Community Ecology

Question 1

Define Community

Answer 1

a group of actual/ potential interacting species living in the same location

Question 2

What are the 4 main times of community interactions?

Answer 2

Competition
Predation (+ parasitism)
Mutualism
Commensalism

Question 3

Which type of community interaction has a negative effect on both populations?

Answer 3

Competition

Question 4

Which type of interaction benefits one population whilst the other is unaffected

Answer 4

Commensalism

Question 5

Which type of interaction benefits both species?

Answer 5

Mutualism

Question 6

Which type of interaction benefits one population and negatively impacts the other?

Answer 6

Predation/ parasitism

Question 7

Define intraspecific and interspecific competition

Answer 7

inTRAspecific = competition among members of the same species
inTERspecific = competition between members of two or more different species

Question 8

explain the 2 types of interspecific competition

Answer 8

Exploitation competition = when individuals exploit or consume the same limiting resources - depleting availability to others
Interference competition = when individuals interfere with the foraging or reproduction of others

Question 9

Give an example of interference competition

Answer 9

• Animals may chase other individuals away from food resources
• Animals defending territories
• Plants producing allopathic chemicals to limit growth and survival of other plants

Question 10

Name 3 limiting resources that may cause competition

Answer 10

Food
Space
Soil
Mates
Nutrients

Question 11

Define competitive exclusion

Answer 11

when one species is displaced by another when their niches overlap and they compete for the same resources

Question 12

What is an ecological niche?

Answer 12

It is the role and position a species has in its environment

Question 13

What is resource partitioning?

Answer 13

when niches become separated to avoid competition for resources in species with similar ecological niches

Question 14

Give an example of resource partitioning

Answer 14

Bumblebees – the length of the proboscises differs with each bumblebee species – allows them to specialize in the exploitation of plants with different length corollas

Question 15

How can species adapt to avoid/ as a result of competition?

Answer 15

Specialisation

Question 16

What is a fundamental niche?

Answer 16

the set of resources and habitats an organism could theoretically use under ideal conditions

Question 17

What is a realised niche?

Answer 17

the set of resources and habitats an organism actually uses due to the effects of competition (compared to the fundamental niche which are the theoretical ideal conditions)

Question 18

what is character displacement?

Answer 18

characteristics of an organism change to avoid competition

Question 19

What are the 3 reasons character displacement can occur?

Answer 19

1) when populations of closely related species have the potential for competition
2) When species live in allopatry (separate ranges) or sympatry (overlapping ranges)
3) When there is pressure from competition from phenotypically similar species that can cause natural selection to favour the phenotypic divergence of individuals of the different species

Question 20

what is sympatric speciation?

Answer 20

speciation that occurs when two groups of the same species live in the same geographical location but they evolve differently until they can no longer interbreed and are considered different species

Question 21

What causes sympatric speciation?

Answer 21

Intraspecific competition

Question 22

what are the 4 types of predators?

Answer 22

True predators
Grazers
Parasites
Parasitoids

Question 23

what is aposematic colouration? and what is it for?

Answer 23

Animals with chemical defences often exhibit bright aposematic colouration – ‘warning colouration’ to warn predators that prey is unpalatable, toxic or dangerous.
It is a defence mechanism to avoid predation

Question 24

What is a common example to a mutualistic (plant) relationship?

Answer 24

the relationship between fungal Mycorrhizae and most rooting plants

Question 25

How does fungal mycorrhizae create a mutualistic relationship?

Answer 25

The fungi increases the plants ability to absorb nutrients

The host plant provides support and carbohydrates for the fungi

Question 26

what is

Mutualistic symbiosis?

Answer 26

a type of mutualism in which individuals interact physically, or even live within the body of the other mutualistic

Question 27

what is facultative vs obligate mutualism?

Answer 27

Facultative = not essential for the survival of either species.  
Obligate = is essential for the survival of one or both species

Question 28

Give an example of commensalism

Answer 28

• Birds nesting in trees
• Nurse plants protecting seedlings
• Treefrogs using plants for protection and egg laying
• Golden jackal following a tiger to eat leftovers