Unit 2.5ai

Question 1

What is a niche?

Answer 1

An ecological niche is a multidimensional summary of tolerances and requirements of a species

Question 2

What are species tolerances?

Answer 2

It’s the range within which species can survive. This could be abiotic or biotic.

Question 3

What are species requirements?

Answer 3

The availability of what that species needs to survive. This can be abiotic or biotic.

Question 4

What are the two subcategories niche can be divided into?

Answer 4

Fundamental niche
-The niche occupied in the absence of any interspecific competition
Realised niche
- The niche occupied in response to interspecific competition

Question 5

What causes competitive exclusion?

Answer 5

Interspecific competition

Question 6

What is competitive exclusion?

Answer 6

It’s when the realised niche of the two species in interspecific competition are very similar, so one species declines to local extinction

Question 7

What is an example of competitive exclusion?

Answer 7

Grey squirrel versus red squirrel. Grace close can eat seeds from deciduous trees before they are fully ripe and so can outcompete red squirrels.

Question 8

What is resource partitioning?

Answer 8

This is when the realised niches of two species are sufficiently different so potential competitors can coexist

Question 9

What causes resource partitioning?

Answer 9

Interspecific competition

Question 10

How is resource partitioning used by shorebirds?

Answer 10

Birds beak lengths, have evolved and the foraging behaviours of wading birds have changed to allow various species to exploit food of different types and different depths in the shared habitat