35

Estimate of the amount of land required to provide the raw materials an individual or a nation consumes (food, fuel, housing, etc.)

Question 36

Ecological deficit

Answer 36

Not enough resources in own nation to self-sustain