Population Terminology?

Question 1

Defining ecology

Answer 1

Coined by Ernst Haeckel 1896
Extended by Krebs 1972
‘ the scientific study of interactions that determine the distribution, abundance and activity of organisms’

Question 2

Levels on integration in a community

Answer 2

3 main levels: ecosystems, communities, populations

• explanatory mechanisms are drawn from lower levels and mechanisms of significance are from higher
• everything is always interacting in nature

Question 3

The issue of defining individuals

Answer 3

Expeditions to the rule: e.g. slime moulds, bacteria with colonies and films, yeasts are chains of buds
Are they multiple individuals?

Question 4

Autecology

Answer 4

describing growth needs of an individual

E.g. max, min, optimum; PH, temp etc..

Question 5

Habitat

Answer 5

Where an organism lives

Question 6

Ecological niche can be split into..

Answer 6

Fundamental

Realised

Question 7

Practical problems in measuring a niche

Answer 7

• Indefinite number of dimensions with variables that cant be linearly ordered or measured
• often focuses on a set point in time but most interactions dynamic and vary during life cycle e.g. competition
  = need 2 or 3D models
• models can often only be defined in retrospect

Question 8

A realised niche

Answer 8

Subset of fundamental niche; is narrower
The niche actually occupied in nature
Nearly impossible to replicate in a lab

Factors in the affects of other species within its habitat e.g. role,of competition
Smaller than fundamental

Question 9

Fundamental niche

Answer 9

Often the same size or larger than realised niche
All environmental conditions a species could live in
Doesn’t factor in affects such as competition

Question 10

Define populations

Answer 10

Group of organisms of the same species
Occupying particular space at particular time

• boundary’s arbitrary and fixed by investigator

Question 11

Features of a population

Answer 11

Size poor density
Age distribution
Genetic composition
Dispersion (in space and time)

Question 12

How can population SIZE change over time

Answer 12

Birth
Death
Immigration
Emigration

Question 13

Define communities

Answer 13

Any assemblage of living populations

In a prescribed area or habitat

Question 14

What affects community structure

Answer 14

• species diversity; components, richness, evenness
• dominance
• relative abundance
• patterns
• intra/inter-specific interactions

Question 15

Interspecific

Answer 15

Between members of different species

Question 16

Intraspecific

Answer 16

Between members of the same species

Question 17

Two ways to classify the interactions between 2 species

Answer 17

• the effects (end result)
• the mechanisms
  Neither give perfect results

Question 18

System of measuring interactions

Answer 18

Odum 1953

- interaction stated as positive, negative or neutral

Question 19

Different types of interactions

Answer 19

Neutralism 
Competition 
Amensalism 
Parasitism and predation 
Commensalism 
Mutualism

Question 20

Neutralism

Answer 20

Neither pop affects the other

00

Question 21

Competition

Answer 21

Inhibition of each species by the other

- -

Question 22

Amensalism

Answer 22

One pop inhibited. The other unaffected

- 0

Question 23

Parasitism and predation

Answer 23

The predators/parasites increase. The other pop decreases

+ -

Question 24

Commensalism

Answer 24

One pop increase. The other is unaffected

+ 0

Question 25

Mutualism

Answer 25

Mutual increase

++

Question 26

Factor that affect species distribution

Answer 26

Abiotic factors 
Resource requirements 
Interspecific interactions.g. Predation 
Conditions 
- natural 
- anthropogenic

Question 27

Measuring an organisms performance

Answer 27

Often focus on fitness… but hard to measure
Can use simpler measures
- hierarchy of conditions : survival, growth rate, reproduction

Can use long term persistence threshold

• intrinsic rate of increase =/> 0
• reproducing at a rate that balances mortality

Question 28

Types of response curve

Answer 28

Monotonic

Unimodal

Question 29

Monotonic response curve

Answer 29

Threshold point = conditions too unfavourable, R below 0

Narrowing chance of reproduction, then growth then survival

Question 30

Unimodal response curve

Answer 30

Species unable to survive at either end of extremities

Can get multiple peaks with multiple conditions, but not common with one factor

Question 31

Defining resources

Answer 31

Consumed/used by resources
Leaves potential for competition

Single conditions/resources are a gross simplification