Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

2nd Year: Ecology > Interspecific competition > Flashcards

Interspecific competition Flashcards

1
Q

What is intraspecific competition?

A

Competition within a species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 2 types of intraspecific competition? Briefly describe them.

A
  1. Exploitation - direct and symmetrical.

2. Interference - indirect and asymmetrical.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is another name for intraspecific competition?

A

Conspecific.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is interspecific competition?

A

Competition between species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is another word for interspecific competition?

A

Heterospecific.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the ‘competitive exclusion principle’, also called Gause’s Law?

A

Two species cannot coexist on the same limiting resource. The resource must be limiting to both species.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Gause’s Law is dependent on population size. True or false?

A

False - ‘the species that is largest in isolation does not necessarily prevail’.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What was Tilman’s experiment to demonstrate Gause’s Law in 1981?

A

Grew 2 different algae species in monoculture to find the limiting factor, then grew them together.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What were the 2 algal species used in Tilman’s experiment in 1981?

A

Synedra and Astrionella.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What was the limiting factor for both algal species in monoculture in Tilman’s experiment in 1981?

A

Silica.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

In Tilman’s experiment in 1981, which species drove silica down to a lower level in monoculture? Why was this important?

A

Synedra, even though their population size was smaller than astrionella.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

In Tilman’s experiment in 1981, what happened when the 2 algal species were grown together?

A

Synedra outcompeted astrionella.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Gause conducted an experiment to prove his law with 2 species of paramecium, what were they?

A

P. Aurelia and P. caudata.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In Gause’s experiment, with paramecium species was better at exploiting the resource?

A

P. Aurelia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When 2 species are under the competitive exclusion principle, which one succeeds?

A

The species that is able to exploit the (limiting) resource the best, regardless of their population size.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What was Tansley’s experiment in 1917?

A

He grew 2 bacterial species in monoculture and found that although they could both grow on either calcareous or acidic soil, they each preferred a soil type. When he grew them together, they each only grew in the soil type they preferred - they had competitively excluded each other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Lokta-Volterra is a logistic growth model. What kind of time does this use?

A

Continuous.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does Lokta-Volterra do?

A

It describes and predicts the relationship of 2 interacting populations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In Lokta-Volterra, what is α(12)?

A

The per capita effect of a species. ‘α(12) means the ‘effect of species 1 on species 2’.

If it were α(21) it would mean ‘the effect of species 2 on species 1’ etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

dN1/dt = N1[r1 - α11N1 - α12N2]

This is a simplified version of Lokta-Volterra. Explain each term, using 1 as ‘species 1’ and 2 as ‘species 2’.

A 
dN1/dt = the rate of change in species 1 at time t
N1 = density of species 1
r1 = net fecundity of species 1 (births - deaths)
α(11) = intraspecific competition, the effect of species 1 on species 1
α(12) = interspecific competition, the effect of species 1 on species 2.
N2 = density of species 2.
21
Q

In this example of Lokta-Volterra, which terms are variable?

dN1/dt = N1[r1 - α11N1 - α12N2]

A

N and dN/dt.

22
Q

In this example of Lokta-Volterra, which terms are fixed?

dN1/dt = N1[r1 - α11N1 - α12N2]

A

r, α11 and α12

23
Q

dN/dt represents population change. What does it say about a population if the right hand side of the equation is negative?

A

The population is shrinking.

24
Q

dN/dt represents population change. What does it say about a population if the right hand side of the equation is positive?

A

The population is growing.

25
Q

dN/dt represents population change. What does it say about a population if the right hand side of the equation is zero?

A

The population is at equilibrium.

26
Q

Invasion analyses are conducted to assess the impact of invading species. What is the first step and the assumption it follows?

A

Grow species 1 in a monoculture and assume it reaches equilibrium of dN/dt = 0.

27
Q

Invasion analyses are conducted to assess the impact of invading species. What is the second step?

A

Add a low density of species 2.

28
Q

After the addition of species 2 in an invasion analysis, the simplified equation of Ň1 = r1/α11 is created. How?

A

Species 2 is in such low density that it can be omitted from the Lokta-Volterra equation, which is then simplified to Ň1 = r1/α11. This means we can work out the density of species 1 ‘in the absence of’ species 2.

29
Q

In invasion analyses our only interest lies in the initial phase of invasion of species 2. True or false?

A

True, we do not care about long-term population dynamics.

30
Q

If we only care about the initial phase of invasion, is it okay to make assumptions when formulating equations?

A

Yes.

31
Q

In an invasion analysis, with regards to species 2 the only equation we are concerned with is dN2/dt = N2[r2 – α21Ň1]. Explain this.

A 
dN2/dt = change in density of species 2
N2 = density of species 2
r2 = net fecundity of species 2
α21 = effect of species 2 on species 1
Ň1 = effective density of species 1 in the absence of species 2.
32
Q

In order for species 2 to invade, dN2/dt = N2[r2 – α21Ň1] must be what?

A

Greater than 0.

33
Q

We have just added species 2, thus we know N2 > 0. This means that r2 > α21Ň1, otherwise dN2/dt = N2[r2 – α21Ň1] would equal 0. True or false?

A

True, otherwise the inside of the brackets would be 0 or negative.

34
Q

We already know Ň1 = r1/α11. If we combine this with r2 > α21Ň1, we get r2 > α21(r1/α11). What does this simplify to?

A

r2/α21 < r1/α11

35
Q

In order for species 2 to invade, we need α21 < α11. What does this mean?

A

The interspecific competition, specifically the effect of species 2 on species 1, to be greater than the intraspecific competition within species 1.

36
Q

What is the whole principle of invasion analyses?

A

To assess whether a species can invade, the interspecific competition is compared to the intraspecific competition.

37
Q

In invasion analyses what must be true for a species to invade?

A

The interspecific competition, i.e. the effect of the invader species on the existing species, must be greater than the intraspecific competition within the invading species.

38
Q

You can perform invasion analysis to see if ‘species 1’ can invade ‘species 2’. How do you assess whether ‘species 2’ can invade ‘species 1’?

A

Change the equations so that they focus on species 2, essentially to the opposite of what you have just done.

39
Q

Define coexistence in terms of invasion.

A

Both species can invade each other, then live together and thrive independently.

40
Q

For coexistence to work, which kind of competition must be strongest?

A

Intraspecific competition must outweigh interspecific competition

41
Q

How does intraspecific become more important than interspecific competition?

A

The two species differentiate into separate niches.

42
Q

Define exclusion in terms of invasion.

A

One species can invade the other, but not vice versa.

43
Q

For exclusion to work, which kind of competition must be strongest?

A

Interspecific competition must outweigh intraspecific competition.

44
Q

Define Founder Control.

A

Neither species can invade the other, but the one that thrives is either the one that arrives first or the largest.

45
Q

Define a fundamental niche.

A

The full range of environmental conditions, both biotic and abiotic, under which an organism can exist.

46
Q

Define a realised niche.

A

The niche an organism actually lives in that is restricted by competition.

47
Q

Chance can affect niches. True or false?

A

True.

48
Q

Why are overlapping niches not often observed in nature?

A

They cause fierce competition which is only solved by extinction of one species or by coevolution.

49
Q

Define coevolution.

A

Evolution driven by the close association of another species, causing niche differentiation.

2nd Year: Ecology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions