Population Ecology

Question 1

Define population ecology.

Answer 1

How populations change over space and time.

Question 2

What factors influence population?

Answer 2

Density dependent forces.

Density independent forces.

Question 3

What is an example of a density dependent force?

Answer 3

Competition for food.

Question 4

What are examples of density independent forces?

Answer 4

Fires, floods etc.

Question 5

What is the mark and recapture method?

Answer 5

1. Capture animals.
2. Mark/Tag the animals.
3. Release.
4. Return to site and recapture.
5. Compare marked proportion to unmarked.

Question 6

What are the pros/cons of mark and recapture?

Answer 6

You can assess other aspects of the population.

Very labour intensive.

Question 7

What are life tables?

Answer 7

They use population census data to summarize birth/death rate of organisms at different life stages.

Question 8

How many types of survivorship curve are there?

Answer 8

3

Question 9

What organisms have a Type I survivorship curve?

Answer 9

Those with a high survival rate when young and a rapid decline when old.

Question 10

What organisms have a Type II survivorship curve?

Answer 10

Those with a relatively constant death rate throughout life.

Question 11

What organisms have a Type III survivorship curve?

Answer 11

Those with low survival rate when young but a high survival rate once mature.

Question 12

What is the most basic form of population change?

Answer 12

Exponential increase/Unconstrained growth.

Question 13

What factors are linked to population change?

Answer 13

Current population size and population growth rate.

Question 14

What are life history traits?

Answer 14

An individual’s lifetime allocation of time and energy.

Question 15

What are some examples of life history traits?

Answer 15

Growth, repair, defence and reproduction.

Question 16

What are semelparous organisms?

Answer 16

Organisms that only reproduce once in their lifetime.

Question 17

What are iteroparous organisms?

Answer 17

Organisms that reproduce multiple times during their life.

Question 18

What is the life strategy of an r-selected species?

Answer 18

Live fast, die young, produce lots of offspring.

Question 19

What is the life strategy of a k-selected species?

Answer 19

Slow to mature, slow to reproduce, high survival rate.

Question 20

What is modular growth?

Answer 20

When a plant grows in modules that can be added intermittently.

Question 21

Give some vertical module examples.

Answer 21

Leaves, buds, twigs, branches, flowers and fruits.

Question 22

Give an example of a horizontal module example.

Answer 22

Clones.

Question 23

Define genets.

Answer 23

Genetic individuals produced by sexual reproduction.

Question 24

Define ramets.

Answer 24

Asexually produced individuals, derived from the same genetic parent.

Question 25

What is a clone in terms of plant populations?

Answer 25

A group of ramets arising from a genet.

Question 26

What is a ubiquitous species?

Answer 26

A species with a broad, widespread range made up of many populations.

Question 27

What is an endemic species?

Answer 27

A species with a narrow range containing just a few populations.

Question 28

What are the 3 dispersion patterns?

Answer 28

Random, clumped and uniform.

Question 29

Which is the rarest dispersion pattern?

Answer 29

Random - it requires a uniform environment.

Question 30

Which is the commonest dispersion pattern?

Answer 30

Clumped.

Question 31

What are propagules?

Answer 31

Plant structures that detach from a plant and give rise to a new plant.

Question 32

How can propagules be distributed?

Answer 32

By biotic or abiotic vectors or in other forms such as ballistically.

Question 33

How are plant and animal populations structured differently?

Answer 33

Animal populations are usually age structured.

Plant populations are usually stage structured - based on size.

Question 34

What aspect of a plant is used to determine its ‘stage’?

Answer 34

Size.

Question 35

Define negative density dependence.

Answer 35

Plants responding to resource competition by slowing their growth.

Question 36

Define self-thinning.

Answer 36

Progressive decline in density but an increase in biomass of the remaining individuals.

Question 37

Define the Allee effect.

Answer 37

Increased reproduction/survival rate as a result of increased population density.

Question 38

What are the 2 forms of reproduction in plants?

Answer 38

Monocarpic plants (semelparous).
Polycarpic plants (iteroparous).

Question 39

What are physiological stresses?

Answer 39

All external factors to a plant that limit growth.

Question 40

What are the 3 points to Grime’s Triangular Model?

Answer 40

Stress tolerators, competitors and ruderals.

Question 41

What is a stress tolerator plant?

Answer 41

Slow growing species found in unfertile areas. They conserve captured resources.

Question 42

What is a competitor plant?

Answer 42

Fast growing species that inhabit highly fertile areas. They maximise resource capture.

Question 43

What is a ruderal plant?

Answer 43

Fast growing species that inhabit highly fertile areas. They have high seed production.

Question 44

What is the rate of living theory?

Answer 44

The faster an organism’s metabolism, the shorter its lifespan.

Question 45

What is the mutation accumulation theory?

Answer 45

The severity of inbreeding depression increases with age.