Lecture 5-Introducing the niche Flashcards Preview

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Flashcards in Lecture 5-Introducing the niche Deck (16)
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1

What is ecological niche?

-the limits for all important environmental variables, within which individuals of a species can survive, grow and reproduce -includes environmental and resource gradients

2

What is a fundamental niche?

-the largest niche that an organism or species can occupy in the ABSENCE of interactions with other species including disease organisms (essentially unknowable)

3

What is realised niche?

-the portion of fundamental niche that is occupied by a species in the PRESENCE of interactions with other species (e.g. competitors, predators etc.)

4

What is the competition exclusion principle?

-complete competitors cannot coexist -the fundamental niches may overlap a lot but the realised won't

5

Is it possible for niches to overlap in one dimension provided they are separated on at least one other?

-yes

6

How does predation affect the prey species?

-negatively- the fundamental will overlap and realised won't at all

7

Can the realised niche be bigger than the fundamental niche?

-yes, if there is facilitation where the interaction with other species increases the fitness of a species = positive interaction

8

How does competition for resources affect niche?

-alter the dimension and affect fitness

9

Are niches different from the bell curve?

-yes

10

Are niches fixed in time and space?

-no

11

Are they hard to measure?

-yes

12

Do niches only apply to animals?

-no, all organisms

13

Describe what's happening:

-the predation has negative effects on the prey species

-fundamental niches overlap but the predation makes the prey species adapt

14

Describe:

-the competitive excluison principle

- complete competitors can't coexist so they adapt

15

Describe:

-predators have to eat

-so the realised niches overlap

-the right: not likely to happen to this extent

16

Describe:

-facilitation

-where species benefits from the presence of another species= postive interaction